Method for evaluating intestinal immunity

Abstract

To provide a method for non-invasively and more simply evaluating immunity in an intestinal tract of a subject.SOLUTION: A method for evaluating immunity in an intestinal tract of a subject, includes the steps of: (a) measuring an amount of transepidermal water loss on a skin surface of a subject; (b) evaluating an amount of an antibody contained in feces of the subject based on the transepidermal water loss obtained in the step (a); and (c) evaluating immunity in the intestinal tract of the subject based on the amount of the antibody obtained in the step (b).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for evaluating immunity in the intestinal tract. [Background technology]

[0002] The immune system in the body consists of two major systems: innate immunity and adaptive immunity. Innate immunity is a non-antigen-specific, innate immunity that is primarily responsible for the initial immune response, while adaptive immunity is an antigen-specific, acquired immunity that is primarily driven by lymphocytes such as B cells and T cells. Adaptive immunity also has two mechanisms: cellular immunity and humoral immunity. The former directly eliminates intracellular antigens through the action of CD4+ helper T cells or CD8+ killer T cells. Meanwhile, the latter eliminates extracellular antigens and neutralizes toxins through the secretion of antibodies produced by B cells into the blood. Furthermore, adaptive immunity, once induced, retains antigen memory for a long period of time, allowing for rapid responses when the same antigen invades again.

[0003] The primary route of entry for antigens is through the respiratory and digestive mucosa. Therefore, these organs possess particularly complex immune systems. It is said that 70% of the immune cells in the entire body are concentrated in the intestine, and the intestinal mucosa plays a particularly important role as the largest immune organ in the body. Various immune cells reside in the intestinal mucosa epithelium, forming lymphoid tissue called Peyer's patches. Upon contact with antigens, immune cells in Peyer's patches transmit antigen information to other immune cells, establishing an antigen-specific defense system. For example, B cells, one type of immune cell, produce antigen-specific IgA in response to signaling from cytokines such as IL-12, IL-5, and IL-10, which inhibits antigen adhesion and fixation to epithelial cells.

[0004] Considering the burden on the subject, it is desirable to evaluate immunity in the intestinal tract, including this evaluation, using a non-invasive method (Patent Document 1). In this field, for example, the amount of antibodies such as IgA contained in the feces of a subject is measured using a stool test or other test, and immunity in the intestinal tract is evaluated based on the measurement results. However, tests such as stool tests are sometimes avoided by subjects because they are embarrassing and the sample collection is tedious, and there are also problems such as the relatively long time required to obtain test results. Therefore, there is a need for a non-invasive and more convenient method for evaluating the amount of antibodies contained in feces or immunity in the intestinal tract.

[0005] In recent years, it has become clear that intestinal immune regulation contributes to the improvement of symptoms of skin diseases such as atopic dermatitis and psoriasis, and it has also been suggested that there may be some relationship between the immune system in the intestinal tract and the skin (Non-Patent Documents 1 and 2). However, there are still many unknowns regarding the relationship between immune status and skin condition in healthy individuals. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-112407 [Non-patent literature]

[0007] [Non-Patent Document 1] JAMA Dermatol.2018;154(1):37-43. [Non-patent document 2] PLOS ONE 15(4):e0231268. Summary of the Invention

[0008] The present invention provides a non-invasive and simpler method for evaluating the amount of antibodies contained in the feces of a subject or the immune strength in the intestinal tract.

[0009] The present inventors have found that by measuring the amount of transepidermal water loss from the skin surface of a subject, the amount of antibodies contained in the feces of the subject can be evaluated, and thereby the immune strength of the intestinal tract of the subject can be evaluated. The present invention is based on these findings.

[0010] According to the present invention, the following inventions are provided. (1) A method for evaluating immunity in the intestinal tract of a subject, comprising: (a) measuring the transepidermal water loss from the skin surface of the subject; (b) evaluating the amount of antibodies contained in the feces of the subject based on the transepidermal water loss obtained in step (a); and (c) evaluating the immunity in the intestinal tract of the subject based on the amount of antibody obtained in step (b). The method comprising: (2) A method for evaluating the amount of antibodies contained in the feces of a subject, comprising: (a) measuring the transepidermal water loss of the skin surface of the subject; and (b) evaluating the amount of antibodies contained in the feces of the subject based on the transepidermal water loss obtained in step (a); The method comprising: (3) A method for identifying a food material for enhancing immunity in the intestinal tract of a subject, comprising: (a) measuring the transepidermal water loss from the skin surface of the subject; (b) evaluating the amount of antibodies contained in the feces of the subject based on the transepidermal water loss obtained in step (a); (c) after step (a) or (b), having the subject eat a food product comprising the candidate food material; (d) after step (c), measuring the transepidermal water loss of the skin surface of the subject again; (e) re-evaluating the amount of antibody contained in the feces of the subject based on the transepidermal water loss obtained in step (d); and (f) selecting the candidate food material when the amount of antibody obtained from step (e) is evaluated to be greater than the amount of antibody obtained from step (b); The method comprising: (4) A method for identifying a food material that increases the amount of antibodies contained in the feces of a subject, comprising: (a) measuring the transepidermal water loss from the skin surface of the subject; (b) evaluating the amount of antibodies contained in the feces of the subject based on the transepidermal water loss obtained in step (a); (c) after step (a) or (b), having the subject eat a food product comprising the candidate food material; (d) after step (c), measuring the transepidermal water loss of the skin surface of the subject again; (e) re-evaluating the amount of antibody contained in the feces of the subject based on the transepidermal water loss obtained in step (d); and (f) selecting the candidate food material when the amount of antibody obtained from step (e) is evaluated to be greater than the amount of antibody obtained from step (b); The method comprising: (5) The method according to any one of (1) to (4), wherein the amount of antibody is the amount of IgA antibody. (6) The method according to any one of (1) to (5), wherein the subject is a human. (7) A food composition for enhancing immunity in the intestinal tract, comprising a food material identified by the method according to (3) or (4). (8) A food composition for increasing the amount of antibodies contained in feces, comprising a food material identified by the method described in (3) or (4). (9) A food composition according to (7) or (8), which is a health functional food. (10) The food composition according to any one of (7) to (9), which is a food for specified health uses, a food with nutrient functions, or a food with functional claims.

[0011] The present invention provides a non-invasive and simple method for evaluating the amount of antibodies contained in the feces of a subject. The present invention can also provide a non-invasive and simple method for evaluating the immune strength in the intestinal tract of a subject. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 shows the correlation between transepidermal water loss (TEWL) on the skin surface and IgA concentration in the feces of subjects. Specific Description of the Invention

[0013] According to one embodiment of the present invention, there is provided a method for evaluating the immune strength in the intestinal tract of a subject, the method comprising the steps of: (a) measuring the transepidermal water loss of the skin surface of the subject; (b) evaluating the amount of antibodies contained in the feces of the subject based on the transepidermal water loss obtained in step (a); and (c) evaluating the immune strength in the intestinal tract of the subject based on the amount of antibodies obtained in step (b).

[0014] In addition, according to another aspect of the present invention, there is provided a method for evaluating the amount of antibodies contained in the feces of a subject, the method comprising the steps of (a) measuring the transepidermal water loss from the skin surface of the subject, and (b) evaluating the amount of IgA antibodies contained in the feces of the subject based on the transepidermal water loss obtained in step (a).

[0015] The subject of the present invention may be any animal, and is not particularly limited, but is preferably a mammal, for example, a primate such as a human or chimpanzee, a pet animal such as a dog or cat, a livestock animal such as a cow, a horse, a sheep or a goat, or a rodent such as a mouse or a rat, and more preferably a human.

[0016] Generally, immunity refers to one of the biological defense mechanisms that distinguishes pathogens, toxins, foreign substances, and unnecessary substances produced within the body as non-self and eliminates them in order for living organisms to live in a healthy state. It is said that immunity first became known around 430 BC when people who survived an infectious disease were found to be free from the same disease thereafter.

[0017] In the present invention, immunity refers to the ability of a subject to fight against and kill or neutralize infectious agents such as external pathogens or viruses. Thus, even when exposed to the same external infectious agent, a subject with high immunity will not become infected, while a subject with low immunity will be susceptible to infection. The immunity of the present invention may refer to either or both of innate immunity (natural immunity) and acquired immunity (acquired immunity) acquired by exposure to an external infectious agent or vaccination, etc., but acquired immunity, particularly humoral immunity among acquired immunity, is preferred.

[0018] Known indicators for evaluating intestinal immunity in the present invention include, for example, the proliferation capacity of T cells, the production amount of IgA antibodies, and the amount of peptides and cytokines produced by cells with various functions. Among these, IgA, an immunoglobulin (Ig) secreted in the intestinal tract, plays a particularly important role in mucosal immune function, such as preventing the adhesion of bacteria and viruses to mucosal surfaces and capturing foreign antigens and eliminating them from the body. Therefore, the amount of antibodies such as IgA is considered a useful indicator for evaluating intestinal immunity. The amount of antibodies used as indicators can be measured by known methods, for example, the amount contained in a subject's feces can be measured using ELISA (Enzyme-Linked Immunosorbent Assay) or the like. While the antibody is not limited, IgA antibodies are preferred.

[0019] Immunoglobulins are a type of glycoprotein, and in addition to IgA, there are other classes such as IgD, IgE, IgG, and IgM. Of these, IgA is found in mammals and birds. In particular, the IgA contained in exocrine fluids such as saliva, tears, nasal secretions, respiratory mucus, gastrointestinal secretions, and milk is called secretory IgA, and plays an important role as the front line of the immune system, protecting mucosal surfaces from antigens and microorganisms.

[0020] Step (a) of the present invention is a step of measuring the transepidermal water loss of the skin surface of a subject. Specific techniques are not particularly limited, but examples include measurements in an open system and a closed system. In open-system measurements, the humidity of the skin surface is measured directly, while in closed-system measurements, the moisture content is measured by circulating dry air or nitrogen gas over the skin surface. Therefore, since accurate measurement of transepidermal water loss is difficult under conditions that cause sweating, it is preferable to measure transepidermal water loss under constant temperature, constant humidity, and windless conditions, specifically, at a temperature of 19 to 23°C and a humidity of 40 to 50%.

[0021] In step (a) of the present invention, the site where transepidermal water loss on the skin surface is measured may be any part of the skin, and examples include, but are not limited to, the skin of the forehead, cheek, forearm, upper arm, back, stomach, etc., with the cheek or upper arm being preferred. The method of the present invention may be performed, but is not limited to, in a beauty salon, a cosmetics store, an esthetic salon, etc., and may be a non-diagnostic method or a diagnostic aid method.

[0022] The method of the present invention can evaluate the amount of antibody contained in the feces of a subject based on the amount of transepidermal water loss from the skin surface of the subject. Furthermore, the results of evaluating the amount of antibody contained in the feces of the subject can also be used to evaluate the immune strength of the subject's intestinal tract. Furthermore, according to one embodiment of the present invention, the antibody is an IgA antibody.

[0023] According to another aspect of the present invention, there is provided a method for identifying a food material for enhancing immunity in the intestinal tract of a subject, the method comprising: (a) measuring the transepidermal water loss of the subject's skin surface; (b) evaluating the amount of antibodies contained in the subject's stool based on the transepidermal water loss obtained in step (a); (c) after step (a) or (b), having the subject eat a food comprising a candidate food material; (d) after step (c), measuring the transepidermal water loss of the subject's skin surface again; (e) evaluating the amount of antibodies contained in the subject's stool again based on the transepidermal water loss obtained in step (d); and (f) selecting the candidate food material when the amount of antibodies obtained in step (e) is evaluated to be greater than the amount of antibodies obtained in step (b).

[0024] In another aspect of the present invention, there is provided a method for identifying a food material that increases the amount of antibodies contained in the feces of a subject, the method comprising: (a) measuring the transepidermal water loss on the skin surface of the subject; (b) evaluating the amount of antibodies contained in the feces of the subject based on the transepidermal water loss obtained in step (a); (c) after step (a) or (b), having the subject eat a food containing a candidate food material; (d) after step (c), measuring the transepidermal water loss on the skin surface of the subject again; (e) evaluating the amount of antibodies contained in the feces of the subject again based on the transepidermal water loss obtained in step (d); and (f) selecting the candidate food material when the amount of antibodies obtained in step (e) is evaluated to be greater than the amount of antibodies obtained in step (b).

[0025] The food material identified by the method of the present invention may be, but is not limited to, a food composition containing the identified food material, for enhancing intestinal immunity or increasing the amount of antibodies in feces. In this case, known ingredients that are typically incorporated into food compositions may also be incorporated. Examples of such ingredients include, but are not limited to, foods such as sugars, fruits, fruit juices, vegetables, and meats, as well as food additives such as sweeteners, high-intensity sweeteners (e.g., aspartame, sucralose, glycyrrhizin, saccharin, stevia, dulcin, trichlorosucrose, thaumatin, and acesulfame potassium), flavorings, colorings, acidulants, antioxidants, emulsifiers, preservatives, and stabilizers.

[0026] Food compositions containing food ingredients identified by the method of the present invention may be health functional foods such as nutritional functional foods, foods for specified health uses, and foods with functional claims, or may be manufactured as therapeutic foods (i.e., foods that serve therapeutic purposes, or foods prepared based on a menu prepared by a nutritionist or other professional in accordance with a doctor's dietary prescription), dietary therapy foods, nursing care foods, etc.

[0027] The recommended intake amount (amount of active ingredient) per serving or per day of a food composition comprising a food material identified by the method of the present invention can be appropriately determined depending on the age, weight, and sex of the subject for whom the immune system in the intestinal tract is to be enhanced or the amount of antibodies contained in the feces is to be increased, as well as on indicators related to the enhancement of the immune system in the intestinal tract or the increase in the amount of antibodies contained in the feces before ingestion, and on the basis of non-clinical or clinical test results, etc. The intake period of the composition of the present invention can also be appropriately determined, and it is preferable to ingest the composition repeatedly and daily over a long period of time.

[0028] The use of a food composition containing a food ingredient identified by the method of the present invention, such as "enhancing intestinal immunity" or "increasing the amount of antibodies in feces," can be directly or indirectly labeled. Labeling includes all actions aimed at informing consumers of the above-mentioned use, and any expression that evokes or infers the above-mentioned use falls under the labeling category of the present invention, regardless of the purpose, content, object, or medium of the labeling. Examples of direct labeling include inscriptions on tangible objects such as the product itself, packaging, containers, labels, and tags. Examples of indirect labeling include advertising and promotional activities in places or by means such as websites, storefronts, exhibitions, signs, bulletin boards, newspapers, magazines, television, radio, mail, and email. When a food composition containing a food material identified by the method of the present invention is manufactured as a food with functional claims, the functionality can be displayed based on the action and effect of the components contained as functional ingredients, such as, for example, "improves immune function," "boosts immunity," "prevents colds," "promotes health," "suppresses viral infections," "suppresses bacterial infections," "suppresses fungal infections," "eliminates parasites," "reduces fatigue," or other similar claims or functional claims.

[0029] The method of the present invention can identify a food material that increases the amount of antibodies in the feces of a subject based on the change in transepidermal water loss before and after the subject ingests a food containing a candidate food material. Furthermore, it can also identify a food material that enhances the immune system in the intestinal tract of the subject based on the change in the estimated amount of antibodies in the feces before and after the subject ingests a food containing the candidate food material. Furthermore, according to one embodiment of the present invention, the antibody is an IgA antibody. [Example]

[0030] The present invention will be described in detail based on the following examples, but the present invention is not limited to these examples. Contents are expressed in mass % unless otherwise specified.

[0031] Measurement of transepidermal water loss (TEWL) The transepidermal water loss of the human subjects was measured by the following method.

[0032] Transepidermal water loss on the cheeks or inner upper arms of 65 healthy women aged 20 to 50 was measured using a Tewameter TM300 (manufactured by Courage+Khazaka Electronic GmbH). The measurement device was set to a standard deviation of 0.2, and the stable threshold value was used. Measurements were performed twice, and the data with the better stability was used. Each measurement was performed after the subjects' skin had been washed, and after they had rested for approximately 20 minutes in an environment with a temperature of 21±2°C and a relative humidity of 45±5%.

[0033] Measurement of fecal IgA antibody levels The amount of IgA antibody in the feces of the human subjects was measured by the following method.

[0034] Feces from 65 healthy women aged 20 to 50 were collected using a stool collection kit (product name: Fecal Collection Kit (manufactured by Techno Suruga Lab Co., Ltd.)), and the IgA concentration (μg / g) in the feces was quantified. The quantification was outsourced to a specialized third-party institution.

[0035] statistical processing We investigated the correlation between transepidermal water loss and fecal IgA antibody levels. When we plotted the data on a scatter plot and calculated the correlation coefficient, we found a significant (p<0.008) negative correlation between transepidermal water loss and fecal IgA antibody levels (Figure 1).

[0036] Therefore, it was shown that the amount of IgA antibodies in the feces can be evaluated by measuring the transepidermal water loss of a subject, and that the immune strength of the intestinal tract can be evaluated based on the results of this evaluation.

Claims

1. A method for assisting in evaluating humoral immunity in the intestinal tract of a subject based on the amount of IgA antibodies contained in the feces of the subject, comprising: (a) measuring the transepidermal water loss of the skin surface of the subject; and (b) evaluating the amount of IgA antibodies contained in the feces of the subject based on the amount of transepidermal water loss obtained in step (a); The method comprising:

2. A method for assessing the amount of IgA antibodies contained in the feces of a subject, comprising: (a) measuring the transepidermal water loss of the skin surface of the subject; and (b) evaluating the amount of IgA antibodies contained in the feces of the subject based on the amount of transepidermal water loss obtained in step (a). The method comprising:

3. A method for identifying a food material for enhancing humoral immunity in the intestinal tract of a subject, comprising: (a) measuring the transepidermal water loss of the skin surface of the subject; (b) evaluating the amount of IgA antibodies contained in the feces of the subject based on the amount of transepidermal water loss obtained in step (a); (c) after step (a) or (b), having the subject eat a food product comprising the candidate food material; (d) after step (c), measuring the transepidermal water loss of the skin surface of the subject again; (e) re-evaluating the amount of IgA antibodies contained in the feces of the subject based on the transepidermal water loss obtained in step (d); and (f) selecting the candidate food material when the amount of IgA antibody obtained in step (e) is evaluated to be greater than the amount of IgA antibody obtained in step (b); The method comprising:

4. A method for identifying a food material that increases the amount of IgA antibodies contained in the feces of a subject, comprising: (a) measuring the transepidermal water loss of the skin surface of the subject; (b) evaluating the amount of IgA antibodies contained in the feces of the subject based on the amount of transepidermal water loss obtained in step (a); (c) after step (a) or (b), having the subject eat a food comprising the candidate food material; (d) after step (c), measuring the transepidermal water loss of the skin surface of the subject again; (e) re-evaluating the amount of IgA antibodies contained in the feces of the subject based on the transepidermal water loss obtained in step (d); and (f) selecting the candidate food material when the amount of IgA antibody obtained in step (e) is evaluated to be greater than the amount of IgA antibody obtained in step (b); The method comprising:

5. The method of any one of claims 1 to 4, wherein the subject is a human.

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