CN113475720B

CN113475720B - Application of osteopontin in increasing intestinal flora diversity and increasing intestinal short-chain fatty acid content

Info

Publication number: CN113475720B
Application number: CN202110664218.7A
Authority: CN
Inventors: 陈桔淳; 刘斐童; 郑雨星; 陆泽荣
Original assignee: Biostime Guangzhou Health Product Co ltd
Current assignee: Biostime Guangzhou Health Product Co ltd
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2023-07-25
Anticipated expiration: 2041-06-15
Also published as: CN113475720A

Abstract

The invention discloses application of osteopontin in increasing intestinal flora diversity and increasing intestinal short-chain fatty acid content, and provides a new direction for preparing medicines or foods with the functions of increasing intestinal flora diversity and increasing intestinal short-chain fatty acid content.

Description

Application of osteopontin in increasing intestinal flora diversity and increasing intestinal short-chain fatty acid content

Technical Field

The invention relates to application of osteopontin, in particular to application of osteopontin in increasing intestinal flora diversity and increasing intestinal short chain fatty acid content.

Background

Osteopontin (OPN) is a phosphorylated acidic protein, which is present in relatively high concentrations in human milk, at 50-180mg/L, and only 18mg/L in milk. OPN has various biological activities such as promoting cell proliferation and differentiation, enhancing immune function and promoting bone development.

OPN has positive effects on early infant development, especially on early infant immunomodulation. In early life, insufficient production and reduced responsiveness of Th1 cytokines may be the main causes of low innate cellular immunity in newborns and shift to Th2 immune responses. Research shows that OPN actsThe key is its regulation of Th1 and Th2 immune balance. Clinical researches show that the infant tolerance is good and the growth and development state is good when the formula powder for strengthening the OPN of the cow milk is eaten; compared with the common formula powder, the formula powder feeding for strengthening OPN can reduce the occurrence of fever and proinflammatory immune reaction (cytokine) of infantset al.2016)。

In addition, studies have shown that OPN can stimulate intestinal epithelial cell proliferation, support intestinal development and intestinal health, and studies have found that feeding fortified bovine milk OPN formulas can reduce the severity of necrotizing enterocolitis in newborn piglets (Moller et al 2011). In addition, OPN was found to promote myelin-related protein synthesis and myelination, thereby promoting cognitive development, and experiments found that mice fed cow milk-enriched OPN milk exhibited better memory and learning ability in cognitive tests (Jiang 2020). Therefore, OPN has various functions of improving infant immunity, promoting intestinal health, promoting cognitive development and the like. However, no research is currently conducted on the mechanism of action of OPN in the intestinal tract to promote intestinal health.

Disclosure of Invention

In view of the problems of the prior art, it is an object of the present invention to provide an application of osteopontin in increasing intestinal flora diversity or increasing intestinal flora diversity during in vitro culture.

Intestinal flora and organisms are symbiotic, and have a plurality of effects on the aspects of metabolism, development and maturation of immune functions, intestinal protection and the like. The effect on the metabolism of the body, such as the production of short chain fatty acids, mainly acetate, propionate and butyrate, can provide energy and maintain the growth and development of the gastrointestinal tract, and is important for the intestinal health of infants. Some intestinal flora may synthesize vitamins that have an important role in infants, such as vitamin K and other multi-vitamin B groups. Some bacteria in the intestinal tract can also produce conjugated linoleic acid, which plays an important role in the normal growth and development of newborns, and is associated with obesity, diabetes and immune function. The intestinal flora can also influence the blood concentration of tryptophan, an essential amino acid in the development of the central nervous system, via the kynurenine pathway. The interaction between the intestines and the brain forms a brain-intestine axis, the mechanisms of nerves, immunity and endocrine are integrated, and intestinal flora can play a role similar to signal molecules in the brain-intestine axis and play a role in regulating in the aspects of immunity, central nervous system, gastrointestinal tract functions and the like in early life. The intestinal flora can influence the colonization and reproduction of pathogenic bacteria through biological antagonism, thereby protecting the organism from being injured by the pathogenic bacteria. The intestinal bacteria have regulating effects on innate immunity and adaptive immunity. Through aseptic animal experimental study, intestinal microorganisms are proved to be necessary for maintaining the normal form and immune maturation of the intestinal tract, and mice living under aseptic conditions show impaired development of the intestinal immune system and oral immune tolerance defects. Bifidobacteria in the recombinant intestinal flora during neonatal periods may regain the ability to be orally tolerated.

The change of maternal bacterial flora in pregnancy can indirectly influence the fetus, the original bacterial flora of maternal system can be vertically transferred to the next generation during delivery, and bacterial flora obtained by breast milk can guide the establishment of bacterial flora of newborns, immune development and the like; infants develop along with growth, so that flora diversity is increased, and the infants are immune-matured.

Intestinal flora diversity is a healthy intestinal flora feature, and the finished food significantly reduces the intestinal flora diversity and increases the risk of depression. Intestinal flora may be involved in regulating mental health through the intestinal axis, and disorders of intestinal flora are associated with many mental diseases. Food is directly related to changes in intestinal flora, so a good diet can promote mental well-being.

Intestinal microbiome alpha diversity is associated with human health, and lower levels of diversity are associated with some acute and chronic diseases.

According to the invention, the application of the osteopontin in increasing the diversity of intestinal flora is found in the process of culturing the intestinal flora outside the intestinal flora.

Preferably, the intestinal flora diversity is intestinal flora alpha diversity.

Preferably, the intestinal flora diversity is infant intestinal flora diversity.

Preferably, the concentration of the osteopontin in the nutrient solution is 0.065-1.5 mg/mL; more preferably, the concentration of osteopontin in the nutrient solution is 1.375mg/mL.

The second purpose of the invention is to provide the application of the osteopontin in increasing the content of intestinal short-chain fatty acid or increasing the content of intestinal short-chain fatty acid in an in-vitro culture process.

Intestinal microorganisms are an important component of the human body and they play a very important role in the development, function and regulation of the human immune system from the beginning of life by various means.

The evolving symbiotic relationship between humans and intestinal microorganisms has many benefits in humans, including modulating host immunity, producing vitamin K and vitamin B, protecting the gut from pathogens, enhancing gut integrity, and producing metabolite Short Chain Fatty Acids (SCFAs). Short chain fatty acids are produced by intestinal flora through fermentation of carbohydrates, mainly acetic acid, propionic acid, butyric acid, etc. Short Chain Fatty Acids (SCFA) are mediators of the interaction of intestinal flora and host metabolism, and both prebiotic and probiotic action depend on SCFA. Short chain fatty acids are thought to mediate communication between the intestinal flora and the immune system, inhibiting proliferation of certain bacteria by lowering the pH of the gut, which is critical for gut homeostasis. SCFAs can signal through G-protein-sensitive G-protein coupled receptors, and SCFAs circulating in blood can affect tissue-specific acetylation of histones 3 and 4, inducing epigenetic changes in the genome; the special diet can be used for increasing the content of SCFAs in intestinal tracts, so that the diabetes of the non-obese diabetic mice can be prevented; SCFAs can cause epigenetic marks in utero during pregnancy and prevent allergic diseases of infant airways; SCFAs also regulate blood brain barrier and neuroimmune endocrine functions. Short chain fatty acids can inhibit Histone Deacetylase (HDACs), which are involved in regulating gene expression in many diseases, and promote the onset of the disease. SCFA play a beneficial role in the metabolism and function of adipose tissue, skeletal muscle, and liver matrix and help improve insulin sensitivity.

Acetic acid, propionic acid, butyric acid are the major SCFA, lactic acid, succinic acid are the precursor substances of SCFA, produced by specific intestinal microbial enzymes, at the highest concentration in the cecum and proximal colon, and are the source of colonic cell energy.

Animal and human data indicate that acetic acid affects host energy and substrate metabolism by regulating the secretion of intestinal hormones and metabolizing substrates such as glucagon-like peptide-1 and peptide YY. Appetite is affected by decreasing systemic lipolysis, systemic inflammatory cytokine levels, increasing energy expenditure and fat oxidation.

Acetate may also be produced by deacetylation of endogenous proteins, such as histones.

Acetate plays a key role in maintaining intracellular acetyl-coa levels, whereas acetate metabolism disorders are associated with several human diseases.

Short Chain Fatty Acids (SCFA) produced by intestinal flora fermentation of dietary fibers have an immunomodulatory function. Animal studies have shown that SCFA such as propionic acid can increase intestinal-related regulatory T cells (tregs), reduce inflammation, or can be used to treat autoimmune and inflammatory diseases. A recently published study by Cell analyzed SCFA content and gut flora composition of about 300 patients with multiple sclerosis (MS, an autoimmune neurodegenerative disease), and initially demonstrated in an intervention study that oral supplementation with propionic acid reversed the imbalance of tregs and pro-inflammatory helper T cells in MS patients, thereby improving the disease. Notably, oral propionic acid also increases Treg numbers in healthy people as well as in rheumatoid arthritis patients, suggesting that propionic acid has a general role in immunomodulation in humans. These findings suggest that propionic acid can be used as an immunomodulator for the adjuvant treatment of autoimmune diseases such as MS.

Colonization resistance of the gut commensal flora is an important mechanism for combating gut pathogenic infection. Studies have shown that Bacteroides bacteria produce propionic acid, a short chain fatty acid, which impedes their growth by disrupting the intracellular acid-base balance of Salmonella typhimurium, resulting in colonization resistance against infection by the pathogen; propionic acid mediates the colonization resistance of symbiotic bacteria to salmonella, and resists salmonella infection; propionic acid produces a direct growth inhibitory effect on the pathogenic bacteria by disrupting the intracellular pH homeostasis of salmonella, increasing propionic acid levels in the mouse gut helps to combat salmonella typhimurium infection.

Acetate and propionate are involved in energy synthesis in most eukaryotic cells, butyrate being the source of energy for normal colon epithelial cells; has strong tumor inhibiting effect on colon epithelial cells; can be used for protecting small intestine ischemic injury by relieving inflammation and maintaining intestinal barrier structure.

The application of the osteopontin in increasing the content of the short-chain fatty acid in the intestinal tract is found in the in-vitro culture research process of the content of the short-chain fatty acid in the intestinal tract by using the osteopontin. Preferably, the short chain fatty acid is at least one of acetic acid, propionic acid and butyric acid.

Preferably, the intestinal short-chain fatty acid content is that of infants.

The third object of the present invention is to provide the use of osteopontin for the preparation of a medicament or food product with increased intestinal flora diversity or with increased intestinal short chain fatty acid content. Preferably, the food is a formula, a biscuit, a bread, a candy, an ice cream, a pastry, a condiment, a health product or a drink.

The invention has the beneficial effects that: the invention provides application of osteopontin in increasing intestinal flora diversity and increasing intestinal short-chain fatty acid content, and provides a new direction for improving intestinal flora structure.

Drawings

FIG. 1 shows the Chao1 index change in the alpha diversity of the flora during the fermentation of osteopontin;

FIG. 2 shows Faith's PD index variation in the alpha diversity of the flora during the fermentation of osteopontin;

FIG. 3 shows Shannon index variation in alpha diversity of flora during the fermentation of osteopontin;

FIG. 4 shows the production of acetic acid during the fermentation of osteopontin;

FIG. 5 shows the production of propionic acid during the fermentation of osteopontin;

FIG. 6 shows the production of butyric acid during the fermentation of osteopontin;

FIG. 7 shows the production of total short chain fatty acids during the fermentation of osteopontin.

Detailed Description

For a better description of the objects, technical solutions and advantages of the present invention, the present invention will be further described with reference to the following specific examples.

Example 1

Use of osteopontin for increasing intestinal flora diversity:

10 infants of 0-6 months are recruited in the company, the information of the diet condition of the infants, the use condition of probiotics and the like is investigated, and 4 volunteers meeting the experimental requirements are selected from the information: pure breast feeding is carried out, no supplementary food is added, no diarrhea or constipation exists within one month, no probiotics, medicines, antibiotics and the like are used, an informed consent is filled in, and a fecal sample of the human breast feeding is collected.

Preparing a microelement solution: called FeSO ₄ ·7H ₂ O 3.68g、MnSO _4· H ₂ O 1.159g、ZnSO _4· 7H ₂ O 0.44g、CoCl _2· 6H ₂ O 0.12g、NiCl ₂ 0.10g、CuSO _4· 5H ₂ O0.098 g and Mo ₇ (CH ₄ ) ₆ O ₂₄ H ₂ O0.017 g was dissolved in 1L of sterilized water.

Preparing a buffer solution: mgCl ₂ ·6H ₂ O 0.1g、NaSO ₄ 0.1g、CaCl ₂ ·2H ₂ 0.728g of O, 0.4g of urea, 0.45g of KCl, 0.47g of NaCl and Na ₂ HPO ₄ 2.824g、NaHCO ₃ 9.24g, 0.001mg of resazurin and 10ml of microelement solution are mixed, the volume is fixed to 1L, and the mixture is sterilized for standby.

The fecal samples are tested one by one, the fecal samples are filtered first, and the prepared buffer solution is added, the samples are: buffer = 1:4, preparing the excrement homogenate. 1ml of feces was homogenized into a fermentation vial containing 5.5mg of Osteopontin (OPN), and 3ml of buffer was added thereto, and after capping, anaerobic fermentation was performed in an anaerobic incubator at 37 ℃. 1ml of the 0-spot sample was removed from the 1.5ml centrifuge tube and the pellet was collected by centrifugation for determination of the flora as a blank. During the fermentation, 4h,8h,24h and 48h were sampled, centrifuged at 12000rpm and 4 ℃ for 10min, the precipitate was collected, then 16s rDNA sequencing was performed using an illuminea second generation sequencer, the flora composition and relative abundance in the sample were determined, and then the flora analysis was performed on the determined structure using the person bioinformatics system. The test results are shown in Table 1 and FIGS. 1 to 3.

TABLE 1 3 exponential changes in the alpha diversity of the flora during fermentation of OPN

Time	Chao1	Faith_pd	Shannon
				0h	400.59±83.79	20.37±4.69	3.16±0.80
4h	450.15±218.53	18.43±3.44	3.05±1.53
				8h	499.85±115.34	20.28±3.14	3.74±1.13
24h	695.24±138.78	24.46±2.12	4.65±0.72
				48h	763.42±118.81	28.35±4.02	4.71±1.22

alpha diversity refers to an index of species under a locally uniform habitat in terms of richness, diversity, and uniformity, and is also known as intrahabitat diversity (witlin-habitat diversity).

Chao1: the Chao algorithm is used for estimating the number of OTUs contained in the sample and reflecting the number of species in the sample. Chao1 is an index for measuring the abundance of species, is independent of abundance and uniformity, but is sensitive to rare species. A larger Chao1 value represents a greater total number of species.

As can be seen from table 1 and fig. 1, as the fermentation time is prolonged, the value of the Chao1 index of the bacterial population in the sample is increased along with the time, and the samples at 24h and 48h are significantly different from the samples at 0h, and from the increase of the value of the Chao1 index, the total number of the bacterial population in the sample is increased continuously in the fermentation process.

Faith's PD (Faith, 1992) index characterization is based on evolutionary diversity.

As can be seen from table 1 and fig. 2, during the fermentation of osteopontin, the Faith's PD value increased over time, indicating the evolutionary diversity of the flora in the sample, the Faith's PD value was significantly higher than 0h for 48h, and significantly higher than 4h, indicating that the flora diversity was increasing.

Shannon: (Shannon, 1948a, b) comprehensively considers the richness and uniformity of communities. The higher Shannon index value indicates a higher diversity of the community.

As can be seen from table 1 and fig. 3, shannon values increased with the increase of fermentation time during the fermentation of osteopontin, indicating a tendency for the diversity of the bacterial flora in the samples to increase.

From the above, it is presumed that the intestinal flora of infants and infants is fermented to have a tendency to increase the diversity of the flora, and the intestinal flora of infants and infants can be regulated, which may affect the intestinal health of infants and infants.

Example 2

Use of osteopontin for increasing the content of short chain fatty acids in the intestinal tract:

Preparing a microelement solution: called FeSO ₄ ·7H ₂ O 3.68g、MnSO _4· H ₂ O 1.159g、ZnSO _4· 7H ₂ O 0.44g、CoCl _2· 6H ₂ O 0.12g、NiCl ₂ 0.10g、CuSO ₄ 5H ₂ O0.098 g and Mo ₇ (CH ₄ ) ₆ O ₂₄ H ₂ O0.017 g was dissolved in 1L of sterilized water.

The fecal samples are tested one by one, the fecal samples are filtered first, and the prepared buffer solution is added, the samples are: buffer = 1:4, preparing the excrement homogenate. 1ml of feces was homogenized into a fermentation vial containing 5.5mg of Osteopontin (OPN), and 3ml of buffer was added thereto, and after capping, anaerobic fermentation was performed in an anaerobic incubator at 37 ℃. 1ml of the 0-spot sample was removed from the 1.5ml centrifuge tube and the pellet was collected by centrifugation for determination of the flora as a blank. During fermentation, samples were taken for 4h,8h,24h,48h, centrifuged at 12000rpm at 4℃for 10min, and the supernatant was collected, followed by gas phase measurement of the content of short chain fatty acids such as acetic acid, propionic acid, butyric acid, etc. The test results are shown in tables 2 to 5 and FIGS. 4 to 7.

TABLE 2 acetic acid production during fermentation

Fermentation time	4h	8h	24h	48h
					Acetic acid	6.73±3.24	10.73±3.94	25.52±9.51	25.64±5.36

TABLE 3 Propionic acid production during fermentation

Fermentation time	4h	8h	24h	48h
					Propionic acid	0.25±0.28	0.79±0.77	3.10±1.88	3.32±1.43

TABLE 4 production of butyric acid during fermentation

Fermentation time	4h	8h	24h	48h
					Butyric acid	0.00±0.00	0.11±0.22	1.28±1.82	1.68±1.72

TABLE 5 production of total short-chain fatty acids during fermentation

Fermentation time	4h	8h	24h	48h
					Total SCFA	7.35±3.64	12.72±4.48	31.77±12.50	32.37±6.97

As can be seen from table 2 and fig. 4, the amount of acetic acid produced was increasing with the increase of fermentation time during the fermentation of osteopontin. Acetic acid produced by intestinal flora metabolism in the fermented osteopontin samples is significantly different from 4h at 24h and 48h, and also significantly different from 8h at 24h and 48 h. Indicating that the metabolite acetic acid of the flora increases significantly with the fermentation time.

As can be seen from table 3 and fig. 5, the amount of propionic acid produced was increasing with the increase of fermentation time during the fermentation of osteopontin. Propionic acid produced by intestinal flora metabolism in the fermented osteopontin sample is significantly different from 24h and 48h and 4h, and is significantly different from 48h and 8 h. Indicating that the metabolite propionic acid of the flora increases significantly with the fermentation time.

As can be seen from table 4 and fig. 6, the amount of butyric acid produced was increasing with the increase of fermentation time during the fermentation of osteopontin. Indicating that the metabolite butyric acid of the intestinal flora tends to increase with increasing fermentation time.

As can be seen from table 5 and fig. 7, the total short chain fatty acid production increased with increasing fermentation time during the process of fermenting osteopontin. Total acids produced by intestinal flora metabolism in the fermented osteopontin samples were significantly different from 24h and 48h and 4h, and also from 24h and 48h and 8 h. Indicating that the total short chain fatty acid of the metabolites of the flora increases significantly with the fermentation time.

In summary, in the process of in vitro fermentation of osteopontin by using intestinal flora of infants for 0-6 months, total short chain fatty acids of metabolites of the intestinal flora are increased along with the extension of fermentation time, especially acetic acid, propionic acid and butyric acid. It is therefore speculated that during fermentation the diversity of the intestinal flora is increasing, leading to an increasing production of the metabolite short-acid fatty acids by metabolism. The results show that the fermented osteopontin can increase the content of short-chain fatty acid in the intestinal tract of infants.

Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted equally without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. Use of osteopontin for the preparation of a food product for increasing the Chao1 index, the Faith's PD index and the Shannon index in the alpha diversity of intestinal flora in infants.

2. The use according to claim 1, wherein the food product is a formula, biscuit, bread, candy, ice cream, pastry, condiment, health product or drink.