A strain of Lactobacillus rhamnosus derived from breast milk and its application

Abstract

The present invention provides a strain of Lactobacillus rhamnosus derived from breast milk and its application. Lactobacillus rhamnosus B2‑1 has been deposited in the China General Microbial Culture Collection Management Center on December 8, 2022, with a deposit number of CGMCC NO.26167. The present invention also provides the application of the above-mentioned Lactobacillus rhamnosus in the preparation of medicines and / or foods and a composition including the Lactobacillus rhamnosus and / or its fermentation product. The Lactobacillus rhamnosus of the present invention is separated from breast milk and is more easily accepted by consumers than lactobacillus from other sources; at the same time, the strain also has good acid resistance, bile salt resistance, antibacterial and immunomodulatory properties, and has good application prospects in the fields of medicine and food.

Description

[0001] Cross-references

[0002] The present invention claims the priority of the Chinese patent application filed with the Chinese Patent Office, with application number 202310050530.6, application date February 1, 2023, and application name “A strain of Lactobacillus rhamnosus derived from breast milk and its application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The invention relates to the field of microorganisms, and in particular to a lactobacillus rhamnosus strain derived from breast milk and an application thereof. Background Art

[0004] Probiotics are essential for human growth and development, and immune regulation. A large number of research documents have shown that probiotics are closely related to gastrointestinal dysfunction (such as diarrhea, constipation, inflammatory bowel disease, etc.), metabolic diseases (such as osteoporosis, obesity, hyperlipidemia, hypertension, diabetes, hyperuricemia, etc.), and nervous system diseases (such as insomnia, depression, Alzheimer's disease, anxiety, etc.).

[0005] There are many kinds of probiotics on the market. However, most probiotics come from intestinal flora or food. Lactobacillus rhamnosus is one of the common probiotics. The National Health Commission of China announced that there are 14 strains of probiotics that can be used in infant food in China, including 3 strains of Lactobacillus rhamnosus, two of which come from the intestines and one from food. Due to the limited sample source and low probiotic content, the proportion of commercial probiotics derived from breast milk is very small.

[0006] In view of this, this invention is proposed. Summary of the invention

[0007] The purpose of the present invention is to provide a strain of Lactobacillus rhamnosus derived from breast milk, which has good acid resistance, bile salt resistance, antibacterial property and good immunomodulatory effect, and has good application prospects in the fields of medicine and food.

[0008] In order to achieve the above-mentioned purpose, the present invention provides a strain of Lactobacillus rhamnosus B2-1 derived from breast milk, which has been deposited in the General Microbiology Center of China National Microbiological Culture Collection Administration on December 8, 2022, with a deposit number of CGMCC No.26167.

[0009] On the other hand, the present invention also provides the use of the above-mentioned Lactobacillus rhamnosus B2-1 in the preparation of medicines and / or foods.

[0010] Preferably or optionally, the drug is a drug for treating, preventing or alleviating one or more of gastrointestinal dysfunction, metabolic diseases, nervous system diseases, and allergic rhinitis.

[0011] Preferably or optionally, the symptom of gastrointestinal dysfunction is at least one of diarrhea, constipation and inflammatory bowel disease.

[0012] Preferably or optionally, the symptom of the metabolic disease is at least one of osteoporosis, obesity, hyperlipidemia, hypertension, diabetes, and hyperuricemia; optionally, the treatment, prevention or alleviation of the metabolic disease includes lowering uric acid.

[0013] Preferably or optionally, the neurological disease is at least one of insomnia, depression, Alzheimer's disease, and anxiety.

[0014] Preferably or optionally, the food is a functional food for immunomodulation, relief of one or several symptoms of gastrointestinal dysfunction, metabolic diseases, and nervous system diseases.

[0015] Preferably or optionally, the symptom of gastrointestinal dysfunction is at least one of diarrhea, constipation and inflammatory bowel disease.

[0016] Preferably or optionally, the symptom of the metabolic disease is at least one of osteoporosis, obesity, hyperlipidemia, hypertension, diabetes, and hyperuricemia.

[0017] Preferably or optionally, the neurological disease is at least one of insomnia, depression, Alzheimer's disease, and anxiety.

[0018] In other aspects, the present invention also provides a composition comprising the above-mentioned Lactobacillus rhamnosus B2-1 and / or its fermentation product.

[0019] Beneficial Effects

[0020] The rhamnosus lactobacillus provided by the present invention is separated from breast milk and is more easily accepted by consumers than lactobacillus from other sources. At the same time, the strain also has good acid resistance, bile resistance, antibacterial and immunomodulatory properties, and rhamnosus lactobacillus B2-1 significantly down-regulates the expression of splenocyte TNFα, IL-1β, IL-6, and up-regulates the expression of IL-12. TNFα, IL-1β, IL-6 are relatively important inflammatory factors, and IL-12 plays an important role in hypersensitivity reactions and has the effect of reducing uric acid. Therefore, rhamnosus lactobacillus B2-1 has good application prospects in both medicine and food fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the complete genome map of Lactobacillus rhamnosus B2-1;

[0022] Figure 2 This is a graph showing the results of the acid resistance test for 1 hour in Example 2;

[0023] Figure 3 This is a graph showing the results of a 3-hour acid resistance test in Example 2;

[0024] Figure 4 This is a graph showing the bile salt resistance test results in Example 3;

[0025] Figure 5 This is a production curve diagram of Lactobacillus rhamnosus B2-1 obtained in Example 4;

[0026] Figure 6 is a graph showing the concentration of TNFα in each group measured in Example 7;

[0027] Figure 7 is a graph showing the concentration of IL-1β in each group measured in Example 7;

[0028] Figure 8 is a graph showing the concentration of IL-6 in each group measured in Example 7;

[0029] Fig. 9 is a graph showing the concentration of IL-12 in each group measured in Example 7;

[0030] Fig.10 The uric acid concentration of honey bee hemolymph in each group measured in Example 8. ** indicates P < 0.01, *** indicates P < 0.001;

[0031] Fig.11 The Wnt_Rho1 gene expression in the intestinal tissues of each group measured in Example 8. * indicates P < 0.05;

[0032] Fig.12 The intestinal Atg1 gene expression of each group measured in Example 8. *** indicates P < 0.001;

[0033] Fig.13 The intestinal tissue MAPK_phl gene expression of each group measured in Example 8. *** indicates P < 0.001;

[0034] Fig.14 The PGRP_LC gene expression in the intestinal tissue of each group was measured in Example 8. ** indicates P < 0.01.

[0035] Fig.15 The Toll gene expression in intestinal tissues measured in Example 8. * indicates P < 0.05, ** indicates P < 0.01. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are 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.

[0037] In addition, in order to better illustrate the present invention, numerous specific details are provided in the specific embodiments below. It should be understood by those skilled in the art that the present invention can also be implemented without certain specific details. In some embodiments, raw materials, elements, methods, means, etc. well known to those skilled in the art are not described in detail, so as to highlight the main purpose of the present invention.

[0038] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0039] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0040] The present invention proposes a strain of Lactobacillus rhamnosus B2-1, which was deposited in the General Microbiology Center of China Culture Collection Administration (CGMCC for short, address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101) on December 8, 2022, with a deposit number of CGMCC NO.26167.

[0041] Among them, the reagents and raw materials used in the embodiments of the present invention are

[0042] MRS / MRSA culture medium was purchased from Beijing Luqiao Technology Co., Ltd.;

[0043] Mouse TNFα, IL-1β, IL-6, and IL-12 ELISA kits were purchased from Abcam;

[0044] The remaining reagents are commercially available.

[0045] The control commercial strain, Lactobacillus rhamnosus D001, was deposited in the General Microbiology Center of China Culture Collection Administration (CGMCC for short, address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Building 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101) on February 8, 2023, with the deposit number CGMCC No. 26533.

[0046] MRS broth medium was purchased from Beijing Luqiao Technology Co., Ltd. with the catalog number CM187.

[0047] Nutrient agar was purchased from Beijing Luqiao Technology Co., Ltd. with the product number CM107.

[0048] Escherichia coli ATCC 25922 was purchased from Guangdong Microbiological Strain Collection Center.

[0049] Staphylococcus aureus ATCC 25923 was purchased from Guangdong Microbiological Strain Collection Center.

[0050] Shigella sonnei ATCC25931 was purchased from Guangdong Microbiological Strain Collection Center.

[0051] Salmonella enteritidis ATCC14028 was purchased from Guangdong Microbiological Strain Collection Center.

[0052] The preparation method of the corresponding strain supernatant used in each embodiment of the present invention is as follows: 100 μL of the corresponding strain cultured for 8 hours is inoculated into 10 mL of MRS broth medium, cultured at 37°C, 220 rpm for 12 hours, then centrifuged at 10,000 rpm for 10 minutes, and the supernatant is obtained.

[0053] Example 1

[0054] This example provides the isolation and identification of Lactobacillus rhamnosus B2-1 from human milk.

[0055] Fresh breast milk samples were selected, gradiently diluted with sterile PBS buffer, and then spread on MRS solid culture medium containing 1% calcium carbonate. The samples were cultured under anaerobic conditions at 37°C for 48 hours, and then single colonies with good growth were picked for amplification and 16S sequencing. According to the sequencing results, they were named Lactobacillus rhamnosus B2-1 and enriched in an anaerobic incubator at 37°C. After the cultivation was completed, the amplification laboratory was preserved and sent to the China General Microbiological Culture Collection Center for preservation on December 8, 2022, with the preservation number CGMCC No.26167.

[0056] The strain B2-1 was identified as Lactobacillus rhamnosus by 16S sequencing, and the whole genome of the strain was sequenced using Pacbio (10Kb SMRTBell library) and Illumina PE150 (350bp small fragment library) sequencing platforms. The whole genome obtained by sequencing is shown in Figure 1 As shown, it was determined that Lactobacillus rhamnosus B2-1 contained 2,961,839 bases and 2,896 genes, and the plasmid contained 30,650 bases and 36 genes.

[0057] The sequencing results were annotated using the NR database.

[0058] Example 2

[0059] This example provides a test of the acid resistance of the above strain and a comparison with other strains.

[0060] The rhamnosus Lactobacillus strain B2-1, the rhamnosus Lactobacillus D001 (preservation number CGMCCNO.26533) and the control Lactobacillus plantarum P6 (the preservation number of Lactobacillus plantarum P6 is CGMCC No.19748, and the strain has been disclosed in the patent CN111778180A applied for on June 12, 2020) were activated and washed with sterile PBS buffer, and then added to sterile MRS broth medium with pH=1.5, pH=2.0, and pH=3.0 adjusted with 1 mol / L hydrochloric acid, respectively, and cultured anaerobically at 37°C, and samples were taken at 0, 1, and 3h, respectively. The samples were gradiently diluted and spread on MRS solid culture medium plates, counted after anaerobic culture at 37°C for 48h, and the survival rate was calculated according to the following formula.

[0061] Survival rate (%) = (N / N 0h )×100

[0062] Where N is the sampling count data at 1 or 3 hours, N 0h It is the sampling count data at 0h.

[0063] Acid resistance test results Figure 2-3 shown.

[0064] Since probiotics need to pass through the gastric juice after entering the human body, only the surviving probiotics can play a probiotic role. Figure 2 and 3It can be seen that Lactobacillus rhamnosus B2-1, Lactobacillus rhamnosus D001 and Lactobacillus plantarum P6 cannot survive at pH = 1.5 for 1 hour and 3 hours; but at pH = 2.0, the survival rates of Lactobacillus rhamnosus B2-1 strain at 1 hour and 3 hours are 21.45±2.45% and 13.41±0.81%, respectively; while the control strain Lactobacillus rhamnosus D001 cannot survive at 1 hour and 3 hours; P6 has a survival rate of 15.54±2.30% at 1 hour and cannot survive at 3 hours. Under the condition of pH=3.0, the survival rates of B2-1 strain at 1 hour and 3 hours were 42.15±12.00% and 115.38±15.84%, respectively; the survival rates of the control strain D001 strain at 1 hour and 3 hours were 30.59±8.98% and 82.35±18.15%, respectively; the survival rates of P6 at 1 hour and 3 hours were 80.36±8.75% and 61.43±19.01%, respectively. In short, B2-1 has a better survival rate than the control group under the condition of pH=2.0. Under the condition of pH=3.0, the survival rate at 3 hours is significantly higher than that of the control group. Under the condition of pH=3.0, the survival rate of B2-1 at 3 hours is higher than that at 1 hour, indicating that B2-1 has adapted to the environment of pH 3.0 and started to proliferate. The above results show that the acid resistance of Lactobacillus rhamnosus strain B2-1 is better than that of the control group.

[0065] Example 3

[0066] This example provides a bile salt tolerance test of the above strain and a comparison with other strains.

[0067] After activation, the Lactobacillus rhamnosus strain B2-1 and the control Lactobacillus rhamnosus D001 and Lactobacillus plantarum P6 (deposit number CGMCC No.19748) were washed with sterile PBS buffer, then resuspended in sterile MRS broth medium containing 0.3% bile salt, cultured anaerobically at 37°C, and sampled at 0, 1, and 3 hours, respectively. The samples were gradiently diluted and spread on MRS solid culture medium plates, and counted after anaerobically cultured at 37°C for 48 hours, and the survival rate was calculated according to the following formula.

[0068] Survival rate (%) = (N / N 0h )×100

[0069] Where N is the sampling count data at 1 or 3 hours, N 0h It is the sampling count data at 0h.

[0070] The bile salt resistance test results are as follows Figure 4 shown.

[0071] from Figure 4It can be seen that under the condition of 1h of culture in MRS broth containing 0.3% bile salts, the survival rate of strain B2-1 was 12.54±2.36%, while the survival rates of the control strains D001 and P6 were 10.39±3.61% and 20.43±4.12%, respectively. The survival rate of the control group P6 was significantly higher than that of B2-1 and D001. Under the condition of 3h of culture, the survival rate of B2-1 dropped to about 5%, while the survival rates of D001 and P6 dropped more significantly, with only about 1% surviving. In short, in the culture of MRS broth with 0.3% bile salts, the 3-hour survival rate of B2-1 was significantly higher than that of the control group D001 and P6, indicating that strain B2-1 has good bile salt tolerance.

[0072] Example 4

[0073] This example provides a growth curve of Lactobacillus rhamnosus strain B2-1.

[0074] The activated strain B2-1 was inoculated into MRS broth medium and placed in a 37°C incubator for anaerobically culture. The absorbance OD at each time point was measured at 0, 2, 4, 6, 8, 10, 12, 16, 20, 24, 28, 32, 36, 40 and 48 h. 600 , and draw a growth curve.

[0075] The growth curve drawn is as follows Figure 5 shown.

[0076] from Figure 5 It can be seen that the lag phase of strain B2-1 is relatively short, being in the logarithmic phase within 2-6 hours, entering the stable phase after 6 hours of culture, and reaching a higher bacterial liquid concentration. It is in the stable phase between 8-40 hours of culture, and begins to enter the decline phase after 40 hours.

[0077] Example 5

[0078] This example provides a test of the antibacterial performance of the above strain and a comparison with other strains.

[0079] Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Shigella sonnei ATCC25931, and Salmonella enteritidis ATCC14028 were used as indicator bacteria. The activated indicator bacteria were spread on nutrient agar, and the agar diffusion method was used to perform a preliminary determination of antibacterial activity. The Oxford cup was placed on the plate with sterile tweezers, and sterile nutrient agar was poured in to fix the Oxford cup. After it solidified, the Oxford cup was taken out, and 100 μL of the prepared B2-1, D001, and P6 supernatants were respectively drawn and added to the wells. The plate was placed in a 4°C refrigerator for diffusion for about 3 hours, and then placed at 37°C for constant temperature culture for 24 hours. The diameter of the inhibition zone was observed and the size was recorded. The results were expressed as mean ± standard deviation.

[0080] The antibacterial performance test results are shown in Table 1.

[0081] Table 1 Antibacterial performance test results

[0082]

[0083] Probiotics can come into contact with pathogenic bacteria in the body, so probiotics must have a certain antibacterial ability to play a role in the human body. From Table 1, it can be seen that strain B2-1 has a certain inhibitory ability against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC25923, Shigella sonnei ATCC 25931 and Salmonella enteritidis ATCC 14028; while D001 only has a certain antibacterial effect on Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, that is, B2-1 has better comprehensive antibacterial performance than the same strain D001.

[0084] Example 6

[0085] This example provides a test for the drug resistance of Lactobacillus rhamnosus strain B2-1.

[0086] The concentration of the third generation B2-1 bacterial solution was diluted to 10 7 CFU / mL, take 100 μL of diluted bacterial solution, evenly apply it on MRS solid culture medium with a coating rod, and after standing for 20 minutes, take each antibiotic's drug-sensitive paper and blank paper at an equal distance and place them in MRS solid culture medium, gently compact to ensure that they will not slide. Under 37 ° C conditions, after anaerobic culture for 18-24 hours, the diameter (mm) was measured using a vernier caliper, and the results were expressed as mean ± standard deviation. The antibiotic drug-sensitive paper used in this embodiment includes 6 antibiotics including ceftriaxone, tetracycline, penicillin, gentamicin, enrofloxacin, and polymyxin B.

[0087] The drug resistance test results are shown in Table 2.

[0088] Table 2 Drug resistance test results of Lactobacillus rhamnosus strain B2-1

[0089]

[0090] As can be seen from Table 2, strain B2-1 is sensitive to ceftriaxone, penicillin and gentamicin, and resistant to tetracycline, enrofloxacin and polymyxin B.

[0091] Example 7

[0092] This example provides a test of the immunomodulatory properties of the above strains and a comparison with other strains.

[0093] C57BL / 6 mice aged 6-8 weeks were killed by dislocation, soaked in 75% ethanol for 3 minutes, and placed on sterile filter paper. The spleen was removed and placed in a culture dish containing 5 mL of Hanks solution. The spleen was placed on a sterile 100-mesh filter and ground and filtered with a sterile needle plug to obtain a mouse spleen cell suspension, and the concentration of the mouse spleen cell suspension was adjusted to 1×10 6 The cells / mL suspension is ready for use.

[0094] Take a 96-well plate, add 100 μL of the mouse spleen cell suspension prepared above to each well, then add 20 μL of the supernatant of B2-1, D001 or P6, and add LPS (lipopolysaccharide) and ConA (concanavalin A) to each well, so that the final concentration of LPS in each well is 500 μg / mL, and the final concentration of ConA is 250 μg / mL, and at the same time, replace the supernatant with an equal volume of Hanks solution to set up a blank model group. Culture at 37°C, 5% CO2 for 48 hours.

[0095] The supernatant of each well was taken and the concentration of the corresponding immune factors in the supernatant was detected using TNFα, IL-1β, IL-6 and IL-12 ELISA kits respectively.

[0096] The results of the test are as follows Figure 6-9 shown.

[0097] Immunomodulation is a very important probiotic function of probiotics. Many chronic diseases and metabolic diseases are closely related to immune disorders. In this example, LPS and ConA were used to stimulate mouse spleen cells, which then interacted with the culture supernatant of each strain for 48 hours. Figure 6-9 It can be seen that Lactobacillus rhamnosus B2-1 can significantly downregulate the concentrations of TNFα, IL-1β and IL-6 in the supernatant of spleen cell culture, and upregulate the content of IL-12. The D001 strain, which is also Lactobacillus rhamnosus, can only downregulate the content of TNFα and has no regulatory effect on other inflammations; Lactobacillus plantarum P6 can downregulate the concentrations of IL-1β and IL-6, but has no effect on TNFα and IL-12. These in vitro cell experiments prove that Lactobacillus rhamnosus B2-1 has a strong immunomodulatory function and has a strong probiotic potential.

[0098] Example 8

[0099] Strains and animals Example 1: The isolated Lactobacillus rhamnosus B2-1 and honey bees (Apis mellifera) were purchased from China Agricultural University. This experiment was commissioned by Suzhou Fenghua Biotechnology Co., Ltd.

[0100] Experimental methods

[0101] 1) Grouping: blank group, model group and intervention group, each with 120 one-day-old honey bees.

[0102] 2) Hyperuric acid modeling and probiotic intervention. Modeling: 120 one-day-old bees in the blank group were fed with 50% sugar water + milk powder for 12 days; another 240 one-day-old bees were modeled with hyperuric acid - fed with 50% sugar water + milk powder + 1% yeast RNA for 7 days. The blood uric acid value of the model group (the blood uric acid of bees refers to the uric acid in the hemolymph of bees, which is equivalent to uric acid in human blood) increased significantly, and the hyperuric acid model was successfully established. The bees were randomly divided into a modeling group and an intervention group (240 bees in each group). The bees in the modeling group and the intervention group continued to be fed with high uric acid modeling bee food. At the same time, the intervention group was fed with probiotic samples every day at a rate of 10 10 CFU / g was supplemented (probiotic powder and pollen were added to bee feed at a ratio of 1:20, and new diet was replaced every 24 hours to maintain the activity of probiotics.). Uric acid was evaluated 5 days after probiotic nutritional intervention, and the blood uric acid levels and inflammatory factor gene expression indicators were compared among the control group, model group and intervention group.

[0103] The above modeling method can be used to obtain a hyperuricemia model in honey bees. In mammals, such as rats / mice, it is not easy to obtain a stable chronic hyperuricemia model due to the presence of uricase. Literature reports that it is easier to obtain a stable hyperuricemia model using fruit flies. We used Italian honey bees to model hyperuricemia and also obtained a stable hyperuricemia model. Compared with mammals, the hyperuricemia modeling cycle of honey bees is short, the cost is low, the sample size is large, and the hyperuricemia level is stable. For specific modeling methods, please refer to the literature:

[0104] ①), Tyler AU Hilsabeck, Ru Liu-Bryan, Tracy Guo, et al. A fly GWAS forpurine metabolites identifies human FAM214 homolog medusa, which acts in aconserved manner to enhance hyperuricemia-driven pathologies by modulating purine metabolism and the inflammatory response.Geroscience.2022Aug;44(4):2195-2211.doi:10.1007 / s11357-022-00557-9.

[0105] ②),Pawel Migdal,Agnieszka Murawska,Ewelina et al.SelectedBiochemical Markers Change after Oral Administration of Pesticide Mixtures inHoney Bees.Toxics.2022Oct 5;10(10):590.doi:10.3390 / toxics10100590.

[0106] ③), Yang Tong, Yifeng Wei, Yingjie Ju, et al. Anaerobic purinolyticenzymes enable dietary purine clearance by engineered gut bacteria. Cell ChemBiol.2023Sep21;30(9):1104-1114.e7.doi:10.1016 / j.chembiol.2023.04.008.

[0107] ④), Jin Mengjie, Li Zhen, Liu Jianhui, et al. Comparison of morphological and physiological and biochemical indicators between queen bees and worker bees emerging from the hive. Journal of Jiangxi Agricultural University. 2023, 45(5). DOI: 10.13836 / j.jjau.2023112.

[0108] 3) Expression of mRNA of inflammatory factors: The intestinal tissue of honey bees was extracted and quickly frozen with liquid nitrogen and then stored in a -80°C refrigerator. The intestine was taken out to extract RNA and then reverse transcribed to obtain sample cDNA. The expression levels of Wnt_Rho1, Atg1, MAPK_phl, PGRP-LC, and Toll immune factor genes were detected by qPCR.

[0109] Experimental Results :

[0110] The uric acid in the hemolymph of bees in each group Fig.10 As shown in the figure, the hemolymph uric acid concentration of normal bees in the blank group was 981.91±226.84μmol / L, and that in the model group was 1523.70±357.42μmol / L, which was significantly higher in the model group than in the blank group (P<0.01), indicating that the hyperuricemia model of bees was successfully established. After intervention with Lactobacillus rhamnosus B2-1, the hemolymph uric acid concentration dropped to 394.55±130.11μmol / L, which was significantly lower than that in the model group (P<0.001) and the blank group (P<0.01).

[0111] The results of mRNA detection on honey bees are shown in Figures 11 to 15. The results showed that the mRNA of important factors related to the inflammatory pathway in the model group increased significantly, such as Wnt_Rho1, which increased by 2 times ( Fig.11 ), Atg1 gene expression increased more than 20 times ( Fig.12 ), the expression of MAPK_phl and PGRP_LC genes increased by 3 times ( Fig.13 , Fig.14 ), Toll gene expression increased 2-fold ( Fig.15 ). After intervention with Lactobacillus rhamnosus B2-1, the expression of these genes decreased significantly and returned to the level of the blank group. This indicates that Lactobacillus rhamnosus B2-1 can not only significantly reduce the uric acid concentration in the hemolymph of bees, but also regulate the immune pathway and reduce the expression of inflammatory factors.

[0112] It can be seen from the above embodiments that the Lactobacillus rhamnosus B2-1 provided by the present invention has good acid resistance and bile salt resistance, and in vitro experiments have also been shown to have good pathogen inhibition and immunomodulatory functions. Therefore, it has good application prospects, especially for the treatment of one or more of gastrointestinal dysfunction, metabolic diseases, and nervous system diseases. Drugs and functional foods that alleviate one or several symptoms of gastrointestinal dysfunction, metabolic diseases, and nervous system diseases.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A strain of Lactobacillus rhamnosus from breast milk ( Lacticaseibacillus rhamnosus ) B2-1, characterized in that, The rhamnosus Lactobacillus was deposited in the General Microbiology Center of the China Microorganism Culture Collection Administration on December 8, 2022, with the deposit number CGMCC No.26167.

2. Use of the Lactobacillus rhamnosus B2-1 according to claim 1 in the preparation of a drug for treating, preventing or alleviating gastrointestinal dysfunction; in, The symptom of gastrointestinal dysfunction is at least one of diarrhea, constipation and inflammatory bowel disease.

3. Use of the Lactobacillus rhamnosus B2-1 as claimed in claim 1 in the preparation of a medicament for treating, preventing or allergic rhinitis.

4. Use of the Lactobacillus rhamnosus B2-1 as claimed in claim 1 in the preparation of a medicament for treating, preventing or alleviating hyperuricemia.

5. Use of Lactobacillus rhamnosus B2-1 as claimed in claim 1 in preparing food.

6. A composition, characterized in that The composition comprises the Lactobacillus rhamnosus B2-1 described in claim 1.

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