A strain of Lactobacillus reuteri Glory LR15 and its composition and application

Abstract

The present invention discloses a strain of Lactobacillus reuteri Glory LR15, a composition and an application thereof. The Lactobacillus reuteri Glory LR15 is classified and named as Lactobacillus reuteri Glory LR15 ( Limosilactobacillus reuteri )Glory LR15, the deposit number is CGMCC No.26972. Limosilactobacillus reuteri ) Glory LR15 is used to prepare a drug for allergic reactions induced by cow's milk. The Lactobacillus reuteri of the present invention can effectively reduce the specific IgE level in the serum of people with allergic reactions induced by cow's milk, regulate the gene expression of Th1 and Th2 cytokines in the body, and thus regulate the immune function of the body to prevent or treat cow's milk-induced allergic reactions.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and specifically relates to a strain of Lactobacillus reuteri Glory LR15 and a composition and application thereof. Background Art

[0002] Allergy is the body's immune response beyond the normal range, that is, the immune system attacks harmless substances, also known as allergic reaction. Immune response is one of the important functions of the human defense system. Allergy is a disease that is very detrimental to human health. The global prevalence of allergies exceeds 40,000 and is increasing every year, making it a major global health problem. The disruption of normal immune response leads to an imbalance between helper T cells type 1 (Th1) and helper T cells type 2 (Th2). In addition, macrophages are involved in the immune response during allergic inflammation.

[0003] In the past few decades, the prevalence of food allergies has increased dramatically, leading to major public health problems worldwide. Allergies are inflammatory diseases caused by immune system disorders and hypersensitivity reactions. Allergies are caused by various allergens, including food, insects, drugs and the environment, and manifest as such allergic diseases, such as rhinitis, systemic anaphylaxis, asthma and atopic dermatitis, which can be life-threatening in severe cases. The most common allergic foods are milk, eggs, peanuts, fish, crustaceans, etc. Among them, cow's milk allergy is an immunological reaction that is harmful to the health of the body caused by one or more milk proteins. Its allergic reaction may include three immunological mechanisms: one is milk protein-specific IgE-mediated allergic reaction; the second is non-IgE-mediated allergic reaction (cytotoxic hypersensitivity reaction and delayed hypersensitivity reaction); the third is IgE and non-IgE-mediated mixed allergic reaction, among which cow's milk allergy reaction is mainly milk protein-specific IgE-mediated allergic reaction. About 5%-15% of infants in developed countries may suffer from cow's milk allergy.

[0004] Cow's milk allergy is the most common food protein allergy in early childhood. According to statistics, the incidence rate in the first year after birth is about 2% to 3%, while the allergy rate of peanuts, soybeans, etc. is much lower than cow's milk allergy. It is reported that most infants with cow's milk allergy will develop it within one month after birth, after consuming cow's milk formula. Most allergic people will have skin symptoms, gastrointestinal symptoms, and respiratory symptoms. Among children who are exclusively breastfed, the main symptom is atopic eczema.

[0005] According to the literature, casein, β-lactoglobulin and α-lactalbumin may all lead to cow milk allergy. Further research has found that β-lactoglobulin and α-lactalbumin are the main allergens in milk. At present, the treatment methods for food allergies mainly include allergen-specific immunotherapy and non-specific immunotherapy. Allergen-specific immunotherapy has significant efficacy in desensitization, but it may cause systemic side effects such as allergic reactions and gastrointestinal symptoms; non-specific immunotherapy includes anti-allergic drugs, monoclonal antibodies, natural bioactive substances, etc. Anti-allergic drugs mainly include antihistamines, epinephrine and glucocorticoids, etc., which have rapid effects but may cause drug resistance and side effects.

[0006] Nowadays, the main method for treating acute or chronic allergic diseases is chemical medicine treatment, but the drugs generally relieve the condition after the symptoms appear, and the symptoms will recur after stopping the drugs. Therefore, it is very necessary to explore a method that can prevent and relieve allergic diseases. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a strain of Lactobacillus reuteri Glory LR15 and its composition and application. The present invention constructs a cow milk mouse model by gavage of a mixture of sensitized raw cow milk and an immune adjuvant, screens probiotic strains that are beneficial for allergy relief, especially allergic reactions induced by cow milk, and finally screens out a strain of Lactobacillus reuteri, which can be used to relieve cow milk-induced allergic reactions.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A strain of Lactobacillus reuteri Glory LR15, the classification name of the Lactobacillus reuteri Glory LR15, is deposited in the General Microbiology Center of the China Culture Collection Administration, with a deposit number of CGMCC No.26972, a deposit date of March 31, 2023, and a deposit address of No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences.

[0010] The present invention also protects an application of the Lactobacillus reuteri Glory LR15, and adopts the Lactobacillus reuteri Glory LR15 to prepare a composition for regulating the expression level of cytokine IFN-γ.

[0011] The present invention also protects an application of the Lactobacillus reuteri Glory LR15, and adopts the Lactobacillus reuteri Glory LR15 to prepare a composition for regulating the expression level of the cytokine IL-10 gene.

[0012] The present invention also protects an application of the Lactobacillus reuteri Glory LR15, characterized in that the drug for alleviating the allergic reaction induced by cow's milk is prepared by using Lactobacillus reuteri Glory LR15.

[0013] Preferably, the Lactobacillus reuteri Glory LR15 upregulates the expression level of Th1 cytokine IFN-γ and downregulates the gene expression level of Th2 cytokine IL-10, thereby affecting the secretion of immunoglobulins, while reducing the pro-inflammatory factors and specific IgE in the serum of allergic people to alleviate cow's milk-induced allergic reactions.

[0014] The present invention also protects a composition of the Lactobacillus reuteri Glory LR15.

[0015] Preferably, the Lactobacillus reuteri Glory LR15 in the composition is live or inactivated.

[0016] Preferably, the composition is a medicine.

[0017] More preferably, the composition is prepared by mixing the Lactobacillus reuteri Glory LR15 with other probiotic plant extracts, and is added to the medicine as an excipient.

[0018] Specifically, the composition is a mixture of Lactobacillus reuteri Glory LR15 and one or more probiotics such as Lactobacillus plantarum, Lactobacillus rhamnosus, Bifidobacterium lactis, Lactobacillus acidophilus, etc.; or a mixture of Lactobacillus reuteri Glory LR15 and probiotics, plant extracts (including but not limited to one or more of mulberry extract, dandelion extract, sophora flavescens extract, perilla extract, etc.).

[0019] Preferably, the composition is in the form of microcapsules, tablets, powders or liquid preparations.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The Lactobacillus reuteri Glory LR15 provided by the present invention can effectively reduce the specific IgE level in the serum of people with allergic reactions induced by cow's milk, regulate the expression of Th1 and Th2 cytokine genes in the body, thereby regulating the body's immune function, and preventing or treating cow's milk-induced allergic reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The phylogenetic tree is constructed by the neighbor-joining method as described in Example 1 of the present invention;

[0023] Figure 2 This is the ANI value heat map described in Example 1 of the present invention;

[0024] Figure 3 The prediction result of the iprobiotics platform described in Example 1 of the present invention;

[0025] Figure 4 This is a symptom scoring diagram of the allergic symptoms of Lactobacillus reuteri Glory LR15 on mice allergic to cow milk described in Example 3 of the present invention;

[0026] Figure 5 This is a diagram showing changes in rectal temperature of mice allergic to cow milk by Lactobacillus reuteri Glory LR15 as described in Example 3 of the present invention;

[0027] Figure 6 This is a HE staining microscopic examination of the allergic symptoms of the jejunum and colon of mice allergic to cow milk by Lactobacillus reuteri Glory LR15 described in Example 3 of the present invention;

[0028] Figure 7 The thickness of the muscular layer of the jejunum (A) and colon (B) of mice allergic to cow milk by Lactobacillus reuteri Glory LR15 described in Example 3 of the present invention;

[0029] Figure 8 The effect of Lactobacillus reuteri Glory LR15 described in Example 3 of the present invention on specific IgE in the serum of mice allergic to cow milk;

[0030] Fig. 9 The effect of Lactobacillus reuteri Glory LR15 on the mRNA gene expression of Th1 cytokines in the intestine of mice allergic to cow milk described in Example 3 of the present invention;

[0031] Fig.10 The effect of Lactobacillus reuteri Glory LR15 on the mRNA gene expression of Th2 cytokines in the intestine of mice allergic to cow milk described in Example 3 of the present invention;

[0032] Fig.11This is a symptom scoring diagram of the allergic symptoms of Lactobacillus reuteri Glory LR15 on mice allergic to cow milk described in Example 4 of the present invention;

[0033] Fig.12 This is a diagram showing changes in rectal temperature of mice allergic to cow milk by Lactobacillus reuteri Glory LR15 as described in Example 4 of the present invention;

[0034] Fig.13 This is a HE staining microscopic examination of the allergic symptoms of the jejunum and colon of mice allergic to cow milk by Lactobacillus reuteri Glory LR15 described in Example 4 of the present invention;

[0035] Fig.14 The thickness of the muscular layer of the jejunum (A) and colon (B) of mice allergic to cow milk by Lactobacillus reuteri Glory LR15 as described in Example 4 of the present invention;

[0036] Fig.15 The effect of Lactobacillus reuteri Glory LR15 described in Example 4 of the present invention on specific IgE in the serum of mice allergic to cow milk;

[0037] Fig.16 The effect of Lactobacillus reuteri Glory LR15 on the mRNA gene expression of Th1 cytokines in the intestine of mice allergic to cow milk described in Example 4 of the present invention;

[0038] Fig.17 This is the effect of Lactobacillus reuteri Glory LR15 described in Example 4 of the present invention on the expression of Th2 cytokine mRNA genes in the intestine of mice allergic to cow's milk. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially. In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below.

[0041] The data of the test results of the following examples are all expressed as mean ± standard error of the mean (Means ± SEM). One-way analysis of variance (One-way ANOVA) was used for statistical analysis, and Tukey's Multiple Comparison Test was used as a post-test to compare the differences between the groups. When p < 0.05 (*) or < 0.01 (**) or < 0.001 (***) or < 0.0001 (****), the difference between the control group and the other groups was considered to be statistically significant.

[0042] The present invention provides a strain of Lactobacillus reuteri, which is classified and named as Lactobacillus reuteri (Limosilactobacillus reuteri) Glory LR15, and is deposited in the General Microbiology Center (CGMCC) of China Microorganism Culture Collection Administration, address: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, with a deposit date of March 31, 2023 and a deposit number of CGMCC No. 26972.

[0043] Example 1

[0044] Strain screening, isolation and culture methods

[0045] 1 mL of yogurt sample was vortexed and mixed in 9 mL of sterile 0.85% saline solution (NaCl) to make 10 -1 dilution, and so on, continuously dilute to 10 -8 Gradient, then take 1mL of dilution into the culture dish, pour into MRS agar medium at about 45℃ and mix well, incubate anaerobically at 37℃ for 24h, when growing on MRS (ManRogosa Sharpe Broth) agar medium, the colony diameter is about 1mm, shiny, dome-shaped and opaque, and sticky when touched with an inoculation loop. According to the above biological characteristics, the suspected colony is picked up with an inoculation needle and streaked inoculated in the MRS plate, incubated at 37℃ for 24h, and then its whole genome is analyzed.

[0046] Example 2

[0047] Genetic characterization of strains

[0048] As shown in Table 1, the chromosome genome length of Limosilactobacillus reuteri Glory LR15 is 2.24Mb, with a total of 2,330 CDS (coding genes); the plasmid genome length is 1.31kb. Using Limosilactobacillus reuteri DSM 20016T as the model strain, together with Limosilactobacillus reuteri CECT8605, Limosilactobacillus reuteri RC-14 and Limosilactobacillus reuteri ZLR003, an ANI heat map and a phylogenetic tree constructed with 1201 core genes were drawn. Combined with the phylogenetic tree ( Figure 1 ) and ANI results ( Figure 2 ) showed that the ANI between Glory LR15 and Limosilactobacillus reuteri DSM 20016T was 95.39%, and the ANI values ​​between strains within the species were in the range of 94.87%-98.74%, indicating that the nucleotide identity within Limosilactobacillus reuteri was low. Glory LR15 and RC-14 were clustered in the same branch, and the two had a common ancestor, but the genetic distance between them was far. Figure 3 Using iProbiotics platform Model1: Probiotic Predictor analysis, it was found that the probability of GloryLR15 being a probiotic was 99.96%, slightly higher than RC-14 (98.97%).

[0049] Table 1 Basic information of strain genome

[0050]

[0051] Example 3

[0052] The oral whey protein sensitization model of C57BL / 6 mice was established. The C57BL / 6 mice were female mice with a volume of 18-22g. There were three groups in total, including a negative control group (G1, n = 5), a positive control group (G2, n = 5, whey sensitization), and a Lactobacillus reuteri preparation intervention group (G3, n = 5, Lactobacillus reuteri gavage group). The mice in the G1 group were gavaged with 200 μL of PBS daily, the mice in the G2 group were gavaged with 200 μL of PBS daily, and they were also gavaged with 0.2 mL of PBS containing 20 mg of homogenized whey protein and 10 μg of adjuvant MC903 (calcipotriol) daily. The mice in the G3 group were gavaged with 200 μL of 4*10 8cfu / ml Lactobacillus reuteri preparation, and also gavage 0.2mL of PBS containing 20mg homogenized whey protein and 10ug adjuvant MC903 (calcipotriol) every day for 4 weeks. Blood was collected from the canthus before stimulation and the supernatant was centrifuged. Finally, 0.2mL of PBS containing 100mg whey protein was gavaged. The rectal body temperature was measured once 30min before and after gavage. The allergic symptoms were observed during 30-60 minutes after gavage and each mouse was scored according to the standards in Table 2 below.

[0053] Afterwards, the mice were killed and samples were taken for testing. Serum-specific IgE was measured using enzyme-linked immunosorbent assay. Intestinal tissue was taken, mRNA was extracted and reverse transcribed into cDNA, and the expression of cytokine IFN-γ gene and cytokine IL-10 gene was detected using fluorescence quantitative method. After the mice were killed, they were soaked in 75% alcohol for 10 minutes, dissected in a biosafety cabinet, and then the intestinal tissue was unfolded. 1 cm of jejunum and colon tissue was taken along the lower part of the stomach in the order of duodenum, jejunum, ileum, and colon, immersed in 1 mL4% polyformaldehyde, embedded in paraffin, and sliced. HE staining was performed and immune cell infiltration and intestinal epithelial damage were observed under a microscope.

[0054] Table 2 Scoring criteria for mouse allergy symptoms

[0055]

[0056] Experimental results:

[0057] (1) The Lactobacillus reuteri preparation of the present invention significantly improves allergic symptoms

[0058] The allergic symptom scores of mice are shown in Table 3 and Figure 4 As shown, the scores of G2 and G3 groups increased compared with those of G1 group, indicating that mice in G2 and G3 groups had allergic symptoms, but compared with the sensitized group G2, the allergic symptom scores of mice in G3 group decreased significantly, and increased significantly compared with those in G1 group. This indicates that oral administration of Lactobacillus reuteri Glory LR15 preparation can significantly improve the allergic symptoms of mice and achieve the purpose of alleviating cow milk allergy.

[0059] Table 3 Behavioral scores

[0060]

[0061] (2) The Lactobacillus reuteri preparation of the present invention relieves allergic pathological symptoms

[0062] By measuring the changes in rectal temperature half an hour before and after the stimulation with whey protein, as shown in Table 4 and Figure 5It can be seen that compared with the negative control group G1, the body temperature of mice in groups G2 and G3 decreased significantly in a short period of time; compared with group G2, the body temperature of group G3 decreased less than that of group G2, indicating that the symptoms were relieved. This shows that the present invention can alleviate the purpose of whey protein allergy by intragastric administration of Lactobacillus reuteri Glory LR15.

[0063] Table 4 Results of changes in rectal temperature of mice before and after stimulation

[0064]

[0065]

[0066] (3) The Lactobacillus reuteri preparation of the present invention relieves allergic pathological symptoms

[0067] HE staining and microscopic examination were used to observe immune cell infiltration and intestinal epithelial damage. Figure 6 It can be seen that in the jejunum, compared with the negative control group G1, the G2 group had broken villi and immune cell infiltration; compared with the G2 group, the G3 group had alleviated the broken villi. Figure 7 It can be seen that the thickness of the muscular layer of the jejunum and colon in the G3 group was increased compared with the G2 group, indicating that the present invention can alleviate the purpose of whey protein allergy by intragastric administration of Lactobacillus reuteri Glory LR15.

[0068] (4) The Lactobacillus reuteri preparation of the present invention significantly reduces the content of IgE

[0069] like Figure 8 As shown in the figure, whey sensitization in group G2 led to a significant increase in specific IgE levels in mice. However, supplementation of Lactobacillus reuteri preparation in group G3 significantly reduced IgE levels and reduced them to a level that was not significantly different from that in healthy mice, indicating that supplementation of Lactobacillus reuteri Glory LR15 can effectively alleviate the problem of elevated IgE caused by whey protein allergy.

[0070] (5) The Lactobacillus reuteri preparation of the present invention regulates the expression of Th1 and Th2 type cytokine related genes

[0071] By measuring the expression of related genes in the intestine. Fig. 9 , 10 It can be seen that compared with the sensitized group G2, the expression level of Th1 cytokine IFN-γ in the intestine of mice in group G3 was significantly upregulated, while the gene level of Th2 cytokine IL-10 was significantly decreased, indicating that the Lactobacillus reuteri Glory LR15 of the present invention can alleviate whey protein allergy by regulating the expression of Th1 and Th2 cytokine related genes.

[0072] Example 4

[0073] The oral whey protein sensitization model of C57BL / 6 mice was established, with a total of three groups, including a negative control group (G1, n=5), a positive control group (G2, n=5, whey sensitization), and a Lactobacillus reuteri preparation intervention group (G3, n=5, Lactobacillus reuteri gavage group). The mice in group G1 were gavaged with 200 μL of PBS daily, the mice in group G2 were gavaged with 0.2 mL of PBS containing 20 mg of homogenized whey protein and 10 ug of adjuvant MC903 daily for sensitization, and the mice in group G3 were gavaged with 0.2 mL of PBS containing 20 mg of homogenized whey protein and 10 ug of adjuvant MC903 (calcipotriol) daily, and 200 μL of 4*10 8 cfu / mL inactivated Lactobacillus reuteri preparation for 4 weeks. The preparation method of the inactivated Lactobacillus reuteri preparation is as follows: Lactobacillus reuteri is cultured in a culture medium at 37°C for 12h and then heat-killed at 90°C for 15min. The bacterial cells are obtained by centrifugation (4000rpm / min, 15min, 4°C) and washed three times with sterile phosphate buffered saline. After washing, they are mixed with a protective agent and placed at -80°C for pre-freezing. Under sterile conditions, inactivated Lactobacillus reuteri powder is obtained by vacuum freeze drying and grinding. In order to confirm that the bacteria are inactivated, a small amount of inactivated Lactobacillus reuteri powder prepared is incubated in a culture medium at 37°C for 24 hours to ensure that the bacteria do not survive. Before stimulation, blood was collected from the canthus and centrifuged to obtain the supernatant. Finally, the rats were gavaged with 0.2 mL of PBS containing 100 mg of whey. The rectal temperature was measured once 30 minutes before and after gavage. The allergic symptoms were observed during 30-60 minutes after gavage and scored according to the following Table 2.

[0074] Afterwards, the mice were killed and samples were taken for testing. Serum-specific IgE was measured using enzyme-linked immunosorbent assay. Intestinal tissue was taken, mRNA was extracted and reverse transcribed into cDNA, and gene expression was detected using fluorescence quantification. After the mice were killed, they were soaked in 75% alcohol for 10 minutes, dissected in a biosafety cabinet, and then the intestinal tissue was unfolded. 1 cm of jejunum and colon tissue was taken along the lower part of the stomach in the order of duodenum, jejunum, ileum, and colon, and immersed in 1 mL of 4% polyformaldehyde, embedded in paraffin, and sliced. HE staining was performed and immune cell infiltration and intestinal epithelial damage were observed under a microscope.

[0075] Experimental results:

[0076] (1) The Lactobacillus reuteri preparation of the present invention significantly improves allergic symptoms

[0077] The allergic symptom scores of mice are shown in Table 5 and Fig.11As shown, compared with the sensitized group G2, the allergic symptom score of mice in group G3 decreased significantly, and increased significantly compared with group G1, which shows that oral administration of Lactobacillus reuteri preparation can significantly improve the allergic symptoms of mice and achieve the purpose of alleviating cow's milk allergy.

[0078] Table 5 Behavioral scores

[0079]

[0080] (2) The Lactobacillus reuteri preparation of the present invention relieves allergic pathological symptoms

[0081] The changes in rectal temperature before and after half an hour of stimulation by intragastric whey protein were measured. Fig.12 It can be seen that compared with the negative control group G1, the body temperature of mice in groups G2 and G3 decreased significantly in a short period of time; compared with group G2, the symptom of body temperature decrease in group G3 was alleviated, indicating that the present invention can alleviate the purpose of whey protein allergy by intragastric administration of Lactobacillus reuteri.

[0082] Table 6 Results of changes in rectal temperature of mice before and after stimulation

[0083]

[0084] (3) The Lactobacillus reuteri preparation of the present invention relieves allergic pathological symptoms

[0085] HE staining and microscopic examination were used to observe immune cell infiltration and intestinal epithelial damage. Fig.13 It can be seen that in the jejunum, compared with the negative control group G1, the G2 group had broken villi and immune cell infiltration; compared with the G2 group, the G3 group had alleviated the broken villi. Fig.14 It can be seen that compared with the G2 group, the thickness of the muscular layer of the jejunum and colon increased, indicating that the present invention can alleviate the purpose of whey protein allergy by intragastric administration of Lactobacillus reuteri.

[0086] (4) The Lactobacillus reuteri preparation of the present invention significantly reduces the content of IgE

[0087] like Fig.15 As shown in the figure, whey sensitization caused a significant increase in specific IgE levels in mice. However, supplementation with Lactobacillus reuteri preparations can significantly reduce IgE levels and reduce them to a level that is not significantly different from that of healthy mice, indicating that supplementation with Lactobacillus reuteri can effectively alleviate the problem of increased IgE caused by whey protein allergy.

[0088] (5) The Lactobacillus reuteri preparation of the present invention regulates the expression of Th1 and Th2 type cytokine related genes

[0089] By measuring the expression of related genes in the intestine. Fig.16 ,17 It can be seen that compared with the sensitized group, the expression level of Th1 cytokine IFN-γ in the intestine of mice in group G3 was significantly upregulated, while the gene level of Th2 cytokine IL-10 was significantly decreased, indicating that the present invention can alleviate whey protein allergy by regulating the expression of Th1 and Th2 cytokine related genes.

[0090] Primer sequence list:

[0091]

[0092] q-PCR reaction procedure

[0093]

[0094]

[0095] In summary, the Lactobacillus reuteri of the present invention can significantly reduce the allergic reaction-specific antibody IgE of milk-allergic mice and regulate the expression of Th1 and Th2 cytokine genes in the body, thereby regulating the body's immune function to prevent or treat milk-induced allergic reactions, thereby alleviating allergic reactions. Therefore, the Lactobacillus reuteri can be used to alleviate milk-induced allergic reactions.

[0096] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A strain of Lactobacillus reuteri Glory LR15, characterized in that: The classification name of the Lactobacillus reuteri Glory LR15 is Limosilactobacillus reuteri, which is deposited in the General Microbiology Center of the China Culture Collection Administration, with a deposit number of CGMCC No. 26972. The deposit date is March 31, 2023, and the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences.

2. A use of Lactobacillus reuteri Glory LR15 as claimed in claim 1, characterized in that: Limosilactobacillus reuteri Glory LR15 is used to prepare a medicine for allergic reaction induced by cow's milk.

3. The use according to claim 2, characterized in that: The Lactobacillus reuteri Glory LR15 upregulates the expression level of Th1 cytokine IFN-γ and downregulates the gene expression level of Th2 cytokine IL-10, thereby affecting the secretion of immunoglobulins, and at the same time reduces the pro-inflammatory factors and specific IgE in the serum of allergic people to alleviate the allergic reaction induced by cow's milk.

4. A composition comprising the Lactobacillus reuteri Glory LR15 according to claim 1.

5. The composition according to claim 4, characterized in that The Lactobacillus reuteri GloryLR15 in the composition is a live bacterium or an inactivated bacterium.

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