Food for improving intestinal environment

Abstract

The present invention provides a food product for improving the intestinal environment by promoting the proliferation of lactic acid bacteria and other bacteria in the intestine. The present invention provides a food product for improving the intestinal environment, which comprises a combination of (1) γ-polyglutamic acid or a composition containing γ-polyglutamic acid, and (2) an oligosaccharide or a composition containing an oligosaccharide.

Description

[Technical field]

[0001] The present invention relates to a food that promotes the proliferation of lactic acid bacteria and bifidobacteria in the intestines and improves the intestinal environment. [Background technology]

[0002] Promoting the proliferation of beneficial bacteria in the intestines, such as lactic acid bacteria and bifidobacteria, and improving the intestinal environment (normalizing the intestinal flora) is important for preventing various diseases and maintaining and promoting health. Patent Document 1 describes the effect of γ-polyglutamic acid in improving bowel movements. Non-Patent Document 1 describes the effect of γ-polyglutamic acid in increasing lactic acid bacteria. It is known that oligosaccharides are difficult to digest and absorb in the stomach and small intestine, but reach the large intestine and become food for good bacteria such as lactic acid bacteria and bifidobacteria. However, it is not known that the combined use of γ-polyglutamic acid and oligosaccharides significantly increases lactic acid bacteria and bifidobacteria compared to the use of either alone. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-22982 A [Non-patent literature]

[0004] [Non-Patent Document 1] J. Microbiol. Biotechnol. (2017), 27(2), 412-415 Summary of the Invention [Problem to be solved by the invention]

[0005] An objective of the present invention is to provide a food that promotes the proliferation of lactic acid bacteria and bifidobacteria in the intestines and improves the intestinal environment. [Means for solving the problem]

[0006] In order to solve the above problems, the present inventors conducted extensive research and found that the combined use of γ-polyglutamic acid and oligosaccharides significantly increased lactic acid bacteria and bifidobacteria compared to the use of either alone. Based on the above findings, the present inventors conducted further research and completed the present invention.

[0007] That is, the present invention provides the following. [1] A food for improving intestinal environment, comprising a combination of (1) gamma-polyglutamic acid or a composition containing gamma-polyglutamic acid, and (2) an oligosaccharide or a composition containing an oligosaccharide. [2] The food described in [1] above, wherein the composition containing oligosaccharides is in liquid form. [3] The food described in [2] above, wherein the composition containing oligosaccharides in liquid form is a liquid preparation containing oligosaccharides. [4] The food described in [2] above, wherein the composition containing oligosaccharides in liquid form is a beverage containing oligosaccharides. Effect of the Invention

[0008] According to the present invention, by supplying γ-polyglutamic acid and oligosaccharides in combination, a food product can be provided that has a significantly superior effect of promoting the growth of lactic acid bacteria and bifidobacteria compared to when each is used alone, and has the function of improving the intestinal environment. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 shows the results (mean value±standard error, n=6) of Test Example 1 (test of adding γ-polyglutamic acid and fructooligosaccharides to a human fecal suspension). [Diagram 2] FIG. 2 shows the results (mean value ± standard error, n=3) of Test Example 2 (test of adding γ-polyglutamic acid and various oligosaccharides to a human fecal suspension). [Diagram 3] FIG. 3 shows the results (mean ± standard deviation, n=3) of Test Example 3 (test of administering γ-polyglutamic acid and fructooligosaccharides to pigs). [Figure 4]FIG. 4 shows the results of Test Example 4 (test of administering γ-polyglutamic acid and fructooligosaccharides to pigs) (mean value ± standard deviation, n=6, *: P<0.05, Student's t-test). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in detail below. The intestinal environment-improving food of the present invention comprises a combination of (1) γ-polyglutamic acid or a composition containing γ-polyglutamic acid, and (2) oligosaccharides or a composition containing oligosaccharides. The food of the present invention is a combined food of (1) and (2) in which (1) and (2) are used in combination. In the food of the present invention, (1) and (2) may be formulated simultaneously and contained in the same formulation (food), or (1) and (2) may be formulated separately and ingested simultaneously or separately at different times, by the same route or by different routes. In other words, the food of the present invention includes foods containing (1) and (2) in a single formulation, and foods in which (1) and (2) are formulated separately and used in combination.

[0011] In this specification, food is a concept that broadly encompasses anything that can be taken orally (excluding pharmaceuticals), and includes not only so-called "food" but also beverages, dietary supplements, health functional foods (e.g., foods for specified health uses, foods with functional claims), supplements, etc.

[0012] In this specification, "improving the intestinal environment" refers to relatively increasing the number of lactic acid bacteria and / or bifidobacteria present in the lower digestive tract. Relative increase means promoting the dominance of lactic acid bacteria and / or bifidobacteria in the intestinal flora. The dominance of lactic acid bacteria and bifidobacteria in the intestinal flora can be confirmed by measuring the amount of lactic acid bacteria and bifidobacteria in feces using quantitative PCR or the like. As used herein, "lower digestive tract" means the ileum, cecum, colon, and rectum.

[0013] (1) γ-Polyglutamic acid or a composition containing γ-polyglutamic acid In the present invention, as (1), γ-polyglutamic acid can be used as it is, or can be used as a composition containing γ-polyglutamic acid. In the present invention, the γ-polyglutamic acid is preferably a γ-polyglutamic acid that is a polymer (high molecular weight substance) in which about 30 to about 5,000 D-glutamic acid and L-glutamic acid are bonded together in a ratio of about 8:2. γ-polyglutamic acid is also called polyglutamic acid. As γ-polyglutamic acid, commercially available products (for example, Caltake (trade name) manufactured by Ajinomoto Co., Inc.) can also be used.

[0014] The composition containing γ-polyglutamic acid in the present invention may be in any form, and examples thereof include powders, granules (including fine granules), tablets, hard capsules, soft capsules, liquids (e.g., solutions, suspensions, emulsions), beverages, jellies, puddings, yogurt, candies, chewing gums, and the like. These can be produced by known methods. For example, γ-polyglutamic acid can be mixed with a carrier (e.g., excipient, binder, disintegrant, lubricant, solvent) to produce powders, granules, tablets, capsules, liquids, and the like by known methods in the field of food preparations or pharmaceutical preparations. γ-polyglutamic acid can also be added to and mixed with food or beverages (e.g., water, soft drinks) to produce the composition.

[0015] (2) Oligosaccharides or compositions containing oligosaccharides In the present invention, as (2), oligosaccharides can be used as they are, or can be used as a composition containing oligosaccharides. In the present invention, examples of oligosaccharides include coffee bean mannooligosaccharides, lactofructose oligosaccharides, galactooligosaccharides, fructooligosaccharides, soybean oligosaccharides, xylooligosaccharides, and isomaltooligosaccharides, and fructooligosaccharides, coffee bean mannooligosaccharides, isomaltooligosaccharides, and galactooligosaccharides are preferred. Oligosaccharides can be used alone or in combination of two or more.

[0016] The composition containing oligosaccharides in the present invention may be in any form, and examples thereof include powders, granules (including fine granules), tablets, hard capsules, soft capsules, liquids (e.g., solutions, suspensions, emulsions, liquid seasonings (e.g., liquid sweeteners)), beverages, jellies, puddings, yogurt, candies, chewing gums, etc. Among these, liquid forms (e.g., liquids (e.g., solutions, suspensions, emulsions, liquid seasonings (e.g., liquid sweeteners)), beverages) are preferred. These can be produced by known methods. For example, oligosaccharides can be mixed with carriers (e.g., excipients, binders, disintegrants, lubricants, solvents) to produce powders, granules, tablets, capsules, liquids, etc., by known methods in the fields of food preparations or pharmaceutical preparations. They can also be produced by adding and mixing oligosaccharides with foods and beverages (e.g., water, soft drinks). They can also be produced by adding and mixing liquid sweeteners containing oligosaccharides with foods and beverages.

[0017] As described above, the food of the present invention includes a food containing the above (1) and (2) in a single formulation, and a food in which the above (1) and (2) are formulated separately and used in combination.

[0018] Examples of foods in which (1) and (2) are formulated separately and used in combination include foods in which (1) is in the form of granules, tablets, hard capsules, or soft capsules containing γ-polyglutamic acid, and (2) is in the form of a beverage containing oligosaccharides, and these are used in combination. In the present invention, (1) and (2) may be taken simultaneously or separately at different times, via the same route or different routes. Specifically, for example, capsules (e.g., hard capsules, soft capsules), granules, tablets, etc. containing γ-polyglutamic acid may be taken together with an oligosaccharide-containing beverage.

[0019] Foods containing (1) and (2) in one preparation can be in any form, and examples of such foods include powders, granules (including fine granules), tablets, hard capsules, soft capsules, liquids (e.g., solutions, suspensions, emulsions, liquid seasonings (e.g., liquid sweeteners)), beverages, jellies, puddings, yogurt, candies, chewing gums, etc. These can be produced by known methods.

[0020] The intake amount of γ-polyglutamic acid in the intestinal environment-improving food of the present invention is usually 0.1 to 100 g, preferably 0.1 to 50 g, and more preferably 1 to 20 g per day for an adult (body weight 60 kg). The intake amount of oligosaccharides in the intestinal environment-improving food of the present invention is usually 0.1 to 100 g, preferably 0.1 to 50 g, and more preferably 1 to 20 g per day for an adult (body weight 60 kg). In the intestinal environment improving food of the present invention, the weight ratio of oligosaccharides to γ-polyglutamic acid (oligosaccharides:γ-polyglutamic acid) is preferably 1:0.05-20, more preferably 1:0.1-10, even more preferably 1:0.1-5, still more preferably 1:0.1-3, and particularly preferably 1:0.2-2.

[0021] The food of the present invention can be safely ingested by humans and non-human animals (e.g., mammals and birds, such as livestock, poultry, and laboratory animals). The food may be added to feed for ingestion by non-human animals.

[0022] Other aspects of the present invention include "a food product comprising a combination of (1) γ-polyglutamic acid or a composition containing γ-polyglutamic acid, and (2) oligosaccharides or a composition containing oligosaccharides, and a commercial package including a written material with an explanation of the use for improving the intestinal environment," "a food product comprising a combination of (1) γ-polyglutamic acid or a composition containing γ-polyglutamic acid, and (2) oligosaccharides or a composition containing oligosaccharides, and labeled for use in improving the intestinal environment," "a food product for enhancing the intestinal environment-improving effect, comprising a combination of (1) γ-polyglutamic acid or a composition containing γ-polyglutamic acid, and (2) oligosaccharides or a composition containing oligosaccharides," and "a food product for enhancing the intestinal environment-improving effect of oligosaccharides or a composition containing oligosaccharides, which is a composition containing γ-polyglutamic acid or a composition containing γ-polyglutamic acid." The terms "γ-polyglutamic acid or a composition containing γ-polyglutamic acid," "oligosaccharides or a composition containing oligosaccharides," "improvement of intestinal environment," "intake of γ-polyglutamic acid," and "intake of oligosaccharides" are the same as the examples and definitions explained for the food for improving intestinal environment above. EXAMPLES

[0023] The present invention will be described in more detail below based on Test Examples, Examples, Comparative Examples, and Reference Examples, but the present invention is not limited to these. The abbreviations stand for the following: γ-PGA: γ-Polyglutamic Acid FOS: Fructooligosaccharides PBS: Phosphate-buffered saline CMOS: Coffee bean mannooligosaccharides IMOS: Isomalto-oligosaccharides GOS: Galactooligosaccharides

[0024] [Test Example 1] Test of adding γ-PGA and fructooligosaccharides to human fecal suspension The PBS solutions of the Examples and Comparative Examples shown in Table 1 were prepared and used as media for fecal culture. PBS alone was used as a negative control. γ-PGA was polyglutamic acid "Caltake" manufactured by Ajinomoto Co., Ltd., and FOS was fructooligosaccharide manufactured by Wako Pure Chemical Industries, Ltd. Then, 10 ml of each solution was dispensed into glass vials, sterilized in an autoclave, anaerobicized, and sealed with a butyl rubber stopper. The fecal suspension was prepared by collecting approximately 10 g of feces from six healthy individuals (three men and three women) in their 20s to 40s, and suspending them in 80 ml of anaerobic PBS. 0.5 ml of this fecal suspension was added to each vial, placed in a 37°C incubator, and anaerobically cultured for four days while mixing by inversion once a day. After the culture was completed, enterobacteria pellets were obtained from the entire culture solution by centrifugation (8,000×g, 5 minutes). DNA was extracted from the pellets using ISOFECAL for BeadsBeat (manufactured by Nippon Gene Co., Ltd.), and quantitative PCR was performed using GeneAce SYBR qPCR Mix α (manufactured by Nippon Gene Co., Ltd.). Quantitative PCR was performed under the following conditions: 95°C for 10 minutes, followed by 45 cycles of 95°C for 30 seconds and 60°C for 60 seconds. The quantitative PCR primers used for detection of lactic acid bacteria (mainly Lactobacillus spp.) are as follows. LAB-F: 5'-AGCAGTAGGGAATCTTCCA-3' (SEQ ID NO: 1) (Appl Environ Microbiol. 67(6):2578-2585, 2001) LAB-R: 5'-CACCGCTACACATGGAG-3' (SEQ ID NO: 2) (Appl Environ Microbiol. 68(1):114-123, 2002)

[0025] [Table 1]

[0026] The results obtained by quantitative PCR were calculated as the relative amount when PBS alone (negative control) was set to 1, and the results were standardized by z-score. The results are shown in Figure 1. Data are shown as the mean z-score ± standard error (n = 6). Significant differences were determined by Dunnett's test using the positive control as a control (*: P < 0.05). As a result, the addition of γ-PGA alone did not result in the proliferation of lactic acid bacteria, but the addition of γ-PGA together with 0.5% FOS resulted in a concentration-dependent proliferation of lactic acid bacteria that was more pronounced than that observed with FOS alone. Thus, in the present invention, a synergistic effect exceeding the additive effect was observed with the combination of γ-PGA and oligosaccharides on the proliferation of lactic acid bacteria.

[0027] [Test Example 2] Test of adding γ-PGA and various oligosaccharides to human fecal suspension The PBS solutions of the Examples and Comparative Examples shown in Table 2 were prepared and used as media for fecal culture. PBS alone was used as a negative control. CMOS was coffee bean mannooligosaccharide manufactured by Ajinomoto General Foods Co., Ltd., IMOS was isomaltooligosaccharide manufactured by Wako Pure Chemical Industries, Ltd., and GOS was galactooligosaccharide manufactured by Wako Pure Chemical Industries, Ltd. Fecal culture and detection of lactic acid bacteria were performed in the same manner as in Test Example 1.

[0028] [Table 2]

[0029] The results obtained by quantitative PCR were calculated as the relative amount when PBS alone (negative control) was set to 1, and the results were standardized by z-score. The results are shown in Figure 2. Data are shown as the mean z-score ± standard error (n = 3). Significant differences were determined by Dunnett's test using the positive control as a control (*: P < 0.05). As a result, it was found that the combination of any oligosaccharide with γ-PGA induced a more pronounced proliferation of lactic acid bacteria than the oligosaccharide alone. Thus, in the present invention, a synergistic effect exceeding the additive effect was observed in the proliferation of lactic acid bacteria when combined with γ-PGA, regardless of the type of oligosaccharide.

[0030] [Test Example 3] Administration of γ-PGA and FOS to pigs Six male pigs (Hi-Co-op SPF pigs LWD) aged 2 to 3 months were purchased from the National Federation of Agricultural Cooperative Associations, and divided into two test groups of three pigs each to ensure uniform average body weight, and were raised for four weeks in a pen of three pigs each. Each test group was fed 400 g / head of Pig Mirai CEX (National Federation of Agricultural Cooperative Associations) twice a day. The test substances were administered to each test group at the doses and methods shown in Table 3. For γ-PGA, Ajinomoto Co.'s polyglutamic acid "Caltake" and for FOS, Meiji Food Material Co.'s fructooligosaccharide "Mei Oligo P Granules". After four weeks from the start of administration, the cecum was sampled and the lactic acid bacteria in the cecal contents were examined by quantitative PCR using the same method as in Test Examples 1 and 2.

[0031] [Table 3]

[0032] The results are shown in Figure 3. The data are shown as relative amounts when the copy number of DNA derived from the lactic acid bacteria in Comparative Example 6 was set to 1 (mean value ± standard deviation, n = 3). As a result, it was confirmed that the combination of γ-PGA and FOS increased the average proliferation of lactic acid bacteria in the pig intestines by approximately twice as much as FOS alone.

[0033] [Test Example 4] Administration of γ-PGA and FOS to pigs Twenty-four male pigs (Hi-Co-op SPF pigs LWD) aged 2 to 3 months were purchased from the National Federation of Agricultural Cooperative Associations, and divided into four test groups of six pigs each to ensure uniform average body weight, with three pigs per pen, for four weeks. Each test group was fed 400 g / head of Pig Mirai CEX (National Federation of Agricultural Cooperative Associations) twice a day. The test substances were administered to each test group at the doses and methods shown in Table 4. For γ-PGA, Ajinomoto Co.'s polyglutamic acid "Caltake" and for FOS, Meiji Food Materia Co.'s fructooligosaccharide "Mei Oligo P Granules". After four weeks from the start of administration, the cecum was sampled and bifidobacteria in the cecal contents were examined by quantitative PCR. Quantitative PCR was performed under the following conditions: 95°C for 10 minutes, followed by 45 cycles of 95°C for 30 seconds and 60°C for 60 seconds. The quantitative PCR primers used for detecting bifidobacteria are as follows. g-Bifid-F: 5'-CTCCTGGAAACGGGTGG-3' (SEQ ID NO: 3) g-Bifid-R: 5'-GGTGTTCTTCCCGATATCTACA-3' (SEQ ID NO: 4)

[0034] [Table 4]

[0035] The results are shown in Figure 4. The data are shown as relative amounts when the copy number of the Bifidobacterium-derived DNA in Comparative Example 7 was set to 1 (mean value ± standard deviation, n = 6). As a result, it was confirmed that the combination of γ-PGA and FOS increased bifidobacteria in the pig intestines by an average of 10 times more than when FOS was consumed alone. In particular, the additional intake of γ-PGA in an amount half that of FOS was found to have a more significant effect on increasing bifidobacteria than when FOS was consumed alone.

[0036] This application is based on patent application No. 2017-195311 filed in Japan, the contents of which are incorporated in their entirety herein.

Claims

1. A food for improving intestinal environment, comprising a combination of (1) γ-polyglutamic acid or a composition containing γ-polyglutamic acid, and (2) an oligosaccharide or a composition containing an oligosaccharide, The γ-polyglutamic acid is a polymer having about 30 to about 5,000 glutamic acid units bound thereto, The oligosaccharide is at least one selected from the group consisting of fructooligosaccharides, coffee bean mannooligosaccharides, isomaltooligosaccharides, and galactooligosaccharides; The weight ratio of the oligosaccharide to the γ-polyglutamic acid (oligosaccharide:γ-polyglutamic acid) is 1:0.1-3.

2. The food product of claim 1 , wherein the composition containing oligosaccharides is in liquid form.

3. The food product according to claim 2 , wherein the composition containing oligosaccharides in liquid form is a liquid preparation containing oligosaccharides.

4. The food product according to claim 2 , wherein the composition containing oligosaccharides in liquid form is a beverage containing oligosaccharides.

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