Food for improving intestinal environment

Abstract

The purpose of the present invention is to provide a food capable of increasing the production amount of indole-3-propionic acid produced by intestinal bacteria.　This food for improving intestinal environment is obtained by combining (1) a digestion-resistant polysaccharide or a composition containing a digestion-resistant polysaccharide, and (2) a digestion-resistant protein or a composition containing a digestion-resistant protein. The food for improving intestinal environment contains at least one selected from the group consisting of enteric compositions that contain tryptophan or a salt thereof, digestion-resistant proteins that include tryptophan as a constituent amino acid, and compositions that contain a digestion-resistant protein including tryptophan as a constituent amino acid.

Description

Foods for improving the intestinal environment

[0001] The present invention relates to a food product that can increase the amount of indole-3-propionic acid produced by intestinal bacteria by improving the intestinal environment.

[0002] Recent advances in intestinal bacterial research have revealed that substances produced by metabolic conversion of dietary components by intestinal bacteria play an important role in the host's health and the onset of disease. Indole-3-propionic acid (hereinafter referred to as "IPA") is produced in the intestine through metabolic conversion of dietary tryptophan ingested by the host by intestinal bacteria such as Clostridium sporogenes. IPA is known to have beneficial effects on the host's health, such as anti-obesity effects (Non-Patent Document 1), intestinal barrier function protection effects (Non-Patent Document 2), antioxidant effects (Non-Patent Document 3), neuroprotection effects (Non-Patent Document 4), endoplasmic reticulum stress improvement effects (Non-Patent Document 5), muscle mass increase effects (Non-Patent Document 6), bone formation promotion effects (Non-Patent Document 7), antibacterial effects (Non-Patent Document 8), and glucose tolerance improvement effects (Non-Patent Document 9). Furthermore, intestinal permeability, which is thought to be one of the underlying causes of obesity and type 2 diabetes, has been shown to improve intestinal permeability by activating the nuclear receptor PXR in intestinal epithelial cells in mice (Non-Patent Document 10), suggesting that the improvement of intestinal permeability by IPA suppresses obesity and impaired glucose tolerance. Therefore, there is a need for the development of foods that can increase IPA, which is expected to have the above-mentioned beneficial effects. However, IPA itself is not approved as a food additive and cannot be used directly in foods. Furthermore, even if tryptophan, the precursor of IPA, is orally ingested, it is rapidly absorbed, making it difficult to deliver it to the large intestine, where many intestinal bacteria reside. Although resistant starch is known to increase IPA production in the intestine (Non-Patent Document 11), further food development is needed.

[0003] Nutrients 2019, 11, 591Exp Mol Med.2019 Sep 10;51(9):1-14Membranes 2021, 11, 571.Nature 607, 585-592 (2022)Biochem Biophys Res Commun. 2019, 517(4), 623-628Int. J. Mol. Sci. 2021, 22, 12435Theranostics 2021, Vol. 11, Issue 17Life Sci. 2021, 285:120003FEBS J. 2022 Oct;289(19):5985-6004Immunity, 2014; 41(2): 293-310FASEB J.2019 Jul;33(7):8033-8042

[0004] An object of the present invention is to provide a food product that can increase the amount of IPA produced by intestinal bacteria.

[0005] The present inventors conducted extensive research to solve the above problems and found that ingesting tryptophan, a precursor of IPA, in an enteric-coated composition can increase IPA production by intestinal bacteria; phenylalanine is essential for promoting the growth of Clostridium sporogenes, an intestinal bacterium that produces IPA; ingesting an enteric-coated composition combining tryptophan and phenylalanine can increase IPA production by intestinal bacteria more significantly than ingesting an enteric-coated tryptophan composition alone; and ingesting a tryptophan enteric-coated composition in combination with a non-digestible polysaccharide such as an oligosaccharide can increase IPA production by intestinal bacteria more significantly than ingesting an enteric-coated tryptophan composition alone. Furthermore, the present inventors found that ingesting a non-digestible protein such as soy protein in combination with a non-digestible polysaccharide such as an oligosaccharide can significantly increase IPA production by intestinal bacteria. Based on these findings, the present inventors conducted further research and completed the present invention.

[0006] That is, the present invention is as follows. [1] A food for improving intestinal environment, comprising a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide, and (2) a resistant protein or a composition containing a resistant protein. (Herein, also referred to as the first invention.) [2] The food according to [1] above, further comprising (3) an enteric composition containing an amino acid or a salt thereof. [3] The food according to [1] above, wherein the resistant polysaccharide or the composition containing a resistant polysaccharide is an oligosaccharide or a composition containing an oligosaccharide. [4] The food according to [1] above, wherein the resistant protein or the composition containing a resistant protein is a vegetable protein or a composition containing a vegetable protein. [5] The food according to [1] above, wherein the resistant protein or the composition containing a resistant protein is selected from the group consisting of soy protein, sake lees, koyadofu, buckwheat, wheat, rice, peas, and corn. [6] The food product according to [2] above, wherein the amino acid is tryptophan or a combination of tryptophan and phenylalanine. [7] The food product according to any one of [1] to [6] above, for increasing indole-3-propionic acid production by intestinal bacteria in the intestine. [8] A food product for improving the intestinal environment, comprising at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid. (Herein, also referred to as the second invention.) [9] The food product according to [8] above, further comprising an enteric composition containing phenylalanine or a salt thereof.

[10] The food product according to [8] above, wherein the indigestible protein containing tryptophan as a constituent amino acid or the composition containing an indigestible protein containing tryptophan as a constituent amino acid is selected from the group consisting of soy protein, sake lees, koya-dofu, buckwheat, wheat, rice, peas, and corn.

[11] The food product according to the above item [8], further comprising a composition containing a non-digestible polysaccharide or a non-digestible polysaccharide.

[12] The food product according to any one of the above items [8] to

[11] , for increasing the production of indole-3-propionic acid by enterobacteria in the intestine.

[0007]

[13] A method for improving the intestinal environment in a subject, comprising administering to the subject an effective amount of a food product comprising a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide, and (2) a resistant protein or a composition containing a resistant protein.

[14] The method of

[13] above, wherein the food product further comprises (3) an enteric composition containing an amino acid or a salt thereof.

[15] The method of

[13] above, wherein the resistant polysaccharide or the composition containing a resistant polysaccharide is an oligosaccharide or a composition containing an oligosaccharide.

[16] The method of

[13] above, wherein the resistant protein or the composition containing a resistant protein is a vegetable protein or a composition containing a vegetable protein.

[17] The method of

[13] above, wherein the resistant protein or the composition containing a resistant protein is selected from the group consisting of soy protein, sake lees, koyadofu, buckwheat, wheat, rice, peas, and corn.

[18] The method according to

[14] above, wherein the amino acid is tryptophan or a combination of tryptophan and phenylalanine.

[19] The method according to any one of

[13] to

[18] above, for increasing indole-3-propionic acid production by enterobacteria in the intestine.

[20] A method for improving the intestinal environment in a subject, comprising having the subject ingest an effective amount of a food product containing at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid.

[21] The method according to

[20] above, wherein the food product is further combined with an enteric composition containing phenylalanine or a salt thereof.

[22] The method according to

[20] above, wherein the indigestible protein containing tryptophan as a constituent amino acid or the composition containing the indigestible protein containing tryptophan as a constituent amino acid is selected from the group consisting of soy protein, sake lees, freeze-dried tofu, buckwheat, wheat, rice, peas, and corn.

[23] The method according to

[20] above, wherein the food is further combined with an indigestible polysaccharide or a composition containing an indigestible polysaccharide.

[24] The method according to any one of

[20] to

[23] above, for increasing production of indole-3-propionic acid by enterobacteria in the intestine.

[0008]

[25] Use of a food product comprising a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide and (2) a resistant protein or a composition containing a resistant protein for improving the intestinal environment.

[26] The use according to

[25] above, wherein the food product further comprises (3) an enteric composition containing an amino acid or a salt thereof.

[27] The use according to

[25] above, wherein the resistant polysaccharide or a composition containing a resistant polysaccharide is an oligosaccharide or a composition containing an oligosaccharide.

[28] The use according to

[25] above, wherein the resistant protein or a composition containing a resistant protein is a vegetable protein or a composition containing a vegetable protein.

[29] The use according to

[25] above, wherein the resistant protein or a composition containing a resistant protein is selected from the group consisting of soy protein, sake lees, koyadofu, buckwheat, wheat, rice, peas, and corn.

[30] The use according to

[26] above, wherein the amino acid is tryptophan or a combination of tryptophan and phenylalanine.

[31] The use according to any one of

[25] to

[30] above, for increasing intestinal production of indole-3-propionic acid by enterobacteria.

[32] Use of a food product containing at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid, for improving the intestinal environment.

[33] The use according to

[32] above, wherein the food product is further combined with an enteric composition containing phenylalanine or a salt thereof.

[34] The use according to

[32] above, wherein the indigestible protein containing tryptophan as a constituent amino acid or the composition containing an indigestible protein containing tryptophan as a constituent amino acid is selected from the group consisting of soy protein, sake lees, koya-dofu, buckwheat, wheat, rice, peas, and corn.

[35] The use according to the above-mentioned

[32] , wherein the food product further comprises a composition containing a non-digestible polysaccharide or a non-digestible polysaccharide.

[36] The use according to any one of the above-mentioned

[32] to

[35] , for increasing the production of indole-3-propionic acid by enterobacteria in the intestine.

[0009] The intestinal environment-improving food (first invention) of the present invention is a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide (e.g., a fructooligosaccharide or a composition containing a fructooligosaccharide), and (2) a resistant protein or a composition containing a resistant protein (e.g., a soy protein or a composition containing a soy protein). This combination is expected to significantly increase the amount of IPA produced by intestinal bacteria in the intestines of a subject who ingests the food, compared to when either (1) or (2) is ingested alone, resulting in an increase in blood IPA concentration (see Test Example 4). Furthermore, the intestinal environment-improving food (first invention) of the present invention is expected to improve intestinal permeability by combining (1) a resistant polysaccharide or a composition containing a resistant polysaccharide (e.g., a fructooligosaccharide or a composition containing a fructooligosaccharide), and (2) a resistant protein or a composition containing a resistant protein (e.g., a soy protein or a composition containing a soy protein) (see Test Example 5).

[0010] The intestinal environment-improving food (Invention 2) of the present invention contains at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, a resistant protein containing tryptophan as a constituent amino acid (e.g., soy protein), and a composition containing a resistant protein containing tryptophan as a constituent amino acid. This significantly increases the amount of IPA produced by intestinal bacteria in the intestines of a subject who ingests the food, thereby increasing the blood IPA concentration (see Test Example 1-2, Figures 1-3). Furthermore, when the intestinal environment-improving food (Invention 2) of the present invention is further combined with an enteric composition containing phenylalanine, it is expected to significantly increase the amount of IPA produced by intestinal bacteria, thereby increasing the blood IPA concentration, compared to when an enteric composition containing tryptophan, a resistant protein containing tryptophan as a constituent amino acid (e.g., soy protein), or a composition containing a resistant protein containing tryptophan as a constituent amino acid is ingested alone (see Test Example 1-2, Figures 1-3, 1-4). Furthermore, by further combining the intestinal environment improving food of the present invention (Invention 2) with a resistant polysaccharide (e.g., fructooligosaccharide) or a composition containing a resistant polysaccharide, it is expected that the amount of IPA produced by intestinal bacteria will be more significantly increased, and as a result, the blood IPA concentration will be increased, compared to when an enteric composition containing tryptophan, a resistant protein containing tryptophan as a constituent amino acid (e.g., soy protein), or a composition containing a resistant protein containing tryptophan as a constituent amino acid is ingested alone (see Test Example 2-2 and Figure 2-2).

[0011] FIG. 1-1 is a graph showing the results of Test Example 1-1. FIG. 1-2 is a graph showing the results of Test Example 1-1. FIG. 1-3 is a graph showing the results of Test Example 1-2. FIG. 1-4 is a graph showing the results of Test Example 1-2. FIG. 2-1 is a graph showing the results of Test Example 2-1. FIG. 2-2 is a graph showing the results of Test Example 2-2. FIG. 3 is a graph showing the results of Test Example 3. FIG. 4 is a graph showing the results of Test Example 4. FIG. 5 is a graph showing the results of Test Example 5.

[0012] [First Invention] The intestinal environment-improving food of the present invention comprises a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide, and (2) a resistant protein or a composition containing a resistant protein. The intestinal environment-improving food of the present invention preferably further comprises (3) an enteric composition containing an amino acid or a salt thereof. The food of the present invention is a combination of (1) and (2) (preferably a combination of (1), (2), and (3)), or a combined food of (1) and (2) (preferably a combined food of (1), (2), and (3)). In the food of the present invention, (1) and (2) (or (1), (2), and (3)) may be formulated simultaneously and contained in the same formulation (food), or (1) and (2) (or (1), (2), and (3)) may be formulated separately and ingested simultaneously or separately with a time lag, by the same route or by different routes. That is, the food of the present invention includes foods containing (1) and (2) (or (1), (2) and (3)) in a single formulation, and foods in which (1) and (2) (or (1), (2) and (3)) are separately formulated and used in combination.

[0013] (1) Resistant Polysaccharides or Compositions Containing Resistant Polysaccharides In the present specification, the term "resistant polysaccharides" refers to polysaccharides that are difficult to digest and absorb in the stomach or small intestine, but reach the large intestine and are metabolized by intestinal bacteria such as Clostridium sporogenes. In the present invention, the degree of polymerization of the resistant polysaccharide is 2 or more, or 3 or more. In the present invention, the upper limit of the degree of polymerization of the resistant polysaccharide is not particularly limited, but is, for example, 100 or less, preferably 60 or less, more preferably 10 or less, even more preferably 6 or less, and still more preferably 5 or less. In the present invention, the degree of polymerization of the resistant polysaccharide is preferably 2 to 100, more preferably 2 to 60, even more preferably 2 to 10, and even more preferably 2 to 6. In the present invention, examples of the resistant polysaccharide include oligosaccharides, guar gum, resistant maltodextrin, pectin, chitosan, alginic acid, and inulin. In the present invention, as (1), indigestible polysaccharides (e.g., oligosaccharides) can be used as they are, or can be used as a composition containing indigestible polysaccharides (e.g., oligosaccharides). As used herein, oligosaccharides refer to those in which 2 to 10 monosaccharides are linked together. In the present invention, examples of oligosaccharides include coffee bean mannooligosaccharides, lactoferrin oligosaccharides, galactooligosaccharides (GOS), fructooligosaccharides (FOS), soybean oligosaccharides, xylooligosaccharides, and isomaltooligosaccharides (IMOS). Fructooligosaccharides, galactooligosaccharides, and isomaltooligosaccharides are preferred, with fructooligosaccharides being particularly preferred. Oligosaccharides can be used alone or in combination of two or more.

[0014] Oligosaccharides can be produced by known methods, or commercially available products can be used. Examples of fructooligosaccharides include 1-kestose, nystose, and 1-β-fructofuranosylnystose, which have a degree of polymerization of 3 to 5 and are formed by bonding one to three fructose units to sucrose. Specific examples include FOS (Fujifilm Wako Pure Chemical Industries, #064-02385). Examples of galactooligosaccharides include galactosyllactose, which has a structure in which one or more galactose units are bonded to lactose via β-1,4 bonding and has a degree of polymerization of 2 to 6. Specific examples include GOS (Fujifilm Wako Pure Chemical Industries, #076-05945). Examples of isomaltooligosaccharides include branched oligosaccharides containing glucose as a constituent sugar and having one or more α-1,6, α-1,2, or α-1,3 bonds in the molecule, such as isomaltose, nigerose, kojibiose, panose, isomaltotriose, and isomaltotetraose. Specific examples include IMOS (Fujifilm Wako Pure Chemical Industries, #090-03485).

[0015] The composition containing the indigestible polysaccharide (e.g., oligosaccharide) of the present invention may be in any form, including 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, the indigestible polysaccharide (e.g., oligosaccharide) can be mixed with a carrier (e.g., excipient, binder, disintegrant, lubricant, solvent) to produce powders, granules, tablets, capsules, liquids, and the like, using methods known in the fields of food formulation and pharmaceutical formulation. The indigestible polysaccharide (e.g., oligosaccharide) can also be added to and mixed with food or beverages (e.g., water, soft drinks) to produce the composition. Commercially available products (e.g., Meiji Food Materials' fructooligosaccharide "Mei Oligo P Granules") can also be used.

[0016] (2) Resistant-to-digestible protein or composition containing a resistant-to-digestible protein In this specification, a resistant-to-digestible protein refers to a protein that is difficult to digest and absorb in the stomach or small intestine, reaches the large intestine, and is metabolized by intestinal bacteria such as Clostridium sporogenes.

[0017] In the present invention, an example of a resistant protein is a vegetable protein. In the present invention, the resistant protein (e.g., vegetable protein) can be used as is, or can be used as a composition containing the resistant protein (e.g., vegetable protein). Examples of vegetable proteins or compositions containing vegetable proteins include ground products, refined products, and processed products of protein-rich plants (e.g., soybeans, buckwheat, wheat, rice, peas, and corn). Examples include soy protein, buckwheat protein, wheat protein, rice protein, pea protein, corn protein, soy flour, buckwheat flour, wheat flour, rice flour, pea flour, corn flour, soybean processed products (e.g., freeze-dried tofu, miso, and miso soup), buckwheat processed products (e.g., buckwheat noodles), wheat processed products, rice processed products (e.g., sake lees), pea processed products (e.g., pea soup), and corn processed products (e.g., corn soup). In the present invention, the indigestible protein is preferably soy protein.

[0018] In the present invention, the blending ratio (weight ratio) ((1):(2)) of (1) indigestible polysaccharide (e.g., fructooligosaccharide) to (2) indigestible protein (e.g., soy protein) is preferably 1:0.1-10, more preferably 1:0.5-5, and particularly preferably 1:1.

[0019] (3) Enteric composition containing an amino acid or a salt thereof In the present invention, examples of the amino acid include tryptophan and phenylalanine, with tryptophan and phenylalanine being preferred. These amino acids are preferably in the L-form. One or more amino acids can be used in combination. In the present invention, the amino acid preferably contains at least tryptophan, with a combination of tryptophan and phenylalanine being particularly preferred. The amino acid in the present invention may be in the form of a salt (e.g., sodium salt, hydrochloride). Examples of salts acceptable for pharmaceuticals or foods include: when tryptophan and phenylalanine are used in combination as amino acids in the present invention, the blending ratio of tryptophan to phenylalanine (tryptophan:phenylalanine (molar ratio)) is preferably 1:0.01-100, more preferably 1:0.1-10, even more preferably 1:1-10, and particularly preferably 1:1-4.

[0020] In the present invention, the enteric composition is a composition that does not disintegrate in the stomach or upper part of the small intestine, where the pH is low, but disintegrates in the lower part of the small intestine or large intestine, where the pH is high, to release an amino acid or a salt thereof. The enteric composition of the present invention is stable, for example, at a pH of less than 2, and the outermost coating layer peels off at a pH of 2 or higher, and then disintegrates preferably at a pH of 3.5 or higher (more preferably, a pH range of 3.5 to 9). Disintegrability can be measured, for example, in accordance with the provisions for enteric-coated preparations in the disintegration test method of the Japanese Pharmacopoeia, 17th Edition.

[0021] Examples of the enteric composition of the present invention include granules (including fine granules), granules, tablets, hard capsules, and soft capsules. The enteric composition of the present invention can be produced by methods known in the fields of food formulation or pharmaceutical formulation. For example, an amino acid or its salt is mixed with a carrier (e.g., excipient, binder, disintegrant, lubricant, protective agent) and granulated and / or compressed to obtain granules or tablets, which are then enterically coated to obtain enteric-coated granules or enteric-coated tablets; an enteric-coated hard capsule is filled with granules or tablets containing an amino acid or its salt; or a soft capsule made of an enteric-coated base material is encapsulated with a carrier (e.g., an oil component) to obtain enteric-coated capsules. The enteric-coated granules may also be encapsulated in a capsule (e.g., a cellulose capsule) to produce an enteric-coated granule. Alternatively, an enteric-coated granule may be obtained by mixing dissolved oil (protective agent) with an amino acid or its salt and cooling and solidifying the mixture. Commercially available products can also be used.

[0022] Examples of enteric coating bases include cellulose polymers such as hydroxypropyl cellulose, hydroxypropyl methylcellulose phthalate, hydroxypropyl methylcellulose acetate succinate, carboxymethylethyl cellulose, and cellulose acetate phthalate; acrylic acid polymers such as methacrylic acid copolymer L, methacrylic acid copolymer LD, and methacrylic acid copolymer S; and natural products such as chitosan and shellac. Coating additives (e.g., plasticizers) may also be used during coating. The carriers, coating bases, and coating additives are used in amounts conventionally used in the pharmaceutical formulation technology.

[0023] In the present invention, when (3) an amino acid or a salt thereof is used, the blending ratio (weight ratio) ((1):(2):(3)) of (1) an indigestible polysaccharide (e.g., fructooligosaccharide), (2) an indigestible protein (e.g., soy protein), and (3) an amino acid or a salt thereof (e.g., tryptophan, phenylalanine) is preferably 1:0.1-10:0.0003-1, more preferably 1:0.5-5:0.0001-0.1, and particularly preferably 1:1:0.005-0.05.

[0024] The intake amount of a resistant polysaccharide (e.g., oligosaccharide) or a composition containing a resistant polysaccharide in the intestinal environment-improving food of the present invention is typically 0.1 to 20 g, preferably 0.1 to 10 g, and more preferably 0.1 to 5 g, of resistant polysaccharide per day for an adult (body weight 60 kg). The intake amount of a resistant protein (e.g., soy protein) or a composition containing a resistant protein in the intestinal environment-improving food of the present invention is typically 0.1 to 20 g, preferably 0.1 to 10 g, and more preferably 0.1 to 5 g, of resistant protein per day for an adult (body weight 60 kg). When an amino acid or a salt thereof is used in the intestinal environment-improving food of the present invention, the intake amount of the amino acid or a salt thereof in the intestinal environment-improving food of the present invention is typically 0.01 to 10 g, preferably 0.01 to 5 g, and more preferably 0.01 to 1 g, of amino acid per day for an adult (body weight 60 kg).

[0025] Other aspects of the present invention include: "a food product comprising a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide, and (2) a resistant protein or a composition containing a resistant protein, and a commercial package including a written matter with an explanation regarding the use for improving the intestinal environment," "a food product comprising a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide, (2) a resistant protein or a composition containing a resistant protein, and (3) an enteric composition containing an amino acid or a salt thereof, and a commercial package including a written matter with an explanation regarding the use for improving the intestinal environment," "a food product comprising a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide, and (2) a resistant protein or a composition containing a resistant protein, and labeled for use in improving the intestinal environment," and Examples of such foods include "a food labeled for use in improving the intestinal environment, which is a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide, (2) a resistant protein or a composition containing a resistant protein, and (3) an enteric composition containing an amino acid or a salt thereof." The definitions, examples, intake amounts, etc. of "resistant polysaccharide or a composition containing a resistant polysaccharide," "resistant protein or a composition containing a resistant protein," and "enteric composition containing an amino acid or a salt thereof" are the same as those described for the intestinal environment-improving food products.

[0026] [Second Invention] The intestinal environment-improving food of the present invention comprises at least one member selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid.

[0027] The intestinal environment-improving food of the present invention is preferably further combined with an enteric composition containing phenylalanine or a salt thereof, and / or a non-digestible polysaccharide or a composition containing a non-digestible polysaccharide.

[0028] In the intestinal environment-improving food of the present invention, when at least one selected from the group consisting of (I) an enteric composition containing tryptophan or a salt thereof, a resistant protein containing tryptophan as a constituent amino acid, and a composition containing a resistant protein containing tryptophan as a constituent amino acid is used in combination with (II) an enteric composition containing phenylalanine or a salt thereof and / or (III) a resistant polysaccharide or a composition containing a resistant polysaccharide, examples of the food for improving intestinal environment of the present invention include the following: (i) a food for improving intestinal environment comprising a combination of an enteric composition containing tryptophan or a salt thereof and an enteric composition containing phenylalanine or a salt thereof; (ii) a food for improving intestinal environment comprising a combination of a resistant protein containing tryptophan as a constituent amino acid (e.g., soy protein) and an enteric composition containing phenylalanine or a salt thereof; (iii) a food for improving intestinal environment comprising a combination of a composition containing a resistant protein containing tryptophan as a constituent amino acid (e.g., soy protein) and an enteric composition containing phenylalanine or a salt thereof. (iv) A food for improving the intestinal environment, which is a combination of an enteric composition containing tryptophan or a salt thereof and a composition containing a resistant polysaccharide (for example, an oligosaccharide (preferably, a fructooligosaccharide)) or a composition containing a resistant polysaccharide. (v) A food for improving the intestinal environment, which is a combination of an resistant protein (for example, soy protein) containing tryptophan as a constituent amino acid and a composition containing a resistant polysaccharide (for example, an oligosaccharide (preferably, a fructooligosaccharide)) or a composition containing a resistant polysaccharide. (vi) A food for improving the intestinal environment, which is a combination of a composition containing an resistant protein (for example, soy protein) containing tryptophan as a constituent amino acid and a composition containing a resistant polysaccharide (for example, an oligosaccharide (preferably, a fructooligosaccharide)) or a composition containing a resistant polysaccharide. (vii) A food for improving the intestinal environment, comprising a combination of an enteric composition containing tryptophan or a salt thereof, an enteric composition containing phenylalanine or a salt thereof, and a composition containing a non-digestible polysaccharide (e.g., an oligosaccharide (preferably, a fructooligosaccharide)) or a non-digestible polysaccharide).(viii) A food for improving the intestinal environment, which is a combination of an indigestible protein containing tryptophan as a constituent amino acid (e.g., soy protein), an enteric composition containing phenylalanine or a salt thereof, and a composition containing an indigestible polysaccharide (e.g., an oligosaccharide (preferably, a fructooligosaccharide)) or an indigestible polysaccharide. (ix) A food for improving the intestinal environment, which is a combination of a composition containing an indigestible protein containing tryptophan as a constituent amino acid (e.g., soy protein), an enteric composition containing phenylalanine or a salt thereof, and a composition containing an indigestible polysaccharide (e.g., an oligosaccharide (preferably, a fructooligosaccharide)) or an indigestible polysaccharide.

[0029] In the intestinal environment-improving food of the present invention, when at least one selected from the group consisting of (I) an enteric composition containing tryptophan or a salt thereof, a resistant protein containing tryptophan as a constituent amino acid, and a composition containing a resistant protein containing tryptophan as a constituent amino acid is used in combination with (II) an enteric composition containing phenylalanine or a salt thereof and / or (III) a resistant polysaccharide or a composition containing a resistant polysaccharide, (I) and (II) and / or (III) may be formulated simultaneously and contained in the same preparation (food), or (I) and (II) and / or (III) may be formulated separately and ingested simultaneously or separately at different times, by the same route or by different routes. That is, the food of the present invention includes foods containing (I), (II), and / or (III) in a single preparation, and foods in which (I), (II), and / or (III) are formulated separately and used in combination.

[0030] In the present invention, tryptophan and phenylalanine are preferably in the L-form. In the present invention, tryptophan and phenylalanine may be in the form of a salt (e.g., sodium salt, hydrochloride). Examples of such salts include those acceptable for pharmaceuticals or foods.

[0031] In the present invention, when (I) at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid, and (II) an enteric composition containing phenylalanine or a salt thereof are used in combination, the blending ratio of (I) to (II) is preferably 1:0.01-100, more preferably 1:0.1-10, even more preferably 1:1-10, and particularly preferably 1:1-4, in terms of the molar ratio of tryptophan in (I) to phenylalanine in (II) (tryptophan:phenylalanine).

[0032] In the present invention, when (I) at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, a resistant protein containing tryptophan as a constituent amino acid, and a composition containing a resistant protein containing tryptophan as a constituent amino acid is used in combination with (III) a resistant polysaccharide or a composition containing a resistant polysaccharide, the blending ratio of (I) to (III) is preferably 1:1 to 3000, more preferably 1:10 to 2000, even more preferably 1:20 to 1000, and particularly preferably 1:30 to 500, as the weight ratio of tryptophan in (I) to the resistant polysaccharide (e.g., oligosaccharide (preferably fructooligosaccharide)) in (III).

[0033] In the present invention, when (I) at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid, (II) an enteric composition containing phenylalanine or a salt thereof, and (III) an indigestible polysaccharide or a composition containing an indigestible polysaccharide are used in combination, (I), (II), and (III) are used in combination. The blending ratio, expressed as a weight ratio (tryptophan:phenylalanine:resistant polysaccharide) of tryptophan in (I), phenylalanine in (II), and indigestible polysaccharide (e.g., oligosaccharide (preferably fructooligosaccharide)) in (III), is preferably 1:0.01-100:1-3000, more preferably 1:0.05-10:10-2000, even more preferably 1:0.1-10:20-1000, and particularly preferably 1:0.5-4:30-500.

[0034] In the present invention, the definition, examples, and production method of the "enteric composition" of the enteric composition containing tryptophan and the enteric composition containing phenylalanine, the definition, degree of polymerization, examples of the indigestible polysaccharide (oligosaccharide), examples of the composition containing the indigestible polysaccharide, etc. are the same as the definition, examples, production method, definition, degree of polymerization, examples of the indigestible polysaccharide (oligosaccharide), examples of the composition containing the indigestible polysaccharide, etc. of the "enteric composition" explained in the first invention above.

[0035] In the present invention, an example of an "indigestible protein containing tryptophan as a constituent amino acid" is a vegetable protein containing tryptophan as a constituent amino acid. In the present invention, an example of a "composition containing an indigestible protein containing tryptophan as a constituent amino acid" is a composition containing a vegetable protein containing tryptophan as a constituent amino acid.

[0036] Examples of vegetable proteins containing tryptophan as a constituent amino acid or compositions containing vegetable proteins containing tryptophan as a constituent amino acid include ground products, refined products, and processed products of protein-rich plants (e.g., soybeans, buckwheat, wheat, rice, peas, and corn), such as soy protein, buckwheat protein, wheat protein, rice protein, pea protein, corn protein, soy flour, buckwheat flour, wheat flour, rice flour, pea flour, corn flour, soybean processed products (e.g., freeze-dried tofu, miso, and miso soup), buckwheat processed products (e.g., buckwheat noodles), wheat processed products, rice processed products (e.g., sake lees), pea processed products (e.g., pea soup), and corn processed products (e.g., corn soup). In the present invention, soy protein is preferred as the indigestible protein.

[0037] The intake of "at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid" in the intestinal environment-improving food of the present invention is usually 0.01 to 5 g, preferably 0.01 to 1 g, and more preferably 0.01 to 0.5 g, in terms of tryptophan, per day for an adult (body weight 60 kg). When an "enteric composition containing phenylalanine or a salt thereof" is used in the intestinal environment-improving food of the present invention, the intake of the "enteric composition containing phenylalanine or a salt thereof" in the intestinal environment-improving food of the present invention is usually 0.01 to 5 g, preferably 0.01 to 1 g, and more preferably 0.01 to 0.5 g, in terms of phenylalanine, per day for an adult (body weight 60 kg). When a "resistant polysaccharide or a composition containing a resistant polysaccharide" is used in the intestinal environment-improving food of the present invention, the intake amount of the "resistant polysaccharide or a composition containing a resistant polysaccharide" in the intestinal environment-improving food of the present invention is usually 0.1 to 20 g, preferably 0.5 to 10 g, and more preferably 1 to 5 g, in terms of resistant polysaccharide per day for an adult (body weight 60 kg).

[0038] Other aspects of the present invention include: "a food product containing at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid, and a commercial package containing a written matter with instructions for use in improving the intestinal environment," "a food product comprising a combination of at least one selected from the group consisting of (I) an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid, and (II) an enteric composition containing phenylalanine or a salt thereof and / or (III) an indigestible polysaccharide or a composition containing an indigestible polysaccharide, and a commercial package containing a written matter with instructions for use in improving the intestinal environment," "a food product containing at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid, and a commercial package containing a written matter with instructions for use in improving the intestinal environment," and "a food product labeled for use in improving the intestinal environment, containing at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, an indigestible protein containing tryptophan as a constituent amino acid, and a composition containing an indigestible protein containing tryptophan as a constituent amino acid." Examples of such foods include "foods labeled for use in improving the intestinal environment, which are composed of a combination of at least one selected from the group consisting of (I) an enteric composition containing tryptophan or a salt thereof, a resistant protein containing tryptophan as a constituent amino acid, and a composition containing a resistant protein containing tryptophan as a constituent amino acid, and (II) an enteric composition containing phenylalanine or a salt thereof and / or (III) a resistant polysaccharide or a composition containing a resistant polysaccharide." The definitions, examples, intake amounts, etc. of the "enteric composition containing tryptophan or a salt thereof," "resistant protein containing tryptophan as a constituent amino acid," "composition containing a resistant protein containing tryptophan as a constituent amino acid," "enteric composition containing phenylalanine or a salt thereof," and "composition containing a resistant polysaccharide" are the same as those described for the above-mentioned foods for improving the intestinal environment.

[0039] The food products of the present invention (first and second inventions) can be safely ingested by humans and non-human animals (e.g., mammals and birds such as livestock, poultry, and laboratory animals). The food products may be added to feed for ingestion by non-human animals.

[0040] As used herein, "intestinal environment" refers to an "intestinal environment in which IPA is easily produced." As used herein, "improvement of the intestinal environment" refers to an increase in IPA production by intestinal bacteria in the intestine, specifically, an increase in IPA production by intestinal bacteria in the intestine when the food of the present invention is ingested compared to when the food of the present invention is not ingested (resulting in an increase in the IPA concentration in the host's blood). As used herein, "for improving the intestinal environment" refers to use to increase IPA production by intestinal bacteria in the intestine by creating an intestinal environment in which IPA is easily produced. As used herein, "improvement of intestinal permeability" refers to bringing enhanced intestinal permeability closer to normal. Intestinal permeability can be confirmed according to the method described in Test Example 5 below.

[0041] In this specification, the term "food" is a concept that broadly encompasses anything that can be taken orally (excluding pharmaceuticals), and includes not only so-called "foods" but also beverages, health supplements, health functional foods (e.g., foods for specified health uses, foods with functional claims), supplements, etc. Examples of foods in the present invention (first invention and second invention) include soup, miso soup, meat substitutes, protein bars, etc.

[0042] The present invention will be explained in more detail below by way of test examples as examples, but the present invention is not limited to these test examples. Trp: L-tryptophan Phe: L-phenylalanine Gly: glycine Ile: L-isoleucine Val: L-valine Ala: L-alanine Arg: L-arginine Asn: L-asparagine Asp: L-aspartic acid Cys: L-cysteine ​​Gln: L-glutamine Glu: L-glutamic acid His: L-histidine Leu: L-leucine Lys: L-lysine Met: L-methionine Pro: L-proline Ser: L-serine Thr: L-threonine Tyr: L-tyrosine IMOS: isomaltooligosaccharide GOS: galactooligosaccharide FOS: fructooligosaccharide PBS: phosphate buffered saline C. sporogenes: Clostridium sporogenes RS: Resistant starch HFD: High-fat diet SPI: Soy protein isolate LFD: Low-fat diet

[0043] [Test Example 1-1] Cultivation test of C. sporogenes in the presence of various amino acids (Gly, Ile, Phe, Trp, Val) Amino acids that promote the growth of the IPA-producing bacterium C. sporogenes were narrowed down by simulation using a genome-scale metabolic model (GEM), and then evaluated in a pure culture system. Simulations using GEM were performed using COBRAtoolbox in MATLAB (registered trademark), and amino acids that affect the growth of C. sporogenes when 20 types of amino acids were removed one by one were selected. Next, the effect of the amino acids selected by GEM analysis on the growth of C. sporogenes was verified in a pure culture system. C. sporogenes was an in-house strain of Ajinomoto Co., Inc., and the medium used was a 1 / 5 diluted enriched clostridium medium (Difico, #62620609). The amino acids were added to the medium to a final concentration of 4 mM, and the growth of C. sporogenes was evaluated using OD600 as an index. The control was a medium containing no amino acids (medium only).

[0044] The results are shown in Figures 1-1 and 1-2. From the results in Figure 1-1, GEM simulations showed that the addition of Gly, Ile, Phe, Trp, and Val reduced growth by more than 10% compared to before amino acid removal (Figure 1-1). The effects of these amino acids on C. sporogenes growth were evaluated in a pure culture system, and the addition of Phe was shown to promote C. sporogenes growth (Figure 1-2; in the figure, *** indicates p < 0.001, Dunnett's significant difference test from the control, n = 6, means ± SD). This demonstrates that phenylalanine is essential for promoting C. sporogenes growth.

[0045] Test Example 1-2: Effect of Combined Use of Tryptophan and Phenylalanine on IPA Production (Test Method) To evaluate the effect of Trp and the combination of Trp and Phe on IPA production, a pure culture experiment using C. sporogenes was conducted. An in-house strain of C. sporogenes was used. First, 800 μL of C. sporogenes glycerol stock was added to 40 mL of enriched clostridial medium and cultured at 37°C for 18 hours under anaerobic conditions. After culture, the mixture was centrifuged at 9,100 × g for 5 minutes at 4°C, and the precipitate was collected under anaerobic conditions. The precipitate was washed twice with PBS and finally suspended in 5 mL of anaerobically treated PBS to obtain a concentrated bacterial suspension. This concentrated bacterial suspension was used to examine the effect of IPA production. The Trp concentrations used to evaluate the effect of Trp on IPA production are shown in Table 1. The Trp or Phe concentrations used to evaluate the effect of the combination of Trp and Phe on IPA production are shown in Table 2. 10 mM Trp or 10 mM Phe was added to 500 μL of concentrated bacterial solution in the amounts shown in Table 1 or Table 2, and the total volume was adjusted to 1 mL with PBS, followed by 24 hours of culture at 37°C under anaerobic conditions. Furthermore, using GEM analysis as in Test Example 1, the effect of Phe / Trp molar ratios ranging from 1 to 10 on IPA production by C. sporogenes was evaluated. (Method for Analyzing IPA Concentration) The IPA concentration in the culture supernatant was analyzed using an LC-MS / MS mass spectrometry system (mass spectrometer: SCIEX API3200, pump: Shimadzu Corporation LC-20AD, autosampler: Shimadzu Corporation SIL-20AC, column oven: Shimadzu Corporation CTO-20AC, system controller: Shimadzu Corporation CBM-20A, degasser: Shimadzu Corporation DGU-20A, nitrogen generator: Airtec AT5NP-25CSL). Separation was performed by injecting 5 μL of sample and then using an L-Column 2 (2.1 × 150 mm, 3 μm, Chemicals Evaluation and Research Institute, Japan) column. The mobile phases were 0.2% acetic acid (A) and 0.2% acetic acid / acetonitrile solution (B). The mobile phase B concentrations were 2% (1 min), 10% (1.1 min), 25% (3 min), 50% (4 min), 70% (7 min), 95% (9.5-12.5 min), and 2% (12.6-19 min) at a constant flow rate (0.2 mL / min).Mass measurements were performed under the following conditions: CUR: 30 psi, IS: 5500 V, TEM: 700°C, GAS1: 70 psi, GAS2: 70 psi, CAD: 4, CXP: 4 V, ionization method: ESI (+). The peak area ratios of standard solutions of IPA (Tokyo Chemical Industry Co., Ltd., P / N: I0032) with known concentrations (six concentrations from 0.002 to 0.5 μM) were calculated, and the concentrations were determined based on a standard curve prepared from these.

[0046]

[0047]

[0048] The results are shown in Figure 1-3. In the figure, 1:1, 1:2, 1:3, and 1:4 indicate the ratio of Trp to Phe. The results in Figure 1-3 indicate that the absence of Trp in the medium and the presence of Phe alone had no effect on IPA production. On the other hand, when the Trp concentration was fixed and the molar ratio of Phe to Trp was increased, an increase in IPA in the culture supernatant was observed depending on the Phe molar ratio. The results of GEM analysis are also shown in Figure 1-4. The results in Figure 1-4 indicate that IPA production by C. sporogenes was maximized at a Phe / Trp molar ratio of 4.

[0049] Test Example 2-1: Evaluation of Sugar Sources that Enhance IPA Production (In Vivo Test Using Mice) (Test Method) 10-20 week-old C57BL / 6J mice (Charles River Japan) were used, with one mouse per cage. The test sugar source materials, fructooligosaccharide (Fujifilm Wako Pure Chemical Industries, #064-02385), galactooligosaccharide (Fujifilm Wako Pure Chemical Industries, #076-05945), and isomaltooligosaccharide (Fujifilm Wako Pure Chemical Industries, #090-03485), were mixed with powdered feed AIN93G (Research Diet) in the proportions shown in Table 3. Approximately 10% water was added and the mixture was kneaded. The mixture was then formed into approximately 5g balls and dried at room temperature for two days. The mice were fasted from 4:00 PM the previous day, and blood samples were taken at 4:00 PM on the day of the experiment. They were then fed until 9:00 AM the following day, and blood samples were taken after the feed was collected. After the blood was converted into plasma, the IPA concentration was measured and the change in IPA, ΔIPA, was compared.

[0050]

[0051] The results are shown in Figure 2-1. The results in Figure 2-1 show that ingestion of FOS significantly increased blood IPA levels.

[0052] Test Example 2-2 Evaluation of Sugar Sources that Enhance IPA Production (In Vitro Test Using Human Fecal Suspension) (Test Method) Oligosaccharides (fructooligosaccharides (Fujifilm Wako Pure Chemical Industries, Ltd., #064-02385), galactooligosaccharides (Fujifilm Wako Pure Chemical Industries, Ltd., #076-05945), isomaltooligosaccharides (Fujifilm Wako Pure Chemical Industries, Ltd., #090-03485)) were prepared in PBS solutions according to the compositions shown in Table 4. Five mL of each solution was sterilized by filtration and dispensed into sterilized glass vials, which were then anaerobized in an anaerobic chamber. Feces were collected from six healthy individuals (three males and three females) in their 20s to 40s. Approximately 1 g of each feces was suspended in 10 mL of anaerobically treated PBS in the anaerobic chamber to prepare a fecal suspension. 0.1 mL of this fecal suspension was added to each vial, which was then sealed with a butyl rubber stopper and placed in a 37°C incubator for 3 days of anaerobic culture, with mixing by inversion once a day. After the culture was completed, a portion of the culture medium was centrifuged (8,000 × g, 5 minutes) and the IPA concentration in the culture supernatant was measured. The data was standardized based on the results for each subject's feces and presented as the mean z-score ± standard error (n = 6).

[0053]

[0054] The results are shown in Figure 2-2. The results in Figure 2-2 indicate that the addition of oligosaccharides alone did not significantly increase the IPA concentration in the culture medium, but the combined use of oligosaccharides and Trp was able to increase the IPA concentration in the culture medium. The combined use of FOS and Trp was shown to have the most significant effect.

[0055] Test Example 3: Evaluation of Proteins That Enhance IPA Production (In Vivo Test Using Mice) (Test Method) 10-20 week-old C57BL / 6J mice (Charles River Japan) were used, with one mouse per cage. The test protein ingredients, soy protein (Fuji Oil, Prolina (isolated soy protein)), whey (Fonterra, WPC), and casein (Fonterra, sodium caseinate), were mixed with powdered feed AIN93G (Research Diet) in the proportions shown in Table 5. Approximately 10% water was added and the mixture was kneaded. The mixture was then formed into approximately 5g balls and dried at room temperature for 2 days. The mice were fasted from 4:00 PM the previous day, and blood was collected at 4:00 PM the same day. The mice were then fed until 9:00 AM the following day, and blood was collected again after the feed was collected. The blood was purified to plasma, and the IPA concentration was measured, and the change in IPA (ΔIPA) was compared.

[0056]

[0057] The results are shown in Figure 3. The results in Figure 3 show that ingestion of soy protein significantly increased blood IPA levels.

[0058] Test Example 4: Fructooligosaccharide and Soy Protein Blend Ratio (Test Method) 10-20 week-old C57BL / 6J mice (Charles River Japan) were used, with one mouse per cage. The test sugar source, fructooligosaccharide (Fujifilm Wako Pure Chemical Industries, #064-02385), and the test protein, soy protein (Fuji Oil, Prolina (isolated soy protein)), were mixed with powdered feed AIN93G (Research Diet) at the ratios shown in Table 6. Approximately 10% water was added and the mixture was kneaded. After shaping into approximately 5g balls, the mixture was dried at room temperature for two days. The mice were fasted from 4:00 PM the previous day, and blood was collected at 4:00 PM the same day. After feeding, the mice were fed until 9:00 AM the following day. Blood was then collected and blood was collected again. The blood was converted to plasma, and the IPA concentration was measured, and the change in IPA (ΔIPA) was compared.

[0059]

[0060] The results are shown in Figure 4. The results in Figure 4 show that by combining soy protein and FOS, blood IPA concentrations increased significantly compared to when soy protein or FOS was ingested alone. This confirmed the synergistic effect of combining soy protein and FOS. In particular, it was shown that a soy protein:FOS ratio of 1:1 is optimal for intestinal IPA production.

[0061] [Test Example 5] Long-Term Test (Test Method) 15-week-old C57BL / 6J mice (Charles River Japan) were used, with one mouse per cage. The test sugar source, fructooligosaccharide (Fujifilm Wako Pure Chemical Industries, #064-02385), the test protein, soy protein (Fuji Oil, Prolina (isolated soy protein)), and the comparative material, resistant starch (J-Oil Mills, Amylo Fiber SH), were mixed with powdered high-fat feed (Research Diet, 60 kcal Fat, #D12492) in the proportions shown in Table 7. Approximately 10% water was added and the mixture was kneaded, then formed into approximately 5g balls and dried at room temperature for 2 days. To match the fat content of the other feeds, 15% cellulose was added to the high-fat control feed. Approximately 10% water was added and the mixture was kneaded, then formed into approximately 5g balls and dried at room temperature for 2 days. The normal control diet was prepared by adding approximately 10% water to powdered low-fat diet (Research Diet, 10 kcal Fat, #D12450B) and kneading it, then forming it into approximately 5 g balls and drying it at room temperature for two days. Mice were allowed to eat these diets ad libitum, and after four weeks, blood samples were collected and an intestinal permeability test was performed. The blood was converted to plasma and the IPA concentration was measured. For the intestinal permeability test, 0.5 mL of 22 mg / mL FITC fluorescent-labeled 4,000 Da dextran (Sigma-Aldrich, #FD4) was orally administered to mice after an overnight fast, and blood samples were collected four hours later. The blood was centrifuged at 12,000 × g, and the concentration of FITC-labeled dextran in the plasma was measured using a fluorescence plate reader (Molecular Devices, SpectraMax) at an excitation wavelength of 485 nm and an emission wavelength of 530 nm. The concentration was determined based on a standard curve prepared from the fluorescence intensity of FITC-labeled dextran of known concentrations.

[0062]

[0063] The results are shown in Figure 5. In the figure, HFD represents the high-fat control group, SPI+FOS represents the soy protein:FOS = 1:1 group, RS represents the RS group, and LFD represents the normal control group. The results in Figure 5 show that the combination of soy protein and FOS had the same or greater effect on increasing blood IPA and improving intestinal permeability as resident starch (positive control).

[0064] Test Example 6: Study of Trp Colon Delivery Formulations 100 mg of Trp was mixed with 150 mg of excipients (a mixture of sorbitol, crystalline cellulose, hydroxypropyl cellulose, fine silicon dioxide, hardened rapeseed oil, and calcium stearate) to prepare tablets. These tablets were then coated using a spray-type rotary tablet coating device with the following: a first layer: hydroxypropyl cellulose (CELNY®, manufactured by Nippon Soda Co., Ltd.), a second layer: chitosan (Chitocoat®, manufactured by Freund Corporation), and a third layer: shellac (AQsherax®, manufactured by Freund Corporation). The Trp colon delivery formulations prepared in this manner were subjected to a disintegration test in accordance with the Japanese Pharmacopoeia. Specifically, the tablets were immersed in disintegration test fluid 1 for 2 hours (without an auxiliary disc), then in disintegration test fluid 2 for 2 hours (with an auxiliary disc), and then in simulated colonic fluid (with an auxiliary disc), and the disintegration time was measured. The simulated large intestine fluid used was an acetate buffer solution (Michaelis buffer solution) with a pH of 3.5. The disintegration test was performed using a DT110 (manufactured by Freund Corporation). The temperature and speed of the device were set at 37°C and 30 strokes per minute. The results are shown in Table 8.

[0065]

[0066] The results in Table 8 demonstrate that a Trp colon delivery formulation can be produced, that it does not disintegrate in the stomach or small intestine, but disintegrates after reaching the large intestine, and that Trp can be delivered to the large intestine.

[0067] According to the present invention, by preparing a food (including a beverage or preparation) containing a combination of a resistant polysaccharide (preferably a fructooligosaccharide) and a resistant protein (preferably a soy protein), it is possible to provide an intestinal environment-improving food (including a beverage or preparation) that adjusts the intestinal environment to a state where IPA is easily produced. According to the present invention, by preparing a food (including a beverage or preparation) containing an enteric composition of tryptophan (particularly a food containing an enteric composition in combination with tryptophan and phenylalanine, or a food containing an enteric composition of tryptophan and a resistant polysaccharide (preferably a fructooligosaccharide) in combination), it is possible to provide an intestinal environment-improving food (including a beverage or preparation) that adjusts the intestinal environment to a state where IPA is easily produced.

[0068] This application is based on patent application No. 2023-173408 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) a resistant polysaccharide or a composition containing a resistant polysaccharide, and (2) a resistant protein or a composition containing a resistant protein.

2. The food according to claim 1, further comprising (3) an enteric composition containing an amino acid or a salt thereof.

3. The food according to claim 1, wherein the indigestible polysaccharide or the composition containing the indigestible polysaccharide is an oligosaccharide or a composition containing an oligosaccharide.

4. The food according to claim 1, wherein the resistant protein or a composition containing a resistant protein is a vegetable protein or a composition containing a vegetable protein.

5. The food product according to claim 1, wherein the resistant protein or a composition containing the resistant protein is selected from the group consisting of soy protein, sake lees, freeze-dried tofu, buckwheat, wheat, rice, peas, and corn.

6. The food product according to claim 2, wherein the amino acid is tryptophan or a combination of tryptophan and phenylalanine.

7. The food according to any one of claims 1 to 6 for increasing the production of indole-3-propionic acid by intestinal bacteria in the intestine.

8. A food for improving intestinal environment, comprising at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, a non-digestible protein containing tryptophan as a constituent amino acid, and a composition containing a non-digestible protein containing tryptophan as a constituent amino acid.

9. The food according to claim 8, further comprising an enteric composition containing phenylalanine or a salt thereof.

10. The food according to claim 8, wherein the indigestible protein containing tryptophan as a constituent amino acid or the composition containing the indigestible protein containing tryptophan as a constituent amino acid is selected from the group consisting of soy protein, sake lees, freeze-dried tofu, buckwheat, wheat, rice, peas, and corn.

11. The food according to claim 8, further comprising in combination a resistant polysaccharide or a composition containing a resistant polysaccharide.

12. The food according to any one of claims 8 to 11 for increasing the production of indole-3-propionic acid by intestinal bacteria in the intestine.

13. A method for improving the intestinal environment in a subject, comprising having the subject ingest an effective amount of a food comprising a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide, and (2) a resistant protein or a composition containing a resistant protein.

14. The method according to claim 13, wherein the food product further comprises in combination an enteric composition containing (3) an amino acid or a salt thereof.

15. The method of claim 13, wherein the resistant polysaccharide or a composition containing a resistant polysaccharide is an oligosaccharide or a composition containing an oligosaccharide.

16. The method of claim 13, wherein the resistant protein or a composition containing a resistant protein is a vegetable protein or a composition containing a vegetable protein.

17. The method of claim 13, wherein the resistant protein or a composition containing a resistant protein is selected from the group consisting of soy protein, sake lees, freeze-dried tofu, buckwheat, wheat, rice, peas, and corn.

18. The method of claim 14, wherein the amino acid is tryptophan or a combination of tryptophan and phenylalanine.

19. The method according to any one of claims 13 to 18 for increasing the production of indole-3-propionic acid by enterobacteria in the intestine.

20. A method for improving the intestinal environment in a subject, comprising having the subject ingest an effective amount of a food containing at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, a non-digestible protein containing tryptophan as a constituent amino acid, and a composition containing a non-digestible protein containing tryptophan as a constituent amino acid.

21. The method of claim 20, wherein the food product is further combined with an enteric composition containing phenylalanine or a salt thereof.

22. The method according to claim 20, wherein the indigestible protein containing tryptophan as a constituent amino acid or a composition containing an indigestible protein containing tryptophan as a constituent amino acid is selected from the group consisting of soy protein, sake lees, freeze-dried tofu, buckwheat, wheat, rice, peas, and corn.

23. The method according to claim 20, wherein the food product further comprises in combination a resistant polysaccharide or a composition containing a resistant polysaccharide.

24. The method according to any one of claims 20 to 23 for increasing the production of indole-3-propionic acid by enterobacteria in the intestine.

25. Use of a food product comprising a combination of (1) a resistant polysaccharide or a composition containing a resistant polysaccharide and (2) a resistant protein or a composition containing a resistant protein, for improving the intestinal environment.

26. The use according to claim 25, wherein the food product further comprises in combination an enteric composition containing (3) an amino acid or a salt thereof.

27. The use according to claim 25, wherein the indigestible polysaccharide or a composition containing a indigestible polysaccharide is an oligosaccharide or a composition containing an oligosaccharide.

28. The use according to claim 25, wherein the resistant protein or a composition containing a resistant protein is a vegetable protein or a composition containing a vegetable protein.

29. The use according to claim 25, wherein the resistant protein or a composition containing a resistant protein is selected from the group consisting of soy protein, sake lees, freeze-dried tofu, buckwheat, wheat, rice, peas, and corn.

30. The use according to claim 26, wherein the amino acid is tryptophan or a combination of tryptophan and phenylalanine.

31. The use according to any one of claims 25 to 30 for increasing the production of indole-3-propionic acid by enterobacteria in the intestine.

32. Use of a food product containing at least one selected from the group consisting of an enteric composition containing tryptophan or a salt thereof, a non-digestible protein containing tryptophan as a constituent amino acid, and a composition containing a non-digestible protein containing tryptophan as a constituent amino acid, for improving the intestinal environment.

33. The use according to claim 32, wherein the food product is further combined with an enteric composition containing phenylalanine or a salt thereof.

34. The use according to claim 32, wherein the indigestible protein containing tryptophan as a constituent amino acid or a composition containing an indigestible protein containing tryptophan as a constituent amino acid is selected from the group consisting of soy protein, sake lees, freeze-dried tofu, buckwheat, wheat, rice, peas, and corn.

35. The use according to claim 32, wherein the food product further comprises in combination a resistant polysaccharide or a composition containing a resistant polysaccharide.

36. The use according to any one of claims 32 to 35 for increasing the production of indole-3-propionic acid by enterobacteria in the intestine.

Images