Immunoglobulin a secretagogue

Abstract

To provide a substance with IgA secretagogue action.SOLUTION: An immunoglobulin A secretagogue contains high-amylose wheat flour as an active ingredient, which is a flour with an amylose content of 40 mass% or more in the total starch, as analyzed by the concanavalin A method.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an immunoglobulin A secretagogue. [Background technology]

[0002] Immunoglobulin A (IgA) is an immunoglobulin present in mucous membranes throughout the body, including the respiratory tract, lacrimal glands, and digestive tract. IgA is secreted onto the surface of the mucous membrane and binds to foreign substances such as pathogens and viruses to eliminate their entry into the body. This allows IgA to contribute to the prevention or improvement of infectious diseases, allergic diseases, and other conditions. IgA plays an important role in mucosal immune function.

[0003] Known compounds that have the effect of promoting IgA secretion include fructooligosaccharides (Patent Document 1), galactooligosaccharides (Patent Document 2, Non-Patent Document 1), lactulose (Patent Document 2), resistant starch (Non-Patent Document 2), resistant dextrin (Patent Document 3), polydextrose (Patent Document 4), pectin, glucomannan, etc. (Non-Patent Document 3).

[0004] Starch contained in grains contains amylose and amylopectin. Amylose is classified as a resistant starch that cannot be digested by human digestive enzymes and can function as dietary fiber. Wheat with a higher amylose content than regular wheat, known as high-amylose wheat, has attracted attention as a source of dietary fiber. In recent years, high-amylose wheat has been developed by increasing the amylose content through mutations in enzymes related to starch synthesis (Non-Patent Documents 4 and 5). Patent Documents 5 to 8 disclose high-amylose wheat that has a point mutation in the gene encoding the starch branching enzyme SBEIIa, resulting in reduced SBEIIa activity and a high amylose content in the starch contained in the grain. Patent Document 6 discloses that rats fed wheat flour with an increased amylose content due to a mutation that reduces SBEIIa enzyme activity showed effects of improving intestinal health, such as increasing the amount of short-chain fatty acids in the intestinal contents. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-201239 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-057174 [Patent Document 3] Patent No. 6160011 [Patent Document 4] Patent No. 4793533 [Patent Document 5] Special Publication No. 2007-504803 [Patent Document 6] Special Publication No. 2008-526690 [Patent Document 7] Special Publication No. 2015-504301 [Patent Document 8] Special Publication No. 2019-527054 [Non-patent literature]

[0006] [Non-Patent Document 1] Takeharu Sato, Journal of the Japanese Society of Nutrition and Food Science, Vol. 61, No. 2 (2008) [Non-patent document 2] Hiroki Tanabe, Journal of the Japanese Society for Dietary Fiber, Vol. 8, No. 1 (2004) [Non-patent document 3] Koji Yamada, Journal of the Japanese Society for Dietary Fiber Research, Vol. 5, No. 1 (2001) [Non-patent document 4] J Jpn Assoc Dietary Fiber Res, 2003, 7(1):20-25 [Non-Patent Document 5] Trends in Food Science and Technology, 2006, 17:448-456 Summary of the Invention [Problem to be solved by the invention]

[0007] Promoting IgA secretion is expected to enhance mucosal immune function and prevent or improve infectious diseases and allergic diseases. There is a need for the development of substances that promote IgA secretion. [Means for solving the problem]

[0008] As representative embodiments of the present invention, the following are provided. [1] Contains high amylose wheat flour as an active ingredient, The high amylose wheat flour is wheat flour having an amylose content of 40% by mass or more in total starch as analyzed by the concanavalin A method. Immunoglobulin A secretagogue. [2] The immunoglobulin A secretion promoter according to [1], wherein the raw material high amylose wheat flour is wheat flour derived from modified wheat having low SBEIIa activity. [3] The immunoglobulin A secretion promoter according to [1] or [2], for immunostimulation. [4] The immunoglobulin A secretion enhancer according to any one of [1] to [3], which is for human use. [5] The immunoglobulin A secretion enhancer according to any one of [1] to [4], which is orally ingested. [6] The immunoglobulin A secretion enhancer according to any one of [1] to [5], which is a food or drink. [7] The immunoglobulin A secretion enhancer according to any one of [1] to [6], which contains the resistant starch derived from high amylose wheat flour as an active ingredient. [8] The immunoglobulin A secretion enhancer according to [7], having a daily intake of 1.0 g or more, calculated as the amount of resistant starch. [9] The immunoglobulin A secretion enhancer according to [7], having a daily intake of 15 mg / kg body weight or more, calculated as the amount of resistant starch. [Effects of the Invention]

[0009] The IgA secretion-promoting agent of the present invention can enhance mucosal immune function by promoting IgA secretion. [Brief explanation of the drawings]

[0010] [Figure 1] Changes in fecal short-chain fatty acid total (A) and fecal IgA (B) levels after 12 weeks of high-amylose wheat flour intake. n=20 for each group. DETAILED DESCRIPTION OF THE INVENTION

[0011] The IgA secretion promoter of the present invention contains high-amylose wheat flour as an active ingredient. As used herein, high-amylose wheat flour refers to wheat flour with an amylose content of preferably 40% by mass or more, more preferably 43% by mass or more, and even more preferably 47% by mass or more.

[0012] As used herein, the amylose content of wheat flour refers to the amylose content in the total starch contained in the wheat flour. The amylose content of wheat flour is defined as the value determined by the concanavalin A (ConA) method and can be measured, for example, by analyzing the wheat flour using an amylose / amylopectin assay kit (AMYLOSE / AMYLOPECTIN ASSAY KIT) from Megazyme. Conventional methods for analyzing amylose content include (1) methods utilizing the high iodine-binding ability of amylose (iodine affinity assays; e.g., amperometric titration, colorimetry, AACC61-03, etc.) and (2) methods utilizing the specific binding of amylopectin to ConA (ConA method). However, methods utilizing (1) tend to calculate higher amylose contents. For example, the amylose content of high-amylose wheat flour having a loss-of-function mutation (null mutation) of the SGP-1 gene described in Non-Patent Documents 4 and 5 is about 37% by mass when measured by the iodine affinity assay, but about 31% by mass when measured by the ConA method. Note that the amylose content of conventional wheat flour is less than 32% by mass when measured by the iodine affinity assay, and less than 28% by mass when measured by the ConA method.

[0013] Examples of high-amylose wheat flour used in the present invention include wheat flour derived from modified wheat with reduced activity of the starch branching enzyme SBEIIa. Examples of such modified wheat flour include wheat flour derived from high-amylose wheat with a mutation in the SBEIIa gene and reduced SBEIIa activity, as described in Patent Documents 5 to 8. More specific examples include wheat flour derived from high-amylose wheat in which the amount or activity of SBEIIa protein in the grain is less than 2% of the amount or activity in wild-type wheat grain, and wheat flour derived from high-amylose wheat with null mutations in one or more, for example, one or two, SBEIIa genes.

[0014] High-amylose wheat flour can be produced by milling the grains of such high-amylose wheat according to a conventional method. The high-amylose wheat flour used in the present invention may be wheat flour containing essentially only the endosperm fraction of wheat grains, or may be wheat flour containing the endosperm fraction of wheat grains as well as germ and bran fractions (e.g., whole wheat flour).

[0015] Since amylose is classified as a resistant starch (RS), high-amylose wheat flour is characterized by a higher content of resistant starch, including amylose, compared to regular wheat flour. Therefore, the present invention also provides an IgA secretion promoter containing resistant starch derived from high-amylose wheat flour as an active ingredient.

[0016] As used herein, the term "resistant starch (RS) content" refers to the RS content per dry matter of the sample measured according to the AOAC 2002.02 method. To measure the RS content according to the AOAC 2002.02 method, a commercially available kit (e.g., MegaZyme's resistant starch analysis kit; K-RSTAR) can be used.

[0017] The IgA secretion-promoting agent of the present invention can be applied to living organisms capable of secreting IgA, such as mammals and birds, and is preferably applied to humans.

[0018] In the IgA secretion promoter of the present invention, the high amylose wheat flour or resistant starch derived therefrom functions as an active ingredient for promoting IgA secretion. In addition to the active ingredient, the high amylose wheat flour or resistant starch derived therefrom, the IgA secretion promoter of the present invention may contain, as necessary, a pharmaceutically or edibly acceptable carrier or additive, or may further contain other medicinal ingredients, food ingredients, etc. Preferably, the IgA secretion promoter of the present invention is provided in the form of a medicine, food or drink, supplement, feed, etc. Preferably, the IgA secretion promoter of the present invention is taken orally. Furthermore, considering that high amylose wheat flour is a food ingredient, the IgA secretion promoter of the present invention is more preferably a food or drink.

[0019] Therefore, the high amylose wheat flour or resistant starch derived therefrom can be used to produce the IgA secretion promoter of the present invention in the form of a medicine, food or drink, supplement, feed, etc. These medicines, food or drink, supplement, feed, etc. can be produced according to conventional methods using the high amylose wheat flour or resistant starch derived therefrom, and optionally blending other ingredients such as the above-mentioned carriers, other medicinal ingredients, nutritional ingredients, food materials, etc. The production method for the medicine, food or drink, supplement, feed, etc., and the other ingredients to be blended therein can be appropriately selected depending on the conventional production method and blending of the desired medicine, food or drink, supplement, feed, etc.

[0020] The dosage form of the IgA secretion promoter of the present invention is not particularly limited and may be solid, semi-solid, or liquid. Examples of dosage forms include tablets, chewable tablets, powders, capsules, granules, drinks, gels, syrups, and liquid foods for tube-based enteral nutrition when the IgA secretion promoter is a medicine or supplement. Furthermore, examples of dosage forms include flour-based foods such as breads, confectioneries (e.g., biscuits, cookies, cakes, etc.), and noodles; liquid or fluid foods such as liquid meals, risotto, jellies, soups, and sauces; and beverages such as coffee drinks, milk drinks, cocoa drinks, tea drinks, soft drinks, jelly drinks, and alcoholic beverages.

[0021] The intake amount of the IgA secretion promoter of the present invention may be any amount sufficient to achieve the desired IgA secretion-promoting effect. More specifically, the intake amount of the IgA secretion promoter of the present invention, in terms of the amount of resistant starch derived from high-amylose wheat flour, is preferably 1.0 g or more, more preferably 3.0 g or more, even more preferably 5.0 g or more, and even more preferably 6.1 g or more per day in humans. Alternatively, the daily intake amount of the IgA secretion promoter of the present invention, in terms of the amount of resistant starch derived from high-amylose wheat flour, is preferably 15 mg / kg body weight or more, more preferably 45 mg / kg body weight or more, even more preferably 75 mg / kg body weight or more, and even more preferably 90 mg / kg body weight or more in humans. On the other hand, taking into account the intake volume of high-amylose wheat flour, the daily intake amount of the IgA secretion promoter of the present invention, in terms of the amount of resistant starch derived from high-amylose wheat flour, may be 20 g or less or 300 mg / kg body weight or less in humans. The intake amount can be appropriately adjusted depending on the species, condition, age, sex, weight, etc. of the individual taking the IgA secretion promoter. The daily intake amount may be taken once a day or in several divided doses. The dosage form of the IgA secretion promoter of the present invention, such as a medicine, food or drink, supplement, or feed, and the amount of the high-amylose wheat flour or resistant starch derived therefrom, are not particularly limited, but are preferably set so that the intake amount can be appropriately controlled.

[0022] The IgA secretion-promoting agent of the present invention promotes IgA secretion, thereby exerting an immunostimulatory effect. In a more specific example, oral administration of the IgA secretion-promoting agent of the present invention promotes IgA secretion into the intestinal tract, thereby enhancing the mucosal immune function of the intestinal tract. This can result in effects such as improvement of immune function and prevention or amelioration of infectious diseases or allergic diseases. [Example]

[0023] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0024] (subject) After receiving an explanation of the study and providing consent, 40 healthy subjects were selected based on the results of a bowel movement and dietary survey and a background questionnaire. The subjects were divided into two groups using a stratified block randomization method, adjusting for age, sex, total fecal short-chain fatty acid content (the sum of acetic acid, propionic acid, and n-butyric acid) at screening, and bowel movement frequency during the two-week observation period. The control (placebo) group consisted of 8 men and 12 women (total of 20 subjects), with an age of 51.2 ± 6.9 years. The test food group consisted of 7 men and 13 women (total of 20 subjects), with an age of 51.2 ± 6.8 years. The mean weight of the test food group was 55.5 kg. Subjects were coded with identification numbers during the study, and all study-related data were anonymized. No subjects dropped out during the study period, and all subjects were included in the analysis.

[0025] (Test food) The test foods were frozen rolls (68±5g / piece), and two types were prepared: a test food containing high-amylose wheat flour and a control food (placebo) that did not. The compositions of the test and control foods are shown in Table 1. One day's worth of the test food (two pieces) contained 6.1g of resistant starch. The resistant starch in the test food was substantially derived from high-amylose wheat flour. The control food was manufactured using ordinary wheat flour so that it was indistinguishable from the test food in appearance. One day's worth of the control food (two pieces) contained 0.8g of resistant starch, but did not contain any resistant starch derived from high-amylose wheat. The high-amylose wheat flour was obtained from wheat grains with a mutant SBEIIa gene and low SBEIIa expression (amylose content: approximately 47% by mass; total starch). The control wheat flour was a commercially available strong flour (wheat flour without a mutant SBEIIa gene, amylose content: approximately 25% by mass; total starch). The amylose content of the wheat flour was measured using an amylose / amylopectin analysis kit (Megazyme). The resistant starch (RS) content of the test foods was measured using a resistant starch analysis kit (MegaZyme, K-RSTAR).

[0026] [Table 1]

[0027] (Study Design) A randomized, double-blind, placebo-controlled, parallel-group comparative study was conducted. This study was reviewed by the Ethics Committee of Chiyoda Paramedical Care Clinic (IRB number: 15000088) and its scientific and ethical validity was confirmed before the study began. Prior to the study initiation, a summary of the study was registered in the UMIN Clinical Trial Registry (UMIN-CTR) (UMIN ID: UMIN000051359). The test food intake period was 12 weeks, the same as the general testing period for specified health foods. Throughout the 12-week study period, subjects were given either the test food (test food intake group) or the control food (control food intake group). Subjects consumed two test food servings per day at breakfast, lunch, or dinner. The test food was heated (microwaved at 500W for 50 seconds or at 600W for 40 seconds) and then consumed on the same day. At the start and end of the test food intake (12 weeks later), fecal samples were collected from each subject, and the amount of short-chain fatty acids (acetic acid, propionic acid, and n-butyric acid) and IgA in the feces were measured.

[0028] (measurement) For the measurement of short-chain fatty acid and IgA levels, stool samples were pretreated. A fixed amount of stool sample was weighed into a bead tube, suspended in extraction solution, heat-treated (85°C, 1 minute), disrupted with beads, and centrifuged (18,400 g, 10 minutes). The supernatant was filtered through a 0.20 μm pore membrane filter and used as the sample solution.

[0029] The amount of short-chain fatty acids in the sample solution was measured by high performance liquid chromatography under the measurement conditions described below. <Measurement conditions> System: Shimadzu Organic Acid Analysis System (Shimadzu, Japan) Column: Shim-pack Fast―OA, 100mm x 7.8mm ID (3 columns used in series) Guard column Shim-pack Fast―OA 10mm×4.0mm ID Eluent: 5mmol / L p-toluenesulfonic acid ·Reaction solution 5mmol / L p-toluenesulfonic acid, 100μmol / L EDTA, 20mmol / L Bis-Tris ·Flow rate 0.8mL / min Oven temperature 50℃ Detector: Electrical conductivity detector CDD-10Avp

[0030] The amount of IgA in the feces was measured using an ELISA method with a Human IgA ELISA Quantitation Kit (Bethyl Laboratories, USA) according to the kit manual.

[0031] (result) Figure 1 shows the total amount of short-chain fatty acids (A) and fecal IgA (B) at the start (0W) and end (12W) of the study. The amount of IgA in the feces at the end of the study (12 weeks after ingestion) in the test food intake group was statistically significantly higher than in the control food intake group (Student's t-test, p<0.05). However, there was no difference in the total amount of short-chain fatty acids between the test food intake group and the control food intake group, suggesting that the increase in IgA secretion in this study was not due to an increase in short-chain fatty acids.

Claims

1. Contains high amylose wheat flour as an active ingredient, The high-amylose wheat flour is wheat flour having an amylose content of 40% by mass or more in total starch as analyzed by the Concanavalin A method. Immunoglobulin A secretagogue.

2. The immunoglobulin A secretion promoter according to claim 1, wherein the high amylose wheat flour used as the raw material is wheat flour derived from modified wheat having low SBEIIa activity.

3. The immunoglobulin A secretagogue according to claim 1, for immunostimulation.

4. The immunoglobulin A secretion enhancer according to claim 1, which is for human use.

5. The immunoglobulin A secretagogue according to claim 1, which is taken orally.

6. The immunoglobulin A secretion enhancer according to claim 1, which is a food or drink.

7. The immunoglobulin A secretion promoter according to claim 1, wherein the resistant starch derived from high amylose wheat flour is used as an active ingredient.

8. The immunoglobulin A secretion promoter according to claim 7, wherein the daily intake amount is 1.0 g or more in terms of the amount of resistant starch.

9. The immunoglobulin A secretion promoter according to claim 7, wherein the daily intake amount, converted into the amount of resistant starch, is 15 mg / kg body weight or more.

Images