Yak-derived Lactobacillus reuteri with anti-oxidation, anti-inflammatory and anti-hypoxia capabilities and application of Lactobacillus reuteri

Abstract

The invention discloses lactobacillus reuteri with antioxidant, anti-inflammatory and anti-hypoxia capabilities, the name of the lactobacillus reuteri is QM11, the classification name of the lactobacillus reuteri is CGMCC NO.31541, the preservation number of the lactobacillus reuteri is CGMCC NO.31541, the preservation date of the lactobacillus reuteri is No.3, Yard 1, Beichen West Road, Chaoyang District, Beijing on August 5, 2024, and the preservation number of the lactobacillus reuteri is CGMCC NO.31541, the preservation number of the lactobacillus reuteri is CGMCC NO.31541, the preservation number of the lactobacillus reuteri is CGMCC NO.31541, and the preservation number of the lactobacillus reuteri is CGMCC NO.31541. The preservation unit is China General Microbiological Culture Collection Center (CGMCC). The lactobacillus reuteri is separated from faeces of healthy yaks in Qinghai province, has relatively strong acid and cholate tolerance, has relatively good antioxidant and anti-inflammatory capacities, and has a relatively strong inhibition effect on pathogenic bacteria such as yak-derived pathogenic escherichia coli, staphylococcus aureus and salmonella typhimurium; the sodium dextran sulfate induced mouse colitis symptom is relieved, and the hypoxia tolerance of the mouse is improved. The lactobacillus reuteri disclosed by the invention can be used for preparing medicines or microecological preparations for resisting oxidation, inflammation and hypoxia, and has a very wide application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and specifically relates to a yak-derived Lactobacillus reuteri strain with antioxidant, anti-inflammatory and hypoxia-resistant capabilities and an application thereof. Background Art

[0002] Oxygen is very important for maintaining the body's vital activities. If tissue cells do not get enough oxygen or cannot effectively use oxygen, it will cause a series of functional, metabolic and morphological changes in the body. my country has a vast plateau area, and hypoxia in the plateau can cause a series of altitude sicknesses such as headaches, dyspnea, fatigue, and insomnia. Whether entering the plateau quickly or living in the plateau for a long time, the low oxygen and hypoxic environment of the plateau will induce inflammatory reactions, oxidative stress damage, cell damage and apoptosis in the body, affecting the oxidative function, so that all tissues and organs of the body will be affected and reversible or irreversible changes will occur, leading to lung damage, brain damage, myocardial damage, etc.

[0003] Yaks are a species unique to the plateau, able to survive extreme conditions of low temperature and lack of oxygen. Yak farming is an important source of income for people in high-altitude areas, and is also an important source of milk, meat products and leather for local herders. However, yak calves are very susceptible to diarrhea due to the influence of climate, environment, pathogens and other factors, as their gastrointestinal systems and immune systems have not yet matured. Traditional antibiotic treatment accelerates the development of bacterial resistance, and antibiotic residues in meat products can also cause food safety issues. With the country's high attention to the comprehensive management of veterinary antibiotics, the accelerated implementation of the "antibiotic reduction, antibiotic ban, and antibiotic-free products in the breeding industry" action plan has made it urgent to find new methods to prevent and treat diarrhea in yak calves and enhance their growth performance.

[0004] Probiotics are a type of microecological regulator for humans or animals. They have physiological effects such as antibacterial, improving the intestinal environment, lowering blood lipids, anti-tumor and participating in immune regulation. They play an increasingly important role in preventing and treating certain diseases or ensuring the health of humans and animals. Lactobacillus reuteri is a probiotic that exists naturally in the intestines of almost all mammals and vertebrates. Lactobacillus reuteri has a strong adhesion and colonization ability in the intestinal mucosa. It can improve the distribution of intestinal symbiotic flora and antagonize the colonization of pathogenic bacteria. It has obvious antibacterial ability and the function of preventing and treating intestinal infections. However, there is no report on the research on Lactobacillus reuteri in terms of hypoxia tolerance.

[0005] Therefore, it is of great significance to find a strain with antioxidant, anti-inflammatory ability and improved hypoxia tolerance. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a yak-derived Lactobacillus reuteri strain having antioxidant, anti-inflammatory and hypoxia-resistant capabilities and application thereof.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A strain of Lactobacillus reuteri with antioxidant, anti-inflammatory and hypoxia-resistant abilities, wherein the Lactobacillus reuteri is named QM11, the classification name is Lactobacillus reuteri, the preservation number is CGMCC NO.31541, the preservation date is August 5, 2024, No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and the preservation unit is the General Microbiology Center of China Microbiological Culture Collection Administration.

[0009] Furthermore, the Lactobacillus reuteri is isolated from healthy yak feces.

[0010] Furthermore, the colony morphology of the Lactobacillus reuteri on the MRS solid culture medium is small, milky white, round and has neat edges.

[0011] Furthermore, the Lactobacillus reuteri has strong acid and bile salt tolerance.

[0012] The Lactobacillus reuteri has adhesion to the intestines and has antioxidant and anti-inflammatory capabilities;

[0013] The Lactobacillus reuteri has a strong inhibitory effect on pathogenic bacteria such as yak-derived pathogenic Escherichia coli, Staphylococcus aureus and Salmonella typhimurium;

[0014] The Lactobacillus reuteri can alleviate colitis induced by sodium dextran sulfate and improve the survival time of mice in a normal pressure hypoxia tolerance experiment.

[0015] Furthermore, the gene sequence of the Lactobacillus reuteri is SEQ ID NO.1.

[0016] The use of the Lactobacillus reuteri as described above in the preparation of health products or medicines or microecological preparations with antioxidant, anti-inflammatory and hypoxia-resistant effects.

[0017] The advantages and positive effects achieved by the present invention are:

[0018] 1. The Lactobacillus reuteri QM11 strain of the present invention is derived from healthy yaks, has strong tolerance to acid and bile salts, has adhesion to the intestine, has good antioxidant and anti-inflammatory capabilities, and has a strong inhibitory effect on pathogenic bacteria such as yak-derived pathogenic Escherichia coli, Staphylococcus aureus and Salmonella typhimurium.

[0019] 2. Lactobacillus reuteri QM11 of the present invention can alleviate colitis induced by sodium dextran sulfate. The weight loss and disease activity index of mice in the group pretreated with Lactobacillus reuteri were significantly lower than those in the model group, and the colon length was significantly increased compared with the model group.

[0020] 3. The Lactobacillus reuteri QM11 of the present invention can increase the survival time of mice in a normal pressure hypoxia tolerance experiment.

[0021] 4. The Lactobacillus reuteri QM11 of the present invention has good antioxidant, anti-inflammatory and hypoxia resistance capabilities, and is expected to be used in medicines or microecological preparations or feed additives, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a colony morphology diagram of Lactobacillus reuteri QM11 in the present invention;

[0023] Figure 2 is a growth curve diagram of Lactobacillus reuteri QM11 in the present invention;

[0024] Figure 3 is a graph showing the acid resistance of Lactobacillus reuteri QM11 in the present invention;

[0025] Figure 4 is a graph showing the bile salt tolerance of Lactobacillus reuteri QM11 in the present invention;

[0026] Figure 5 This is a graph showing the effect of Lactobacillus reuteri QM11 on the activity of RAW264.7 cells induced by LPS in the present invention, "#" indicates that the LPS group is significantly different from the control group (P < 0.05), and "*" indicates that the different concentration treatment groups are significantly different from the LPS group (P < 0.05);

[0027] Figure 6 This is a graph showing the effect of Lactobacillus reuteri QM11 on NO in LPS-induced RAW264.7 cells in the present invention, "#" indicates that the LPS group was significantly different from the control group (P < 0.05), and "*" indicates that the different concentration treatment groups were significantly different from the LPS group (P < 0.05);

[0028] Figure 7 This is a graph showing the effect of Lactobacillus reuteri QM11 on the disease activity index of colitis mice in the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the embodiments. The following embodiments are descriptive rather than restrictive, and the protection scope of the present invention cannot be limited by the following embodiments.

[0030] The raw materials used in the present invention, unless otherwise specified, are all conventional commercially available products. The methods used in the present invention, unless otherwise specified, are all conventional methods in the art. The quality of each substance used in the present invention is the quality of conventional use.

[0031] A strain of Lactobacillus reuteri with antioxidant, anti-inflammatory and hypoxia-resistant abilities, wherein the Lactobacillus reuteri is named QM11, the classification name is Lactobacillus reuteri, the preservation number is CGMCC NO.31541, the preservation date is August 5, 2024, No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and the preservation unit is the General Microbiology Center of China Microbiological Culture Collection Administration.

[0032] Preferably, the Lactobacillus reuteri is isolated from healthy yak feces.

[0033] Preferably, the colony morphology of the Lactobacillus reuteri on the MRS solid culture medium is small, milky white, round and has neat edges.

[0034] Preferably, the Lactobacillus reuteri has strong acid and bile salt tolerance.

[0035] The Lactobacillus reuteri has adhesion to the intestines and has antioxidant and anti-inflammatory capabilities;

[0036] The Lactobacillus reuteri has a strong inhibitory effect on pathogenic bacteria such as yak-derived pathogenic Escherichia coli, Staphylococcus aureus and Salmonella typhimurium;

[0037] The Lactobacillus reuteri can alleviate colitis induced by sodium dextran sulfate and improve the survival time of mice in a normal pressure hypoxia tolerance experiment.

[0038] Preferably, the gene sequence of Lactobacillus reuteri is SEQ ID NO.1:

[0039]

[0040] The use of the Lactobacillus reuteri as described above in the preparation of health products or medicines or microecological preparations with antioxidant, anti-inflammatory and hypoxia-resistant effects.

[0041] Specifically, the relevant preparation and detection are as follows:

[0042] Example 1: Isolation, purification and identification of strains

[0043] (1) Isolation and purification of strains

[0044] Yak feces samples collected in Maduo County, Golog Tibetan Autonomous Prefecture, Qinghai Province were used to isolate Lactobacillus reuteri. -4 , 10 -5 , 10 -6 100 μL of three gradient dilutions were spread on MRS solid plates respectively, and cultured at 37°C for 48 h. Colonies with different morphologies were selected for streaking separation until pure single colonies with consistent colony morphology were obtained. Single colonies were picked and inoculated into 5 mL MRS liquid culture medium, cultured overnight, and 500 μL of bacterial solution was added with 500 μL 50% glycerol and stored at -80°C.

[0045] (2) Identification of strains

[0046] The isolated strain was subjected to PCR amplification of 16S rDNA, and the PCR product was sent to GENEWISE for sequencing. The sequencing results were subjected to BLAST comparison analysis to obtain a strain of Lactobacillus reuteri, which was named Lactobacillus reuteri QM11.

[0047] (3) Cultivation

[0048] After Lactobacillus reuteri was inoculated onto MRS solid medium and cultured anaerobically at 37°C for 48 hours, the colonies were observed to be small, round, milky white, and with neat edges. Figure 1 shown.

[0049] Example 2: Growth curve of strains

[0050] The Lactobacillus reuteri in Example 1 was inoculated into MRS liquid culture medium and cultured at 37° C. for 24 h. Samples were taken every 2 h. The absorbance at a wavelength of 600 nm was measured using a multifunctional microplate reader to draw a growth curve of the strain. Figure 2 This is the growth curve of Lactobacillus reuteri QM11. Lactobacillus reuteri QM11 entered the logarithmic growth phase after 2 hours, and the 8-24h period was the stable period. The OD 600 It is about 1.2.

[0051] Example 3: Acid and bile resistance test of Lactobacillus reuteri QM11

[0052] The bacteria were resuspended in MRS liquid culture medium with pH 2, 3, 4 and containing 0.1%, 0.2%, and 0.3% bile salts, respectively, and the bacterial solution under normal growth state was used as a control. The absorbance value of each well at 490nm was measured by a multifunctional microplate reader (A experimental group), and compared with the absorbance value of the control group (A control group) to determine the survival rate. Absorbance value. The survival rate was calculated as follows:

[0053] Survival rate (%) = (A experimental group) / (A control group) × 100 Formula (1)

[0054] The results are as follows Figure 3 As shown in the figure, the survival rate of Lactobacillus reuteri QM11 under pH 4 was 96.71% ± 3.5%, which had good acid resistance. The survival rate of Lactobacillus reuteri QM11 after 0.1% bile salt treatment reached 86.04% ± 6.35%, which had good bile salt resistance, as shown in the figure. Figure 4 shown.

[0055] Example 4: Determination of antibacterial ability of Lactobacillus reuteri QM11

[0056] Adjust the concentration of overnight cultured lactic acid bacteria and indicator bacteria suspension to 10 7 CFU / mL, then inoculate the lactic acid bacteria and indicator bacteria into liquid MRS medium at a 2% inoculation rate, and co-culture at 37°C for 12 hours. The bacterial suspension after co-culture is diluted with physiological saline to different dilution gradient concentrations, mixed and 100 μL is spread on LB solid medium, and cultured at 37°C for 48 hours. Count the number of viable indicator bacteria, and use the number of viable indicator bacteria cultured alone as the control group. The antibacterial rate is calculated as follows:

[0057] Inhibition rate (%) = (1-concentration of bacterial solution in experimental group / concentration of bacterial solution in control group) × 100 Formula (2)

[0058] Table 1 Antibacterial ability of Lactobacillus reuteri QM11

[0059]

[0060]

[0061] QM11 has obvious inhibitory effects on 9 pathogenic bacteria, and the results are shown in Table 1. The inhibition rate against Shigella and Listeria monocytogenes is as high as 90%, the inhibition rate against Escherichia coli O157, Escherichia coli QH03 and Cronobacter sakazakii is between 85.68% and 89.21%; the inhibition rate against Escherichia coli QH02 and Salmonella typhimurium is about 74%.

[0062] Example 5: Determination of adhesion of Lactobacillus reuteri QM11

[0063] In this example, Lactobacillus rhamnosus LGG was used as a reference strain.

[0064] HCT-116 cells were cultured at 1×10 5 After the cells grew into a dense monolayer, 10 7 After culturing the CFU bacterial solution for 2 hours, rinse with PBS three times. The absorbance after rinsing with PBS (OD1), the absorbance without rinsing (OD2), and the absorbance of the control group without bacterial solution (OD0) were measured by MTT method. The calculation method of strain adhesion rate is as follows:

[0065] Adhesion capacity (%) = [(OD1-OD0) / (OD2-OD0)] × 100 Formula (3)

[0066] Table 2 Adhesion rate of Lactobacillus reuteri QM11 and Lactobacillus rhamnosus LGG

[0067]

[0068] The results of the strains' adhesion to cells are shown in Table 2. The adhesion rates of LGG and QM11 were 28.86% ± 3.44% and 54.38% ± 2.15%, respectively, which were higher than those of the control strain LGG.

[0069] Example 6: Determination of the Antioxidant Capacity of Lactobacillus reuteri QM11

[0070] In this example, Lactobacillus rhamnosus LGG was used as a reference strain.

[0071] (1) Sample preparation

[0072] The activated bacterial solution was inoculated into liquid MRS medium at a 2% inoculum volume, and the bacterial solution was cultured at 37°C overnight to obtain a culture solution. 1) Preparation of fermentation supernatant: The culture solution was adjusted to a bacterial concentration of 10 9 CFU / mL, centrifuge at 4°C and 6796×g for 15 min, and collect the fermentation supernatant. 2) Preparation of bacterial suspension: The bacterial pellet after centrifugation was resuspended and washed with PBS, centrifuged at 4°C and 6796×g for 15 min, repeated 3 times, and then resuspended in PBS and the bacterial concentration was adjusted to 10 9 3) Preparation of sterile fragments: The bacterial suspension was ultrasonically disrupted on ice, and then centrifuged to obtain the supernatant, which was the sterile fragment.

[0073] (2) Determination of DPPH free radical scavenging rate

[0074] 1 mL of sample solution and 1 mL of 0.15 mmol / L DPPH-ethanol solution were mixed thoroughly and then allowed to stand at room temperature in the dark for 30 min. The supernatant was taken and the absorbance of the sample solution was measured at 517 nm (OD1). PBS was used instead of the sample solution as the absorbance of the blank group (OD0), and ethanol was used instead of the DPPH-ethanol solution as the absorbance of the control group (OD2).

[0075] DPPH free radical scavenging rate = [OD0-(OD1-OD0)] / A0×100% Formula (4)

[0076] (3) Determination of hydroxyl radical scavenging rate

[0077] Take 1mL of sample solution in a test tube, add 1mL of 6 mmol / L ferrous sulfate (FeSO4) and 6mmol / L hydrogen peroxide (H2O2) in turn, let it stand at room temperature for 10 minutes, then add 1mL of 6 mmol / L salicylic acid solution and mix thoroughly, let it stand at room temperature for 30 minutes, and measure the absorbance at 510nm (OD1). Distilled water replaces the sample solution as the absorbance of the blank group (OD0), and distilled water replaces salicylic acid as the absorbance of the control group (OD2).

[0078] Hydroxyl radical scavenging rate = [OD0-(OD1-OD0)] / OD0×100% Formula (5)

[0079] (4) Determination of reducing ability

[0080] Take 0.5mL sample solution, 0.5mL 1% potassium ferricyanide and 0.5mL PBS and mix thoroughly, then react in a 50℃ water bath for 20min. After cooling, add 0.5mL 10% trichloroacetic acid and centrifuge for 10min. Take 1mL supernatant and react with 1mL 0.1% ferric chloride for 30min, and measure the absorbance (OD) at 700nm. PBS replaces the sample solution as the absorbance of the blank group (OD0).

[0081] Reducing ability = (OD-OD0) × 100% Formula (6)

[0082] Table 3 Antioxidant capacity of Lactobacillus reuteri QM11 and Lactobacillus rhamnosus LGG

[0083]

[0084] Note: “-” indicates a low clearance rate, <0.5%. Different letters represent significant differences in the same treatment methods for different strains (P < 0.05).

[0085] The antioxidant capacity of the strains is shown in Table 3. The fermentation supernatant, bacterial suspension and sterile body fragments of QM11 all have DPPH free radical scavenging ability, hydroxyl free radical scavenging ability and reducing ability. Among them, the DPPH free radical scavenging rate of the sterile body fragments of QM11 was 38.57%±8.16%, which was significantly higher than that of LGG. The hydroxyl free radical scavenging rate and reducing ability of the QM11 bacterial suspension were 180.29%±9.28% and 6.07%±0.6%, respectively, which were significantly higher than those of LGG (P<0.05). This shows that QM11 has good antioxidant capacity.

[0086] Example 7: Regulatory effect of strains on NO production in RAW264.7 cells stimulated by LPS

[0087] In this example, Lactobacillus rhamnosus LGG was used as a reference strain.

[0088] (1) Determination of RAW264.7 cell viability

[0089] Adjust the concentration of lactic acid bacteria to 10 8 CFU / mL, and the fermentation supernatant was collected by centrifugation at 4°C and 6796×g for 15 min, freeze-dried and dissolved in PBS to obtain freeze-dried fermentation supernatant. RAW264.7 cells were cultured at 1×10 5 Cells / mL were inoculated into 96-well plates, and different concentrations of lactic acid bacteria freeze-dried fermentation supernatant (0.2mg / mL, 0.4mg / mL, 0.8mg / mL, 1.6mg / mL, 3.2mg / mL, 6.4mg / mL) were incubated in a 37℃ incubator containing 5% CO2 for 2h, and then 0.1μg / mL lipopolysaccharide (LPS) was added and incubated for 24h. The absorbance at 490nm was measured by MTT method.

[0090] (2) Determination of NO generation

[0091] After pretreatment with freeze-dried fermentation supernatant for 2 h, RAW264.7 cells were stimulated with LPS (0.1 μg / mL) for 24 h, and the cell supernatant was collected. The secretion of NO was measured using a nitric oxide detection kit.

[0092] from Figure 5 It can be seen that different concentrations of fermentation supernatant have no significant effect on cell viability. Compared with the control group, the NO content in the LPS group increased significantly; different concentrations of strain QM11 fermentation supernatant can significantly reduce the NO content, and high concentrations of strain QM11 fermentation supernatant show higher anti-inflammatory ability. Figure 6 The results showed that QM11 could reduce the production of NO in LPS-stimulated RAW264.7 cells and had a certain anti-inflammatory ability, which was similar to that of the LGG-treated group.

[0093] Example 8: Effects of Lactobacillus reuteri QM11 on colitis mice

[0094] (1) Animal husbandry and grouping

[0095] Thirty SPF C57BL / 6 male mice aged 6 to 8 weeks were selected, and the experiment was started after one week of adaptive feeding. The mice were randomly divided into 5 groups, 6 in each group, and the experimental groupings are shown in Table 4. In this example, the experimental scheme of prevention first and then treatment was adopted, and 2.5% DSS was selected for model establishment, and the weight of mice in each group was recorded every other day.

[0096] Table 4 Animal test groups

[0097]

[0098] (2) Effects of Lactobacillus reuteri QM11 on body weight and disease activity index in mice with colitis

[0099] The effect of QM11 on the body weight of mice with colitis is shown in Table 5. During DSS-induced colitis, the body weight of mice in the control group showed a steady upward trend, while the body weight of mice in the model group was severely reduced, which was lower than that in the control group; the body weight loss of the low-dose QM11 group and the high-dose QM11 group was lower than that in the model group.

[0100] Table 5 Body weight changes of mice in each group

[0101]

[0102] The disease activity index (DAI) score was recorded based on the weight loss percentage, stool consistency and stool bleeding of the mice. Figure 7 As shown, the DAI score of the model group was significantly increased compared with the control group, and both the low-dose and high-dose QM11 groups could reduce the DAI scores of colitis mice.

[0103] (3) Effect of Lactobacillus reuteri QM11 on colon length in colitis mice

[0104] The effect of QM11 on the colon length of colitis mice is shown in Table 6. The colon length of mice in the model group was lower than that in the control group. The colon length of mice in the QM11 pretreatment group was higher than that in the model group, and the colon length of the high-dose QM11 group was the longest at 7.01±0.41 cm, which was higher than that in the model group.

[0105] Table 6 Colon length of mice in each group

[0106]

[0107] Example 9: Effect of Lactobacillus reuteri QM11 on the survival time of mice in the normobaric hypoxia tolerance experiment

[0108] Twenty SPF BALB / c female mice aged 6 to 8 weeks were selected and the experiment was started after one week of adaptive feeding. The mice were randomly divided into two groups, 10 in each group; the control group and the QM11 group. The mice were intragastrically administered with sterile PBS, and the QM11 group was intragastrically administered with 10 9 CFU / mL Lactobacillus reuteri QM11 bacterial suspension; intragastric administration once a day, continuous intragastric administration.

[0109] One hour after the last oral administration, each group of mice was placed in a 250 mL ground-mouth bottle containing 10 g of soda lime (one mouse in each bottle). The bottle mouth was sealed with vaseline and covered tightly to prevent air leakage. The time was immediately started, using respiratory arrest as an indicator to observe the time when the mice died due to lack of oxygen.

[0110] Table 7 Survival time of mice in each group in normobaric hypoxia tolerance experiment

[0111]

[0112] The results are shown in Table 7. In the normobaric hypoxia tolerance experiment, the survival time of mice in the QM11 group was increased compared with that in the control group, indicating that strain QM11 can prolong the survival time of normobaric hypoxia mice and has hypoxia tolerance activity.

[0113] Although the embodiments of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments.

Claims

1. A strain of Lactobacillus reuteri having antioxidant, anti-inflammatory and hypoxia tolerance capabilities, characterized in that: The name of the Lactobacillus reuteri is QM11, the classification name is: Lactobacillus reuteri (Limosilactobacillus reuteri), the preservation number is: CGMCC NO.31541, the preservation date is: August 5, 2024, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the preservation unit is: General Microbiology Center of China Microbiological Culture Collection Administration.

2. Use of Lactobacillus reuteri QM11 as claimed in claim 1 in the preparation of health products or medicines or microecological preparations with antioxidant effects.

3. Use of Lactobacillus reuteri QM11 as claimed in claim 1 in the preparation of drugs or microecological preparations for inhibiting intestinal pathogens.

4. Use of Lactobacillus reuteri QM11 as claimed in claim 1 in the preparation of a medicament for preventing and treating ulcerative colitis.

5. Use of Lactobacillus reuteri QM11 as claimed in claim 1 in the preparation of health products, medicines or microecological preparations resistant to hypoxia.

Images