JPH0570416B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Industrial Application] The present invention belongs to the field of food additives, and relates to food additives containing sialic acids as active ingredients, which have a preventive action against pathogenic bacteria. especially,
By adding it to food, it can be used to impart a function to food that prevents symptoms such as diarrhea caused by infection with pathogenic bacteria. [Prior art and its problems] Sialic acids are acidic sugars containing pyruvic acid and N-acetylmannosamine, which are abundantly contained in blood proteins, mammalian milk, brain glycolipids, etc. In recent years, it has attracted attention as a sugar involved in the activity of pathogenic microorganisms and virus receptors, and the activity of promoting neuronal cell growth in glycolipids. However, sialic acids are difficult to prepare from natural products that contain them, and are not easy to obtain.Although the above-mentioned physiological activities have been confirmed in vitro, their in vivo activities have not yet been confirmed. Currently, there is almost no practical use of sialic acids for reasons such as the lack of practical use of sialic acids. The object of the present invention is that sialic acids can be
By confirming that it has the same physiological activity as in vitro, we will solve problems in the use of sialic acids as food additives, which have not been done so far. [Means for Solving the Problems] The present invention is directed to a food additive containing sialic acids as an active ingredient and having an activity for preventing infection by pathogenic bacteria. In the process of investigating the use of sialic acids prepared from milk, the present inventor discovered that sialic acids have the ability to prevent pathogenic microorganisms and viruses from adhering to human epithelial cells. Obtained. In other words, the first step in humans being infected by pathogenic microorganisms and viruses is the attachment of these pathogens to human epithelial cells, so the fact that sialic acids have the above activity can act as a protective factor against pathogenic microorganisms. That's true. The present invention provides a food additive for imparting the function of preventing pathogen infection to food by adding sialic acids that have the activity of preventing pathogen infection even in vivo to food as described above. can. The present invention will be explained in detail below. A feature of the present invention is that sialic acids are used as food additives to prevent infection by pathogenic bacteria. The sialic acids mentioned herein include, for example, N-acetylneuraminic acid, N-acetylneuraminic acid-bonded oligosaccharides, and gangliosides. The sialic acids used as active ingredients in the present invention are obtained by desalting a milky raw material such as milk by electrodialysis, passing it through an ion exchange resin to adsorb the sialic acids to the resin, and then eluting it. Gangliosides prepared by spray-drying or freeze-drying a liquid, or commercially available gangliosides are used. In the present invention, the above-mentioned sialic acids are added to foods so that the daily intake amount is 5 mg or more. If the amount is less than 5 mg, the effect of addition is of course effective, but it cannot be said to be sufficient. For example, when adding it to milk, 2.5 mg or more of sialic acids should be added by weight, assuming that 200 ml of sialic acid is consumed per day, and in the case of butter, 25 mg of sialic acids should be added, assuming that 20 g of sialic acids are consumed per day.
It is better to add more than that. Targeted foods include a wide range of foods, including general foods, dairy products, beverages, and health foods. Note that since the daily intake amount varies depending on the type of food, it is desirable to adjust the amount of sialic acids added according to the amount so that the intake amount is as described above. Next, the results of investigating the protective effect of sialic acids prepared from milk against pathogenic bacteria infection will be described below. Test method: Human small intestine-derived cell line 407 cultured in a monolayer using pathogenic E. coli and rotavirus as test bacteria.
A suspension of tritium-labeled E. coli and rotavirus containing 10 mg of sialic acids by weight was added to the strain, and after reacting at 30°C for 1 hour, the amount of E. coli and rotavirus attached to the cells was measured using liquid scintillation. Measured with a shock counter. As controls, similar operations were performed using suspensions of Escherichia coli and rotavirus that do not contain sialic acids. The results are shown in Figure 1 for E. coli and Figure 2 for rotavirus. As can be seen in Figures 1 and 2, in the control, the amount of E. coli and rotavirus bacteria attached to the cells increased rapidly as the reaction time progressed, whereas in the cells to which sialic acids were added, there was a tendency for an increase. was found to be lower than that of the control. Next, the results of investigating the protective effect against infection by pathogenic bacteria when sialic acids are actually given to living organisms are described below. Test method: 30-day-old rats were used as test animals, and each test group consisting of 10 rats was given 0 to 100% of sialic acids.
Each rat was fed a feed supplemented with 50 mg wt%, and a certain amount of pathogenic E. coli was orally administered to each rat to examine the incidence of diarrhea. The results are shown in Table 1.

〔Effect of the invention〕

According to the present invention, since sialic acids have excellent activity in preventing infection with pathogenic microorganisms and viruses as described above, by adding appropriate amounts of sialic acids to various foods, it is possible to prevent infections caused by these pathogenic bacteria. It becomes possible to provide functions such as preventing the occurrence of symptoms such as diarrhea, which has a large impact on dietary habits. Incidentally, sialic acids can be effectively applied as food additives because they do not impair the original flavor of food and do not cause any side effects due to continuous use. Hereinafter, the present invention will be explained in more detail with reference to Examples. [Example] Function of foods containing sialic acids: Rats fed a diet containing powdered milk sialic acids were orally administered with pathogenic E. coli to measure the incidence of diarrhea. Test method: Groups of 20 rats, 30 days old, were used as test animals; one group was administered a diet containing 10 mg of the above sialic acids by weight, and the other group was administered the same diet without the addition of sialic acids. was administered. Next, after orally administering a certain amount of pathogenic E. coli (5 ml of solution containing 10 ¹⁰ cells/ml) to each group,
Their diarrhea incidence was measured. The results are shown in Table 2.

[Table] As shown in Table 2, the incidence of diarrhea was significantly lower in the group to which the feed supplemented with sialic acids according to the present invention was administered than in the group to which no additives were added.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the effect of addition of sialic acids on preventing attachment of pathogenic E. coli to human epithelial cells, and FIG. 2 is a graph showing the effect of addition of sialic acids on preventing attachment of rotavirus cells. 〇...Addition of sialic acids, ×...No addition.

Claims (1)

[Scope of Claims] 1. A food additive containing sialic acids as an active ingredient and having an activity for preventing infection by pathogenic bacteria. 2. The food additive according to claim 1, wherein the sialic acid is N-acetylneuraminic acid. 3. The food additive according to claim 1, wherein the sialic acid is an N-acetylneuraminic acid-bonded oligosaccharide. 4. The food additive according to claim 1, wherein the sialic acid is a ganglioside.