Immunostimulatory composition and immunostimulation method

Abstract

Disclosed is an immunostimulatory composition comprising: a bacterium having an immunostimulating ability; and a plant extract having the effect of enhancing the immunostimulating ability of said bacterium.

Description

Title of Invention: IMMUNOSTIMULATORY COMPOSITION AND IMMUNOSTIMULATION METHOD Technical Field

[0001] The present invention relates to an immunostimulatory composition and an immunostimulatory method. Background Art

[0002] Immunity is a biological defense mechanism that prevents foreign substances from entering the body and senses and eliminates foreign substances that have entered the body, and plays a very important role in maintaining health. On the other hand, causes of reduced immune function include lack of exercise, overwork, stress, lack of sleep, smoking, and alcohol consumption and the like, and there is a daily risk of reduced immune function. For these reasons, development of technical means for stimulating immune function is being promoted.

[0003] As such technical means, for example, compositions and the like capable of stimulating immune function by ingesting pharmaceuticals and foods and the like have been developed. For example, Patent Literature 1 discloses an interferon (IFN) production inducer containing, as an active ingredient, a lactic acid bacterium or a culture or processed product thereof capable of activating plasmacytoid dendritic cells (pDCs) and inducing interferon (IFN) production. Patent Literature 2 discloses an immunostimulatory activity-enhancing composition containing, as active ingredients, a lactic acid bacterium having immunostimulatory activity and an ester-linked product of a polyhydric alcohol and a saturated fatty acid. Patent Literature 3 discloses a method for producing a lactic acid bacterium having enhanced immunostimulatory activity and free of an ester-linked product of a polyhydric alcohol and a fatty acid, the method including contacting an immunostimulatory activity-enhancing composition containing an ester-linked product of a polyhydric alcohol and a fatty acid as an active ingredient with a lactic acid bacterium having immunostimulatory activity, and then removing the above-described immunostimulatory activity-enhancing composition.

[0004] Here, in order to use a composition capable of stimulating immune function as a pharmaceutical or food and the like for which quality control is required, it is required to control the immune function-stimulating activity of the composition by enhancing or suppressing it. Citation List Patent Literature

[0005] [Patent Literature 1] International Publication No. 2012 / 091081 [Patent  Literature  2]  Japanese  Unexamined  Patent  Application Publication No. 2016-005452 [Patent  Literature  3]  Japanese  Unexamined  Patent  Application Publication No. 2017-085975 Summary of Invention

[0006] The present invention aims to provide a novel immunostimulatory composition.

[0007] The present inventors have found that a predetermined plant extract enhances the activation of pDCs induced by predetermined bacteria having immunostimulatory activity and the accompanying IFN-a production, and have completed the present invention.

[0008] The present invention provides, for example, the following inventions. [1] An immunostimulatory composition comprising a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the bacterium. [2] An immunostimulatory method comprising administering to a subject or causing a subject to ingest a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the bacterium. [3] A method for enhancing an immunostimulatory action induced by a bacterium having immunostimulatory activity, the method comprising administering to a subject or causing a subject to ingest a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the bacterium. [4] An enhancer of an immunostimulatory action induced by a bacterium having immunostimulatory activity, the enhancer comprising a plant extract having an immunostimulatory activity-enhancing action on the bacterium having immunostimulatory activity. [5] An enhancer of an immunostimulatory action induced by a bacterium having immunostimulatory activity, the enhancer comprising a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the bacterium. [6] A composition for immunostimulation induced by a bacterium having immunostimulatory activity, the composition comprising a plant extract having an immunostimulatory activity-enhancing action on the bacterium having immunostimulatory activity. [7] Use of a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the bacterium for producing an immunostimulatory composition. [8] Use of a plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity for producing a composition for immunostimulation induced by the bacterium. [9] Use of a plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity for producing an immunostimulatory composition to be administered or ingested in combination with the bacterium having immunostimulatory activity.

[10] Use of a bacterium having immunostimulatory activity for producing an immunostimulatory composition to be administered or ingested  in combination with  a plant extract  having  an immunostimulatory activity-enhancing action on the bacterium having immunostimulatory activity.

[11] A plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity, for use in immunostimulation induced by the bacterium having immunostimulatory activity.

[12] A bacterium having immunostimulatory activity for use in a therapeutic method of immunostimulation, the bacterium being administered or ingested in combination with a plant extract having an immunostimulatory activity-enhancing action on the bacterium.

[13] A plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity, for use in a therapeutic method of immunostimulation, the plant extract being administered or ingested in combination with the bacterium having immunostimulatory activity.

[14] Use of a bacterium having immunostimulatory activity in a non-therapeutic method of immunostimulation, the bacterium being administered or ingested in combination with a plant extract having an immunostimulatory activity-enhancing action on the bacterium.

[15] Use of a plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity in a non-therapeutic method of immunostimulation, the plant extract being administered or ingested in combination with the bacterium having immunostimulatory activity.

[16] The composition, method, enhancer, use, plant extract, or bacterium according to any one of [1] to

[15] , wherein the bacterium having immunostimulatory activity is a lactic acid bacterium and / or an acetic acid bacterium.

[17] The composition, method, enhancer, use, plant extract, or bacterium according to

[16] , wherein the lactic acid bacterium is a bacterium of the genus Lactococcus.

[18] The composition, method, enhancer, use, plant extract, or bacterium according to

[17] , wherein the bacterium of the genus Lactococcus is Lactococcus lactis subsp. lactis.

[19] The composition or use according to any one of [1], [6] to

[10] , and

[16] to

[18] , wherein the content of the bacterium having immunostimulatory activity is 0.001% by mass or more and less than 100% by mass relative to the total amount of the immunostimulatory composition.

[20] The composition or use according to any one of [1], [6] to

[10] , and

[16] to

[19] , wherein the content of the plant extract is 0.000001% by mass or more and 90.0% by mass or less relative to the total amount of the immunostimulatory composition.

[21] The composition, method, enhancer, use, plant extract, or bacterium according to any one of [1] to

[20] , wherein the ratio of the content (% by mass) of the plant extract to the content (% by mass) of the bacterium having immunostimulatory activity ((content of plant extract) / (content of bacterium having immunostimulatory activity)) is 0.001 or more and 50000 or less.

[22] The composition, method, enhancer, use, plant extract, or bacterium according to any one of [1] to

[21] , wherein the immunostimulatory activity is an activity to induce interferon a production in an immune cell.

[23] The composition, method, enhancer, use, plant extract, or bacterium according to any one of [1] to

[22] , wherein the immune cell is a pDC.

[24] The composition, method, enhancer, use, plant extract, or bacterium according to any one of [1] to

[23] , wherein the immunostimulatory activity-enhancing action is an action of enhancing induction of interferon a production in the immune cell by 1.10-fold or more as compared with an immunostimulatory composition containing only the bacterium having immunostimulatory activity.

[25] The composition, method, enhancer, use, plant extract, or bacterium according to any one of [1] to

[24] , wherein the plant extract is one or more plant extracts selected from the group consisting of a pineapple extract, a mangosteen extract, a maca extract, a fermented extract of rice germ and soybean, a St. John’s wort extract, a chrysanthemum extract, an herb extract, a carob extract, a ginger extract, a hop extract, and a red ginseng extract.

[26] An immunostimulatory composition obtained by adding, to a bacterium having immunostimulatory activity, a plant extract having an immunostimulatory activity-enhancing action on the bacterium.

[27] A method for producing an immunostimulatory composition, the method comprising adding, to a bacterium having immunostimulatory activity, a plant extract having an immunostimulatory activity-enhancing action on the bacterium. Description of Embodiments

[0009] Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

[0010] According to the present invention, a novel immunostimulatory composition can be provided.

[0011] Although the present invention is described in connection with specific examples and various embodiments, it will be readily understood by those skilled in the art that many modifications and applications of the embodiments described in the present specification are possible without departing from the spirit and scope of the present invention.

[0012] The present application claims priority based on Japanese Patent Application No. 2024-072381 filed with the Japan Patent Office on April 26, 2024, the contents of which are incorporated herein by reference in their entirety.

[0013] In the present disclosure, the description “one or more selected from the group consisting of” encompasses one element constituting the group or all combinations that can be formed by two or more elements, and may be, for example, one of the elements constituting the group, or a combination of any two, three, four, five, six, seven, eight, nine, or more elements of the elements constituting the group.

[0014] [Immunostimulatory Composition] The first embodiment of the present disclosure relates to an immunostimulatory composition. The immunostimulatory composition contains a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action. The immunostimulatory composition according to one embodiment has an immunostimulatory action because it contains a bacterium having immunostimulatory activity.

[0015] An immunostimulatory action (immunoactivating action) is an action of activating the innate immune system in cells or a living body, and may be an action of increasing or maintaining (suppressing a decrease in) the function of the innate immune system in cells or a living body. The immunostimulatory action (immunostimulatory activity) according to one aspect may include an immune cell-activating action (immune cell-activating activity), may include a dendritic cell-activating action (dendritic cell-activating activity), and may be a dendritic cell-activating action (dendritic cell-activating activity), and when the immunostimulatory action includes a dendritic cell-activating action, or when the immunostimulatory action is a dendritic cell-activating action, the bacterium having immunostimulatory activity has dendritic cell-activating activity.

[0016] The dendritic cell-activating action (dendritic cell-activating activity) may be an action of increasing the amount of cytokine expression by dendritic cells as compared with a case where the bacterium having immunostimulatory activity is not administered or ingested and the like.      The immunostimulatory action (immunostimulatory activity) according to one aspect may include a plasmacytoid dendritic cell-activating action (pDC-activating action) (plasmacytoid dendritic cell-activating activity (pDC-activating activity)), may be a pDC-activating action (pDC-activating activity), and when the immunostimulatory action includes a pDC-activating action, or when the immunostimulatory action is a pDC-activating action, the above-described bacterium has pDC-activating activity. The pDC-activating action (pDC-activating activity) may be an action (activity) of increasing the amount of cytokine expression by pDCs as compared with a case where the bacterium having immunostimulatory activity is not administered or ingested and the like.

[0017] Plasmacytoid dendritic cells are a type of dendritic cell constituting the innate immune system. pDCs are the major producing cells of type I interferon in the body. Type I interferon exhibits proliferation-inhibiting activity against viruses and the like. Interferon a (IFN-a) and interferon p (IFN—P) are known as representative type I interferons, and in addition to these, interferon X (IFN-X) as a type II interferon is also considered to have an immunostimulatory action. Specific examples of pDCs include CAL-1 cells and the like. CAL-1 cells are a cancer cell line of human plasmacytoid dendritic cells established from tumor cells in the peripheral blood of a patient (Japanese Unexamined Patent Application Publication No. 2007-044008), and are a cell line deposited with the Patent Microorganism Depositary, Biotechnology Center, National Institute of Technology and Evaluation (NPMD, Japan) under accession number FERM BP-10914.

[0018] The immunostimulatory action (immunostimulatory activity), dendritic cell-activating action (dendritic cell-activating activity), or pDC-activating action (pDC-activating activity) according to one aspect may include an IFN   production-promoting action (IFN production-promoting activity) of at least one or more IFN selected from the group consisting of interferon a (IFN-a), interferon P (IFN-P), and interferon X (IFN-X), may include an interferon a (IFN-a) production-promoting action (IFN-a production-promoting activity), and may be an IFN-a production-promoting action (IFN-a production-promoting activity).

[0019] Whether or not the immunostimulatory composition according to one embodiment has an immunostimulatory action can be determined as appropriate. For example, when immune cells are cultured in the presence of the immunostimulatory composition according to one embodiment, if the function of the immune cells is enhanced as compared with a case where immune cells are cultured in the absence of the composition, it is determined that the composition has an immunostimulatory action. In addition, when immune cells are cultured in the presence of the immunostimulatory composition according to one embodiment and a substance that reduces the function of immune cells, if the function of the immune cells is maintained (suppression of decrease) as compared with a case where immune cells are cultured in the absence of the composition and in the presence of the substance that reduces the function of immune cells, it is determined that the composition has an immunostimulatory action. The function of immune cells may be evaluated using, for example, an activation marker molecule (protein and the like) indicating that the immune cells are in an activated state as an index, or may be evaluated using a molecule (protein and the like; for example, IFN and the like) produced when the immune cells are in an activated state as an index.

[0020] Whether or not the immunostimulatory composition according to one embodiment has an immunostimulatory action can be confirmed, as a more detailed example, by measuring the IFN-a concentration according to the following procedures (i) to (iv). (i) Mouse-derived bone marrow cells from which erythrocytes have been removed are suspended in RPMI medium prepared so that each component described in the following <Composition of medium> reaches the respective final concentration described in the following <Composition of medium>, to a concentration of 1x106 cells / mL, to prepare a cell suspension. <Composition of medium> • 10% by volume FBS • 100 U / mL penicillin / streptomycin • 1 mM sodium pyruvate • 2.5 mM HEPES • 1% by mass non-essential amino acids for MEM (NEAA) • 50 pM p-mercaptoethanol • 100 ng / mL Flt-3L (ii) The prepared cell suspension is seeded at 1 mL each, and cultured for one week at 37°C and 5% by volume CO2 in a CO2 incubator to induce pDCs. (iii) Bone marrow cells containing the induced pDCs are suspended to a concentration of 2*105 cells / mL, seeded at 200 pL each into a 96-well plate, and 2 pL each of a composition containing bacteria adjusted to a concentration of 1 mg / mL with PBS is added. (iv) After 24 hours, the culture supernatant is collected, and the IFN-a concentration is measured by ELISA using an IFN-a measurement kit.

[0021] In the present specification, “bacterium having immunostimulatory activity” means a bacterium that has an action of stimulating (activating) immune cells. The “immunostimulatory activity” may be any ability to stimulate immune cells, and may be, for example, an activity to induce IFN production in immune cells, an activity to induce production of at least one or more IFN selected from the group consisting of IFN-a, IFN-P, and IFN-X in immune cells, or an activity to induce IFN-a production in immune cells. The “bacterium having immunostimulatory activity” may be either a viable cell or a dead cell, and may be a disrupted product of a viable cell or a dead cell, a freeze-dried product of a viable cell or a dead cell, a disrupted product of the freeze-dried product, a culture solution, a culture solution extract, and the like, or a processed product thereof. Here, the processed product includes, for example, a product processed by enzyme treatment, heat treatment, and the like, or a product obtained by ethanol precipitation of the processed product and recovered. The “bacterium having immunostimulatory activity” is preferably a dead cell, and more preferably a product obtained by subjecting a disrupted product of a dead cell, a freeze-dried product thereof, or a disrupted product of the freeze-dried product to heat treatment (heat-killed cell). When the “bacterium having immunostimulatory activity” is a dead cell, the bacterium can be produced by, for example, killing viable bacteria by heat treatment, pressure treatment, high-pressure steam treatment, electromagnetic wave treatment, electron beam treatment, radiation treatment, ultraviolet treatment, alcohol treatment, or electrolyzed water treatment and the like, and then drying as necessary by freeze-drying, spray drying, drum drying, hot air drying, or vacuum drying and the like.

[0022] Whether or not the bacterium according to the present embodiment has immunostimulatory activity is not particularly limited, and if the function of immune cells is enhanced when immune cells are cultured in the presence of the bacterium having immunostimulatory activity according to the present embodiment as compared with a case where immune cells are cultured in the absence of the bacterium, it may be determined that the bacterium has an immunostimulatory action. Whether or not the bacterium according to the present embodiment has immunostimulatory activity can be confirmed, as a more detailed example, by measuring the IFN-a concentration according to the above procedures (i) to (iv).

[0023] Whether or not the bacterium according to the present embodiment has immunostimulatory activity can be expressed by an index of producing 30 pg / mL or more, preferably 50 pg / mL or more, more preferably 60 pg / mL or more, more preferably 70 pg / mL or more, more preferably 80 pg / mL or more, more preferably 90 pg / mL or more, more preferably 100 pg / mL or more, more preferably 150 pg / mL or more, more preferably 200 pg / mL or more, more preferably 250 pg / mL or more, more preferably 300 pg / mL or more, more preferably 400 pg / mL or more, more preferably 500 pg / mL or more, more preferably 600 pg / mL or more, more preferably 700 pg / mL or more, and particularly preferably 800 pg / mL or more of IFN-a by co-culturing the bacterium at a final concentration of 10 gg / mL for 24 hours with bone marrow cells at a final concentration of 2*105 cells / mL, which contain pDCs and are obtained by collecting from mouse bone marrow and culturing for 7 days in a cell culture medium containing 100 ng / mL Flt3-L.

[0024] The bacterium according to the present embodiment is not particularly limited, but may be a bacterium harmless to the human body. The bacterium according to one aspect may be a Gram-positive bacterium or a Gram-negative bacterium. The bacterium according to the present embodiment may be a lactic acid bacterium and / or an acetic acid bacterium, and may in particular be a lactic acid bacterium. The bacterium having immunostimulatory activity according to the present embodiment may be one type of bacterium or a mixture of two or more types of bacteria, and may be, for example, one or two or more types of lactic acid bacteria, one or two or more types of acetic acid bacteria, or a mixture of one or two or more types of lactic acid bacteria and one or two or more types of acetic acid bacteria.

[0025] Lactic acid bacteria are bacteria that produce lactic acid as a metabolite. Examples of lactic acid bacteria include bacteria of the genus Oenococcus, bacteria of the genus Bifidobacterium, bacteria of the genus Weissella, bacteria of the genus Tetragenococcus, bacteria of the genus Lactococcus, bacteria of the genus Leuconostoc, bacteria of the genus Pediococcus, bacteria of the genus Streptococcus, bacteria of the genus Enterococcus, bacteria of the genus Lactobacillus, bacteria of the genus Bacillus, and bacteria of the genus Heyndrickxia (formerly classified as bacteria of the genus Bacillus) and the like.

[0026] Note that bacteria of the genus Lactobacillus in the present invention include bacteria that were classified in the genus Lactobacillus before the reclassification of the genus Lactobacillus. For example, bacteria reclassified Acetilactobacillus, Apilactobacillus, into the newly Agrilactobacillus, Bombilactobacillus, established genera of Amylolactobacillus, Companilactobacillus, Dellaglioa, Fructilactobacillus, Furfurilactobacillus, Holzapfelia, Lacticaseibacillus, Latilactobacillus, Ligilactobacillus, Loigolactobacillus, Schleiferilactobacillus, Lactiplantibacillus, Lentilactobacillus, Limosilactobacillus, Paralactobacillus, Lapidilactobacillus, Levilactobacillus, Liquorilactobacillus, Paucilactobacillus, and Secundilactobacillus and the like in association with the reclassification of the genus Lactobacillus are included.

[0027] Among the above, the bacterium is preferably a bacterium of the genus Oenococcus, a bacterium of the genus Bifidobacterium, a bacterium of the genus Lentilactobacillus, a bacterium of the genus Weissella, a bacterium of the genus Tetragenococcus, a bacterium of the genus Lactococcus, a bacterium of the genus Leuconostoc, a bacterium of the genus Pediococcus, a bacterium of the genus Enterococcus, a bacterium of the genus Lactobacillus, a bacterium of the genus Lactiplantibacillus, a bacterium of the genus Lacticaseibacillus, or a bacterium of the genus Limosilactobacillus, and more preferably a bacterium of the genus Lactococcus.

[0028] Examples of the above-described bacteria of the genus Oenococcus include, but are not particularly limited to, Oenococcus oeni and the like. Specific examples of bacteria of the genus Oenococcus include Oenococcus oeni JCM 6125 and the like.

[0029] Examples of the above-described bacteria of the genus Bifidobacterium include, but are not particularly limited to, Bifidobacterium animalis subsp. lactis and Bifidobacterium longum subsp. infantis and the like. Specific examples of bacteria of the genus Bifidobacterium include Bifidobacterium animalis subsp. lactis JCM 10602, Bifidobacterium longum subsp. infantis JCM 1222, and Bifidobacterium longum subsp. longum BB536 and the like.

[0030] Examples of the above-described bacteria of the genus Weissella include, but are not particularly limited to, Weissella paramesenteroides and Weissella viridescens and the like. Specific examples of bacteria of the genus Weissella include Weissella paramesenteroides JCM 9890 and Weissella viridescens JCM 1174 and the like.

[0031] Examples of the above-described bacteria of the genus Tetragenococcus include, but are not particularly limited to, Tetragenococcus halophilus and the like. Specific examples of bacteria of the genus Tetragenococcus include Tetragenococcus halophilus NRIC 0098 and Tetragenococcus halophilus No. 1 and the like.

[0032] Examples of the above-described bacteria of the genus Lactococcus include, but are not particularly limited to, Lactococcus lactis, Lactococcus lactis subsp. lactis, Lactococcus garvieae, Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. hordniae, Lactococcus curvatus, and Lactococcus plantarum and the like.

[0033] Specific examples of the above-described bacteria of the genus Lactococcus include Lactococcus lactis subsp. lactis JCM 5805 (hereinafter sometimes referred to as JCM 5805), Lactococcus lactis subsp. lactis NBRC 12007, Lactococcus lactis subsp. lactis NRIC 1150, Lactococcus lactis subsp. lactis JCM 20101, Lactococcus lactis subsp. lactis JCM 7638, Lactococcus lactis subsp. lactis ATCC 7963, Lactococcus lactis subsp. lactis ATCC 7962, Lactococcus lactis subsp. lactis ATCC 29146, Lactococcus lactis subsp. lactis ATCC 27861, Lactococcus lactis subsp. lactis ATCC 19435, Lactococcus lactis subsp. lactis ATCC 15577, Lactococcus lactis subsp. lactis ATCC 15346, Lactococcus lactis subsp. lactis ATCC 13675, Lactococcus lactis subsp. lactis ATCC 12929, Lactococcus lactis subsp. lactis ATCC 11955, Lactococcus lactis subsp. lactis ATCC 11454, Lactococcus lactis subsp. lactis ATCC 11007, Lactococcus garvieae NBRC 100934, Lactococcus lactis subsp. cremoris JCM 16167, Lactococcus lactis subsp. cremoris NBRC 100676, Lactococcus lactis subsp. hordniae JCM 1180, Lactococcus lactis subsp. hordniae JCM 11040, Lactococcus curvatus JCM 1096, and Lactococcus plantarum JCM 11056 and the like.

[0034] Examples of the above-described bacteria of the genus Leuconostoc include, but are not particularly limited to, Leuconostoc carnosum and Leuconostoc lactis and the like. Specific examples of bacteria of the genus Leuconostoc include Leuconostoc carnosum JCM 9695 and Leuconostoc lactis NBRC 12455 and the like.

[0035] Examples of the above-described bacteria of the genus Pediococcus include, but are not particularly limited to, Pediococcus acidilactici, Pediococcus pentosaceus, Pediococcus cellicola, Pediococcus claussenii, Pediococcus damnosus, Pediococcus ethanolidurans, Pediococcus inopinatus, Pediococcus parvulus, and Pediococcus stilesii and the like. Specific examples of bacteria of the genus Pediococcus include, for example, Pediococcus acidilactici JCM 8797, Pediococcus acidilactici K15, and Pediococcus damnosus JCM 5886 and the like.

[0036] Examples of the above-described bacteria of the genus Streptococcus include, but are not particularly limited to, Streptococcus thermophilus and the like. Specific examples of bacteria of the genus Pediococcus include, for example, Streptococcus thermophilus SBC 8781 and the like.

[0037] Examples of the above-described bacteria of the genus Enterococcus include, but are not particularly limited to, Enterococcus alcedinis and Enterococcus faecalis and the like. Specific examples of bacteria of the genus Enterococcus include Enterococcus faecalis EC-12 and the like.

[0038] Examples of the above-described bacteria of the genus Lactobacillus include, but are not particularly limited to, Lactobacillus paracasei, Lactobacillus paracasei subsp. paracasei, Lacticaseibacillus paracasei subsp. paracasei, Lactobacillus delbrueckii, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus fructivorans, Lactobacillus hilgardii, Lactobacillus rhamnosus, Lacticaseibacillus rhamnosus, Lactobacillus gasseri, Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus parakefiri, Lentilactobacillus parakefiri, Lactobacillus plantarum, Lactiplantibacillus plantarum, Lactobacillus plantarum subsp. plantarum, Lactiplantibacillus plantarum subsp. plantarum, Lactobacillus pentosus, Lactiplantibacillus pentosus, Lactobacillus helveticus, Limosilactobacillus reuteri subsp. reuteri, Lactobacillus crispatus, Lactobacillus paraplantarum, Lactiplantibacillus paraplantarum, and Lactobacillus johnsonii and the like.

[0039] Specific examples of bacteria of the genus Lactobacillus include Lactobacillus paracasei KW3110, Lactobacillus paracasei MCC1849, Lactobacillus paracasei K71, Lactobacillus paracasei K-2, Lactobacillus rhamnosus GG, Lactobacillus rhamnosus CRL1505, Lactobacillus gasseri SBT2055, Lactobacillus acidophilus L-92, Lactobacillus casei subsp. casei 327, Lactobacillus (Lacticaseibacillus in the new classification) casei Shirota, Lactobacillus bulgaricus OLL1073R-1, Lactobacillus parakefiri (Lentilactobacillus parakefiri in the new classification) JCM 8573, Lactobacillus plantarum (Lactiplantibacillus plantarum in the new classification) L-137, Lactobacillus pentosus (Lactiplantibacillus pentosus in the new classification) ONRICb0240, Lactobacillus paraplantarum (Lactiplantibacillus paraplantarum in the new classification) JCM 1149, Lactobacillus acidophilus JCM 1021, Lactobacillus acidophilus JCM 1132, Lactobacillus helveticus JCM 1003, Limosilactobacillus reuteri subsp. reuteri JCM 1112, Lactobacillus crispatus JCM 1185, and Lactobacillus johnsonii JCM 2012 and the like.

[0040] Examples of the above-described bacteria of the genus Bacillus include, but are not particularly limited to, Bacillus coagulans and the like. Specific examples of bacteria of the genus Bacillus include, for example, Bacillus coagulans SANK 70258 strain and the like.

[0041] Examples of bacteria of the genus Heyndrickxia include, but are not particularly limited to, Heyndrickxia coagulans (also known as Bacillus coagulans) and the like. Specific examples of bacteria of the genus Heyndrickxia include, for example, Heyndrickxia (Bacillus) coagulans SANK 70258 and Heyndrickxia (Bacillus) coagulans BC99 and the like.

[0042] Acetic acid bacteria are bacteria that produce acetic acid as a metabolite. Examples of acetic acid bacteria include, but are not particularly limited to, bacteria of the genus Gluconacetobacter, bacteria of the genus Acetobacter, and bacteria of the genus Gluconobacter and the like, with bacteria of the genus Gluconacetobacter being preferred, Gluconacetobacter hansenii being more preferred, and Gluconacetobacter hansenii GK-1 being even more preferred.

[0043] In addition to the above, lactic acid bacteria may be bacteria of the genus Akkermansia, bacteria of the genus Bacteroides, bacteria of the genus Blautia, bacteria of the genus Clostridium, bacteria of the genus Collinsella, bacteria of the genus Faecalibacterium, bacteria of the genus Faecalicatena, bacteria of the genus Lacrimispora, bacteria of the genus Paeniclostridium, bacteria of the genus Parabacteroides, or bacteria of the genus Roseburia.

[0044] Specific examples of bacteria of the genus Akkermansia include, for example, Akkermansia muciniphila JCM 30893 and the like.

[0045] Specific examples of bacteria of the genus Bacteroides include, for example, Bacteroides caccae JCM 9498T, Bacteroides fragilis JCM 11019T, Bacteroides fragilis JCM 11017, Bacteroides fragilis JCM 17586, Bacteroides fragilis JCM 17587, Bacteroides ovatus JCM 5824T, Bacteroides thetaiotaomicron ATCC 29148T, Bacteroides thetaiotaomicron ATCC 29741, Bacteroides thetaiotaomicron ATCC 12290, Bacteroides uniformis JCM 5828T, Bacteroides uniformis JCM 13286, Bacteroides uniformis JCM 13287, and Bacteroides uniformis JCM 13288 and the like.

[0046] Specific examples of bacteria of the genus Blautia include, for example, Blautia acetigigens JCM 34803T, Blautia ammoniilytica JCM 34802T, Blautia argi JCM 31394T, Blautia caecimuris JCM 34498T, Blautia coccoides JCM 1395T, Blautia faecis JCM 17205T, Blautia gluceracea JCM 17039T, Blautia hansenii JCM 14655, Blautia hansenii JCM 35484, Blautia hominis JCM 32276T, Blautia hydrogenotrophica JCM 31266, Blautia liquoris JCM 34225T, Blautia luti JCM 17040T, Blautia obeum JCM 31340, Blautia producta JCM 1471T, Blautia pseudococcoides JCM 35243T, Blautia schinkii JCM 14657T, Blautia wexlerae JCM 31267, and Blautia wexlerae JCM 35486 and the like.

[0047] Specific examples of bacteria of the genus Clostridium include, for example, Clostridium butyricum JCM NT, Clostridium nexile JCM 31500T, and Clostridium symbiosum JCM 1297T and the like.

[0048] Specific examples of bacteria of the genus Collinsella include, for example, Collinsella aerofaciens JCM 10188T, Collinsella intestinalis JCM 10643T, Collinsella stercoris JCM 10641T, and Collinsella tanakaei JCM 16071T and the like.

[0049] Specific examples of bacteria of the genus Faecalibacterium include, for example, Faecalibacterium hattorii JCM 39210, Faecalibacterium longum JCM 39208, Faecalibacterium prausnitzii JCM 31915, Faecalibacterium prausnitzii JCM 39207, and Faecalibacterium prausnitzii JCM 39209 and the like.

[0050] Specific examples of bacteria of the genus Faecalicatena include, for example, Faecalicatena orotica JCM 1429T and the like.

[0051] Specific examples of bacteria of the genus Lacrimispora include, for example, Lacrimispora celerecrescens JCM 15734T, Lacrimispora sphenoides JCM 1415T, and Lacrimispora xylanolytica JCM 15735T and the like.

[0052] Specific examples of bacteria of the genus Paeniclostridium include, for example, Paeniclostridium sordellii JCM 3814T and the like.

[0053] Specific examples of bacteria of the genus Parabacteroides include, for example, Parabacteroides merdae JCM 9497T and the like.

[0054] Specific examples of bacteria of the genus Roseburia include, for example, Roseburia hominis JCM 17582, Roseburia intestinalis JCM 17583, and Roseburia inulinivorans JCM 17584 and the like.

[0055] The bacterium according to one preferred aspect may be at least one bacterium selected from the group consisting of Lactobacillus rhamnosus CRL1505 or a mutant strain thereof, Gluconacetobacter hansenii or a mutant strain thereof, Lactobacillus acidophilus (GK-1) L-92 or a mutant strain thereof, Lactobacillus plantarum L-137 or a mutant strain thereof, Lactobacillus bulgaricus OLL1073R-1 or a mutant strain thereof, and Lactococcus lactis subsp. lactis JCM 5805 or a mutant strain thereof.

[0056] Among the above-described lactic acid bacteria and acetic acid bacteria, JCM strains can be obtained from the RIKEN BioResource Center, Microorganism Division (3-1-1 Koyadai, Tsukuba, Ibaraki), NBRC strains can be obtained from the Biological Resource Center, National Institute of Technology and Evaluation (2-5-8 Kazusakamatari, Kisarazu, Chiba), NRIC strains can be obtained from the Culture Collection, Tokyo University of Agriculture (1-1-1 Sakuragaoka, Setagaya, Tokyo), and ATCC strains can be obtained from the American Type Culture Collection (10801 University Boulevard, Manassas, Virginia, USA), respectively. In addition, the above-described lactic acid bacteria and acetic acid bacteria can be obtained not only from public institutions but also by isolating or purifying them from commercially available products containing lactic acid bacteria or acetic acid bacteria using known methods.

[0057] The above-described JCM strains can be obtained from the RIKEN BioResource Center, Microorganism Division as described above, but in the present invention, the same strains as the above-described JCM strains stored at storage institutions other than the RIKEN BioResource Center, Microorganism Division can be used. Specifically, the same strain as Lactococcus lactis subsp. lactis JCM 5805 can be obtained from the Biological Resource Center, National Institute of Technology and Evaluation (2-5-8 Kazusakamatari, Kisarazu, Chiba), the Culture Collection, Tokyo University of Agriculture (1-1-1 Sakuragaoka, Setagaya, Tokyo), the American Type Culture Collection (10801 University Boulevard, Manassas, Virginia, USA), and the like. Lactococcus lactis subsp. lactis JCM 5805 has been deposited with the American Type Culture Collection as Lactococcus lactis subsp. lactis ATCC 9936 and Lactococcus lactis subsp. lactis ATCC 19435.

[0058] The above-described mutant strains may be any strains having characteristics (for example, immunostimulatory activity and the like) capable of achieving the objectives of the present technology. In addition, the mutant strain is preferably a bacterium having the same bacteriological properties as the above-described strain and having immunostimulatory activity equal to or greater than that of the above-described strain. Whether or not a mutant strain has immunostimulatory activity equal to or greater than that of the above-described strain can be confirmed, for example, by the evaluation method described below or the method of the examples described below.

[0059] Such a mutant strain may be constructed by non-artificially introducing a mutation into the above-described strain. In addition, such a mutant strain may be constructed by artificially introducing a mutation into the above-described strain, and may be constructed, for example, by introducing a mutation into the above-described bacterium by treatment with a mutagen such as ultraviolet (UV) light or a DNA alkylating agent, or may be constructed by introducing a mutation into the above-described strain by a genetic manipulation method such as known genetic recombination or gene editing represented by CRISPR-Cas9.

[0060] The bacterium according to the present embodiment can be cultured by a conventional method according to its bacterial species. For example, when the above-described bacterium is a lactic acid bacterium or an acetic acid bacterium, it can be carried out by a known method using a known medium. The medium is not particularly limited as long as it is a medium capable of growing the above-described bacterium, but for example, a medium prepared by appropriately adding plant extracts to MRS medium, GAM medium, or M17 medium can be used, and inorganic salts, vitamins, and / or amino acids and the like may be added as appropriate. Culturing can be carried out at 25 to 40°C for several hours to several days.

[0061] The effective amount of bacteria contained in the composition according to the present embodiment is not particularly limited as long as it is an amount capable of exerting immunostimulatory activity, and may vary depending on the subject of application; when the subject of application is a mammal such as a human, the lower limit thereof can be, for example, 1*108 cells, 1*109 cells, or 1*1010 cells, and the upper limit thereof can be, for example, 1*1014 cells, 1*1013 cells, or 1*1012 cells. These upper and lower limits can each be combined arbitrarily, and the range of the above-described intake amount can be, for example, 1*108 or more and 1*1014 cells or less, 1*108 or more and 1*1013 cells or less, 1*108 or more and 1*1012 cells or less, 1*109 or more and 1*1014 cells or less, 1x109 or more and 1*1013 cells or less, 1*1010 or more and 1*1014 cells or less, 1*1010 or more and 1*1013 cells or less, or 1*1010 or more and 1x1012 cells or less. The number of bacteria can be measured by a known microscope, flow cytometer, or non-culture rapid microbial testing device (for example, ELESTA PixeeMo (AFI Technology Co., Ltd.)) and the like, but measurement by microscope is preferred from the viewpoint of versatility. The composition having immunostimulatory activity may be used, for example, in the form of a food composition, a pharmaceutical composition, a quasi-drug, a bacterial powder (a powder obtained by drying bacterial cells or a powder containing the same and the like), or a feed and the like.

[0062] The content of the bacterium having immunostimulatory activity in the immunostimulatory composition according to one embodiment is not particularly limited and may be any amount that satisfies the effective amount for immunostimulation, and therefore may vary depending on the form of the immunostimulatory composition according to the present embodiment. For example, the dry mass of the bacterium according to the present embodiment relative to the total mass of the immunostimulatory composition according to the present embodiment may be 0.0001% by mass or more, 0.001% by mass or more, 0.005% by mass or more, 0.01% by mass or more, 0.02% by mass or more, 0.05% by mass or more, 0.10% by mass or more, 0.30% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 7.0% by mass or more, or 10.0% by mass or more, and may be less than 100% by mass, 95% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, or 15% by mass or less.

[0063] These lower and upper limits can each be combined arbitrarily, and for example, the dry mass of the bacterium according to the present embodiment relative to the total mass of the immunostimulatory composition according to the present embodiment may be 0.0001% by mass or more and less than 100% by mass, 0.0001% by mass or more and 95% by mass or less, 0.0001% by mass or more and 90% by mass or less, 0.0001% by mass or more and 80% by mass or less, 0.0001% by mass or more and 70% by mass or less, 0.0001% by mass or more and 60% by mass or less, 0.0001% by mass or more and 50% by mass or less, 0.0001% by mass or more and 30% by mass or less, 0.0001% by mass or more and 25% by mass or less, 0.0001% by mass or more and 20% by mass or less, 0.0001% by mass or more and 15% by mass or less, 0.001% by mass or more and less than 100% by mass, 0.001% by mass or more and 95% by mass or less, 0.001% by mass or more and 90% by mass or less, 0.001% by mass or more and 80% by mass or less, 0.001% by mass or more and 70% by mass or less, 0.001% by mass or more and 60% by mass or less, 0.001% by mass or more and 50% by mass or less, 0.001% by mass or more and 30% by mass or less, 0.001% by mass or more and 25% by mass or less, 0.001% by mass or more and 20% by mass or less, 0.001% by mass or more and 15% by mass or less, 0.005% by mass or more and less than 100% by mass, 0.005% by mass or more and 95% by mass or less, 0.005% by mass or more and 90% by mass or less, 0.005% by mass or more and 80% by mass or less, 0.005% by mass or more and 70% by mass or less, 0.005% by mass or more and 60% by mass or less, 0.005% by mass or more and 50% by mass or less, 0.005% by mass or more and 30% by mass or less, 0.005% by mass or more and 25% by mass or less, 0.005% by mass or more and 20% by mass or less, 0.005% by mass or more and 15% by mass or less, 0.01% by mass or more and less than 100% by mass, 0.01% by mass or more and 95% by mass or less, 0.01% by mass or more and 90% by mass or less, 0.01% by mass or more and 80% by mass or less, 0.01% by mass or more and 70% by mass or less, 0.01% by mass or more and 60% by mass or less, 0.01% by mass or more and 50% by mass or less, 0.01% by mass or more and 30% by mass or less, 0.01% by mass or more and 25% by mass or less, 0.01% by mass or more and 20% by mass or less, 0.01% by mass or more and 15% by mass or less, 0.02% by mass or more and less than 100% by mass, 0.02% by mass or more and 95% by mass or less, 0.02% by mass or more and 90% by mass or less, 0.02% by mass or more and 80% by mass or less, 0.02% by mass or more and 70% by mass or less, 0.02% by mass or more and 60% by mass or less, 0.02% by mass or more and 50% by mass or less, 0.02% by mass or more and 30% by mass or less, 0.02% by mass or more and 25% by mass or less, 0.02% by mass or more and 20% by mass or less, 0.02% by mass or more and 15% by mass or less, 0.05% by mass or more and less than 100% by mass, 0.05% by mass or more and 95% by mass or less, 0.05% by mass or more and 90% by mass or less, 0.05% by mass or more and 80% by mass or less, 0.05% by mass or more and 70% by mass or less, 0.05% by mass or more and 60% by mass or less, 0.05% by mass or more and 50% by mass or less, 0.05% by mass or more and 30% by mass or less, 0.05% by mass or more and 25% by mass or less, 0.05% by mass or more and 20% by mass or less, 0.05% by mass or more and 15% by mass or less, 0.10% by mass or more and less than 100% by mass, 0.10% by mass or more and 95% by mass or less, 0.10% by mass or more and 90% by mass or less, 0.10% by mass or more and 80% by mass or less, 0.10% by mass or more and 70% by mass or less, 0.10% by mass or more and 60% by mass or less, 0.10% by mass or more and 50% by mass or less, 0.10% by mass or more and 30% by mass or less, 0.10% by mass or more and 25% by mass or less, 0.10% by mass or more and 20% by mass or less, 0.10% by mass or more and 15% by mass or less, 0.30% by mass or more and less than 100% by mass, 0.30% by mass or more and 95% by mass or less, 0.30% by mass or more and 90% by mass or less, 0.30% by mass or more and 80% by mass or less, 0.30% by mass or more and 70% by mass or less, 0.30% by mass or more and 60% by mass or less, 0.30% by mass or more and 50% by mass or less, 0.30% by mass or more and 30% by mass or less, 0.30% by mass or more and 25% by mass or less, 0.30% by mass or more and 20% by mass or less, 0.30% by mass or more and 15% by mass or less, 1.0% by mass or more and less than 100% by mass, 1.0% by mass or more and 95% by mass or less, 1.0% by mass or more and 90% by mass or less, 1.0% by mass or more and 80% by mass or less, 1.0% by mass or more and 70% by mass or less, 1.0% by mass or more and 60% by mass or less, 1.0% by mass or more and 50% by mass or less, 1.0% by mass or more and 30% by mass or less, 1.0% by mass or more and 25% by mass or less, 1.0% by mass or more and 20% by mass or less, 1.0% by mass or more and 15% by mass or less, 1.5% by mass or more and less than 100% by mass, 1.5% by mass or more and 95% by mass or less, 1.5% by mass or more and 90% by mass or less, 1.5% by mass or more and 80% by mass or less, 1.5% by mass or more and 70% by mass or less, 1.5% by mass or more and 60% by mass or less, 1.5% by mass or more and 50% by mass or less, 1.5% by mass or more and 30% by mass or less, 1.5% by mass or more and 25% by mass or less, 1.5% by mass or more and 20% by mass or less, 1.5% by mass or more and 15% by mass or less, 2.0% by mass or more and less than 100% by mass, 2.0% by mass or more and 95% by mass or less, 2.0% by mass or more and 90% by mass or less, 2.0% by mass or more and 80% by mass or less, 2.0% by mass or more and 70% by mass or less, 2.0% by mass or more and 60% by mass or less, 2.0% by mass or more and 50% by mass or less, 2.0% by mass or more and 30% by mass or less, 2.0% by mass or more and 25% by mass or less, 2.0% by mass or more and 20% by mass or less, 2.0% by mass or more and 15% by mass or less, 2.5% by mass or more and less than 100% by mass, 2.5% by mass or more and 95% by mass or less, 2.5% by mass or more and 90% by mass or less, 2.5% by mass or more and 80% by mass or less, 2.5% by mass or more and 70% by mass or less, 2.5% by mass or more and 60% by mass or less, 2.5% by mass or more and 50% by mass or less, 2.5% by mass or more and 30% by mass or less, 2.5% by mass or more and 25% by mass or less, 2.5% by mass or more and 20% by mass or less, 2.5% by mass or more and 15% by mass or less, 3.0% by mass or more and less than 100% by mass, 3.0% by mass or more and 95% by mass or less, 3.0% by mass or more and 90% by mass or less, 3.0% by mass or more and 80% by mass or less, 3.0% by mass or more and 70% by mass or less, 3.0% by mass or more and 60% by mass or less, 3.0% by mass or more and 50% by mass or less, 3.0% by mass or more and 30% by mass or less, 3.0% by mass or more and 25% by mass or less, 3.0% by mass or more and 20% by mass or less, 3.0% by mass or more and 15% by mass or less, 5.0% by mass or more and less than 100% by mass, 5.0% by mass or more and 95% by mass or less, 5.0% by mass or more and 90% by mass or less, 5.0% by mass or more and 80% by mass or less, 5.0% by mass or more and 70% by mass or less, 5.0% by mass or more and 60% by mass or less, 5.0% by mass or more and 50% by mass or less, 5.0% by mass or more and 30% by mass or less, 5.0% by mass or more and 25% by mass or less, 5.0% by mass or more and 20% by mass or less, 5.0% by mass or more and 15% by mass or less, 7.0% by mass or more and less than 100% by mass, 7.0% by mass or more and 95% by mass or less, 7.0% by mass or more and 90% by mass or less, 7.0% by mass or more and 80% by mass or less, 7.0% by mass or more and 70% by mass or less, 7.0% by mass or more and 60% by mass or less, 7.0% by mass or more and 50% by mass or less, 7.0% by mass or more and 30% by mass or less, 7.0% by mass or more and 25% by mass or less, 7.0% by mass or more and 20% by mass or less, 7.0% by mass or more and 15% by mass or less, 10.0% by mass or more and less than 100% by mass, 10.0% by mass or more and 95% by mass or less, 10.0% by mass or more and 90% by mass or less, 10.0% by mass or more and 80% by mass or less, 10.0% by mass or more and 70% by mass or less, 10.0% by mass or more and 60% by mass or less, 10.0% by mass or more and 50% by mass or less, 10.0% by mass or more and 30% by mass or less, 10.0% by mass or more and 25% by mass or less, 10.0% by mass or more and 20% by mass or less, or 10.0% by mass or more and 15% by mass or less. The above-described dry mass of the bacterium according to the present embodiment can be used, for example, as a daily dose for an adult weighing 60 kg. The dose can be set according to factors such as the health condition of the person receiving or ingesting the dose, the method of administration or ingestion, and the combination with other agents.

[0064] The number of bacteria having immunostimulatory activity in the immunostimulatory composition according to the present embodiment may be 1.0*103 cells / mL or more, 1.0*104 cells / mL or more, 1.0*105 cells / mL or more, 1.0*106 cells / mL or more, 1.0*107 cells / mL or more, or 4.0*107 cells / mL or more, and may be 1.0*1011 cells / mL or less, 1.0*1010 cells / mL or less, 3.0*109 cells / mL or less, or 1.0*109 cells / mL or less. These lower and upper limits can each be combined arbitrarily, and for example, the number of bacteria having immunostimulatory activity in the immunostimulatory composition according to the present embodiment may be 1.0*103 cells / mL or more and 1.0*1011 cells / mL or less, 1.0*103 cells / mL or more and 1.0*1010 cells / mL or less, 1.0*103 cells / mL or more and 3.0*109 cells / mL or less, 1.0*103 cells / mL or more and 1.0*109 cells / mL or less, 1.0*104 cells / mL or more and 1.0*1011 cells / mL or less, 1.0*104 cells / mL or more and 1.0*1010 cells / mL or less, 1.0*104 cells / mL or more and 3.0*109 cells / mL or less, 1.0*104 cells / mL or more and 1.0*109 cells / mL or less, 1.0*105 cells / mL or more and 1.0*1011 cells / mL or less, 1.0*105 cells / mL or more and 1.0*1010 cells / mL or less, 1.0*105 cells / mL or more and 3.0*109 cells / mL or less, 1.0*105 cells / mL or more and 1.0*109 cells / mL or less, 1.0*106 cells / mL or more and 1.0*1011 cells / mL or less, 1.0*106 cells / mL or more and 1.0*1010 cells / mL or less, 1.0*106 cells / mL or more and 3.0*109 cells / mL or less, 1.0*107 cells / mL or more and 1.0*1011 cells / mL or less, 1.0*107 cells / mL or more and 1.0*1010 cells / mL or less, 1.0*107 cells / mL or more and 1.0*109 cells / mL or less, 4.0*107 cells / mL or more and 1.0*1011 cells / mL or less, 4.0*107 cells / mL or more and 1.0*1010 cells / mL or less, or 4.0*107 cells / mL or more and 1.0*109 cells / mL or less. In this case, the daily intake of the liquid immunostimulatory composition may be 10 mL or more and 1,000 mL or less, 30 mL or more and 800 mL or less, 50 mL or more and 500 mL or less, or 100 mL or more and 250 mL or less.

[0065] In the immunostimulatory composition according to the present embodiment, the number of bacteria having immunostimulatory activity in the immunostimulatory composition according to one embodiment per unit package may be 1.0*107 cells or more, 1.0*108 cells or more, 3.0*108 cells or more, 5.0*108 cells or more, 1.0*109 cells or more, 5.0*109 cells or more, 1.0*1010 cells or more, 5.0*1010 cells or more, or 1.0*1011 cells or more, and may be 1.0*1014 cells or less, 1.0*1013 cells or less, or 1.0*1012 cells or less. These upper and lower limits can each be combined arbitrarily, and for example, the number of bacteria according to the present embodiment per unit package in the immunostimulatory composition according to the present embodiment may be 1.0*107 or more and 1.0*1014 cells or less, 1.0*107 or more and 1.0*1013 cells or less, 1.0*107 or more and 1.0*1012 cells or less, 1.0*108 or more and 1.0*1014 cells or less, 1.0*108 or more and 1.0*1013 cells or less, 1.0*108 or more and 1.0*1012 cells or less, 3.0*108 or more and 1.0*1014 cells or less, 3.0*108 or more and 1.0*1013 cells or less, 3.0*108 or more and 1.0*1012 cells or less, 5.0*108 or more and 1.0*1014 cells or less, 5.0*108 or more and 1.0*1013 cells or less, 5.0*108 or more and 1.0*1012 cells or less, 1.0*109 or more and 1.0*1014 cells or less, 1.0*109 or more and 1.0*1013 cells or less, 1.0*109 or more and 1.0*1012 cells or less, 5.0*109 or more and 1.0*1014 cells or less, 5.0*109 or more and 1.0*1013 cells or less, 5.0*109 or more and 1.0*1012 cells or less, 1.0*1010 or more and 1.0*1013 cells or less, 5.0*1010 or more and 5.0*1013 cells or less, 1.0*1011 or more and 1.0*1014 cells or less, 1.0*1010 or more and 1.0*1014 cells or less, 5.0*1010 or more and 1.0*1014 cells or less, 1.0*1010 or more and 1.0*1012 cells or less, 5.0*1010 or more and 1.0*1012 cells or less, 1.0*1011 or more and 1.0*1013 cells or less, or 1.0*1011 or more and 1.0*1012 cells or less.

[0066] In the present specification, “plant extract” means an extract obtained from any part of a plant and / or a processed product thereof as a raw material, and may be an extract obtained by pressing a plant or an extract obtained by leaching a plant in a solvent. “Plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity” means a plant extract having an action of enhancing the immunostimulatory action by a bacterium having immunostimulatory activity, and may be a plant extract that, when the plant extract, a bacterium having immunostimulatory activity, and immune cells are co-cultured, results in a higher degree of immunostimulatory action as compared with a case where only the bacterium having immunostimulatory activity and immune cells are co-cultured.

[0067] Examples of plants include, but are not particularly limited to, fruits, root vegetables, grains, legumes, or herbaceous plants.

[0068] Examples of plants used for extraction include the whole plant, or the fruit, pericarp, rhizome, bulb, leaf, flower, or seed of a plant. The plant may have been subjected to treatments such as roasting, aging, drying, freezing, processing, pulverizing, and sorting.

[0069] Examples of solvents used for extraction include aqueous media and organic solvents and the like. “Aqueous medium” means a liquid having water as an essential component, and examples include water, physiological saline such as phosphate-buffered saline (PBS), and microbial culture media and the like. Examples of organic solvents include methanol and ethanol and the like.

[0070] The method for determining whether or not the plant extract according to the present embodiment has an immunostimulatory activity-enhancing action on bacteria is not particularly limited, and if the function of immune cells in the presence of a bacterium having immunostimulatory action is enhanced in the presence of the plant extract as compared with the absence of the plant extract, it is determined that the plant extract has an immunostimulatory activity-enhancing action on the above-described bacterium. Whether or not the plant extract according to the present embodiment has an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory action can be confirmed, as a more detailed example, by an increase in the IFN-a concentration measured according to the following procedures (i') to (iv') in the presence of the plant extract as compared with the absence of the plant extract. (i') Mouse-derived bone marrow cells from which erythrocytes have been removed are suspended in RPMI medium prepared so that each component described in the following (Composition of medium) reaches the respective final concentration described in the following (Composition of medium), to a concentration of 1*106 cells / mL, to prepare a cell suspension. <Composition of medium> • 10% by volume FBS • 100 U / mL penicillin / streptomycin • 1 mM sodium pyruvate • 2.5 mM HEPES • 1% by mass non-essential amino acids for MEM (NEAA) • 50 pM p-mercaptoethanol • 100 ng / mL Flt-3L (ii') The prepared cell suspension is seeded at 1 mL each, and cultured for one week at 37°C and 5% by volume CO2 in a CO2 incubator to induce pDCs. (iii') Bone marrow cells containing the induced pDCs are suspended to a concentration of 2*105 cells / mL, seeded at 200 pL each into a 96-well plate, and 2 pL each of a bacterial suspension adjusted to a concentration of 1 mg / mL with PBS is added, and further, a plant extract solution adjusted to a predetermined concentration is added. (iv') After 24 hours, the culture supernatant is collected, and the IFN-a concentration is measured by ELISA using an IFN-a measurement kit.

[0071] Examples of plant extracts include plant extracts belonging to the family Bromeliaceae (for example, pineapple extract and the like), plant extracts belonging to the family Hypericaceae (for example, mangosteen extract and St. John’s wort extract and the like), plant extracts belonging to the family Brassicaceae (for example, maca extract and kale extract and the like), plant extracts belonging to the family Poaceae (for example, fermented rice germ extract and the like), plant extracts belonging to the family Fabaceae (for example, fermented soybean extract and carob extract and the like), plant extracts belonging to the family Asteraceae (for example, chrysanthemum extract and the like), plant extracts belonging to the family Zingiberaceae (for example, ginger extract and the like), plant extracts belonging to the family Cannabaceae (for example, hop extract and the like), plant extracts belonging to the family Araliaceae (for example, red ginseng extract and the like), plant extracts belonging to the family Clusiaceae (for example, garcinia extract and the like), plant extracts belonging to the family Lamiaceae (for example, rafuma extract and the like), and plant extracts belonging to the family Lauraceae (for example, laurel extract and the like).

[0072] As plant extracts having an immunostimulation-enhancing action, preferred are plant extracts belonging to the family Bromeliaceae (for example, pineapple extract and the like), plant extracts belonging to the family Hypericaceae (mangosteen extract and St. John’s wort extract and the like), plant extracts belonging to the family Brassicaceae (for example, maca extract and the like), plant extracts belonging to the family Poaceae (for example, fermented rice germ extract and the like), plant extracts belonging to the family Fabaceae (for example, fermented soybean extract and carob extract and the like), plant extracts belonging to the family Asteraceae (for example, chrysanthemum extract and the like), plant extracts belonging to the family Zingiberaceae (for example, ginger extract and the like), plant extracts belonging to the family Cannabaceae (for example, hop extract and the like), plant extracts belonging to the family Araliaceae (for example, red ginseng extract and the like), plant extracts belonging to the family Clusiaceae, plant extracts belonging to the family Lamiaceae, and plant extracts belonging to the family Lauraceae.

[0073] The plant extract in the immunostimulatory composition according to one embodiment may be a plant extract belonging to the genus Ananas (for example, pineapple extract and the like), a plant extract belonging to the genus Garcinia (for example, mangosteen extract and the like), a plant extract belonging to the genus Lepidium (for example, maca extract and the like), a plant extract belonging to the genus Oryza (for example, fermented rice germ extract and the like), a plant extract belonging to the genus Glycine (for example, fermented soybean extract and the like), a plant extract belonging to the genus Hypericum (for example, St. John’s wort extract and the like), a plant extract belonging to the genus Chrysanthemum (for example, chrysanthemum extract and the like), a plant extract belonging to the genus Ceratonia (for example, carob extract and the like), a plant extract belonging to the genus Zingiber (for example, ginger extract and the like), a plant extract belonging to the genus Humulus (for example, hop extract and the like), a plant extract belonging to the genus Panax (for example, red ginseng extract and the like), a plant extract belonging to the genus Brassica (for example, kale extract and the like), a plant extract belonging to the genus Garcinia (for example, garcinia extract and the like), a plant extract belonging to the genus Melissa (for example, rafuma extract and the like), or a plant extract belonging to the genus Laurus (for example, laurel extract and the like).

[0074] As plant extracts having an immunostimulation-enhancing action, preferred are a plant extract belonging to the genus Ananas (for example, pineapple extract and the like), a plant extract belonging to the genus Garcinia (for example, mangosteen extract and the like), a plant extract belonging to the genus Lepidium (for example, maca extract and the like), a plant extract belonging to the genus Oryza (for example, fermented rice germ extract and the like), a plant extract belonging to the genus Glycine (for example, fermented soybean extract and the like), a plant extract belonging to the genus Hypericum (for example, St. John’s wort extract and the like), a plant extract belonging to the genus Chrysanthemum (for example, chrysanthemum extract and the like), a plant extract belonging to the genus Ceratonia (for example, carob extract and the like), a plant extract belonging to the genus Zingiber (for example, ginger extract and the like), a plant extract belonging to the genus Humulus (for example, hop extract and the like), a plant extract belonging to the genus Panax (for example, red ginseng extract and the like), a plant extract belonging to the genus Brassica, a plant extract belonging to the genus Garcinia, a plant extract belonging to the genus Melissa, and a plant extract belonging to the genus Laurus.

[0075] Examples of plant extracts include plant extracts used as skin barrier function-improving agents (for example, pineapple extract, mangosteen extract, and maca extract and the like), plant extracts used as fatigue recovery agents (for example, pineapple extract, maca extract, and kale extract and the like), plant extracts used as anti-aging agents (for example, pineapple extract, maca extract, chrysanthemum extract, and kale extract and the like), plant extracts used as menopausal disorder-improving agents (for example, maca extract and hop extract and the like), plant extracts used as arteriosclerosis-preventing agents (for example, maca extract and kale extract and the like), plant extracts used as anti-inflammatory agents (for example, ginger extract, garcinia extract, and laurel extract and the like), plant extracts used as immunostimulatory agents (for example, ginger extract and kale extract and the like), plant extracts used as antibacterial agents (for example, ginger extract and hop extract and the like), plant extracts used as body fat-reducing agents (for example, hop extract and garcinia extract and the like), and plant extracts used as brain function-improving agents (for example, maca extract and hop extract and the like) and the like.

[0076] As plant extracts having an immunostimulatory-enhancing action, preferred are plant extracts used as skin barrier function-improving agents (for example, pineapple extract, mangosteen extract, and maca extract and the like), plant extracts used as fatigue recovery agents (for example, pineapple extract and maca extract and the like), plant extracts used as anti-aging agents (for example, pineapple extract, maca extract, and chrysanthemum extract and the like), plant extracts used as menopausal disorder-improving agents (for example, maca extract and hop extract and the like), plant extracts used as arteriosclerosis-preventing agents (for example, maca extract and the like), plant extracts used as anti-inflammatory agents (for example, ginger extract and the like), plant extracts used as immunostimulatory agents (for example, ginger extract and the like), plant extracts used as antibacterial agents (for example, ginger extract and hop extract and the like), plant extracts used as body fat-reducing agents (for example, hop extract and the like), and plant extracts used as brain function-improving agents (for example, maca extract and hop extract and the like).

[0077] Examples of plant extracts include plant extracts used as bittering agents (for example, hop extract and the like), plant extracts used as antioxidants (for example, mangosteen extract, ginger extract, kale extract, and garcinia extract and the like), plant extracts used as sweeteners (for example, carob extract and garcinia extract and the like), and plant extracts used as anti-glycation agents (for example, mangosteen extract and herb extract and the like) and the like.

[0078] As plant extracts having an immunostimulatory-enhancing action, preferred are plant extracts used as bittering agents (for example, hop extract and the like), plant extracts used as antioxidants (for example, mangosteen extract and ginger extract and the like), plant extracts used as sweeteners (for example, carob extract and the like), and plant extracts used as anti-glycation agents (for example, mangosteen extract and herb extract and the like) and the like.

[0079] The plant extract in the immunostimulatory composition according to one embodiment may be a pineapple extract, a mangosteen extract, a maca extract, a fermented extract of rice germ and soybean, a St. John’s wort extract, a chrysanthemum extract, an herb extract, a carob extract, a ginger extract, a hop extract, a red ginseng extract, a kale extract, a garcinia extract, a rafuma extract, or a laurel extract and the like, and is preferably one or more plant extracts selected from the group consisting of a pineapple extract, a mangosteen extract, a maca extract, a fermented extract of rice germ and soybean, a St. John’s wort extract, an herb extract, a chrysanthemum extract, a carob extract, a ginger extract, a hop extract, and a red ginseng extract.

[0080] The pineapple extract is preferably a pineapple fruit extract. The pineapple extract may be used in a liquid form or a solid form such as a powder, and for the pineapple fruit extract, a fat-soluble component extracted by heating and refluxing pineapple fruit with an ethanol aqueous solution of 80% by volume or more and 100% by volume or less can be used, and for example, “Brightening Pine (registered trademark)” manufactured by Maruzen Pharmaceuticals Co., Ltd. and the like can be used.

[0081] The mangosteen extract is preferably a mangosteen pericarp extract. The mangosteen extract may be used in a liquid form or a solid form such as a powder, and the mangosteen pericarp extract may be one obtained by boiling mangosteen pericarp, drying it at 70°C for 8 hours, extracting with hot water, filtering, concentrating, and powdering, and for example, “Mangosteen Aqua” manufactured by Nippon Shinyaku Co., Ltd. and the like can be used.

[0082] The maca extract may be used in a liquid form or a solid form such as a powder, and the maca extract may be a material adsorbed on a hyperporous synthetic polymer adsorbent resin obtained by passing an extract obtained from maca with at least one of water and an aqueous ethanol solution through the hyperporous synthetic polymer adsorbent resin, and for example, “MACAXS (registered trademark)” manufactured by TOWA Co., Ltd. and the like can be used.

[0083] The fermented extract of rice germ and soybean may be used in a liquid form or a solid form such as a powder, and may be one obtained by fermenting rice germ and soybean with lactic acid bacteria and then extracting with at least one of water, ethanol, an ethanol aqueous solution, acetone, or hexane without particular limitation, and for example, “Sense Pure (registered trademark)” manufactured by Toyo Hakko and the like can be used.

[0084] The St. John’s wort extract may be used in a liquid form or a solid form such as a powder, and the St. John’s wort extract may be one obtained by extracting St. John’s wort with water, ethanol, or a mixture of water and ethanol, and for example, “St. John’s Wort” manufactured by Fancl Corporation and the like can be used.

[0085] The chrysanthemum extract is preferably a chrysanthemum flower extract. The chrysanthemum extract may be used in a liquid form or a solid form such as a powder, and the chrysanthemum extract may be one obtained by subjecting chrysanthemum flowers to only one of polar solvent extraction and supercritical extraction, and / or both of these, and for example, “Chrysanthemum Flower Extract P” manufactured by Oryza Oil & Fat Chemical Co., Ltd. and the like can be used.

[0086] The herb extract may be used in a liquid form or a solid form such as a powder. The herb extract is preferably a “mixed herb extract” that is a mixture of extracts of a plurality of herbs. The “mixed herb extract” may be one using extracts obtained by hot water extraction from four types of herbs (chamomile, dokudami, hawthorn, and grape leaves), and for example, “AG Herb MIX (registered trademark)” manufactured by Arkray, Inc. and the like can be used.

[0087] The carob extract is preferably a carob pod extract. The carob extract may be used in a liquid form or a solid form such as a powder, and the carob extract may be one obtained by roasting and grinding cultivated carob pods, and for example, “Organic Carob Powder” manufactured by Sakurai Foods Co., Ltd. and the like can be used.

[0088] The ginger extract may be used in a liquid form or a solid form such as a powder, and the ginger extract may be one obtained by extracting the rhizome of Zingiber officinale ROSC. of the family Zingiberaceae with ethanol, acetone, or hexane at room temperature, and for example, “Ginger Extract Powder S” manufactured by Ikeda Tohka Industries Co., Ltd. and the like can be used.

[0089] The hop extract may be used in a liquid form or a solid form such as a powder, and the hop extract can be used as an extract obtained by extraction with a solvent containing water or various organic solvents (lower alcohols having 1 to 4 carbon atoms such as methanol, ethanol, propanol, and butanol; lower alkyl esters such as ethyl acetate; glycols such as ethylene glycol, butylene glycol, propylene glycol, and glycerin; other polar solvents such as acetone and acetic acid; non-polar solvents such as hydrocarbons such as benzene and hexane, and ethers such as ethyl ether and petroleum ether and the like) and the like, or as an extract obtained by supercritical extraction using supercritical carbon dioxide and the like. The extraction temperature with a solvent is preferably 60°C or less from the viewpoint of odor removal, and more preferably 50°C or more and 60°C or less in consideration of extraction efficiency. For the hop extract, for example, “Aged Hop Extract” manufactured by Kirin Holdings Company, Limited and the like can be used.

[0090] The red ginseng extract may be used in a liquid form or a solid form such as a powder, and the aged red ginseng extract may be one obtained by subjecting mainly the root of medicinal ginseng or an extract of the root to heat treatment or fermentation treatment, and for example, a product manufactured by Kanshi Korean Ginseng and the like can be used.

[0091] The kale extract may be used in a liquid form or a solid form such as a powder, and the kale extract may be one obtained by washing kale, and subjecting green leaves, which have been subjected to shearing, blanching treatment, or the like if necessary, to a known juice extraction method after adding water if necessary, and for example, “Koiaona (registered trademark)” manufactured by Nippn Corporation can be used.

[0092] In the present specification, “garcinia extract” means an extract of Garcinia gummi-gutta. The garcinia extract is preferably a garcinia pericarp extract. The garcinia extract may be used in a liquid form or a solid form such as a powder, and the garcinia extract may be one containing hydroxycitric acids obtained by extracting the pericarp of garcinia containing hydroxycitric acids with water or alcohol, and for example, “Garcinia Extract” manufactured by Nippon Shinyaku Co., Ltd. and “Garcinia Powder S” manufactured by Nippon Shinyaku Co., Ltd. and the like can be used.

[0093] The rafuma extract is preferably a rafuma leaf extract. The rafuma extract may be used in a liquid form or a solid form such as a powder, and the rafuma extract may be one obtained by extracting dried leaves of rafuma with water-containing ethanol, followed by purification, concentration, and drying steps, and for example, “Venetron (registered trademark)” manufactured by Tokiwa Phytochemical Co., Ltd. and the like can be used.

[0094] The laurel extract is preferably a laurel leaf extract. The laurel extract may be used in a liquid form or a solid form such as a powder, and the laurel leaf extract may be one obtained by extracting and purifying dried leaves of laurel with at least one of water, ethanol, an ethanol aqueous solution, acetone, or hexane without particular limitation, and for example, “Laureche (registered trademark)” manufactured by Tokiwa Phytochemical Co., Ltd. and the like can be used.

[0095] The immunostimulatory activity-enhancing action of the plant extract according to the present embodiment on bacteria is preferably such that the IFN-a concentration measured according to the above procedures (i') to (iv') in the presence of the plant extract as compared with the absence of the plant extract has a lower limit of 1.01-fold or more, 1.02-fold or more, 1.03-fold or more, 1.05-fold or more, 1.08-fold or more, 1.10-fold or more, 1.13-fold or more, 1.15-fold or more, 1.18-fold or more, 1.20-fold or more, 1.23-fold or more, 1.25-fold or more, 1.28-fold or more, 1.30-fold or more, 1.40-fold or more, 1.50-fold or more, 1.60-fold or more, 1.70-fold or more, 1.80-fold or more, 1.90-fold or more, or 2.0-fold or more, and preferably has an upper limit of 4.0-fold or less, 3.8-fold or less, 3.5-fold or less, 3.3-fold or less, 3.0-fold or less, 2.8-fold or less, 2.5-fold or less, 2.3-fold or less, 2.0-fold or less, 1.80-fold or less, or 1.50-fold or less. These upper and lower limits can each be combined arbitrarily. The immunostimulatory activity-enhancing action of the plant extract according to the present embodiment on bacteria is preferably such that the IFN-a concentration measured according to the above procedures (i') to (iv') in the presence of the plant extract as compared with the absence of the plant extract is, for example, 1.01-fold or more and 4.0-fold or less, 1.01-fold or more and 4.0-fold or less, 1.01-fold or more and 3.8-fold or less, 1.01-fold or more and 3.5-fold or less, 1.01-fold or more and 3.3-fold or less, 1.01-fold or more and 3.0-fold or less, 1.01-fold or more and 2.8-fold or less, 1.01-fold or more and 2.5-fold or less, 1.01-fold or more and 2.3-fold or less, 1.01-fold or more and 2.0-fold or less, 1.01-fold or more and 1.8-fold or less, 1.01-fold or more and 1.5-fold or less, 1.02-fold or more and 4.0-fold or less, 1.02-fold or more and 3.8-fold or less, 1.02-fold or more and 3.5-fold or less, 1.02-fold or more and 3.3-fold or less, 1.02-fold or more and 3.0-fold or less, 1.02-fold or more and 2.8-fold or less, 1.02-fold or more and 2.5-fold or less, 1.02-fold or more and 2.3-fold or less, 1.02-fold or more and 2.0-fold or less, 1.02-fold or more and 1.8-fold or less, 1.02-fold or more and 1.5-fold or less, 1.03-fold or more and 4.0-fold or less, 1.03-fold or more and 3.8-fold or less, 1.03-fold or more and 3.5-fold or less, 1.03-fold or more and 3.3-fold or less, 1.03-fold or more and 3.0-fold or less, 1.03-fold or more and 2.8-fold or less, 1.03-fold or more and 2.5-fold or less, 1.03-fold or more and 2.3-fold or less, 1.03-fold or more and 2.0-fold or less, 1.03-fold or more and 1.8-fold or less, 1.02-fold or more and 1.5-fold or less, 1.05-fold or more and 4.0-fold or less, 1.05-fold or more and 3.8-fold or less, 1.05-fold or more and 3.5-fold or less, 1.05-fold or more and 3.3-fold or less, 1.05-fold or more and 3.0-fold or less, 1.05-fold or more and 2.8-fold or less, 1.05-fold or more and 2.5-fold or less, 1.05-fold or more and 2.3-fold or less, 1.05-fold or more and 2.0-fold or less, 1.05-fold or more and 1.8-fold or less, 1.05-fold or more and 1.5-fold or less, 1.08-fold or more and 4.0-fold or less, 1.08-fold or more and 3.8-fold or less, 1.08-fold or more and 3.5-fold or less, 1.08-fold or more and 3.3-fold or less, 1.08-fold or more and 3.0-fold or less, 1.08-fold or more and 2.8-fold or less, 1.08-fold or more and 2.5-fold or less, 1.08-fold or more and 2.3-fold or less, 1.08-fold or more and 2.0-fold or less, 1.08-fold or more and 1.8-fold or less, 1.08-fold or more and 1.5-fold or less, 1.10-fold or more and 4.0-fold or less, 1.10-fold or more and 3.8-fold or less, 1.10-fold or more and 3.5-fold or less, 1.10-fold or more and 3.3-fold or less, 1.10-fold or more and 3.0-fold or less, 1.10-fold or more and 2.8-fold or less, 1.10-fold or more and 2.5-fold or less, 1.10-fold or more and 2.3-fold or less, 1.10-fold or more and 2.0-fold or less, 1.10-fold or more and 1.8-fold or less, 1.10-fold or more and 1.5-fold or less, 1.13-fold or more and 4.0-fold or less, 1.13-fold or more and 3.8-fold or less, 1.13-fold or more and 3.5-fold or less, 1.13-fold or more and 3.3-fold or less, 1.13-fold or more and 3.0-fold or less, 1.13-fold or more and 2.8-fold or less, 1.13-fold or more and 2.5-fold or less, 1.13-fold or more and 2.3-fold or less, 1.13-fold or more and 2.0-fold or less, 1.13-fold or more and 1.8-fold or less, 1.13-fold or more and 1.5-fold or less, 1.15-fold or more and 4.0-fold or less, 1.15-fold or more and 3.8-fold or less, 1.15-fold or more and 3.5-fold or less, 1.15-fold or more and 3.3-fold or less, 1.15-fold or more and 3.0-fold or less, 1.15-fold or more and 2.8-fold or less, 1.15-fold or more and 2.5-fold or less, 1.15-fold or more and 2.3-fold or less, 1.15-fold or more and 2.0-fold or less, 1.15-fold or more and 1.8-fold or less, 1.15-fold or more and 1.5-fold or less, 1.18-fold or more and 4.0-fold or less, 1.18-fold or more and 3.8-fold or less, 1.18-fold or more and 3.5-fold or less, 1.18-fold or more and 3.3-fold or less, 1.18-fold or more and 3.0-fold or less, 1.18-fold or more and 2.8-fold or less, 1.18-fold or more and 2.5-fold or less, 1.18-fold or more and 2.3-fold or less, 1.18-fold or more and 2.0-fold or less, 1.18-fold or more and 1.8-fold or less, 1.18-fold or more and 1.5-fold or less, 1.20-fold or more and 4.0-fold or less, 1.20-fold or more and 3.8-fold or less, 1.20-fold or more and 3.5-fold or less, 1.20-fold or more and 3.3-fold or less, 1.20-fold or more and 3.0-fold or less, 1.20-fold or more and 2.8-fold or less, 1.20-fold or more and 2.5-fold or less, 1.20-fold or more and 2.3-fold or less, 1.20-fold or more and 2.0-fold or less, 1.20-fold or more and 1.8-fold or less, 1.20-fold or more and 1.5-fold or less, 1.23-fold or more and 4.0-fold or less, 1.23-fold or more and 3.8-fold or less, 1.23-fold or more and 3.5-fold or less, 1.23-fold or more and 3.3-fold or less, 1.23-fold or more and 3.0-fold or less, 1.23-fold or more and 2.8-fold or less, 1.23-fold or more and 2.5-fold or less, 1.23-fold or more and 2.3-fold or less, 1.23-fold or more and 2.0-fold or less, 1.23-fold or more and 1.8-fold or less, 1.23-fold or more and 1.5-fold or less, 1.25-fold or more and 4.0-fold or less, 1.25-fold or more and 3.8-fold or less, 1.25-fold or more and 3.5-fold or less, 1.25-fold or more and 3.3-fold or less, 1.25-fold or more and 3.0-fold or less, 1.25-fold or more and 2.8-fold or less, 1.25-fold or more and 2.5-fold or less, 1.25-fold or more and 2.3-fold or less, 1.25-fold or more and 2.0-fold or less, 1.25-fold or more and 1.8-fold or less, 1.25-fold or more and 1.5-fold or less, 1.28-fold or more and 4.0-fold or less, 1.28-fold or more and 3.8-fold or less, 1.28-fold or more and 3.5-fold or less, 1.28-fold or more and 3.3-fold or less, 1.28-fold or more and 3.0-fold or less, 1.28-fold or more and 2.8-fold or less, 1.28-fold or more and 2.5-fold or less, 1.28-fold or more and 2.3-fold or less, 1.28-fold or more and 2.0-fold or less, 1.28-fold or more and 1.8-fold or less, 1.28-fold or more and 1.5-fold or less, 1.30-fold or more and 4.0-fold or less, 1.30-fold or more and 3.8-fold or less, 1.30-fold or more and 3.5-fold or less, 1.30-fold or more and 3.3-fold or less, 1.30-fold or more and 3.0-fold or less, 1.30-fold or more and 2.8-fold or less, 1.30-fold or more and 2.5-fold or less, 1.30-fold or more and 2.3-fold or less, 1.30-fold or more and 2.0-fold or less, 1.30-fold or more and 1.8-fold or less, 1.30-fold or more and 1.5-fold or less, 1.40-fold or more and 4.0-fold or less, 1.40-fold or more and 3.8-fold or less, 1.40-fold or more and 3.5-fold or less, 1.40-fold or more and 3.3-fold or less, 1.40-fold or more and 3.0-fold or less, 1.40-fold or more and 2.8-fold or less, 1.40-fold or more and 2.5-fold or less, 1.40-fold or more and 2.3-fold or less, 1.40-fold or more and 2.0-fold or less, 1.40-fold or more and 1.8-fold or less, 1.40-fold or more and 1.5-fold or less, 1.50-fold or more and 4.0-fold or less, 1.50-fold or more and 3.8-fold or less, 1.50-fold or more and 3.5-fold or less, 1.50-fold or more and 3.3-fold or less, 1.50-fold or more and 3.0-fold or less, 1.50-fold or more and 2.8-fold or less, 1.50-fold or more and 2.5-fold or less, 1.50-fold or more and 2.3-fold or less, 1.50-fold or more and 2.0-fold or less, 1.50-fold or more and 1.8-fold or less, 1.60-fold or more and 4.0-fold or less, 1.60-fold or more and 3.8-fold or less, 1.60-fold or more and 3.5-fold or less, 1.60-fold or more and 3.3-fold or less, 1.60-fold or more and 3.0-fold or less, 1.60-fold or more and 2.8-fold or less, 1.60-fold or more and 2.5-fold or less, 1.60-fold or more and 2.3-fold or less, 1.60-fold or more and 2.0-fold or less, 1.60-fold or more and 1.8-fold or less, 1.70-fold or more and 4.0-fold or less, 1.70-fold or more and 3.8-fold or less, 1.70-fold or more and 3.5-fold or less, 1.70-fold or more and 3.3-fold or less, 1.70-fold or more and 3.0-fold or less, 1.70-fold or more and 2.8-fold or less, 1.70-fold or more and 2.5-fold or less, 1.70-fold or more and 2.3-fold or less, 1.70-fold or more and 2.0-fold or less, 1.70-fold or more and 1.8-fold or less, 1.80-fold or more and 4.0-fold or less, 1.80-fold or more and 3.8-fold or less, 1.80-fold or more and 3.5-fold or less, 1.80-fold or more and 3.3-fold or less, 1.80-fold or more and 3.0-fold or less, 1.80-fold or more and 2.8-fold or less, 1.80-fold or more and 2.5-fold or less, 1.80-fold or more and 2.3-fold or less, 1.80-fold or more and 2.0-fold or less, 1.90-fold or more and 4.0-fold or less, 1.90-fold or more and 3.8-fold or less, 1.90-fold or more and 3.5-fold or less, 1.90-fold or more and 3.3-fold or less, 1.90-fold or more and 3.0-fold or less, 1.90-fold or more and 2.8-fold or less, 1.90-fold or more and 2.5-fold or less, 1.90-fold or more and 2.3-fold or less, 1.90-fold or more and 2.0-fold or less, 2.00-fold or more and 4.0-fold or less, 2.00-fold or more and 3.8-fold or less, 2.00-fold or more and 3.5-fold or less, 2.00-fold or more and 3.3-fold or less, 2.00-fold or more and 3.0-fold or less, 2.00-fold or more and 2.8-fold or less, 2.00-fold or more and 2.5-fold or less, or 2.00-fold or more and 2.3-fold or less.

[0096] The content of the plant extract in the immunostimulatory composition according to one embodiment relative to the total amount of the immunostimulatory composition can have, for example, a lower limit of 0.000001% by mass or more, 0.00001% by mass or more, 0.001% by mass or more, 0.01% by mass or more, 0.02% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, or 2% by mass or more, and an upper limit of 90.0% by mass or less, 85.0% by mass or less, 80.0% by mass or less, 75.0% by mass or less, 50.0% by mass or less, 25.0% by mass or less, 10.0% by mass or less, 5.0% by mass or less, 1.0% by mass or less, 0.80% by mass or less, 0.50% by mass or less, 0.30% by mass or less, 0.25% by mass or less, 0.20% by mass or less, 0.10% by mass or less, 0.05% by mass or less, 0.02% by mass or less, or 0.01% by mass or less. These upper and lower limits can each be combined arbitrarily. The content of the plant extract in the immunostimulatory composition according to one embodiment relative to the total amount of the immunostimulatory composition may be, for example, 0.000001% by mass or more and 90.0% by mass or less, 0.000001% by mass or more and 85.0% by mass or less, 0.000001% by mass or more and 80.0% by mass or less, 0.000001% by mass or more and 75.0% by mass or less, 0.000001% by mass or more and 50.0% by mass or less, 0.000001% by mass or more and 25.0% by mass or less, 0.000001% by mass or more and 10.0% by mass or less, 0.000001% by mass or more and 5.0% by mass or less, 0.000001% by mass or more and 1.0% by mass or less, 0.000001% by mass or more and 0.80% by mass or less, 0.000001% by mass or more and 0.50% by mass or less, 0.000001% by mass or more and 0.30% by mass or less, 0.000001% by mass or more and 0.25% by mass or less, 0.000001% by mass or more and 0.20% by mass or less, 0.000001% by mass or more and 0.10% by mass or less, 0.000001% by mass or more and 0.05% by mass or less, 0.000001% by mass or more and 0.02% by mass or less, 0.000001% by mass or more and 0.01% by mass or less, 0.00001% by mass or more and 90.0% by mass or less, 0.00001% by mass or more and 85.0% by mass or less, 0.00001% by mass or more and 80.0% by mass or less, 0.00001% by mass or more and 75.0% by mass or less, 0.00001% by mass or more and 50.0% by mass or less, 0.00001% by mass or more and 25.0% by mass or less, 0.00001% by mass or more and 10.0% by mass or less, 0.00001% by mass or more and 5.0% by mass or less, 0.00001% by mass or more and 1.0% by mass or less, 0.00001% by mass or more and 0.80% by mass or less, 0.00001% by mass or more and 0.50% by mass or less, 0.00001% by mass or more and 0.30% by mass or less, 0.00001% by mass or more and 0.25% by mass or less, 0.00001% by mass or more and 0.20% by mass or less, 0.00001% by mass or more and 0.10% by mass or less, 0.00001% by mass or more and 0.05% by mass or less, 0.00001% by mass or more and 0.02% by mass or less, 0.00001% by mass or more and 0.01% by mass or less, 0.001% by mass or more and 90.0% by mass or less, 0.001% by mass or more and 85.0% by mass or less, 0.001% by mass or more and 80.0% by mass or less, 0.001% by mass or more and 75.0% by mass or less, 0.001% by mass or more and 50.0% by mass or less, 0.001% by mass or more and 25.0% by mass or less, 0.001% by mass or more and 10.0% by mass or less, 0.001% by mass or more and 5.0% by mass or less, 0.001% by mass or more and 1.0% by mass or less, 0.001% by mass or more and 0.80% by mass or less, 0.001% by mass or more and 0.50% by mass or less, 0.001% by mass or more and 0.30% by mass or less, 0.001% by mass or more and 0.25% by mass or less, 0.001% by mass or more and 0.20% by mass or less, 0.001% by mass or more and 0.10% by mass or less, 0.001% by mass or more and 0.05% by mass or less, 0.001% by mass or more and 0.02% by mass or less, 0.001% by mass or more and 0.01% by mass or less, 0.01% by mass or more and 90.0% by mass or less, 0.01% by mass or more and 85.0% by mass or less, 0.01% by mass or more and 80.0% by mass or less, 0.01% by mass or more and 75.0% by mass or less, 0.01% by mass or more and 50.0% by mass or less, 0.01% by mass or more and 25.0% by mass or less, 0.01% by mass or more and 10.0% by mass or less, 0.01% by mass or more and 5.0% by mass or less, 0.01% by mass or more and 1.0% by mass or less, 0.01% by mass or more and 0.80% by mass or less, 0.01% by mass or more and 0.50% by mass or less, 0.01% by mass or more and 0.30% by mass or less, 0.01% by mass or more and 0.25% by mass or less, 0.01% by mass or more and 0.20% by mass or less, 0.01% by mass or more and 0.10% by mass or less, 0.01% by mass or more and 0.05% by mass or less, 0.01% by mass or more and 0.02% by mass or less, 0.02% by mass or more and 90.0% by mass or less, 0.02% by mass or more and 85.0% by mass or less, 0.02% by mass or more and 80.0% by mass or less, 0.02% by mass or more and 75.0% by mass or less, 0.02% by mass or more and 50.0% by mass or less, 0.02% by mass or more and 25.0% by mass or less, 0.02% by mass or more and 10.0% by mass or less, 0.02% by mass or more and 5.0% by mass or less, 0.02% by mass or more and 1.0% by mass or less, 0.02% by mass or more and 0.80% by mass or less, 0.02% by mass or more and 0.50% by mass or less, 0.02% by mass or more and 0.30% by mass or less, 0.02% by mass or more and 0.25% by mass or less, 0.02% by mass or more and 0.20% by mass or less, 0.02% by mass or more and 0.10% by mass or less, 0.02% by mass or more and 0.05% by mass or less, 0.05% by mass or more and 90.0% by mass or less, 0.05% by mass or more and 85.0% by mass or less, 0.05% by mass or more and 80.0% by mass or less, 0.05% by mass or more and 75.0% by mass or less, 0.05% by mass or more and 50.0% by mass or less, 0.05% by mass or more and 25.0% by mass or less, 0.05% by mass or more and 10.0% by mass or less, 0.05% by mass or more and 5.0% by mass or less, 0.05% by mass or more and 1.0% by mass or less, 0.05% by mass or more and 0.80% by mass or less, 0.05% by mass or more and 0.50% by mass or less, 0.05% by mass or more and 0.30% by mass or less, 0.05% by mass or more and 0.25% by mass or less, 0.05% by mass or more and 0.20% by mass or less, 0.05% by mass or more and 0.10% by mass or less, 0.10% by mass or more and 90.0% by mass or less, 0.10% by mass or more and 85.0% by mass or less, 0.10% by mass or more and 80.0% by mass or less, 0.10% by mass or more and 75.0% by mass or less, 0.10% by mass or more and 50.0% by mass or less, 0.10% by mass or more and 25.0% by mass or less, 0.10% by mass or more and 10.0% by mass or less, 0.10% by mass or more and 5.0% by mass or less, 0.10% by mass or more and 1.0% by mass or less, 0.10% by mass or more and 0.80% by mass or less, 0.10% by mass or more and 0.50% by mass or less, 0.10% by mass or more and 0.30% by mass or less, 0.10% by mass or more and 0.25% by mass or less, 0.10% by mass or more and 0.20% by mass or less, 0.50% by mass or more and 90.0% by mass or less, 0.50% by mass or more and 85.0% by mass or less, 0.50% by mass or more and 80.0% by mass or less, 0.50% by mass or more and 75.0% by mass or less, 0.50% by mass or more and 50.0% by mass or less, 0.50% by mass or more and 25.0% by mass or less, 0.50% by mass or more and 10.0% by mass or less, 0.50% by mass or more and 5.0% by mass or less, 0.50% by mass or more and 1.0% by mass or less, 0.50% by mass or more and 0.80% by mass or less, 1% by mass or more and 90.0% by mass or less, 1% by mass or more and 85.0% by mass or less, 1% by mass or more and 80.0% by mass or less, 1% by mass or more and 75.0% by mass or less, 1% by mass or more and 50.0% by mass or less, 1% by mass or more and 25.0% by mass or less, 1% by mass or more and 10.0% by mass or less, 1% by mass or more and 5.0% by mass or less, 2% by mass or more and 90.0% by mass or less, 2% by mass or more and 85.0% by mass or less, 2% by mass or more and 80.0% by mass or less, 2% by mass or more and 75.0% by mass or less, 2% by mass or more and 50.0% by mass or less, 2% by mass or more and 25.0% by mass or less, 2% by mass or more and 10.0% by mass or less, or 2% by mass or more and 5.0% by mass or less.

[0097] The ratio of the content (% by mass) of the bacterium having immunostimulatory activity to the content (% by mass) of the plant extract in the immunostimulatory composition according to one embodiment ((content of the bacterium having immunostimulatory activity) / (content of the plant extract)) can have, for example, a lower limit of 0.001 or more, 0.003 or more, 0.005 or more, 0.01 or more, 0.015 or more, 0.02 or more, 0.025 or more, or 0.03 or more, and an upper limit of 50000 or less, 10000 or less, 1000 or less, 500 or less, 100 or less, 50 or less, 10 or less, 5 or less, 1.0 or less, 0.75 or less, 0.5 or less, or 0.3 or less. These upper and lower limits can each be combined arbitrarily. The ratio of the content (% by mass) of the bacterium having immunostimulatory activity to the content (% by mass) of the plant extract in the immunostimulatory composition according to one embodiment ((content of the bacterium having immunostimulatory activity) / (content of the plant extract)) may be, for example, 0.001 or more and 50000 or less, 0.001 or more and 10000 or less, 0.001 or more and 1000 or less, 0.001 or more and 500 or less, 0.001 or more and 100 or less, 0.001 or more and 50 or less, 0.001 or more and 10 or less, 0.001 or more and 5 or less, 0.001 or more and 1.0 or less, 0.001 or more and 0.75 or less, 0.001 or more and 0.5 or less, 0.001 or more and 0.3 or less, 0.003 or more and 50000 or less, 0.003 or more and 10000 or less, 0.003 or more and 1000 or less, 0.003 or more and 500 or less, 0.003 or more and 100 or less, 0.003 or more and 50 or less, 0.003 or more and 10 or less, 0.003 or more and 5 or less, 0.003 or more and 1.0 or less, 0.003 or more and 0.75 or less, 0.003 or more and 0.5 or less, 0.003 or more and 0.3 or less, 0.005 or more and 50000 or less, 0.005 or more and 10000 or less, 0.005 or more and 1000 or less, 0.005 or more and 500 or less, 0.005 or more and 100 or less, 0.005 or more and 50 or less, 0.005 or more and 10 or less, 0.005 or more and 5 or less, 0.005 or more and 1.0 or less, 0.005 or more and 0.75 or less, 0.005 or more and 0.5 or less, 0.005 or more and 0.3 or less, 0.01 or more and 50000 or less, 0.01 or more and 10000 or less, 0.01 or more and 1000 or less, 0.01 or more and 500 or less, 0.01 or more and 100 or less, 0.01 or more and 50 or less, 0.01 or more and 10 or less, 0.01 or more and 5 or less, 0.01 or more and 1.0 or less, 0.01 or more and 0.75 or less, 0.01 or more and 0.5 or less, 0.01 or more and 0.3 or less, 0.015 or more and 50000 or less, 0.015 or more and 10000 or less, 0.015 or more and 1000 or less, 0.015 or more and 500 or less, 0.015 or more and 100 or less, 0.015 or more and 50 or less, 0.015 or more and 10 or less, 0.015 or more and 5 or less, 0.015 or more and 1.0 or less, 0.015 or more and 0.75 or less, 0.015 or more and 0.5 or less, 0.015 or more and 0.3 or less, 0.02 or more and 50000 or less, 0.02 or more and 10000 or less, 0.02 or more and 1000 or less, 0.02 or more and 500 or less, 0.02 or more and 100 or less, 0.02 or more and 50 or less, 0.02 or more and 10 or less, 0.02 or more and 5 or less, 0.02 or more and 1.0 or less, 0.02 or more and 0.75 or less, 0.02 or more and 0.5 or less, 0.02 or more and 0.3 or less, 0.025 or more and 50000 or less, 0.025 or more and 10000 or less, 0.025 or more and 1000 or less, 0.025 or more and 500 or less, 0.025 or more and 100 or less, 0.025 or more and 50 or less, 0.025 or more and 10 or less, 0.025 or more and 5 or less, 0.025 or more and 1.0 or less, 0.025 or more and 0.75 or less, 0.025 or more and 0.5 or less, 0.025 or more and 0.3 or less, 0.03 or more and 50000 or less, 0.03 or more and 10000 or less, 0.03 or more and 1000 or less, 0.03 or more and 500 or less, 0.03 or more and 100 or less, 0.03 or more and 50 or less, 0.03 or more and 10 or less, 0.03 or more and 5 or less, 0.03 or more and 1.0 or less, 0.03 or more and 0.75 or less, 0.03 or more and 0.5 or less, or 0.03 or more and 0.3 or less.

[0098] The immunostimulatory composition according to one embodiment may be a food (including beverages), a pharmaceutical, or a quasi-drug. The food, pharmaceutical, or quasi-drug can each be produced by a conventional method. The content of the bacterium having immunostimulatory activity and the plant extract in the food, pharmaceutical, or quasi-drug is not particularly limited and can be freely set according to the purpose.

[0099] When the immunostimulatory composition according to one embodiment is a food, a pharmaceutical, or a quasi-drug, the food, pharmaceutical, or quasi-drug may contain, in addition to the bacterium having immunostimulatory activity and the plant extract, components that can be ordinarily used in foods, pharmaceuticals, or quasi-drugs. The food, pharmaceutical, or quasi-drug according to one embodiment may contain bases, carriers, additives, and the like ordinarily used in foods, pharmaceuticals, or quasi-drugs. Examples of additives include excipients, oils, powders, buffers, solubilizing agents, antioxidants, surfactants, thickeners, preservatives, pH adjusters, chelating agents, stabilizers, irritation-reducing agents, antiseptics, pigments, colorants, fragrances, gloss-imparting agents, gelling agents, alcohols, water-soluble polymers, film-forming agents, and resins. The bases, carriers, and the various additives described above can be used alone or in combination of two or more as necessary.

[0100] When the immunostimulatory composition according to one embodiment is a food, examples of the food include health food, functional food, nutritional composition, dietary supplement, supplement, food for health, food for specified health uses, food with nutrient function claims, and food with functional claims and the like. Such food compositions can be labeled with, for example, support for maintaining immune function in healthy people (immune care), for those concerned about decreased immune function, suppression of decreased immune function, and the like. In addition, the immunostimulatory composition according to one embodiment can also be used as a food additive.

[0101] Examples of the food include seasonings, processed meat products, processed agricultural products, beverages (lactic acid bacteria beverages, soft drinks, alcoholic beverages, carbonated beverages, milk beverages, fruit juice beverages, tea, coffee, nutritional drinks, and the like), powdered beverages (powdered juice, powdered soup, powdered milk, and the like), concentrated beverages, confectioneries (candy (throat lozenges), cookies, biscuits, gum, gummies, chewables, tablets, chocolate, and the like), bread, cereals, and the like. In addition, in the case of food for specified health uses, food with nutrient function claims, food with functional claims, and the like, the form may be capsules, granules, powder, syrup, troches, and the like.

[0102] When the immunostimulatory composition according to one embodiment is a pharmaceutical or a quasi-drug, the dosage form of the pharmaceutical or quasi-drug may be, for example, a liquid preparation, a suspension, a capsule, a granule, a pill, a powder, a tablet, a syrup, a troche, and the like. Examples of indications as a pharmaceutical include allergy, obesity, and heart failure and the like.

[0103] The immunostimulatory composition according to one embodiment is preferably administered or ingested into the body. The mode of administration or ingestion may be oral administration or oral ingestion, or parenteral administration or parenteral ingestion, but oral administration or oral ingestion is preferred. The immunostimulatory composition according to one embodiment may be administered or ingested only once, or may be administered or ingested multiple times, and when sustained immunostimulation is desired, it is preferably administered or ingested continuously or intermittently over a certain period of time. The food composition according to one aspect may be ingested, for example, for 1 week or more, 2 weeks or more, 1 month or more, 3 months or more, 6 months or more, 1 year or more, 3 years or more, 5 years or more, or 10 years or more, at a frequency of 1 to 5 times per day, once every 2 days, once every 3 days, once every 4 days, or once per week.

[0104] The immunostimulatory composition according to one embodiment is a composition for immunostimulation induced by a bacterium having immunostimulatory activity, and contains a plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium. “Immunostimulation induced by a bacterium having immunostimulatory activity” means immunostimulation induced depending on the action of stimulating (activating) immune cells that is inherently possessed by the bacterium having immunostimulatory activity.

[0105] The immunostimulatory composition according to one embodiment is an immunostimulatory composition or an immunostimulatory composition with enhanced immunostimulatory action, obtained by adding, to a bacterium having immunostimulatory activity, a plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium. The immunostimulatory composition or the immunostimulatory composition with enhanced immunostimulatory action is preferred from the viewpoint of bringing about enhancement of the immunostimulatory activity of the bacterium by the addition of the plant extract.

[0106] [Enhancer of Immunostimulatory Action Induced by Bacterium Having Immunostimulatory Activity] The second embodiment of the present disclosure relates to an enhancer of an immunostimulatory action induced by a bacterium having immunostimulatory activity (hereinafter also simply referred to as “enhancer”). The enhancer according to one aspect contains a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium. In addition, the enhancer according to another aspect is an enhancer of an immunostimulatory action induced by a bacterium having immunostimulatory activity, and contains a plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium. The enhancer according to the present embodiment has an action of enhancing the immunostimulatory action induced by the above-described bacterium having immunostimulatory activity. That is, the enhancer according to the present embodiment has an enhanced immunostimulatory action as compared with an immunostimulatory composition containing only the bacterium having immunostimulatory activity.

[0107] The enhancer according to one embodiment preferably has an activity to induce interferon a production in immune cells that has a lower limit of, for example, 1.01-fold or more, 1.02-fold or more, 1.03-fold or more, 1.05-fold or more, 1.08-fold or more, 1.10-fold or more, 1.13-fold or more, 1.15-fold or more, 1.18-fold or more, 1.20-fold or more, 1.23-fold or more, 1.25-fold or more, 1.28-fold or more, 1.30-fold or more, 1.40-fold or more, 1.50-fold or more, 1.60-fold or more, 1.70-fold or more, 1.80-fold or more, 1.90-fold or more, or 2.0-fold or more as compared with an immunostimulatory composition containing only the bacterium having immunostimulatory activity, and preferably has an upper limit of 4.0-fold or less, 3.8-fold or less, 3.5-fold or less, 3.3-fold or less, 3.0-fold or less, 2.8-fold or less, 2.5-fold or less, 2.3-fold or less, 2.0-fold or less, 1.8-fold or less, or 1.50-fold or less. These upper and lower limits can each be combined arbitrarily, and may be the same range as described for the immunostimulatory activity-enhancing action of the plant extract according to the present embodiment on the bacterium.

[0108] As other specific aspects of the enhancer according to the present embodiment, the aspects of the immunostimulatory composition according to the present embodiment can be appropriately applied.

[0109] [Immunostimulatory Method, Method for Enhancing Immunostimulatory Action Induced by Bacterium Having Immunostimulatory Activity] The third embodiment of the present disclosure relates to an immunostimulatory method and a method for enhancing an immunostimulatory action induced by a bacterium having immunostimulatory activity (hereinafter also simply referred to as “enhancement method”). The immunostimulatory method and the enhancement method include administering to a subject or causing a subject to ingest a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action. The enhancement method according to the present embodiment has an enhanced immunostimulatory action as compared with a case where only the bacterium having immunostimulatory activity is administered or caused to be ingested.

[0110] Examples of subjects in the above-described method include humans and non-human mammals, with humans being preferred. Examples of non-human mammals include mice, rats, guinea pigs, hamsters, rabbits, cats, dogs, sheep, pigs, cattle, horses, goats, and monkeys.

[0111] The subject can be a subject in need of immunostimulation, and the subject in need of immunostimulation is not particularly limited, but examples include a subject infected with a virus, a subject wishing to prevent viral infection, a subject having a cold, a subject wishing to prevent a cold, and a subject aged 65 years or older and the like.

[0112] The bacterium having immunostimulatory activity and the plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium can be administered to or caused to be ingested by a subject, for example, in the form of the composition of the first embodiment described above. In general, the expression “administering to a subject” is used for pharmaceutical compositions, and the expression “causing a subject to ingest” is used for food compositions, but both expressions mean that the composition is taken into the body of the subject and are synonymous. Therefore, the two are interchangeable expressions and there is no essential difference.

[0113] [Method for Producing Composition] The fourth embodiment of the present disclosure relates to a method for producing an immunostimulatory composition. The production method is a method for producing an immunostimulatory composition or an immunostimulatory composition with enhanced immunostimulatory action, the method including adding, to a bacterium having immunostimulatory activity, a plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium.      The immunostimulatory composition or the immunostimulatory composition with enhanced immunostimulatory action is preferred from the viewpoint of bringing about enhancement of the immunostimulatory activity of the bacterium by the addition of the plant extract.

[0114] [Use of Bacterium and Plant Extract for Producing Composition] The fifth embodiment of the present disclosure relates to the use of a bacterium and a plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium for producing a composition. The use according to one aspect is the use of a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium for producing an immunostimulatory composition; the use according to another aspect is the use of a plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity for producing a composition for immunostimulation induced by the above-described bacterium; the use according to yet another aspect is the use of a plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity for producing an immunostimulatory composition to be administered or ingested in combination with the bacterium having immunostimulatory activity; and the use according to another aspect is the use of a bacterium having immunostimulatory activity for producing an immunostimulatory composition to be administered or ingested in combination with a plant extract having an immunostimulatory activity-enhancing action on the bacterium having immunostimulatory activity.     The specific aspects of the immunostimulatory composition, bacterium, and plant extract according to the present embodiment are as described above.

[0115] [Plant Extract for Use] The sixth embodiment of the present disclosure relates to a plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity, for use in immunostimulation induced by the above-described bacterium. The specific aspects of the bacterium and plant extract according to the present embodiment are as described above.

[0116] [Bacterium or Plant Extract for Use in Therapeutic Method] The seventh embodiment of the present disclosure relates to the use of a bacterium or a plant extract for use in a therapeutic method of immunostimulation. In one aspect, the bacterium is a bacterium having immunostimulatory activity for use in a therapeutic method of immunostimulation, the bacterium being administered or ingested in combination with a plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium; and in another aspect, the plant extract is a plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity, for use in a therapeutic method of immunostimulation, the plant extract being administered or ingested in combination with the   above-described   bacterium having immunostimulatory activity. The specific aspects of the bacterium and plant extract according to the present embodiment are as described above. In the present disclosure, use in a “therapeutic” method indicates use in treating the body of a subject. Use in a therapeutic method according to the present disclosure may be, for example, use for the purpose of medical practice or involving medical practice. Use in a therapeutic method according to the present disclosure may involve, for example, a healthcare professional administering a substance to a human or animal or causing a human or animal to ingest a substance, or instructing a human or animal to administer or ingest a substance. Use in a therapeutic method according to the present disclosure may be, for example, use for therapeutic purposes or preventive purposes, may be use for therapeutic purposes or preventive purposes involving ingestion of a food composition, or may be for therapeutic purposes. Use in a therapeutic method according to the present disclosure may be, for example, use for non-healthy individuals.

[0117] [Use of Bacterium or Plant Extract in Non-Therapeutic Method] The eighth embodiment of the present disclosure relates to the use of a bacterium or a plant extract for use in a non-therapeutic method of immunostimulation. In one aspect, the use is the use of a bacterium having immunostimulatory activity in a non-therapeutic method of immunostimulation, the bacterium being administered or ingested in combination with a plant extract having an immunostimulatory activity-enhancing action on the above-described bacterium; and in another aspect, the use is the use of a plant extract having an immunostimulatory activity-enhancing action on a bacterium having immunostimulatory activity in a non-therapeutic method of immunostimulation, the plant extract being administered or ingested in combination with the bacterium having immunostimulatory activity. The specific aspects of the bacterium and plant extract according to the present embodiment are as described above. In the present disclosure, use in a “non-therapeutic” method means use of a substance that does not fall under use in a therapeutic method. Use in a non-therapeutic method according to the present disclosure may be, for example, use that is not for the purpose of medical practice and / or does not involve medical practice. Use in a non-therapeutic method according to the present disclosure need not involve, for example, a healthcare professional administering a substance to a human or animal or causing a human or animal to ingest a substance, and / or instructing a human or animal to administer or ingest a substance. Use in a non-therapeutic method according to the present disclosure may be, for example, use for preventive purposes or health promotion purposes, may be use for preventive purposes involving administration or ingestion of a pharmaceutical composition or quasi-drug, or for health promotion purposes. Use in a non-therapeutic method according to the present disclosure may be, for example, use for healthy individuals. Examples

[0118] Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to the following examples.

[0119] The plant extracts shown in Table 1 were used to examine the enhancing or suppressing action on IFN- production by pDCs induced by JCM 5805.

[0120] <1. Preparation of Lactic Acid Bacterium Suspension> JCM 5805 bacterial cells were seeded in 10 mL of MRS medium (Oxoid) and cultured at 30°C for 24 hours. Thereafter, 1 mL of the cultured lactic acid bacterium cell suspension was seeded in 100 mL of MRS medium and cultured at 30°C for 24 hours. Subsequently, the lactic acid bacteria were collected, washed three times with sterile water, heat-sterilized at 80°C for 30 minutes, and then freeze-dried to obtain heat-killed cells. The heat-killed cells were then adjusted with PBS (Takara Bio Inc.) to a concentration of 1 mg / mL to prepare a lactic acid bacterium suspension.

[0121] <2. Preparation of Plant Extract Solution> “Brightening Pine (registered trademark)” manufactured by Maruzen Pharmaceuticals Co., Ltd. was used as the pineapple fruit extract, “Mangosteen Aqua” manufactured by Nippon Shinyaku Co., Ltd. was used as the mangosteen pericarp extract, “MACAXS (registered trademark)” manufactured by TOWA was used as the maca extract, “Sense Pure (registered trademark)” manufactured by Toyo Hakko was used as the fermented extract of rice germ and soybean, “St. John’s Wort” manufactured by Fancl Corporation was used as the St. John’s wort extract, “Chrysanthemum Flower Extract P” manufactured by Oryza Oil & Fat Chemical Co., Ltd. was used as the chrysanthemum flower extract, “AG Herb MIX (registered trademark)” manufactured by Arkray was used as the herb (mixed herb of chamomile, dokudami, hawthorn, and grape leaves) extract, “Organic Carob Powder” manufactured by Sakurai Foods Co., Ltd. was used as the carob extract, “Ginger Extract Powder S” manufactured by Ikeda Tohka Industries Co., Ltd. was used as the ginger extract, a product manufactured by Kirin was used as the aged hop extract, a product manufactured by Kanshi Korean Ginseng was used as the aged red ginseng extract, “Koiaona (registered trademark)” manufactured by Nippn Corporation was used as the kale extract, “Garcinia Powder S” manufactured by Nippon Shinyaku Co., Ltd. was used as the garcinia pericarp extract, “Venetron  (registered  trademark)”  manufactured  by  Tokiwa Phytochemical Research was used as the rafuma leaf extract, and “Laureche  (registered  trademark)”  manufactured  by  Tokiwa Phytochemical Research was used as the laurel leaf extract. These plant extracts were adjusted with PBS to a concentration of 400 ug / mL to prepare plant extract solutions.

[0122] <3. Test Procedure> The test was carried out according to the following procedures (i) to (iv). (i) Bone marrow cells derived from female BALB / c mice were suspended in RPMI medium (Sigma Co., Ltd.) prepared so that each component described in the following (Composition of medium) reaches the respective final concentration described in the following (Composition of medium), to a concentration of 1*106 cells / mL, to prepare a cell suspension. (Composition of medium) • 10% by volume FBS • 100 U / mL penicillin / streptomycin • 1 mM sodium pyruvate • 2.5 mM HEPES • 1% by mass non-essential amino acids for MEM (NEAA) • 50 pM P—mercaptoethanol • 100 ng / mL Flt-3L (ii) The prepared cell suspension was seeded at 1 mL each, and cultured for one week at 37°C and 5% CO2 in a CO2 incubator to induce pDCs. (iii) Bone marrow cells containing the induced pDCs were suspended to a concentration of 2M05 cells / mL, seeded at 200 pL each into a 96-well plate, and 2 pL each of the JCM 5805 suspension from 1. above was added simultaneously with 5 pL of the plant extract solution from 2. above. Similarly, only the plant extract solution was added to a 96-well plate seeded with bone marrow cells containing pDCs. Furthermore, similarly, only the JCM 5805 suspension was added to a 96-well plate seeded with bone marrow cells containing pDCs. (iv) After 24 hours, the culture supernatant was collected, and the IFN-a concentration was measured using an IFN-a measurement kit (PBL Assay Science Ltd.).

[0123] The relative values of IFN-a production in the presence of each substance, when the IFN-a production in the case where the JCM 5805 suspension was used alone was set to 1, are summarized in the following table. The concentration of each substance in the table indicates the final concentration.

[0124] [Table 1] Table 1: Plant extract 10 pg / mL Pineapple fruit extract 1.70 Mangosteen pericarp extract 1.50 Maca extract 1.49 Fermented extract of rice germ an d soybean 1.21 St. John’s wort extract 1.40 Chrysanthemum flower extract 1.33 Herb extract 1.28 Carob pod extract 1.25 Ginger extract 1.21 Hop extract 1.18 Aged red ginseng extract 1.15 Kale extract 0.98 Garcinia pericarp extract 0.71 Rafuma leaf extract 0.43 Laurel leaf extract 0.13

[0125] When any of the substances was used alone, IFN-a production by pDCs was not induced. It was confirmed that kale extract, garcinia pericarp extract, rafuma leaf extract, and laurel leaf extract suppressed 5      IFN-a production by pDCs induced by JCM 5805, and that pineapple fruit extract, mangosteen pericarp extract, maca extract, fermented extract of rice germ and soybean, St. John’s wort extract, chrysanthemum flower extract, herb extract, carob pod extract, ginger extract, hop extract, and aged red ginseng extract enhanced IFN-a 10      production by pDCs induced by JCM 5805.

Claims

1. An immunostimulatory composition comprising abacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the bacterium.

2. The immunostimulatory composition according to claim1, wherein the bacterium having immunostimulatory activity is a lactic acid bacterium and / or an acetic acid bacterium.

3. The immunostimulatory composition according to claim2, wherein the lactic acid bacterium is a bacterium of the genus Lactococcus.

4. The immunostimulatory composition according to claim3, wherein the bacterium of the genus Lactococcus is Lactococcus lactis subsp. lactis.

5. The immunostimulatory composition according to claim1, wherein the content of the bacterium having immunostimulatory activity is 0.001% by mass or more and less than 100% by mass relative to the total amount of the immunostimulatory composition.

6. The immunostimulatory composition according to claim1, wherein the content of the plant extract is 0.000001% by mass or more and 90.0% by mass or less relative to the total amount of the immunostimulatory composition.

7. The immunostimulatory composition according to claim1, wherein the ratio of the content (% by mass) of the plant extract to the content (% by mass) of the bacterium having immunostimulatory activity ((content of plant extract) / (content of bacterium having immunostimulatory activity)) is 0.001 or more and 50000 or less.

8. The immunostimulatory composition according to anyone of claims 1 to 7, wherein the immunostimulatory activity is an activity to induce interferon a production in an immune cell.

9. The immunostimulatory composition according to claim8, wherein the immune cell is a plasmacytoid dendritic cell.

10. The immunostimulatory composition according to any one of claims 1 to 7, wherein the immunostimulatory activity-enhancing action is an action of enhancing the immunostimulatory activity by 1.10-fold or more.

11. The immunostimulatory composition according to claim 8, wherein the plant extract is one or more plant extracts selected from the group consisting of a pineapple extract, a mangosteen extract, a maca extract, a fermented extract of rice germ and soybean, a St. John’s wort extract, a chrysanthemum extract, an herb extract, a carob extract, a ginger extract, a hop extract, and a red ginseng extract.

12. An immunostimulatory method comprising administering to a subject or causing a subject to ingest a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the bacterium.

13. A method for enhancing an immunostimulatory action induced by a bacterium having immunostimulatory activity, the method comprising administering to a subject or causing a subject to ingest a bacterium having immunostimulatory activity and a plant extract having an immunostimulatory activity-enhancing action on the bacterium.

14. The method according to claim 12 or 13, wherein the immunostimulatory activity is an activity to induce interferon aproduction in an immune cell.

15. An enhancer of an immunostimulatory action induced by a bacterium having immunostimulatory activity, the enhancer comprising a plant extract having an immunostimulatory5       activity-enhancing action on the bacterium having immunostimulatoryactivity.

16. The enhancer according to claim 15, wherein the immunostimulatory activity is an activity to induce interferon a production in an immune cell.10