JP2024043950A - Fecal culture medium and analysis method using the medium - Google Patents

Abstract

[Problem] The present technology aims to provide a method for improving the intestinal environment. The present technology also aims to provide a model of the intestinal environment. [Solution] A fecal culture medium containing urea, the medium being used as a model for reproducing an intestinal environment with a pH of 7 or higher, a model for reproducing the intestinal environment of a human with kidney disease or a human at risk of kidney disease, or a model for reproducing the intestinal environment of a human with a high total body urea amount, or an analytical method using a fecal culture medium containing urea, the analytical method comprising a culture step of culturing a fecal sample in the medium, and an analysis step of analyzing the culture obtained in the culture step. [Selected Figure] Figure 4

Description

The present technology relates to a fecal culture medium and an analysis method using the medium, and particularly relates to a fecal culture medium that can be used as a model of a specific intestinal environment and an analysis method using the medium.

Various studies have been conducted so far regarding the relationship between diseases and the intestinal environment. For example, in patients with kidney disease, the amount of excretion from the kidneys often decreases, which may lead to deterioration of the intestinal environment. This reduction in excretion may lead to the accumulation of toxins derived from, for example, intestinal bacteria in the body, which may lead to worsening of the disease state. Furthermore, research is being conducted on the relationship between the intestinal environment and not only kidney disease but also other diseases such as liver disease.

Various proposals have been made focusing on the relationship between such diseases and the intestinal environment. For example, the following Patent Document 1 discloses "a composition characterized by comprising a mixture of oligosaccharides and dietary fiber to improve the pH environment in the digestive tract and reduce putrefactive products for the purpose of treating/preventing hepatic encephalopathy and/or colon cancer and/or intractable diseases of the large intestine" (Claim 1).

Japanese Patent Application Laid-Open No. 03-151854

As mentioned above, the decrease in renal excretion in patients with kidney disease may cause the deterioration of intestinal environment. In addition, in patients with liver disease, the deterioration of intestinal environment may also occur. Such deterioration of intestinal environment may cause the accumulation of toxins derived from intestinal bacteria in the body and even the deterioration of the condition. Therefore, if the intestinal environment of patients with kidney or liver disease can be improved, it is believed that it can contribute to preventing the accumulation of toxins and further deterioration of the condition.
Therefore, the present technology has an object to provide a method for improving the intestinal environment. The present technology has an object to provide a technology for improving a specific intestinal environment, such as the intestinal environment of a patient with kidney disease or liver disease.

In addition, there has been no model that reproduces the intestinal environment of the above-mentioned patients. Therefore, it has not been possible to evaluate the improvement of the intestinal environment of the patient. Such a model is considered to be useful for examining means for improving the intestinal environment of the patient.
Therefore, an object of the present technology is to provide a model of the intestinal environment. For example, an object of the present technology is to provide a model that reproduces the intestinal environment and to provide an analysis method using the model.

The present inventors have found that specific media are useful as models that reproduce specific intestinal environments. The medium can be used, for example, in analytical methods for investigating or evaluating means for improving the intestinal environment.
Further, the present inventors conducted studies using the medium and found that a specific composition is useful for improving the intestinal environment. More specifically, it has been found that the particular compositions are useful for reducing ammonia concentrations in the intestines.

The technology provides the following:
[1] A composition for reducing intestinal ammonia concentration, comprising resistant dextrin and inulin.
[2] The composition described in [1], wherein the mass ratio of the resistant dextrin to the inulin in the composition is 1:99 to 99:1.
[3] The composition described in [1], wherein the mass ratio of the resistant dextrin to the inulin in the composition is 5:95 to 95:5.
[4] The composition described in [1], wherein the mass ratio of the resistant dextrin to the inulin in the composition is 5:95 to 60:40.
[5] The composition according to any one of [1] to [4], wherein the composition is a nutritional composition.
[6] The composition according to any one of [1] to [5], which is a composition used for improving the intestinal environment.
[7] The composition described in any one of [1] to [6], which is a composition used to suppress the increase of harmful bacteria.
[8] The composition according to any one of [1] to [7], which is a composition used for reducing the amount of urea in the body.
[9] The composition contains the resistant dextrin and the inulin as prebiotic components,
The composition according to any one of [1] to [8], wherein the total mass proportion of the resistant dextrin and the inulin in the prebiotic component is 50 mass% or more.
[10] The composition according to any one of [1] to [9], which is administered to a human having kidney disease or liver disease.
[11] The composition according to any one of [1] to [10], which is intended to suppress ammonia production caused by intestinal bacteria and improve the intestinal environment.

The technology also provides the following:
<1> A fecal culture medium containing urea.
<2> The medium described in <1>, wherein the urea content is 0.1 mass% or more relative to the mass of the medium.
<3> The medium according to <1> or <2>, which is used for culturing enterobacteria.
<4> The medium according to any one of <1> to <3>, further comprising a growth-promoting extract.
<5> The medium according to any one of <1> to <4>, further comprising a protein hydrolysate.
<6> The medium according to any one of <1> to <5>, further comprising a fatty acid.
<7> The medium according to any one of <1> to <6>, wherein the medium is used as a model for reproducing an intestinal environment having a pH of 7 or higher.
<8> The medium according to any one of <1> to <7>, wherein the medium is configured so that an ammonia production amount after 24 hours of fecal culture is 100 mM or more.
<9> The medium according to any one of <1> to <8>, wherein the medium suppresses production of short-chain fatty acids associated with fecal culture.
<10> The medium according to any one of <1> to <9>, which is used as a model for reproducing the intestinal environment of a human having kidney disease or a human at risk of developing kidney disease.
<11> The medium according to any one of <1> to <10>, which is used as a model for reproducing the intestinal environment of a human having a high amount of urea in the whole body.
<12> An analytical method using a fecal culture medium containing urea.
<13> The analysis method according to <12>, wherein the medium has a urea content of 0.1 mass% or more.
<14> The method according to <12> or <13>, further comprising a culture step of culturing a stool sample in the medium.
<15> The analysis method according to <14>, comprising an analysis step of analyzing the culture obtained in the culture step.

Compositions according to the present technology can reduce ammonia concentrations in the intestines. The composition is useful, for example, for suppressing ammonia production by intestinal bacteria. The composition is useful for improving the intestinal environment in humans with diseases related to ammonia or urea metabolism, such as kidney disease or liver disease.

The medium produced according to this technology can be used as an intestinal environment model for humans with the disease. The medium is useful for investigating means (e.g., compositions, methods, etc.) that are useful for improving the intestinal environment of humans with the disease.

Note that the effects of the present technology are not limited to the effects described here, and may be any of the effects described in this specification.

It is a figure which shows the measurement result of pH in anaerobic culture. It is a figure showing the measurement result of the amount of ammonia in anaerobic culture. FIG. 1 shows the results of measuring bacterial occupancy. FIG. 1 shows the results of measuring the amount of ammonia in anaerobic culture. FIG. 1 shows the results of measuring the amount of ammonia in anaerobic culture.

Preferred embodiments of the present technology will be described below. However, the present technology is not limited to the following preferred embodiments, and can be freely modified within the scope of the present technology.

1. Composition

The composition of the present technology includes indigestible dextrin and inulin. A combination of indigestible dextrin and inulin is suitable and used to reduce ammonia concentrations in the intestines. More specifically, the composition of the present technology is suitable for suppressing ammonia production caused by intestinal bacteria, and may be used to suppress ammonia production in the intestine.

The ammonia concentration may refer to the ammonia concentration in the human intestine (particularly in the large intestine). The reduction in ammonia concentration may be a reduction in the intestinal ammonia concentration compared to the intestinal ammonia concentration before administration.
Furthermore, the reduction in the ammonia concentration may be a reduction compared to the intestinal ammonia concentration expected when the composition is not administered, and may mean preventing an increase in the intestinal ammonia concentration, reducing the degree of increase in the intestinal ammonia concentration, or maintaining the intestinal ammonia concentration. That is, the composition of the present technology may be used to maintain the intestinal ammonia concentration or suppress an increase in the intestinal ammonia concentration.
In addition, in the present specification, "intestinal bacteria" may refer to bacteria present in the intestine, particularly bacteria present in the large intestine. The intestinal bacteria may be bacteria that cause ammonia production, for example, bacteria that produce an enzyme that causes ammonia production. The enzyme may be, for example, urease. An example of such bacteria is bacteria belonging to the Enterobacteriaceae family.

The composition of the present technology may be used, for example, to suppress ammonia production in a living body (particularly in the intestine). More specifically, the compositions of the present technology may be used to suppress ammonia production by enteric bacteria, particularly ammonia production by substances produced by enteric bacteria (eg, enzymes, particularly urease).

The composition of the present technology may be used to improve the intestinal environment. The increase in intestinal ammonia concentration and ammonia production in the intestine described above may deteriorate the intestinal environment. The composition of the present technology can reduce the intestinal ammonia concentration. Furthermore, the composition of the present technology can inhibit the ammonia production. The reduction in ammonia concentration and the inhibition of ammonia production contribute to improving the intestinal environment.

Furthermore, the composition of the present technology may be used to suppress the increase in bad bacteria. The above-mentioned ammonia production changes the intestinal environment (eg, intestinal pH), which can lead to an increase in bad bacteria. The composition of the present technology can suppress the ammonia production, thereby suppressing the increase in bad bacteria.
As used herein, bad bacteria may be bacteria that promote putrefaction in the intestines and produce putrefaction products and other harmful substances such as ammonia, hydrogen sulfide, and indole.
Examples of the bad bacteria include, but are not limited to, bacteria of the genus Clostridium, bacteria of the family Enterobacteriacea, bacteria of the family Fusobacteriaceae, and bacteria of the genus Staphylococcus. More specific examples of the bad bacteria include C. perfringens, C. difficile, C. paraputrificum, and E. coli.
For example, in humans with kidney disease, bacteria of the Enterobacteriaceae family, Brachybacterium family, Catenibacterium family, Moraxellaceae family, Nesterenkonia family bacteria, Polyangiaceae family bacteria, Pseudomonadaceae family bacteria, Thiothrix family bacteria, etc. are increased.
In humans with liver disease, bacteria of the Enterococcus family, Enterobacteriaceae family, Streptococcus salivius, etc. are increased.
Compositions of the present technology may be used to inhibit the growth of one or more of these bacteria.

The compositions of the present technology may also be used to reduce the amount of urea in the body. The ammonia present in the intestine due to the ammonia production described above is taken up into the blood again and can increase the blood ammonia concentration. Increased blood ammonia levels can increase the amount of urea in the body. The composition of the present technology can suppress the ammonia production, thereby reducing the amount of urea in the body.

Furthermore, the composition of the present technology may be used to improve body odor. The ammonia present in the intestine due to the ammonia production described above is taken up into the blood again and can increase the blood ammonia concentration. An increase in blood ammonia concentration can cause body odor (such as fatigue odor) caused by ammonia. The composition of the present technology can suppress the ammonia production, thereby improving body odor.

The composition of the present technology may also be administered to humans with kidney disease or liver disease. In humans with such diseases, the intestinal environment is often deteriorated, and this deterioration may be caused by the ammonia production. The composition of the present technology can suppress ammonia production, which helps to improve the intestinal environment in such humans. In addition, the suppression of ammonia production also helps to reduce the amount of urea in the body, which also helps to deal with diseases.
In this way, the composition of the present technology may be used to suppress ammonia production caused by intestinal bacteria and improve the intestinal environment.

The composition of this technology is described in more detail below.

(1) Prebiotic component The indigestible dextrin and inulin are both prebiotic components. That is, the composition of the present technology may include a prebiotic component.
"Prebiotics" are not broken down or absorbed in the upper gastrointestinal tract, but serve as a selective nutritional source for beneficial bacteria that coexist in the large intestine, promoting their growth and maintaining a healthy balance in the intestinal flora composition of the large intestine. Generally refers to something that improves and maintains human health. The prebiotic component is useful for improving the intestinal environment.

The composition of the present technology may be ingested so that the daily intake of the prebiotic component is, for example, 2 to 26 g, preferably 3 to 25 g, more preferably 4 to 24 g, and even more preferably 5 to 23 g. That is, the daily intake of the composition may result in the intake of the prebiotic component in an amount within the above numerical range. Such a daily intake of the prebiotic component not only suppresses the ammonia production, but also effectively improves the intestinal environment. The composition may be ingested so that the intake of the prebiotic component per kg of body weight is, for example, 0.03 g to 0.65 g, preferably 0.04 g to 0.63 g, more preferably 0.05 g to 0.60 g, and even more preferably 0.06 g to 0.58 g.

The composition of the present technology contains resistant dextrin and inulin as the prebiotic components. The combination of these two components is suitable for suppressing the ammonia production. Furthermore, in addition to suppressing the ammonia production, the combination of these two components is also suitable for increasing beneficial intestinal bacteria, more particularly Bifidobacterium bacteria.
That is, the composition of the present technology may be used to suppress ammonia production and increase useful intestinal bacteria. Therefore, the composition of the present technology is very useful for improving the intestinal environment. In addition, the combination of these two components is also useful for suppressing gas production by intestinal bacteria through prebiotics. These components will be described below in (1-1) and (1-2).

The mass ratio of the indigestible dextrin and the inulin in the composition is, for example, 1:99 to 99:1, preferably 5:95 to 95:5. Including these two components in such a ratio is desirable in order to achieve the effects of the composition according to the present technology.

Preferably, the mass ratio of the indigestible dextrin and the inulin in the composition is, for example, 1:99 to 90:10, more preferably 3:97 to 85:15, even more preferably 5 :95 to 80:20, particularly preferably 10:90 to 75:25.

Particularly preferably, the mass ratio of the indigestible dextrin and the inulin in the composition is from 5:95 to 60:40, from 7:93 to 55:45, and from 10:95 to 50:50. It's good. As described above, the fact that the content mass ratio of inulin is higher than the content mass ratio of indigestible dextrin contributes to effectively exhibiting the ammonia production suppressing effect.

The total mass ratio of the resistant dextrin and the inulin in the prebiotic component contained in the composition of the present technology is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, 61% by mass or more, 62% by mass or more, 63% by mass or more, 64% by mass or more, 65% by mass or more, 66% by mass or more, 67% by mass or more, 68% by mass or more, or 69% by mass or more, even more preferably 70% by mass or more, 71% by mass or more, 72% by mass or more, 73% by mass or more, 74% by mass or more, 75% by mass or more, or 80% by mass or more. By having the ratio within such a numerical range, the ammonia production suppression effect can be more effectively exerted.
The total mass proportion of the resistant dextrin and the inulin in the prebiotic component contained in the composition of the present technology may be, for example, 100% by mass or less, preferably 95% by mass or less, and more preferably 90% by mass or less.

In one embodiment, the composition of the present technology may further contain lactulose as the prebiotic component. The inclusion of lactulose in the composition of the present technology is also believed to contribute to the inhibition of ammonia production. The inclusion of lactulose in the composition of the present technology is also believed to contribute to the inhibition of ammonia production. Lactulose also contributes to increasing beneficial intestinal bacteria, and also contributes to the inhibition of gas production from intestinal bacteria by the prebiotic component. That is, in one embodiment, the composition of the present technology may contain resistant dextrin, inulin, and lactulose. Lactulose will be described below in (1-3).

(1-1) Indigestible dextrin The composition of the present technology contains indigestible dextrin. The indigestible dextrin is one of the prebiotic components contained in the composition of the present technology.

Resistant dextrin is a type of water-soluble dietary fiber obtained from starch. In this specification, the term "resistant" in resistant dextrin means that it is difficult to digest with human digestive enzymes. The resistant dextrin may be, for example, a water-soluble dietary fiber obtained by adding acid (adding a mineral acid) and/or heating starch derived from a plant to obtain roasted dextrin, which is optionally enzymatically treated with α-amylase and/or glucoamylase, and then optionally desalted and/or decolorized. The plant-derived starch may be, for example, starch derived from corn, wheat, barley, rice, beans, tubers (potato, sweet potato), or tapioca.

The above-mentioned indigestible dextrin is prepared using high-performance liquid chromatography, which is a dietary fiber analysis method described in Eishin No. 13 dated April 26, 1999 ("Regarding methods for analyzing nutritional components, etc. under nutrition labeling standards"). Dextrins containing indigestible components as measured by a method (enzyme-HPLC method) may be included, preferably dextrins containing 85 to 95% by weight of indigestible components. The indigestible dextrin also includes reduced indigestible dextrin produced by hydrogenating indigestible dextrin. The indigestible dextrin is commercially available in the form of powder, fine particles, granules, etc., and any form can be used in the present technology.

In addition, resistant dextrin can be quantified by high performance liquid chromatography (enzyme-HPLC method (AOAC2001.03)). For the quantification method, see, for example, JP 2001-252064 A.

Examples of the indigestible dextrin include product names such as "Pine Fiber", "Fiber Sol 2" (manufactured by Matsutani Chemical Industry Co., Ltd.), "Okunos Dietary Fiber" (manufactured by Horika Foods Co., Ltd.), and "Nutriose FB06" (Rocket Japan). Indigestible dietary fiber obtained by heating and enzymatically treating starch or wheat flour, such as those manufactured by Co., Ltd., may be used.

The number average molecular weight of the indigestible dextrin is preferably 500 to 10,000, more preferably 500 to 5,000, even more preferably 1,000 to 4,000, and most preferably 1,000 to 3,000. For example, indigestible dextrins having a number average molecular weight of about 2000 may be included in the compositions of the present technology.

The proportion of the mass of the resistant dextrin in the total mass of the prebiotic components contained in the composition of the present technology may be, for example, 1% by mass or more, preferably 5% by mass or more, more preferably 6% by mass or more, and even more preferably 7% by mass or more, 8% by mass or more, 9% by mass or more, or 10% by mass or more. The proportion within such a numerical range is suitable for exerting the ammonia production suppression effect.
The proportion of the mass of the resistant dextrin in the total mass of the prebiotic components contained in the composition of the present technology may be, for example, 99% by mass or less, preferably 95% by mass or less, more preferably 90% by mass or less, 85% by mass or less, 80% by mass or less, or 75% by mass or less, and particularly preferably 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less.
The ratio within this range is suitable for exerting the ammonia production inhibiting effect.
Furthermore, having the ratio within such a numerical range contributes to increasing beneficial intestinal bacteria and also contributes to suppressing gas production from intestinal bacteria by the prebiotic component.

(1-2) Inulin The composition of the present technology contains inulin. The inulin is one of the prebiotic components contained in the composition of the present technology.

The inulin is a polysaccharide in which fructose molecules are linearly linked to fructose residues of sucrose through β(2-1) bonds, for example. The degree of polymerization of the inulin may be preferably 5-40, more preferably 7-20.
As the inulin, commercially available inulin may be used. Examples of the inulin include FujiFF (manufactured by Fuji Nippon Seito Co., Ltd.) and Inulia (manufactured by Teijin Ltd.).

The proportion of the mass of the inulin in the total mass of the prebiotic component contained in the composition of the present technology is, for example, 99% by mass or less, preferably 95% by mass or less, more preferably 94% by mass or less. , 93% by weight or less, 92% by weight or less, 91% by weight or less, or 90% by weight or less.
The proportion of the mass of the inulin in the total mass of the prebiotic component contained in the composition of the present technology is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass. 15% by mass or more, 20% by mass or more, or 25% by mass or more, particularly preferably 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more. It's fine.
It is suitable for the ratio to be within such a numerical range in order to exhibit the ammonia production suppressing effect.
Furthermore, having the above ratio within this numerical range also contributes to increasing the number of beneficial bacteria in the intestine, and also contributes to suppressing gas production from intestinal bacteria due to the prebiotic component. do.

(1-3) Lactulose The composition of the present technology may further contain lactulose. Lactulose is a disaccharide consisting of fructose and galactose. Lactulose may be anhydrous or hydrated.

Lactulose can be produced by a known method. For example, sodium hydroxide is added to a commercially available 10% aqueous solution of lactose, the mixture is heated at a temperature of 70°C for 30 minutes, cooled, and the cooled solution is purified using an ion exchange resin, concentrated, and cooled. The mixture is crystallized and unreacted lactose is removed to obtain an aqueous lactulose solution with a solid content of about 68% (containing about 79% lactulose in solid content). This aqueous solution is passed through an ion exchange resin column, and a fraction containing lactulose is collected and concentrated to obtain a purified lactulose aqueous solution with a solid content of approximately 68% (containing approximately 86% lactulose in solid content). method described in JP-A-3-169888).
Furthermore, the lactulose aqueous solution (syrup) obtained by the above method was concentrated to a solid content of about 72%, this concentrated liquid was cooled to 15°C, lactulose trihydrate crystals were added as seed crystals, and while stirring, It takes 7 days to gradually cool down to 5°C to generate crystals, and after 10 days, the solid content of the supernatant liquid has decreased to about 61%, and the crystals are separated from the liquid containing crystals using a filter cloth centrifuge. Then, by washing with cold water at 5° C. and drying, lactulose crystals with a purity of 95% or more can be obtained (method described in JP-A-6-228179).
Moreover, commercially available lactulose can also be used.

The proportion of the mass of the lactulose in the total mass of the prebiotic components contained in the composition of the present technology may be preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more.
The mass proportion of the lactulose in the prebiotic component may be preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less.
The ratio within this range is suitable for exerting the ammonia production inhibiting effect.
Having the ratio within such a numerical range contributes to a more reliable increase in beneficial intestinal bacteria and/or contributes to a more reliable inhibition of gas production from intestinal bacteria by the prebiotic component.

(1-4) Other prebiotic components In one embodiment of the present technology, the composition includes other prebiotic components other than indigestible dextrin and inulin (or indigestible dextrin) as a prebiotic component. and other prebiotic ingredients other than inulin and lactulose). Examples of the other prebiotic components include galactooligosaccharide, fructooligosaccharide, soybean oligosaccharide, milk oligosaccharide, xylooligosaccharide, isomalooligosaccharide, raffinose, coffee bean mannooligosaccharide, gluconic acid, polydextrose, guar gum decomposition product, and alginate. , pectin, isomaltodextrin, resistant starch, and barley-beta glucan, of which one or a combination of two or more may be included in the compositions of the present technology.
In other embodiments of the present technology, the composition may include only indigestible dextrin and inulin, or only indigestible dextrin, inulin, and lactulose as prebiotic components. That is, in this embodiment, no other prebiotic components are included in the composition.

(2) Other components The composition of the present technology may contain other components other than the prebiotic component. The other components may include, for example, proteins, lipids, carbohydrates, amino acids, peptides, vitamins, and minerals. For example, the composition may further contain lipids, carbohydrates, or both. The other components may be useful intestinal bacteria, such as bifidobacteria, lactic acid bacteria, or a combination thereof. The composition of the present technology may contain one or a combination of two or more of these components, for example, all of them. These components are described below.

(protein)
Compositions of the present technology may further include a protein. The protein is not particularly limited as long as it is used in food, such as animal protein such as milk protein, egg protein, and collagen, and vegetable protein such as soybean protein, rice protein, and wheat protein. The protein is particularly preferably a milk protein. As the milk protein, casein decomposition products, caseinates such as sodium caseinate and calcium caseinate, milk protein concentrates (MPC), whey protein concentrates (WPC), whey protein decomposition products, etc. can be used. Moreover, the peptide contained in the above-mentioned decomposition product may be contained in the composition of the present technology. An example of the peptide is the tripeptide MKP. Tripeptide MKP is a peptide in which three amino acids, methionine (M), lysine (K), and proline (P), are bonded.

The composition of the present technology may be administered to a subject such that the daily dose of the protein is 10 g or more, particularly 15 g or more, or 20 g or more. . The upper limit of the daily dosage may be, for example, 80 g or less, 70 g or less, or 60 g or less.
Furthermore, the composition of the present technology may be administered to a subject such that the daily dosage of the milk protein is 10 g or more, particularly, the daily dosage is 15 g or more, or 20 g or more. It's okay to be. The upper limit of the daily dosage may be, for example, 80 g or less, 70 g or less, or 60 g or less.

The content of the protein may be, for example, 0.5 g or more, 1 g or more, 1.5 g or more, or 2 g or more per 100 kcal of energy of the composition of the present technology. Further, the content of the protein may be, for example, 8 g or less, 7 g or less, or 6 g or less per 100 kcal of energy of the composition.

(lipid)
Compositions of the present technology may further include lipids. As the lipid, oils and fats used in foods, such as vegetable oils such as soybean oil, rapeseed oil, and corn oil, and animal oils such as fish oil, can be used without particular limitation. Preferably, the lipid comprises a vegetable oil.
In a preferred embodiment of the present technology, the lipid includes medium chain fatty acid triglyceride (hereinafter also referred to as MCT). MCTs are better digested and absorbed than long-chain fatty acid triglycerides, and can easily be used as an energy source. Therefore, MCTs serve as an energy source for people who have difficulty utilizing glucose due to illness or have low dietary intake, and are useful from the perspective of improving energy efficiency.
Also, in other preferred embodiments of the present technology, the composition may be lipid-free.

The composition of the present technology may be administered to a subject such that the lipid is administered in a daily dose of 10 g or more, particularly 12 g or more, or 14 g or more. The upper limit of the daily dose may be, for example, 50 g or less, 45 g or less, or 40 g or less.
In addition, the composition of the present technology may be administered to a subject so that the daily dose of the MCT is 1 g or more, and in particular, the daily dose may be 3 g or more, or 5 g or more. The upper limit of the daily dose may be, for example, 30 g or less, 25 g or less, or 20 g or less.

The content of the lipid may be, for example, 1 g or more, 1.2 g or more, or 1.4 g or more per 100 kcal of energy of the composition of the present technology. Further, the content of the lipid may be, for example, 5 g or less, 4.5 g or less, or 4 g or less per 100 kcal of energy of the composition.

(carbohydrate)
The composition of the present technology may further include a carbohydrate. In addition, within this specification, the said carbohydrate|carbohydrate means the carbohydrate other than a prebiotic component. As the carbohydrate, carbohydrates used in foods, such as monosaccharides, disaccharides, oligosaccharides, and polysaccharides, can be used without particular limitation. The carbohydrate preferably includes a polysaccharide, particularly preferably a dextrin.

The composition of the present technology may be administered to a subject such that the daily dosage of the carbohydrate is 30 g or more, particularly, the daily dosage is 30 g or more, or 50 g or more. good. The upper limit of the daily dosage may be, for example, 150 g or less, 120 g or less, or 100 g or less.

The total content of the carbohydrates may be, for example, 8 g or more, 10 g or more, or 12 g or more per 100 kcal of energy of the composition of the present technology. The total content of the carbohydrates may be, for example, 25 g or less, 20 g or less, or 18 g or less per 100 kcal of energy of the composition.

(Amino acids)
The composition of the present technology may further include amino acids, which may be, for example, one or a combination of two or more selected from valine, leucine, isoleucine, glutamine, aspartic acid, glutamic acid, arginine, alanine, proline, cysteine, lysine, threonine, asparagine, phenylalanine, serine, methionine, glycine, tyrosine, histidine, and tryptophan.

The composition of the present technology may be administered to a subject such that the total daily dose of the amino acids is 5 g or more, and in particular, the total daily dose is 7 g or more, or 9 g or more. The upper limit of the total daily dose may be, for example, 40 g or less, 35 g or less, or 30 g or less.

The total content of the amino acids may be, for example, 1 g or more, 1.2 g or more, or 1.4 g or more per 100 kcal of energy of the composition of the present technology. Further, the total content of the amino acids may be, for example, 4 g or less, 3.5 g or less, or 3 g or less per 100 kcal of energy of the composition.

(Vitamins)
The composition of the present technology may further include vitamins, such as any one or more of vitamin A, vitamin B (e.g., vitamin B1, vitamin B2, vitamin B6, niacin, pantothenic acid, biotin, vitamin B12, folic acid, etc.), vitamin C, vitamin D, and vitamin E. In one embodiment, the composition of the present technology may include vitamins A, B, C, D, and E.

The composition of the present technology may be administered to a subject such that the daily dose of vitamin B is 10 mg or more, particularly 20 mg or more, or 25 mg or more. good. The upper limit of the daily dose may be, for example, 80 mg or less, 70 mg or less, 60 mg or less, or 50 mg or less. In addition, the daily dose of vitamin B1 may be administered to the subject so as to be 0.5 mg or more, and in particular, the daily dose may be administered so that the daily dose is 1.0 mg or more, or 1.5 mg or more. It's fine. The upper limit of the daily dose may be, for example, 10 mg or less, 9 mg or less, or 8 mg or less.
The composition of the present technology may be administered to a subject such that the daily dose of vitamin C is 50 mg or more, particularly 100 mg or more, or 300 mg or more. good. The upper limit of the daily dose may be, for example, 2000 mg or less, 1900 mg or less, or 1800 mg or less.
The composition of the present technology may be administered to a subject such that the daily dose of vitamin E is 8 mg or more, particularly, the daily dose is 20 mg or more, or 30 mg or more. good. The upper limit of the daily dose may be, for example, 200 mg or less, 190 mg or less, or 180 mg or less.

The content of the vitamin B may be, for example, 0.5 mg or more, 1.0 mg or more, or 2.0 mg or more per 100 kcal of energy of the composition of the present technology. Further, the content of the vitamin B may be, for example, 10 mg or less, 8 mg or less, or 7 mg or less per 100 kcal of energy of the composition. The content of vitamin B1 may be, for example, 0.05 mg or more, 0.1 mg or more, 0.2 mg or more, or 0.3 mg or more per 100 kcal of energy of the composition of the present technology. Further, the content of the vitamin B1 may be, for example, 1 mg or less, 0.9 mg or less, or 0.8 mg or less per 100 kcal of energy of the composition.
The content of vitamin C may be, for example, 1 mg or more, 5 mg or more, or 10 mg or more per 100 kcal of energy of the composition of the present technology. Further, the content of the vitamin C may be, for example, 200 mg or less, 190 mg or less, or 180 mg or less per 100 kcal of energy of the composition.
The content of vitamin E may be, for example, 1 mg or more, 2 mg or more, or 3 mg or more per 100 kcal of energy of the composition of the present technology. Further, the content of the vitamin E may be, for example, 35 mg or less, 30 mg or less, or 25 mg or less per 100 kcal of energy of the composition.

(mineral)
Compositions of the present technology may further include minerals. Examples of minerals include calcium, magnesium, phosphorus, iron, zinc, copper, manganese, iodine, selenium, chromium, and molybdenum. Compositions of the present technology may include one or more of these minerals.

The composition of the present technology may contain components such as water, sweeteners, fruit juice, vegetable juice, flavors, colorants, and acidulants. The types and content ratios of these components may be appropriately selected by those skilled in the art depending on the desired physical properties, shape, taste, or appearance.
The composition of the present technology may also contain other ingredients believed to be useful for suppressing ammonia production, such as mushroom-derived polyphenols (e.g., champignon extract, etc.).
The composition of the present technology may also contain other ingredients that are believed to be useful for reducing or improving body odor. Such ingredients may include, for example, the mushroom-derived polyphenols, rose oil, persimmon tannin, grape leaf extract, malic acid, and catechin, and one or more of these may be included in the composition of the present technology.
In addition, the composition of the present technology may not contain Salacia extract.

(3) Physical properties of the composition The composition of the present technology may be in the form of liquid, paste, gel (jelly), powder, or solid, and is preferably liquid or gel.

The composition of the present technology is preferably flowable. For example, it may be a flowable liquid or gel composition. For example, the composition of the present technology may be a liquid food.
In addition, the composition of the present technology may be in a powder or solid form. For example, the composition of the present technology may have a powder, granule, or tablet form.
The composition of the present technology may be used as a supplement having such physical properties or form.

Since the composition of the present technology is in liquid form, it can be easily ingested by, for example, elderly people, and furthermore, it can be administered to subjects orally or through a tube. When the composition of the present technology is in liquid form, various physical properties of the composition may be set as follows, for example.

The osmolality of the composition of the present technology may be, for example, 100 mOsm/L to 1000 mOsm/L, preferably 200 mOsm/L to 800 mOsm/L, and more preferably 300 mOsm/L to 700 mOsm/L. The osmolality is measured by an osmometer. The osmometer is an Advanced Instruments Osmometer Model 3250.

The pH of the composition of the present technology at 20°C may be, for example, 3.0 to 8.0, preferably 3.5 to 7.5, and more preferably 4.0 to 7.0.

The specific gravity of the composition of the present technology at 20°C may be, for example, 0.8 to 1.5, preferably 0.9 to 1.4, and more preferably 1.0 to 1.2. The specific gravity is measured using a glass standard hydrometer.

The viscosity of the composition of the present technology at 20°C may be, for example, 1 mPa·s to 30,000 mPa·s, preferably 2 mPa·s to 1,800 mPa·s. When the composition of the present technology is in a liquid state, the viscosity may be, for example, 5 mPa·s to 100 mPa·s. When the composition of the present technology is in a gel state, the viscosity may be, for example, 1,000 mPa·s to 3,000 mPa·s. The viscosity is measured using a viscometer. The viscometer is a VISCOMETER TVB-10.

In one embodiment of the present technology, the amount of energy per ml of the composition of the present technology may be 0.5 kcal or more, 0.6 kcal or more, 0.7 kcal or more, 0.8 kcal or more, or 0.9 kcal or more. Thus, the high amount of energy per ml of the composition allows efficient energy intake. In this embodiment, the amount of energy per ml of the composition of the present technology may be, for example, 5 kcal or less, 4 kcal or less, 3 kcal or less, or 2 kcal or less. For example, the composition of the present technology may have an energy content of 1.2 kcal to 2.0 kcal per ml.

(4) Method of using the composition The composition of the present technology may be used to supplement nutrition to humans. For example, the composition of the present technology may be a nutritional composition. In one embodiment, the composition of the present technology may be used to supplement nutrition to humans and suppress the ammonia production.
In addition, the composition of the present technology may be used to increase beneficial intestinal bacteria (particularly Bifidobacterium bacteria) in the human (and suppress gas production from intestinal bacteria by prebiotic components).

The compositions of the present technology may be taken, for example, orally or by tube. In the latter case, the compositions of the present technology are administered to a human, for example, via a gastrostomy tube.

In one embodiment of the present technology, the composition may be administered such that the composition provides the subject with an energy amount of, for example, 50 kcal to 1400 kcal, preferably 100 kcal to 1200 kcal, preferably 150 kcal to 1000 kcal per day. The composition may be administered to a human at a rate of 100 to 1200 kcal per administration, and the administration may be performed 1 to 5 times, particularly 1 to 3 times, per day.

(5) Method for Producing Composition The method for producing the composition of the present technology includes a mixing step of mixing resistant dextrin and inulin (and lactulose). In the mixing step, these components may be mixed in any medium, for example, a liquid medium. In the mixing step, the other components contained in the composition of the present technology may be further mixed. In the mixing step, a composition having the composition of the final product may be formed.

The method may include a sterilization step of sterilizing the resulting composition. The sterilization may be performed by any method known in the art, such as high temperature short time sterilization (HTST), ultra high temperature sterilization (UHT), or pressurized heat sterilization.

The manufacturing method may further include a filling step of filling a container with the composition obtained in the mixing step before or after the sterilization step. If performed after the sterilization step, the filling step may be performed aseptically. The container may be, for example, a paper pack, a plastic bag, a plastic bottle, a plastic cup, an aluminum pouch, a metal can, or a glass container.

(6) Food and drink composition The composition of the present technology may be used as a food and drink composition. The food and drink composition of the present technology may have, for example, a liquid or gel form.

The food/beverage composition of the present technology can be provided or sold as a food/beverage product labeled with uses such as improving the intestinal environment. In addition, the food and drink compositions of this technology can be ingested by, for example, people who want to improve their intestinal environment, people who want to reduce intestinal ammonia, people who want to reduce bad bacteria in their intestines, and people who want to reduce urea in their body. ``Those who want to reduce the amount of ammonia in the body'', ``Those who want to reduce the amount of urea in the intestines'', ``Those who are concerned about body odor'', ``Those who want to reduce body odor'', ``Those who want to reduce the amount of ammonia in the body'', ``Those who want to reduce the amount of urea nitrogen ( BUN) can be provided and/or sold with a message such as "For those who are concerned about or have a high price." The act of "labeling" includes all acts to inform the consumer of the uses of the composition of the present technology, and if the expression is such that it may remind and/or infer the use, the act of displaying Regardless of the purpose, content of display, object and/or medium to be displayed, all fall under the "display" act of this technology.

Moreover, it is preferable that the "display" be performed using expressions that allow the consumer to directly recognize the above-mentioned use. Specifically, the act of transferring, handing over, exhibiting for transfer or delivery, or importing food and drink products or products with the above-mentioned usage written on their packaging, advertisements related to products, price lists, or transaction documents. Examples include acts such as displaying or distributing information with the above-mentioned uses written thereon, or acts of writing the above-mentioned uses on information containing these items and providing it by electromagnetic (Internet, etc.) method.

On the other hand, the display content is preferably a display approved by the government (for example, a display that has been approved based on various systems established by the government and is performed in a manner based on such approval). Further, it is preferable to attach such display contents to packaging, containers, catalogs, pamphlets, promotional materials at sales sites such as POP, and other documents.

"Labeling" also includes labeling as health food, functional food, enteral nutritional food, special purpose food, health functional food, food for specified health uses, nutrient functional food, functional food, medical and pharmaceutical products, etc.

(7) Pharmaceutical composition The composition of the present technology may be used as a pharmaceutical composition. The pharmaceutical composition in the present technology may have a liquid or gel form, for example.

When the composition according to the present technology is used as a pharmaceutical composition, the pharmaceutical composition may be administered either orally or parenterally, and may be formulated into a desired dosage form as appropriate depending on the administration method. can do. For example, in the case of oral administration, it may be formulated into a desired dosage form (liquid or paste). Furthermore, in the case of parenteral administration, the compositions of the present technology can be administered, for example, via a gastric fistula, and may be administered enterally, for example.

Furthermore, when formulating, the pharmaceutical composition according to the present technology may contain components of additives (for example, pH adjusters, coloring agents, flavoring agents, etc.) that are normally used for formulating. Furthermore, as long as the effects of the present technology are not impaired, the pharmaceutical composition according to the present technology may contain known or future-discovered components for improving the condition of patients in the acute phase.
In addition, formulation can be carried out by appropriately known methods depending on the dosage form. When formulating, a pharmaceutical carrier may be added as appropriate.

(8) Example of Nutritional Composition of Composition An example of the nutritional composition per 100 kcal of the composition of the present technology is described below.

The composition of the present technology may contain 0.5 g to 8 g, preferably 0.5 g to 5 g, of protein per 100 kcal of energy contained in the composition.
The composition of the present technology may contain 1 g to 10 g, preferably 2.5 g to 6 g, of lipid per 100 kcal of energy of the composition.
The composition of the present technology may contain 8 g to 25 g, preferably 10 g to 22 g, of carbohydrates per 100 kcal of energy contained in the composition.
The composition of the present technology may contain 5 g to 20 g, preferably 8 g to 18 g, of carbohydrates per 100 kcal of energy contained in the composition.
The composition of the present technology may contain 0.5 g to 8 g, preferably 1 g to 5 g, of dietary fiber per 100 kcal of energy contained in the composition.
The composition of the present technology may contain 0.03 g to 1.0 g, preferably 0.05 g to 0.7 g, of ash per 100 kcal of energy contained in the composition.
The composition of the present technology may contain 10 g to 80 g, preferably 30 g to 70 g, of water per 100 kcal of energy contained in the composition.

The composition of the present technology may contain, for example, 20 mg to 160 mg, and preferably 30 mg to 120 mg, of sodium per 100 kcal of energy contained in the composition.
The salt equivalent amount of the composition of the present technology may be, for example, 0.03 g to 0.5 g, and preferably 0.05 g to 0.3 g, per 100 kcal of energy contained in the composition.
The compositions of the present technology may have zero or substantially no potassium content, or, if the compositions of the present technology contain potassium, the compositions may contain, for example, greater than 0 mg to 100 mg, preferably 3 mg to 80 mg, of potassium per 100 kcal of energy contained in the composition.
The compositions of the present technology may have zero or substantially no chlorine content, or may contain, for example, greater than 0 mg to 170 mg, preferably 10 mg to 150 mg, of chlorine per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 0.1 mg to 100 mg, and preferably 1 mg to 50 mg, of calcium per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 0.1 mg to 30 mg, and preferably 1.0 mg to 20 mg, of magnesium per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 1 mg to 90 mg, and preferably 3 mg to 70 mg, of phosphorus per 100 kcal of energy contained in the composition.

The composition of the present technology may have zero or substantially no iron content, or if the composition of the present technology contains iron, the composition may contain iron per 100 kcal of energy that the composition has. For example, it may contain more than 0 mg to 1.2 mg, preferably 0.10 mg to 0.9 mg.
The composition of the present technology may contain, for example, 0.5 mg to 4.0 mg, preferably 0.7 mg to 3.5 mg, of zinc per 100 kcal of energy possessed by the composition.
The composition of the present technology may have zero or substantially no copper content, or, if the composition of the present technology contains copper, the composition may contain, for example, more than 0 mg of copper per 100 kcal of energy that the composition has. It may contain 0.15 mg, preferably 0.05 mg to 0.10 mg.
The composition of the present technology may have zero or substantially no manganese content, or if the composition of the present technology contains manganese, it may contain manganese in an amount of, for example, more than 0 mg or more per 100 kcal of energy of the composition. It may contain 0.20 mg, preferably 0.10 mg to 0.18 mg.
The composition of the present technology may contain zero or substantially no iodine, or if the composition of the present technology contains iodine, it may contain, for example, more than 0 μg of iodine per 100 kcal of energy of the composition. It may contain 20 μg, preferably 5 μg to 15 μg.
The composition of the present technology may contain zero or substantially no selenium, or if the composition of the present technology contains selenium, it may contain, for example, more than 0 μg or more of selenium per 100 kcal of energy of the composition. It may contain 10 μg, preferably 1 μg to 5 μg.
The composition of the present technology may contain zero or substantially no chromium, or if the composition of the present technology contains chromium, it may contain, for example, more than 0 μg or more of chromium per 100 kcal of energy of the composition. It may contain 10 μg, preferably 1 μg to 4 μg.
The composition of the present technology may contain zero or substantially no molybdenum, or if the composition of the present technology contains molybdenum, it may contain, for example, more than 0 μg of molybdenum per 100 kcal of energy of the composition. It may contain 8 μg, preferably 1 μg to 3 μg.

The composition of the present technology may contain, for example, 30 μg RAE to 130 μg RAE, preferably 40 μg RAE to 100 μg RAE of vitamin A per 100 kcal of energy possessed by the composition.
The composition of the present technology may contain, for example, 0.1 μg to 13 μg, preferably 0.15 μg to 12 μg, of vitamin D per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 0.5 mg to 35 mg, preferably 1.0 mg to 25 mg, of vitamin E per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 2 μg to 20 μg, preferably 4 μg to 8 μg, of vitamin K per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 0.05 mg to 1.0 mg, preferably 0.1 mg to 0.8 mg, of vitamin B1 per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 0.05 mg to 0.5 mg, preferably 0.1 mg to 0.4 mg, of vitamin B2 per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 1 mg NE to 8 mg NE, preferably 1.2 mg NE to 4.5 mg NE of niacin per 100 kcal of energy possessed by the composition.
The composition of the present technology may contain, for example, 0.1 mg to 1.0 mg, preferably 0.2 mg to 0.9 mg, of vitamin B6 per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 0.1 μg to 2.0 μg, preferably 0.2 μg to 1.5 μg of vitamin B12 per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 10 μg to 100 μg, preferably 20 μg to 80 μg, of folic acid per 100 kcal of energy possessed by the composition.
The composition of the present technology may contain, for example, 0.1 mg to 3 mg, preferably 0.5 mg to 2 mg, of pantothenic acid per 100 kcal of energy possessed by the composition.
The composition of the present technology may contain, for example, 1 μg to 15 μg of biotin, preferably 3 μg to 10 μg, per 100 kcal of energy possessed by the composition.
The composition of the present technology may contain, for example, 1 mg to 70 mg, preferably 5 mg to 50 mg, of vitamin C per 100 kcal of energy contained in the composition.

The composition of the present technology may contain, for example, 0.1 g to 5 g, preferably 0.3 g to 3 g, of MCT per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 10 mg to 120 mg, and preferably 20 mg to 100 mg, of EPA per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 5 mg to 60 mg, and preferably 10 mg to 50 mg, of DHA per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 0.01 g to 1.2 g, preferably 0.05 g to 0.7 g, of lactulose per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 5 mg to 50 mg, and preferably 10 mg to 20 mg, of carnitine per 100 kcal of energy contained in the composition.
The composition of the present technology may contain, for example, 500 million to 20 billion lactic acid bacteria per 100 kcal of energy contained in the composition, and preferably contains 1 billion to 10 billion lactic acid bacteria per 100 kcal of energy contained in the composition.

In addition, the present technology also provides the following methods and products.
[1]
Use of resistant dextrin and inulin for reducing ammonia concentration in the intestine.
[2]
A combination of resistant dextrin and inulin for reducing ammonia levels in the intestine.
[3]
A method for reducing intestinal ammonia concentration comprising administering resistant dextrin and inulin.

The technology also provides prebiotic materials used to reduce ammonia levels in the intestines, including indigestible dextrin and inulin. The composition of the prebiotic material may be as explained in (1) above. The prebiotic material may be added to, for example, a nutritional composition, a food/beverage composition, or a pharmaceutical composition. The prebiotic material may be used to reduce ammonia levels in the intestine in humans who have ingested the composition to which it is added.

The technology also provides a method for reducing ammonia concentration in the intestines. The method includes providing a prebiotic component into the intestine. As described above, the prebiotic component includes at least indigestible dextrin and inulin. The composition of the prebiotic component may be as explained in (1) above.

2. Culture medium

The present technology also provides a medium containing urea. The medium may be used, for example, to perform fecal culture. The medium containing urea is suitable for reproducing a specific intestinal environment. The medium containing urea may also be used, for example, to culture intestinal bacteria.

(urea)
The urea content rate in the medium may be, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, based on the mass of the medium. It may be 0.3% by mass or more, 0.5% by mass or more, or 0.7% by mass or more.
The urea content ratio in the medium may be, for example, 5% by mass or less, preferably 4% by mass or less, more preferably 3% by mass or less, and 2.5% by mass or less, based on the mass of the medium. , or 2% by mass or less, particularly preferably 1.5% by mass or less.
Such a urea content ratio is suitable, for example, for reproducing the intestinal environment of a human who has the below-mentioned disease or a human who may suffer from the below-mentioned disease.

(extract)
The medium may further contain, for example, a growth-promoting extract. The growth-promoting extract may be an extract for promoting the growth or proliferation of a culture target (especially bacteria). The growth-promoting extract may be, for example, an extract used in the field of bacterial culture, and may be appropriately selected by those skilled in the art depending on the subject to be cultured.

The growth-promoting extract may be, for example, but is not limited to, any one or a combination of two or more of yeast extract, meat extract, and plant extract. The yeast extract may be, for example, a hot water infusion, autolysate, or enzymatic digest of baker's yeast or brewer's yeast. The meat extract may be, for example, an animal meat extract or a fish meat extract. The animal meat extract may be, for example, a beef extract or a pork extract. The animal meat extract may also be a heart infusion or a brain heart infusion. The plant extract may be, for example, a malt extract, a potato extract, or a tomato juice.
In one embodiment, the growth promoting extract may be a yeast extract or a combination of yeast extract and other extracts.
In another embodiment, the growth promoting extract may be a meat extract or a combination of meat extract and other extracts.

The content ratio of the growth promoting extract is, for example, 0.0001% by mass or more, preferably 0.001% by mass or more, 0.003% by mass or more, 0.005% by mass or more, 0. It may be .007% by weight or more, 0.01% by weight or more, 0.05% by weight or more, or 0.1% by weight or more.
The content ratio of the growth promoting extract is, for example, 2% by mass or less, preferably 1.5% by mass or less, 1.0% by mass or less, 0.5% by mass or less, or 0.5% by mass or less, based on the mass of the medium. It may be 3% by mass or less.

For example, the growth promoting extract is a yeast extract, and the content of the yeast extract is, for example, 0.05% by mass or more, preferably 0.1% by mass or more, based on the mass of the medium. . Further, the content of the yeast extract may be, for example, 1% by mass or less, preferably 0.5% by mass or less, based on the mass of the medium.

(Protein hydrolysate)
The medium may further include, for example, a protein hydrolysate. The protein hydrolysate may be, for example, an enzymatic hydrolysate of a protein, for example, a peptone. More specific examples of the protein hydrolysate include casein peptone (e.g., casein or tryptone), meat peptone, gelatin peptone, and soybean peptone, and the protein hydrolysate may be one or a combination of two or more of these.
In one embodiment, the protein hydrolysate may comprise an enzymatic hydrolysate of casein, in particular casein peptone. The protein hydrolysate may be casein peptone or a combination of casein peptone and other peptones.
In another embodiment, the protein hydrolysate may include meat peptone. The protein hydrolysate may be meat peptone or a combination of meat peptone and other peptones.

The content of the protein hydrolysate may be, for example, 0.01 mass% or more, preferably 0.03 mass% or more, 0.05 mass% or more, or 0.07 mass% or more, and more preferably 0.1 mass% or more, 0.3 mass% or more, or 0.5 mass% or more, relative to the mass of the culture medium.
The content of the protein hydrolysate may be, for example, 5% by mass or less, preferably 4% by mass or less, 3% by mass or less, 2% by mass or less, or 1% by mass or less, relative to the mass of the medium.

(fatty acid)
In one embodiment, the medium may further comprise a fatty acid. The fatty acid may be, for example, a volatile fatty acid. The fatty acid may include, for example, acetic acid, propionic acid, valeric acid (e.g., n-valeric acid and/or isovaleric acid), and butyric acid (e.g., n-butyric acid and/or isobutyric acid), and the medium may contain one or a combination of two or more of these.

The content of the fatty acid (particularly the volatile fatty acid) may be, for example, 0.01 mass% or more, preferably 0.05 mass% or more, more preferably 0.1 mass% or more, 0.15 mass% or more, or 0.2 mass% or more, relative to the mass of the medium.
The content of the fatty acid (particularly the volatile fatty acid) may be, for example, 2 mass % or less, preferably 1.0 mass % or less, 0.7 mass % or less, or 0.5 mass % or less, relative to the mass of the medium.

(mineral source)
The medium may further include a mineral source. The mineral source may include, for example, an inorganic mineral source. Examples of such mineral sources include phosphorus sources, sulfur sources, potassium sources, calcium sources, magnesium sources, iron sources, and sodium sources, the mineral source being one or more of these. It may include combinations of two or more, especially combinations of two, three, four, five, six, or seven. The mineral source may include, for example, a phosphorus source, and may further include a phosphorus source and a sulfur source. The phosphorus source may be, for example, a phosphate. The sulfur source may be, for example, a sulfate.

The total content of the mineral sources may be, for example, 0.01% by mass or more, preferably 0.1% by mass or more, based on the mass of the medium.
The total content of the mineral sources may be, for example, 10% by mass or less, preferably 1% by mass or less, based on the mass of the medium.

(carbohydrates)
In one embodiment, the medium may further include carbohydrates, for example. The carbohydrate may be, for example, a monosaccharide or a disaccharide. For example, the carbohydrate may be any one or a combination of two or more of glucose, fructose, mannose, maltose, cellobiose, trehalose, and galactose. For example, the carbohydrate may include monosaccharides, such as glucose.
In other embodiments, the medium may be carbohydrate-free, eg, mono- or disaccharide-free. For example, the medium may be free of added carbohydrates, especially mono- or disaccharides.

When the medium contains the carbohydrate, the content of the carbohydrate is, for example, 0.01% by mass or more, preferably 0.03% by mass or more, 0.05% by mass or more, 0.01% by mass or more, preferably 0.03% by mass or more, 0.05% by mass or more, based on the mass of the medium. It may be 0.07% by mass or more, or 0.1% by mass or more.
When the medium contains the carbohydrate, the content of the carbohydrate is, for example, 5% by mass or less, preferably 4% by mass or less, 3% by mass or less, 2% by mass or less, or 1% by mass, based on the mass of the medium. % or less.

(Other ingredients)
The medium may further include vitamins, such as vitamin B1, vitamin B2, vitamin B6, vitamin B12, folic acid, and biotin, and the medium may include one or a combination of two or more of these.
The medium may further include a reducing agent, which may include cysteine and thioglycolic acid, and the medium may include one or a combination of two of these.
The medium may further comprise a porphyrin, which may be, for example, an iron-containing porphyrin, more specifically, hemin.
The medium may further include an indicator. The indicator may be, for example, a redox indicator and a pH indicator, and the medium may include one of these, or may include two of them. The redox indicator may be, but is not limited to, resazurin. The pH indicator may be, but is not limited to, phenol red. In one embodiment, the medium may not include the pH indicator.
The medium may further include a selection substance. The selection substance may be, for example, a substance used to selectively grow a certain bacterium. The selection substance may include, for example, an antibiotic, a tellurite, an azide, a bile salt, etc., and the medium may include one or a combination of two or more of these.
The content ratio of these components may be a normal value in the art and may be appropriately selected by a person skilled in the art.

(Specific examples of culture media)
In one embodiment, the medium contains, for example, urea, a protein hydrolysate, a growth-promoting extract, and a fatty acid. In this embodiment, the protein hydrolysate may be a casein hydrolysate, particularly an enzymatic hydrolysate of casein. In this embodiment, the growth-promoting extract may be a yeast extract. In this embodiment, the fatty acid may be a volatile fatty acid.
The medium may also contain further vitamins, reducing agents and mineral sources. The medium may also contain an indicator, in particular a redox indicator.
An example of such a medium is urea-containing YCFA medium.

(Form of culture medium)
The medium may be a liquid medium or a solid medium. The liquid medium may be a liquid medium in which the above-mentioned components are contained in water. The solid medium may be a medium in which a liquid containing the above-mentioned components is solidified. For the solidification, the solid medium may contain a solidifying agent such as agar.

(Method of producing culture medium)
The medium may be produced by adding and mixing urea and other medium components to a liquid (e.g., water) to prepare a medium liquid, and then sterilizing the medium liquid. In the case of a liquid medium, the medium liquid may be cooled in a container after the sterilization. In the case of a solid medium, the medium liquid may be solidified in a container after the sterilization, for example, by cooling. Each step in the production (adding, mixing, sterilization, cooling, etc.) may be performed by a method commonly used in the art.

(Method of using the medium)
The medium may be used for fecal culture as described above. The medium may also be used for culture other than fecal culture.

The medium may be used, for example, to culture enterobacteria. The enterobacteria may be, for example, bacteria present in a fecal sample. That is, the medium may be used for fecal culture, and in the fecal culture, bacteria present in the feces may be cultured.
The enterobacteria may also be bacteria isolated from fecal samples or other samples.

The medium may be used as a model to reproduce the intestinal environment at pH 7 or higher. By containing urea, the medium can reproduce an intestinal environment with a pH of 7 or more. For example, in the intestinal environment of a person whose intestinal environment is deteriorated or a person who has a disease (eg, kidney disease), the pH in the intestine may become 7 or higher. The medium can reproduce the intestinal environment with a pH of 7 or higher, and is therefore useful as a model for reproducing the intestinal environment in humans.
That is, the medium is configured such that the pH is 7 or more after 24 hours after the start of fecal culture (for example, 24 hours to 48 hours, 24 hours to 36 hours, or 24 hours to 30 hours after the start of fecal culture). It's fine.

The medium may be configured so that the amount of ammonia produced after 24 hours of fecal culture is 100 mM or more. To constitute the medium in this way, the composition as described above may be employed, in particular urea may be included in the medium as described above. The fact that the ammonia production amount is 100 mM or more can be used, for example, as an indicator that the human intestinal environment is deteriorating.

That is, the medium may be used as a model of an intestinal environment in which the amount of ammonia is 100 mM or more. As described above, such a model is useful for investigating or evaluating a method for improving the intestinal environment of kidney disease or those at risk of kidney disease.
As described in the Examples below, the amount of ammonia is measured by centrifuging the medium in which fecal culture was performed, and then measuring the supernatant using a specified kit.

The medium may suppress short chain fatty acid production associated with fecal culture. The suppression can be confirmed, for example, by comparing cases where urea is included in the medium and cases where urea is not included.
For example, the medium may be configured such that the amount of acetic acid produced after 24 hours of fecal culture is, for example, 25 mM or less, preferably 23 mM or less.
Further, the medium may be configured such that the amount of propionic acid produced after 24 hours of fecal culture is, for example, 5.5 mM or less, preferably 5.3 mM or less.
Further, the medium may be configured such that the amount of butyric acid produced after 24 hours of fecal culture is, for example, 1.5 mM or less, preferably 1.0 mM or less.
Further, the medium may be configured such that the total production amount of acetic acid, propionic acid, and butyric acid after 24 hours of fecal culture is, for example, 32 mM or less, preferably 30 mM or less.
To constitute the medium in this way, the composition as described above may be employed, in particular urea may be included in the medium as described above. For example, in kidney disease patients, the number of short chain fatty acid producing bacteria may decrease, and the amount of short chain fatty acids may decrease accordingly. Since the medium has a reduced amount of short chain fatty acids as described above after fecal culture, it can be used as a model of the intestinal environment of such patients.

That is, the medium may be used as a model of the intestinal environment in which the amount of acetic acid is, for example, 25 mM or less, preferably 23 mM or less.
Further, the medium may be used as a model of the intestinal environment in which the amount of propionic acid is, for example, 5.5 mM or less, preferably 5.3 mM or less.
Further, the medium may be used as a model of the intestinal environment in which the amount of butyric acid is, for example, 1.5 mM or less, preferably 1.0 mM or less.
Further, the medium may be used as a model of the intestinal environment in which the total amount of acetic acid, propionic acid, and butyric acid is, for example, 32 mM or less, preferably 30 mM or less.
As mentioned above, such a model is useful for investigating or evaluating methods for improving the intestinal environment of kidney disease patients or potential kidney disease patients.
In addition, the amount of these fatty acids is measured by performing HPLC on the supernatant obtained by centrifuging a medium in which fecal culture has been performed, as explained in Examples below.

The medium may be used as a model to reproduce the intestinal environment of a human with kidney disease or at risk of kidney disease. Ammonia levels in the intestines of people with kidney disease and pre-kidney disease are often elevated. The medium contains urea, and when fecal culture is performed using the medium, the conditions in the medium are similar to those in the intestine of a person with kidney disease or a person at risk of kidney disease. Therefore, the medium is useful for studying the intestinal environment of humans with kidney disease or at risk of kidney disease.
The kidney disease may be a primary kidney disease or a secondary kidney disease. Kidney disease may be acute or chronic kidney disease.
Primary kidney disease is a kidney disease in which problems occur in the kidney itself. An example of primary kidney disease is nephritis. More specific examples of nephritis include glomerulonephritis and interstitial nephritis.
Secondary kidney disease is kidney disease caused by a disease other than the kidneys, such as diabetes, gout, hypertension, or collagen disease. Examples of secondary kidney diseases include diabetic nephropathy, nephrosclerosis, and gouty kidney.
Typical kidney diseases include acute glomerulonephritis, chronic glomerulonephritis, rapidly progressive glomerulonephritis, and diabetic nephropathy.
A person at risk for kidney disease may refer to a person who has not been diagnosed with kidney disease, but who has a high possibility of developing kidney disease, such as a person who has a high urea level as described below.
The medium may be used as a model to reproduce the intestinal environment of a human with such kidney disease or a human at risk of kidney disease.

The medium may be used as a model for reproducing the intestinal environment of a human having a high amount of urea in the whole body (or body). The human having a high amount of urea may mean a human having a higher blood urea nitrogen (BUN) than the normal value. The normal value of blood urea nitrogen is, for example, 23 mg/dl or less, 22 mg/dl or less, 21 mg/dl or less, or 20 mg/dl or less. Therefore, the medium may be used as a model for reproducing the intestinal environment of a human having a blood urea nitrogen test value higher than the upper limit of the normal value range (23 mg/dl, 22 mg/dl, 21 mg/dl, or 20 mg/dl). The blood urea nitrogen may be measured by a measurement method used in a general blood test performed in a health checkup, etc., and is also called BUN (blood urea nitrogen).

The medium may be used, for example, to culture a sample. That is, the present technology also provides a culture method including culturing a sample using the medium. In one embodiment, the sample may be, for example, a fecal sample. In another embodiment, the sample may be bacteria, particularly the above-mentioned enterobacteria. The culture in the culture method may be, for example, anaerobic culture, or may be aerobic culture. More specific procedures of the culture method may be appropriately selected by those skilled in the art depending on, for example, the composition of the medium, the type of sample, or the purpose of culture.

(Composition for producing medium)
The present technology also provides a composition used to produce the medium. The composition may be configured to form the medium by adding the composition to a predetermined liquid (e.g., water, etc.) (and mixing as necessary). The composition may be, for example, in a solid or liquid form. The solid composition may be, for example, in a powder or granule form. The liquid composition may be, for example, configured to form the medium by diluting it with the predetermined liquid.

3. Analysis method

The present technology also provides an analytical method using the medium described in 2. above. The medium may have the composition described in 2. above, and the description also applies to the present analytical method.

The analysis method may include a culturing step of culturing a sample in the medium. The sample may be, for example, a fecal sample. The fecal sample may be a sample containing feces obtained from an animal (e.g., a human), and may be, for example, a sample obtained by adding the feces to a predetermined liquid (e.g., water, saline, or a buffer solution).

The culture may be, for example, anaerobic, but may also be aerobic. These cultures may be carried out using devices known in the art. The duration of the culture may be, for example, 1 hour to 100 hours, in particular 5 hours to 80 hours, more in particular 10 hours to 50 hours. The duration of the culture may be more than 100 hours, for example 100 hours to 200 hours. The culture may be carried out, for example, at 0°C to 70°C, in particular 10°C to 65°C, more in particular 30°C to 40°C, and even more in particular 35°C to 38°C, but the culture temperature may be appropriately changed depending on the type of bacteria to be cultured or the purpose of the culture.

The method may further include an analysis step. In the analysis step, an object to be analyzed may be analyzed. Examples of the subject to be analyzed include, but are not limited to, substances produced or decreased in the culture, the culture itself, and bacteria in the culture. The subject to be analyzed may be one or more of these.
The substances produced or reduced in the culture are, for example, secretions or metabolites derived from bacteria, or substances produced or reduced due to secretions or metabolites derived from bacteria (for example, the ammonia or short chain fatty acids, etc.). It may be a substance, such as a substance that is consumed by bacteria. Analysis of these substances may be performed, for example, by high performance liquid chromatography (HPLC), gas chromatography, GC/MS, or ion chromatography. Moreover, analysis of these substances may be performed using a commercially available measurement kit. In order to measure the ammonia, for example, a measurement based on the Bertellot reaction may be performed, and a measurement kit that measures the amount of ammonia using the reaction may be used. Furthermore, in order to measure the short chain fatty acids, the short chain fatty acids may be derivatized using a derivatization reagent such as 2-nitrophenylhydrazine, and a measurement kit for performing the derivatization may be used. It's fine.
When the object to be analyzed is the culture itself, the object to be analyzed may be, for example, the state (color, shape, etc.) of the culture.
When the target to be analyzed is bacteria in the culture, the target to be analyzed is, for example, one or more types of bacteria (e.g., one or more phylum, family, genus, or species of bacteria). Or it may be bacterial flora. Analysis of bacteria or bacterial flora may be performed, for example, by FISH, clone library methods, real-time PCR, or terminal RFLP.
The analysis method used in the analysis step may be appropriately selected by a person skilled in the art depending on the object to be analyzed.

The present technology will be described in more detail below with reference to Examples, but the present technology is not limited to these Examples.

4. Example

4.1 Culture medium evaluation

4.1.1 Medium Preparation A YCFA medium to which urea was added (hereinafter also referred to as "YCFA medium containing urea") was prepared. The composition of the YCFA medium was as shown in Table 1 below.

The urea-containing YCFA medium was prepared according to the method described in Murakami R et al., Food Res Int., Volume 144, June 2021, and the above vitamin cysteine solution was added.
In addition, a YCFA medium to which urea was not added (hereinafter also referred to as "urea-free YCFA medium") was also created. The urea-free YCFA medium was produced in the same manner as the urea-containing YCFA medium, except that the same amount of water was added instead of urea.

4.1.2 Culture method Three fecal samples were prepared. The three samples were added to the urea-containing YCFA medium and the urea-free YCFA medium, respectively, and anaerobically cultured for 48 hours.

The anaerobic culture was performed as follows. That is, a diluted fecal solution was added to the above medium, and cultured under anaerobic conditions and pH control using a culture device (Bio Jar. 8, Biot Co., Ltd.).
90 mL of urea-containing YCFA medium or urea-free YCFA medium was placed in each of the plurality of vessels of the culture apparatus, and autoclaved at 115° C. for 20 minutes. Thereafter, the filter-sterilized vitamin cysteine solution was added aseptically to the culture medium in each vessel. Thereafter, 10 mL of sterile deionized water was added to each vessel. Thereafter, the culture medium in each vessel was brought to an anaerobic state by nitrogen replacement overnight, and 100 μL of a fecal solution containing a fecal sample adjusted to 10% (w/v) with physiological saline was added to each culture medium. , the pH was adjusted to 6.4 with 1 M Na ₂ CO ₃ solution, and the cells were incubated anaerobically at 37° C. for 48 hours.
Cultivation was started at pH 6.4 to 6.5 and cultured with pH control as the lower limit of pH 6.0.

4.1.3 Analysis method The culture in the anaerobic culture was analyzed for (1) pH, (2) ammonia concentration, (3) short chain fatty acid content, and (4) bacterial flora composition and number of bacteria.
More specifically, the medium in each vessel was collected 24 hours and 48 hours after the start of the anaerobic culture and centrifuged. The centrifugation was performed at 8000 rpm on 1.0 mL of the medium. The supernatant after the centrifugation was used for analysis of short chain fatty acids and ammonia concentration, and the pellet was used for analysis of bacterial flora composition and number of bacteria.
pH was measured by a sensor attached to the culture device.
Ammonia concentration was analyzed using a Lab assay ammonia kit (Wako Pure Chemical Industries, Ltd.) according to the protocol attached to the kit.
The amount of short-chain fatty acids was determined by pre-treating the medium supernatant using a labeling reagent for long-chain and short-chain fatty acid analysis (YMC Co., Ltd.) according to the instructions attached to the reagent, and then extracting the short-chain fatty acids. It was analyzed using HPLC (Waters) with a YMC-Pack column.
The bacterial flora composition was analyzed by extracting the bacterial DNA in the pellet and using a next-generation sequencer Miseq.

4.1.4 Analysis Results The analysis results for (1) pH, (2) ammonia concentration, (3) short chain fatty acid content, and (4) bacterial flora composition and number are as follows.

(1) pH Change The results of measuring pH during the 48-hour anaerobic culture are shown in Figure 1. The results of measuring pH at the start of culture (0 hours) and at 24 and 48 hours after the start of culture are shown in Table 2. These measurement results are the average values of the three samples.

As shown in these measurement results, in the urea-containing YCFA medium, the pH increased from 18 hours after culture, and the pH was maintained at 7.2 to 7.3 from 24 to 48 hours after culture. On the other hand, in the urea-free YCFA medium, the pH was around 6.4 to 6.5 over 48 hours of culture.
Normal human intestinal pH is about 6.5. On the other hand, in humans with kidney disease, intestinal pH is elevated, often exceeding 7.0. Furthermore, in uremic patients, the pH of the lower intestinal tract may rise to 7.5.
As mentioned above, in the urea-containing YCFA medium, the pH increases after the start of fecal culture and is maintained at 7.2 to 7.3. Therefore, the urea-containing YCFA medium can be used as a human intestinal model with a high intestinal pH, especially in humans with an intestinal pH of 7.0 or higher (e.g., people with kidney disease). .

(2) Change in Ammonia Amount The measurement results of the ammonia amount 24 hours and 48 hours after the start of the anaerobic culture are shown in FIG. 2 and Table 3. Note that these measurement results are the average values of the three samples.

As shown in these measurement results, the ammonia production amount at 24 hours and 48 hours after culture in the urea-containing YCFA medium is significantly higher than that in the urea-free YCFA medium.
For example, in patients with kidney disease, intestinal ammonia production increases. This is thought to be due to urease-producing bacteria, based on experiments using a mouse model.
As mentioned above, in the urea-containing YCFA medium, the amount of ammonia produced after the start of fecal culture is high. Therefore, it is thought that the urea-containing YCFA medium can be used as an intestinal model for humans who produce a high amount of ammonia (for example, humans with kidney disease).

(3) Change in the amount of short chain fatty acids Table 4 shows the measurement results of the amount of short chain fatty acids 24 hours and 48 hours after the start of the anaerobic culture. Note that these measurement results are the average values of the three samples.

As shown by these measurement results, the amounts of acetic acid, propionic acid, and butyric acid in the urea-containing YCFA medium were all lower at 24 and 48 hours after culture than those in the urea-free YCFA medium. There was a significant difference in the total amount of acetic acid and short-chain fatty acids at 48 hours.
For example, in patients with kidney disease, the number of short-chain fatty acid-producing bacteria in the intestine decreases, which is thought to result in a decrease in the amount of short-chain fatty acids in the intestine.
As described above, in the urea-containing YCFA medium, the amount of short-chain fatty acids is low after the start of fecal culture, and therefore the urea-containing YCFA medium is considered to be useful as an intestinal model for humans with low levels of short-chain fatty acids in the intestine (e.g., humans with kidney disease).

(4) Bacterial flora The measurement results of the occupancy rates of the phylum Proteobacteria and the family Enterobacteriaceae in the bacterial flora 24 hours and 48 hours after the start of the anaerobic culture are shown in FIG. 3 and Table 5. Note that these measurement results are occupancy rates when the entire bacterial flora is taken as 1. Moreover, these measurement results are the average values of the three samples.

As shown by these measurement results, the occupancy rates of the phylum Proteobacteria and the family Enterobacteriaceae in the urea-containing YCFA medium 24 hours and 48 hours after culture were higher than those in the urea-free YCFA medium.
For example, in patients with kidney disease, the prevalence of bacteria from the phylum Proteobacteria and the family Enterobacteriadeae is increased.
As described above, in the urea-containing YCFA medium, the occupancy rate of bacteria of the phylum Proteobacteria and the family Enterobacteriadeae is high after the start of fecal culture. Therefore, it is considered that the urea-containing YCFA medium can be used as an intestinal model for humans (e.g., humans with kidney disease) who have a high occupancy rate of bacteria of the phylum Proteobacteria and the family Enterobacteriadeae.

The results shown in (1) to (4) above indicate that by including urea in the medium, the medium can be used as a model for reproducing the intestinal environment of humans with diseases such as kidney disease. .

4.2 Evaluation of prebiotic samples using urea-containing medium 1

The following samples 1 to 4 were prepared. Sample 1 is a control sample. Samples 2-4 are prebiotic samples. The amount of prebiotic components in samples 2-4 is the same.
Sample 1: Water sample 2: Inulin sample 3: Indigestible dextrin Sample 4: Combination of indigestible dextrin and inulin (mass ratio of these two components is 1:1)

Each of samples 2 to 4 was dissolved in deionized water to a prebiotic component concentration of 10% (w/v), and a 10% solution of each sample was prepared.

A urea-containing YCFA medium was prepared as described in 4.1.1 above, and anaerobic cultivation was carried out for 24 hours using the urea-containing YCFA medium as described in 4.1.2 above.
Prior to the initiation of the anaerobic culture, 100 μL of the fecal solution and 10 mL of a 10% solution of any of Samples 2 to 4 or 10 mL of Sample 1 (water only) were added to the urea-containing YCFA medium in each vessel.

The amount of ammonia produced after the anaerobic culture was measured as described in 4.1.3 above. The measurement results are shown in Table 6 below and in Figure 4.

As shown in these measurement results, the amount of ammonia produced when indigestible dextrin or inulin is added (in the case of sample 2 or 3) is lower than the amount of ammonia produced in the control group (in the case of sample 1). Therefore, it can be seen that the amount of ammonia produced can be reduced by adding indigestible dextrin or inulin alone.
Furthermore, the amount of ammonia produced when the combination of indigestible dextrin and inulin was added (in the case of sample 4) was also lower than the amount of ammonia produced in the control group (in the case of sample 1). Therefore, it can be seen that the amount of ammonia produced can also be reduced by adding a combination of indigestible dextrin and inulin.
Furthermore, although the amounts of prebiotic components in Samples 2 to 4 are the same, the amount of ammonia produced when a combination of indigestible dextrin and inulin is added (in the case of sample 4) is lower than that of indigestible dextrin. Or, it is even lower than the ammonia production amount when inulin is added (in the case of sample 2 or 3). Therefore, the effect of reducing the amount of ammonia produced by the combination is a synergistic effect.

These results show that the combination of indigestible dextrin and inulin exhibits an extremely excellent ammonia production suppressing effect.
Further, the medium is a model of the intestinal environment of, for example, a human with kidney disease or a person at risk of kidney disease, and is useful, for example, for evaluating ammonia production caused by intestinal bacteria. Since the above combination shows an excellent ammonia production suppressing effect in a culture test using the above medium, it can be seen that the above combination is useful for suppressing ammonia production caused by intestinal bacteria.

4.3 Evaluation of prebiotic samples using urea-containing medium 2

The following samples 11-17 were prepared: Sample 11 is a control sample. Samples 12-17 are prebiotic samples. Samples 12-17 have the same amount of prebiotic ingredient.
Sample 11: Water Sample 12: Inulin Sample 13: Combination of resistant dextrin and inulin (resistant dextrin 10% by weight: inulin 90% by weight)
Sample 14: Combination of resistant dextrin and inulin (resistant dextrin 25% by mass: inulin 75% by mass)
Sample 15: Combination of resistant dextrin and inulin (resistant dextrin 50% by mass: inulin 50% by mass)
Sample 16: Combination of resistant dextrin and inulin (resistant dextrin 75% by mass: inulin 25% by mass)
Sample 17: Resistant dextrin

Each of samples 12 to 17 was dissolved in deionized sterile water to a prebiotic component concentration of 10% (w/v), and a 10% solution of each sample was prepared.

The urea-containing YCFA medium was prepared as described in 4.1.1 above, and anaerobic cultivation was carried out for 24 hours using the urea-containing YCFA medium as described in 4.1.2 above.
Prior to the initiation of the anaerobic culture, 100 μL of fecal solution and 10 mL of a 10% solution of any of Samples 12 to 17 or 10 mL of Sample 1 (deionized sterile water only) were added to the urea-containing YCFA medium in each vessel.

The amount of ammonia produced after the anaerobic culture was measured as described in 4.1.3 above. The measurement results are shown in Table 7 below and Figure 5.

As shown by these measurement results, the amount of ammonia produced when resistant dextrin or inulin was added (in the case of sample 12 or 17) was lower than the amount of ammonia produced in the control group (in the case of sample 11). Therefore, as in 4.2 above, it was confirmed that the amount of ammonia produced can be reduced by adding resistant dextrin or inulin alone.
Furthermore, when a combination of resistant dextrin and inulin was added (samples 13 to 16), the amount of ammonia produced was also lower than the amount of ammonia produced in the control group (sample 1). This shows that the amount of ammonia produced can also be reduced by adding a combination of resistant dextrin and inulin.

Furthermore, although the amounts of prebiotic components in Samples 12 to 17 were the same, the amount of ammonia produced when a combination of resistant dextrin and inulin was added (Samples 13 to 16) was even lower than the amount of ammonia produced when resistant dextrin or inulin was added (Samples 12 and 17). Therefore, the effect of reducing ammonia production by this combination is a synergistic effect.
For example, taking into account the ratio of the resistant dextrin mass to the inulin mass in Samples 13 to 16, it can be seen that in order to suppress the amount of ammonia production, the mass ratio of resistant dextrin to inulin is, for example, 1:99 to 90:10, more preferably 3:97 to 85:15, even more preferably 5:95 to 80:20, and particularly preferably 10:90 to 75:25.

Furthermore, among samples 13 to 16, samples 13 to 15 had particularly low ammonia production. The ratios of resistant dextrin mass to inulin mass in samples 13 to 15 were 10:90, 25:75, and 50:50. Therefore, it can be seen that a mass ratio of resistant dextrin to inulin of, for example, 5:95 to 60:40, particularly 7:93 to 55:45, and more particularly 10:90 to 50:50, is particularly preferred for suppressing ammonia production.

4.4 Production Examples Two compositions having compositions as shown in Production Examples 1 and 2 in Table 8 below were produced. Specifically, starch hydrolysate, resistant dextrin, vegetable oil, inulin, lactulose, refined fish oil, dry yeast, carnitine, sodium caseinate, cellulose, pH adjuster, emulsifier, and zinc gluconate were mixed, and the mixture was subjected to retort sterilization. The values shown in Table 8 are per 125 ml (per 150 kcal), and the content of each component per 100 kcal is the value obtained by multiplying each value shown in the same table by 0.67.

The composition includes a prebiotic component. The prebiotic component is a combination of resistant dextrin and inulin. The composition also includes oligosaccharides. The oligosaccharides include lactulose. The resistant dextrin, the inulin, and the lactulose were the prebiotic components included in the composition.

The ratio of the mass content of the resistant dextrin to the mass content of the inulin was 10:90 or 25:75.

These compositions were liquid and had a viscosity of 7.5 mPa·s at 20°C. The water content of these compositions was approximately 100 g/125 ml.
The composition of the present technology may be configured as a liquid composition having the above composition and physical properties.

Claims (15)

Fecal culture medium containing urea. The medium according to claim 1, wherein the urea content is 0.1% by mass or more based on the mass of the medium. The medium according to claim 1 or 2, wherein the medium is used for culturing intestinal bacteria. The medium according to claim 1 or 2, wherein the medium further contains a growth promoting extract. The medium according to claim 1 or 2, wherein the medium further contains a protein degradation product. The medium according to claim 1 or 2, wherein the medium further contains a fatty acid. The medium according to claim 1 or 2, which is used as a model for reproducing an intestinal environment having a pH of 7 or higher. The medium according to claim 1 or 2, wherein the medium is configured so that the amount of ammonia produced after 24 hours of fecal culture is 100 mM or more. The medium according to claim 1 or 2, which suppresses the production of short-chain fatty acids associated with fecal culture. The medium according to claim 1 or 2, wherein the medium is used as a model for reproducing the intestinal environment of a human with kidney disease or a human at risk of kidney disease. The medium according to claim 1 or 2, wherein the medium is used as a model for reproducing the intestinal environment of a human having a high amount of urea in the whole body. An analytical method using a fecal culture medium containing urea. The analysis method according to claim 12, wherein the medium has a urea content of 0.1% by mass or more. The analytical method according to claim 12 or 13, comprising a culture step of culturing a fecal sample in the medium. The method according to claim 14 , further comprising an analysis step of analyzing the culture obtained in the culturing step.