JPH11286452A - Agent for protecting infection of pathogenic bacterium and virus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infection-protecting agent, a medicine, a drink or a food having a protecting function against the infections of pathogenic bacteria and viruses. SOLUTION: This infection-protecting agent, a medicine, a drink or a food contains an iron-binding lactoferrin as an active ingredient. The iron saturation degree of the iron-binding lactoferrin is desirably 20-100%. The infection- protecting agent, the medicine, the drink or the food can orally be administered to protect the infections of Escherichia coil, Streptococcus mutans, influenza viruses, cytomegaloviruses, etc. The iron-binding lactoferrin is preferably administered at a daily dose of 0.1-5,000 mg per adult.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel agent for preventing infection against pathogenic bacteria and viruses. In addition, the present invention relates to a novel medicine, food and drink which has a function of protecting against infection with pathogenic bacteria and viruses.

[0002]

2. Description of the Related Art In general, infection of living organisms by pathogenic bacteria is
It is said to be formed by recognizing and binding to the sugar chain structure (receptor) of the complex carbohydrate present on the target cell, ie, the cell surface of living epithelium. As a general treatment for infection of living organisms by the pathogenic bacteria, there is use of antibiotics. This antibiotic is used at the final stage of the infection process of pathogenic bacteria, by treating the disease caused by the infection by killing the grown pathogenic bacteria. Thus, treatment of pathogenic bacterial infections with antibiotics is very effective as a treatment for living organisms after the onset of disease, but due to the nature of antibiotics, there are many problems such as causing various side effects and allergic symptoms. .

In general, living organisms have a defense mechanism against infection by pathogenic bacteria at an early stage of infection. For example, secretory immunoglobulin A in the digestive tract
These immunoglobulins are mainly defense mechanisms, and these immunoglobulins protect living bodies from infection by pathogenic bacteria by preventing the attachment of pathogenic bacteria to target cells.

In general, a receptor or a substance having a structure similar to a receptor specifically binds to a receptor binding site on the cell surface of a pathogenic bacterium and specifically inhibits the binding of the pathogenic bacterium to a target cell. Is expected to. This specific action can be said to be similar to the above-mentioned immunoglobulin defense mechanism in that infection of pathogenic bacteria is prevented at an early stage. In other words, a substance that specifically binds to the receptor binding site of such a pathogenic bacterium can prevent infection of the pathogenic bacterium, and has a mild action and has fewer side effects as a protective agent for the pathogenic bacterium infection. obtain.

[0005] On the other hand, with regard to viral infectious diseases, many studies on antiviral agents have been made so far.
However, it is extremely difficult to treat viral infectious diseases with drugs, because viruses have the property of growing depending on the growth function of host cells. For example, amantadine, which inhibits virus entry into cells, is said to be effective against influenza virus A,
The therapeutic effect is weak and side effects such as central nervous system toxicity also appear,
At present, it is hardly used as a clinical drug. Currently, antiviral agents approved for use in Japan include acyclovir, which inhibits the synthesis of viral genes (applied to herpes simplex and herpes simplex encephalitis, etc.), vidarabine (applied to herpes simplex and herpes simplex encephalitis, etc.), eye drops There are known idoxuridine (applied to herpes keratitis), azidothymidine (applied to AIDS) and the like, but azidothymidine often causes serious side effects by systemic administration, and it still has a problem as a therapeutic drug. I have.

[0006] As an antiviral agent, interferon, which has recently attracted attention, is known. This interferon is a factor that suppresses the intracellular growth of the virus, and is produced using a genetic recombination technique, but is expensive and has side effects.

[0007] Under these circumstances, as a measure against viral diseases, the administration of vaccines for preventing infection by viruses is most widespread. The vaccine includes a live vaccine in which the virus is attenuated by some method, an inactivated vaccine prepared by treating the virus with formalin or the like, and a component vaccine in which only the antigen portion of the virus is purified. These vaccines have made it possible to prevent most viral diseases. However, influenza, one of the most typical viral diseases, is difficult to prevent by vaccine.
Because, in the case of influenza, an antigen present in the envelope of the influenza virus is used as a vaccine, and this antigen portion is frequently mutated, and a vaccine against the original virus has no effect on the mutated virus Because. Also, HIV
As described above, it is difficult to prevent infection with a vaccine for cytomegalovirus infection, which frequently occurs when an antigen usable as a vaccine is unknown, or when the immune function decreases due to administration of an immunosuppressant after organ transplantation. Furthermore, some vaccines are at risk of illness, and the side effects of vaccination must be considered.

[0008] In recent years, due to the progress of research in virology, virus infection to humans has been promoted in the same manner as in the case of infection by pathogenic bacteria described above, and the sugar chain structure of complex carbohydrates present on the surface layer of target cells, ie, living epithelium It has been clarified that a virus binds to a receptor composed of the above, and the virus enters the cell. For example, HIV binds to and infects the CD4 receptor present on the surface of T lymphocytes, so that administration of a large amount of CD4 into the blood leads to AID.
It is said that the onset of S can be prevented. Also, influenza virus is infected by binding to a receptor composed of sialic acid-linked glycoconjugate molecules present on the surface of cells, and therefore, administering this sialic acid-linked glycoconjugate molecule or a substance having a similar sugar chain structure. Thus, it is considered to prevent infection by the influenza virus or to prevent the spread of the influenza virus to other cells or tissues after the infection.

Heretofore, kappa casein and kappa casein glycomacropeptide which is a protease degradation product thereof have been known as substances having an effect of preventing the infection by inhibiting the binding of pathogenic bacteria or viruses to the receptor (particularly). Kaisho 6
3-284133). It is also known that κ casein glycomacropeptide is effective as an anti-plaque and anti-caries agent by the same mechanism (Japanese Patent Application Laid-Open No. 63-233911). Furthermore, Yamakawa et al. Isolated a substance that inhibits hemagglutination caused by influenza virus from human blood cells and revealed that this substance is a glycoprotein composed of sialic acid (Biochemistry, vol. 31, pp. .416-421, 195
9).

[0010] Lactoferrin is known as a protein having a protective function against infection contained in milk. The protective function of lactoferrin against pathogenic bacteria is based on the fact that lactoferrin has its iron-chelating ability to remove the iron necessary for its growth from pathogenic bacteria and suppress its growth. However, the effect of lactoferrin on suppressing the growth of pathogenic bacteria is temporary, and when lactoferrin is ingested simultaneously with other foods, lactoferrin chelate all iron contained in the foods, so that large amounts of lactoferrin are chelated. There is a problem that it is necessary to take lactoferrin.

[0011] Lactoferrin has a function of preventing infection of intestinal cells by preventing pathogenic bacteria from adhering to intestinal cells by a mechanism completely different from the function of inhibiting the growth of pathogenic bacteria by its iron chelating ability. The role of iron-binding lactoferrin in the protective function against pathogenic bacterial infection has not been clarified at all. In addition, it is known that lactoferrin is also effective as an antiviral agent because the sugar chain structure in the molecule prevents virus attachment to cells (Japanese Patent Application Laid-Open No. 2-233619). However, the role of iron-binding lactoferrin in this protective function against virus infection has not been clarified at all.

[0012]

DISCLOSURE OF THE INVENTION The present inventors have been paying attention to the pharmacological action of lactoferrin and have been intensively studying it. As a result, regarding the function of blocking the adhesion of pathogenic bacteria and viruses to cells. Found that iron-bound lactoferrin had little activity, whereas iron-bound lactoferrin had strong activity. Then, they found that this activity depends on the iron saturation of iron-binding lactoferrin, and completed the present invention. Therefore, an object of the present invention is to provide a novel infection protective agent against pathogenic bacteria and viruses, or a novel pharmaceutical product and food or drink provided with such an infection protective function. Furthermore, specifically, an object of the present invention is to provide a pathogenic bacterium and a virus infection protective agent containing iron-binding lactoferrin as an active ingredient. Another object of the present invention is to provide a pharmaceutical product and a food or drink which are provided with a protective function against pathogenic bacteria and viruses by blending iron-binding lactoferrin.

[0013]

DISCLOSURE OF THE INVENTION The present invention relates to an iron-binding agent which is used as an active ingredient of an agent for preventing infection against pathogenic bacteria and viruses, or for imparting a function of protecting infection against pathogenic bacteria and viruses to medicines and foods and drinks. It is characterized by using type lactoferrin.

The iron-bound lactoferrin used in the present invention is obtained by subjecting lactoferrin obtained by subjecting milk of mammals such as cattle or the like to skim milk, whey or the like to a material such as ion-exchange chromatography, and the like.
For example, it can be prepared by chelating iron ions in a solution of sodium citrate or the like in which ferric chloride is dissolved, and then dialyzing and desalting. When chelating iron ions to lactoferrin, lactoferrin obtained by a genetic recombination technique may be used, or commercially available lactoferrin may be used.

As a method for obtaining lactoferrin from milk of mammals such as cows or skim milk or whey thereof, a method using a monoclonal anti-lactoferrin antibody (JP-A-60-166619, JP-A-60-166619) No. 60-145200), a method using heparin-immobilized crosslinked cellulose or chitosan as a carrier (Japanese Patent Laid-Open No. 63-255299), a method using a sulfated ester of a crosslinked polysaccharide as a carrier ( JP-A-63-255300),
A method using a polysaccharide affinity carrier into which a sulfone group is introduced (JP-A-3-109400), a method using a cation exchanger as a carrier, and eluting by adjusting the ionic strength and pH (Japanese Patent Laid-Open No. 5-109400). 202098) and the like. The iron-saturated lactoferrin used in the present invention has an iron saturation of preferably 20% or more, more preferably 50% or more and 100% or more.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The protective agent for pathogenic bacteria and viruses of the present invention contains iron-binding lactoferrin as an active ingredient. The dosage form of the agent for preventing pathogenic bacteria and virus infection is desirably tablets, capsules, granules, powders, powders and the like. These are desirably administered orally. In addition, these dosage forms can be produced by a conventionally known ordinary method. For example, the mixture is molded with a carrier, excipient, or the like which is acceptable for the production of the preparation. In addition, the medicines and foods and drinks imparted with the protective function against pathogenic bacteria and viruses of the present invention may be prepared by mixing iron-binding lactoferrin in pharmaceuticals, particularly oral preparations, as described above, or mixing iron-binding lactoferrin with milk. , Milk beverages, coffee beverages, juices, jellies, biscuits, breads, noodles, sausages and other foods and beverages, as well as various types of powdered milk, as well as nutritional compositions for infants, infants, low birth weight infants, etc. Or something. Since they have a function of protecting infection against pathogenic bacteria and viruses, they are used for preventing diseases infected with these pathogenic bacteria or viruses or for treating diseases. Examples of such diseases include diarrhea based on Escherichia coli, food poisoning, dental caries based on Streptococcus mutans, influenza based on influenza virus, and infection of pregnant women based on cytomegalovirus.

In the present invention, in order to exert the effect of protecting against infection with pathogenic bacteria and viruses, the amount of iron-binding lactoferrin may be adjusted so that 0.1 to 5,000 mg per day can be taken for adults. .

Next, the present invention will be described in detail with reference to examples and test examples.

Example 1 Iron-bound lactoferrin (iron saturation 100
%) To a 5% 1% aqueous solution of lactoferrin (manufactured by Oleofina Co.) was added 1/5 of a 0.1 M trisodium citrate solution containing 0.003 M iron (III) chloride, and the mixture was stirred for 1 hour. 1
A 00% iron-bound lactoferrin solution was prepared. Regarding lactoferrin contained in this solution, it was confirmed that iron ions were bound to all lactoferrin molecules and the iron saturation was 100%. Next, the iron-bound lactoferrin solution was sealed in a dialysis tube, dialyzed against distilled water to remove excess salts, and lyophilized to obtain 5 g of iron-bound lactoferrin powder having a 100% iron saturation. Obtained.

Iron-free lactoferrin (iron saturation 0
%, Apolactoferin ) A commercially available lactoferrin (manufactured by Oleofina) 5 g of a 1% aqueous solution was sealed in a dialysis tube, and a 20-fold volume of 0.05% EDTA was prepared.
Was dialyzed at 4 ° C. for 30 hours against a 0.1 M aqueous citric acid solution containing. Subsequently, the dialysis tube was taken out and dialyzed against distilled water for 24 hours to prepare a non-iron-bound lactoferrin (apolactoferrin) solution having an iron saturation of 0%. Regarding lactoferrin contained in this solution, it was confirmed that iron ions were not bound to all lactoferrin molecules and the iron saturation was 0%. Next, the dialyzed solution was freeze-dried to obtain 5 g of iron-free lactoferrin powder having an iron saturation of 0%.

Iron-bound lactoferrin (iron saturation 20%
The iron-binding lactoferrin (iron saturation 100%) powder obtained preparation of fine iron saturation 50%) was dissolved in water, concentration prepare 10mg / ml of iron-binding lactoferrin (iron saturation 100%) aqueous solution At the same time, the obtained powder of iron-free lactoferrin (iron saturation 0%) was dissolved in water to prepare an aqueous solution of iron-free lactoferrin (iron saturation 0%) having a concentration of 10 mg / ml. Then, the aqueous solution of iron-binding lactoferrin (iron saturation 100%) and the aqueous solution of non-iron-binding lactoferrin (iron saturation 0%) are mixed in a ratio of 2: 8.
A lactoferrin solution having an iron saturation of 20% is prepared by mixing at a ratio of
A 20% iron-bound lactoferrin powder was obtained.

The aqueous solution of iron-binding lactoferrin (iron saturation 100%) and the aqueous solution of non-iron-binding lactoferrin (iron saturation 0%) are mixed at a ratio of 5: 5 to give an iron saturation of 50%. An iron-binding lactoferrin solution was prepared and freeze-dried to obtain an iron-binding lactoferrin powder having an iron saturation of 50%.

[0022]

Test Example 1 Using the iron-binding lactoferrin and the non-iron-binding lactoferrin of each iron saturation prepared by the method shown in Example 1, the effect of protecting against infection with pathogenic Escherichia coli was examined. The infection protection test was performed as follows. Human small intestinal cells (JTC-17) (available from Tokyo Medical University)
The cells were cultured in a 5 cm ² bottom area culture flask in Dulbecco's modified Eagle's medium (5% FCS / DMEM) containing 5% fetal calf serum at 37 ° C. and a carbon dioxide concentration of 5%. When the cells had grown to a nearly confluent state, the cells were peeled off using trypsin-EDTA according to a conventional method, and the cells were collected by centrifugation. Aspirate the supernatant and add 5% FCS / D
The cells were suspended in 8 ml of MEM. Each of the obtained cell suspensions 1
ml 10 ml polystyrene tube (Falcon 2095)
And cultured at 37 ° C. for 3 days.

One platinum loop of each of the pathogenic Escherichia coli strains H10407 and Pb176 (obtained from Tokyo Metropolitan Institute of Health) was cultured overnight at 37 ° C. in 4 ml of normal broth medium. After completion of the culture, the cells were collected by centrifugation at 3,000 rpm for 10 minutes and washed three times with PBS adjusted to pH 8. Thereafter, the pathogenic E. coli was suspended in 1 ml of PBS adjusted to pH 8, and FITC (fluorescein isothiocyanate) was suspended.
Fluorescein Isothiocyanate (1 mg) was added, dissolved well, and allowed to react at 4 ° C. for 3 hours with gentle stirring to label the pathogenic E. coli with FITC. The labeled pathogenic E. coli was washed three times with PBS and then suspended in 3 ml of PBS. 200 μl of a PBS solution of each sample was mixed with 400 μl of the suspension of FITC-labeled pathogenic E. coli thus prepared, and incubated at 37 ° C. for 1 hour.

On the other hand, after culturing for 3 days,
The medium of the supernatant was removed by centrifugation at 1,000 rpm for 5 minutes, and further washed three times with PBS. 600 μl of a solution obtained by mixing and incubating the above-mentioned pathogenic Escherichia coli and each sample was added thereto. Incubated for minutes. After the incubation, the cells were centrifuged at 750 rpm for 5 minutes to precipitate only the cells, and the pathogenic E. coli remaining in the supernatant without adhering to the cells was sucked out. Further, the cells were washed twice with PBS. PB
Add 200 U trypsin / PBS 900 μl to cells washed with S
Was added and stirred vigorously. 100% 0.1% SDS
The cells were lysed by adding 1 ml of deionized water, stirring vigorously and allowing to stand for 30 minutes. This solution is used for fluorescence spectrophotometer (Hitachi Fluorescence Spectrometer F-300)
At 0), the relative fluorescence intensity was measured at an excitation wavelength of 520 nm and a fluorescence wavelength of 520 nm, and the attachment of the fluorescently labeled pathogenic E. coli to JTC-17 cells was evaluated. Table 1 shows the relative fluorescence intensity (blank) when no sample was added, non-specific adsorption of pathogenic Escherichia coli labeled with fluorescence onto a polystyrene tube with an adhesion rate of 100% (measured under the same conditions as the sample in the polystyrene tube). (Relative fluorescence intensity) is defined as an adhesion rate of 0%, and the adhesion rate (%) when each sample was added is shown. The experiment was performed in triplicate.

[0025]

[Table 1]

[0026]

Test Example 2 Using the iron-bound lactoferrin and the non-iron-bound lactoferrin of each iron saturation prepared by the method shown in Example 1, samples were used to examine the effect of preventing infection with Streptococcus mutans. The test was performed as follows. Three types of Streptococcus mutans (ATCC-
27670, ATCC-25175, ATCC-27351) were picked from a platinum loop and cultured overnight in 4 ml of brain heart fusion (BHI) medium. After one night, the cells were collected by centrifugation at 3,000 rpm for 10 minutes, and the supernatant medium was sucked out. Further, this was washed three times with PBS, and this was suspended in PBS so that OD650 = 0.8. Equivalent amounts of the bacterial suspension and the sample solution were mixed, placed in a 10 ml polystyrene tube (Falcon 2095), mixed well, and incubated at 37 ° C for 3 hours. After the incubation, measure the OD650 and determine the adhesion rate (%) according to the following equation.
I asked. Adhesion rate (%) = 0.4-(X / 0.4) x 100 x (OD65 of sample
0) The experiment was performed in duplicate, and the results are shown in Table 2. According to this, compared with non-iron-binding lactoferrin, iron-binding lactoferrin tended to prevent adhesion of dental caries to polystyrene tubes, and the higher the iron saturation, the higher the inhibitory effect.

[0027]

[Table 2]

[0028]

Test Example 3 Using an iron-binding lactoferrin and an iron-non-binding lactoferrin of each iron saturation prepared by the method shown in Example 1, the effect of protecting against influenza virus was examined. The test was performed as follows. Agglutination inhibition (HI) activity of influenza virus on chick-stabilized erythrocytes (manufactured by Takeda Pharmaceutical Co., Ltd.) and human erythrocytes (type O) was measured. The HI activity was measured according to the above-mentioned method of Yamakawa et al. (Biochemistry, vol. 31, pp. 416-421, 1959). As influenza viruses, A / Yamagata / 120/86 (H1N1) and A / Niigata / 102/8 of inactivated influenza viruses obtained from Denka Seikaken
1 (H3N2), A / Sichuan / α / 87 (H3N2), A
/ Fukuoka / C29 / 85 (H2N2), B / Nagasaki / 1/8
7, B / Singapore / 222/79, and A / PR / 8/34 (H1N1) of inactivated influenza virus obtained from Shizuoka Pharmaceutical University. Table 3 shows HI activity on chick-stabilized erythrocytes, and Table 4 shows HI activity on human erythrocytes. According to this, iron-bound lactoferrin showed stronger HI activity against influenza virus than iron-free lactoferrin, and the higher the iron saturation, the higher its inhibitory effect.

[0029]

[Table 3] 鉄 Iron saturation (%) ────── ─────────────────── 0 20 50 100 ─────────────────────────── ─────── Yamagata NDNDNDND Niigata 4 0.13 6.25 × 10 ² 1.6 × 10 ² Sichuan 8 0.13 6.25 × 10 ² 1.6 × 10 ² Fukuoka 4 0.25 6.25 × 10 ² 3.1 × 10 ² Nagasaki − 0.5 0.13 6.25 × 10 ² Singapore − 0.5 0.13 6.25 × 10 ² PR − 8 1 0.25 ──────────────────────────────────

[0030]

[Table 4] 度 Iron saturation (%) ────── ─────────────────── 0 20 50 100 ─────────────────────────── ─────── Yamagata 4 0.25 0.13 6.25 × 10 ² Niigata 4 0.13 6.25 × 10 ² 1.6 × 10 ² Sichuan 8 0.13 6.25 × 10 ² 1.6 × 10 ² Fukuoka 4 0.13 6.25 × 10 ² 3.1 × 10 ² Nagasaki − 0.5 0.13 6.25 × 10 ² Singapore − 0.5 0.13 6.25 × 10 ² PR − 8 2 0.5 ─────────────────────────────── ───

[0031]

Test Example 4 Using the iron-bound lactoferrin and iron-free lactoferrin of each iron saturation prepared by the method shown in Example 1 as samples, the A / of inactivated influenza virus obtained from Shizuoka Pharmaceutical University was used. PR / 8/3
4 (H1N1) and A / Aichi / 2/68 (H3N2) were serially diluted, and inoculated into 0.1 ml of 5 chicken 10-day eggs in the space of the urine juice. 50 μl of urine fluid was taken, mixed with 0.5% chick-stabilized erythrocytes, stirred, and the infection rate was determined by agglutination of erythrocytes. Dissolve 0.5 mg each of iron-bound lactoferrin or iron-free lactoferrin adjusted to the respective iron saturation in 0.1 ml of the virus dilution at a dilution ratio showing 100% infection rate,
After incubating at room temperature for 30 minutes, add 10 days
0.1 ml was inoculated into the urine cavity. Three days later, 50 μl of the urine fluid of each egg was taken and the infection rate was determined by hemagglutination. Using five eggs per group, the infection rate (%) of each group was obtained. Table 5 shows the results. According to this, iron-bound lactoferrin showed a stronger protective effect against influenza virus than iron-free lactoferrin.

[0032]

[Table 5]

[0033]

Test Example 5 The protective effect against cytomegalovirus (CMV) was examined using iron-binding lactoferrin and non-iron-binding lactoferrin of each iron saturation prepared by the method shown in Example 1 as samples. In addition, iron-bound lactoferrin and iron-free lactoferrin adjusted to each iron saturation were dissolved at a concentration of 5 mg / ml in MEM medium supplemented with 2% serum, sterilized by filtration through a 0.45 μm filter, and a stock solution was required. It was diluted with a MEM medium supplemented with 2% serum according to the above. Human CMV (Towne strain) was incubated with an iron-binding lactoferrin-containing culture solution (0.1 mg / ml) for each iron saturation for 1 hour, and then infected with human fetal fibroblasts (HEL cells). Further, a culture solution containing no lactoferrin was used as a control. After culturing for 24 hours, the cells were fluorescently stained with human CMV-positive serum, and the ability to adsorb human CMV to cells was measured.
Then, the average value of the number of fluorescence-positive cells per coverslip was determined. Table 6 shows the results. According to this, it was confirmed that the iron-bound lactoferrin having a higher iron saturation than the non-iron-bound lactoferrin suppressed the CMV adsorption invasion ability.

[0034]

[Table 6]

[0035]

Example 2 After mixing the raw materials according to the formulation shown in Table 7, the mixture was tableted with a tableting machine to produce a tablet having a protective function against pathogenic bacteria and viruses.

[0036]

[Table 7] 結合 Iron-bound lactoferrin (iron saturation 100%) 10.0 (% by weight) ) Reduced maltose 52.0 Sugar 15.0 Lactose 18.7 Citric acid 2.0 Flavor 1.0 Lubricant 1.3 ───────────────────────────────

[0037]

Example 3 Raw materials were mixed according to the formulation shown in Table 8, filled in a container, and then sterilized by heating to produce a beverage having a protective function against pathogenic bacteria and viruses.

[0038]

[Table 8] 結合 Iron-bound lactoferrin (iron saturation 100%) 2.0 (% by weight) ) Fructose glucose liquid sugar 8.0 citric acid 0.6 apple juice 10.0 water 79.4 ───────────────────────────────

[0039]

EFFECTS OF THE INVENTION The agent for protecting pathogenic bacteria and viruses of the present invention and the pharmaceuticals and foods and beverages imparting the function of protecting pathogenic bacteria and viruses from infection exhibit an excellent effect of protecting against pathogenic bacteria and viruses. In addition, since iron-binding lactoferrin with an increased iron saturation is used, it can be supplied in large quantities at a relatively low cost, and has a feature of extremely high safety.

Claims (4)

[Claims] 1. A protective agent against pathogenic bacteria and viruses comprising iron-binding lactoferrin as an active ingredient. 2. The iron-bound lactoferrin having an iron saturation of 20.
The infection protective agent according to claim 1, wherein the amount is from 100% to 100%. 3. A medicament or food or drink having an iron-binding lactoferrin compound and a protective function against pathogenic bacteria and viruses. 4. An iron-bound lactoferrin having an iron saturation of 20.
The medicament or food or drink according to claim 3, wherein the amount is from 100% to 100%.