CN114672441B - A kind of lactic acid bacteria composition and application thereof - Google Patents

Abstract

The invention discloses a lactic acid bacteria composition and application thereof, and belongs to the field of microorganisms. The lactobacillus composition comprises lactobacillus rhamnosus BY-02 and lactobacillus plantarum BY-05, wherein the preservation number of the lactobacillus rhamnosus BY-02 is CCTCC NO: m2022363, the preservation number of the lactobacillus plantarum BY-05 is CCTCC NO: m2022364. The invention also discloses application of the lactobacillus rhamnosus BY-02 or the lactobacillus composition in preparing products for preventing and/or treating inflammatory bowel diseases. The two strains of lactobacillus are separated from the feces of healthy infants, and in-vivo experiments on the lactobacillus rhamnosus BY-02 and the composition of the lactobacillus rhamnosus BY-02 and the lactobacillus plantarum BY-05 prove that the composition can safely and effectively prevent and relieve inflammatory bowel diseases, and the lactobacillus composition has wide application prospect in prevention and treatment of inflammatory bowel diseases.

Description

A kind of lactic acid bacteria composition and application thereof

technical field

The invention relates to the field of microorganisms, in particular to a lactic acid bacteria composition and its application.

Background technique

Inflammatory bowel disease is a chronic intestinal inflammatory disease, including two main types of ulcerative colitis and Crohn's disease, patients often show symptoms such as diarrhea, abdominal pain, bloody stool and weight loss, and it is more common in adolescents . Ulcerative colitis was first described by British physician Samuel Wilks in 1859. In the last half-century of the 20th century, rates of ulcerative colitis and Crohn's disease skyrocketed in wealthy Western countries. In 1956, China discovered the first case of ulcerative colitis. In the early 21st century, the incidence of ulcerative colitis and Crohn's disease in Asia was on the rise, similar to the incidence in Western countries in the 20th century. Currently, inflammatory bowel disease has grown into a global disease, with the highest incidence in Western countries, but countries such as newly industrialized Asia and South America have seen the greatest increase in incidence. In the near future, the global impact of inflammatory bowel disease cannot be ignored.

Since the etiology and pathogenesis of inflammatory bowel disease are not yet fully understood, its treatment measures are mainly aimed at controlling symptoms, and there is no effective and specific cure. At present, the traditional drugs targeted are mainly aminosalicylic acid drugs, mainly including sulfasalazine, mesalazine, 5-aminosalicylic acid, etc., which have in common that they can be decomposed into 5-aminosalicylic acid in the colon It can inhibit the growth of some pathogenic bacteria in the intestinal tract and the synthesis of inflammatory mediators such as prostaglandins, thereby alleviating the condition of inflammatory bowel disease. But many treatments are aimed at relieving the condition, not curing it. Drugs for the treatment of enteritis often need to be taken for a long time or even for life, and most of them have relatively large side effects.

With the gradual deepening of the research on intestinal flora, scholars at home and abroad generally believe that the balance interaction between intestinal flora and susceptible hosts is destroyed, which in turn causes barrier function damage and abnormal intestinal immune response, triggering susceptible Intestinal inflammation in individuals. There is about 1.5kg of microbial flora in the intestinal tract of healthy adults, most of which are obligate anaerobic bacteria. Intestinal flora participate in various physiological and biochemical processes such as nutrient metabolism in the host's digestive tract, maintenance of intestinal barrier function, and immune regulation. Disturbance of intestinal flora can affect the occurrence and development of various diseases such as metabolic diseases and immune-related diseases. At present, reasonable adjustment of the balance of the flora is considered to be the best way to improve enteritis, and probiotics are taken directly as food additives, which can inhibit the conditional pathogenic bacteria in the intestinal tract, optimize the intestinal environment, and balance the intestinal flora . In clinical treatment and daily health care, regular supplementation of probiotics such as lactic acid bacteria can effectively regulate intestinal flora and relieve intestinal inflammation. However, not all lactic acid bacteria have probiotic properties, and it is necessary to screen new strains that have excellent probiotic properties and can safely and effectively prevent and treat inflammatory bowel disease.

Contents of the invention

The purpose of the present invention is to provide a lactic acid bacteria composition and its application to solve the problems in the prior art above. The composition can safely and effectively prevent and treat inflammatory bowel disease, and has a role in the prevention and treatment of inflammatory bowel disease. Broad application prospects.

To achieve the above object, the present invention provides the following scheme:

The present invention provides a kind of Lactobacillus rhamnosus BY-02, which has been preserved in China Type Culture Collection Center, the preservation number is CCTCC NO: M 2022363, the preservation address is Wuhan University, Wuhan, China, and the preservation date is April 1, 2022 day.

The present invention also provides a lactic acid bacteria composition, which includes Lactobacillus rhamnosus BY-02 and Lactobacillus plantarum BY-05, and the preservation number of Lactobacillus rhamnosus BY-02 is CCTCC NO: M 2022363 , the preservation number of Lactobacillus plantarum BY-05 is CCTCC NO: M 2022364.

Further, the total viable count of the lactic acid bacteria composition is ≥1.0×10 ¹⁰ CFU/g.

Further, the live bacteria ratio of Lactobacillus plantarum BY-05 and Lactobacillus rhamnosus BY-02 in the lactic acid bacteria composition is 0.5-2:0.5-2.

The present invention also provides the application of the above-mentioned Lactobacillus rhamnosus BY-02 or the above-mentioned lactic acid bacteria composition in the preparation of products for preventing and/or treating inflammatory bowel disease.

Further, the product prevents and/or treats inflammatory bowel disease through one or more of the following methods:

(1) Increase the patient's weight;

(2) Inhibition of diarrhea and blood in the stool:

(3) Down-regulate the expression of TNF-α inflammatory factor;

(4) Increase the length of the colon.

Further, the inflammatory bowel disease includes ulcerative colitis or Crohn's disease.

Further, the product is a medicine.

Further, the effective dosage of active ingredients in the product is ≥1.0×10 ¹⁰ CFU/g.

Further, the product also includes a pharmaceutically acceptable carrier.

The invention discloses the following technical effects:

The present invention isolates two strains of Lactobacillus from healthy infant feces, which are identified as Lactobacillus rhamnosus BY-02 and Lactobacillus plantarum BY-05 respectively through 16S rDNA gene sequence identification. The in vivo experiment with the composition of Lactobacillus plantarum BY-05 confirmed that Lactobacillus rhamnosus BY-02 and its combination with Lactobacillus plantarum BY-05 can safely and effectively alleviate the weight loss caused by intestinal inflammation in mice , increase the DAI score of model mice, alleviate the diarrhea and bloody stools caused by intestinal inflammation in mice, down-regulate the expression of TNF-α inflammatory factors, inhibit the shortening of the colon, and achieve the effect of preventing and treating inflammatory bowel disease. The lactic acid bacteria composition has broad application prospects in the prevention and treatment of inflammatory bowel disease.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the morphological figure of Lactobacillus rhamnosus BY-02 plate colony;

Fig. 2 is the body weight change of each group of mice;

Fig. 3 is the change of DAI score of each group of mice;

Fig. 4 is the change of TNF-α content in the mouse serum of each group;

Figure 5 shows the changes in colon length of mice in each group.

Detailed ways

Various exemplary embodiments of the present invention will now be described in detail. The detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features and embodiments of the present invention.

It should be understood that the terminology described in the present invention is only used to describe specific embodiments, and is not used to limit the present invention. In addition, regarding the numerical ranges in the present invention, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated value or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded from the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only the preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and/or materials in connection with which the documents are described. In case of conflict with any incorporated document, the contents of this specification control.

It will be apparent to those skilled in the art that various modifications and changes can be made in the specific embodiments of the present invention described herein without departing from the scope or spirit of the present invention. Other embodiments will be apparent to the skilled person from the description of the present invention. The description and examples of the invention are illustrative only.

As used herein, "comprising", "comprising", "having", "comprising" and so on are all open terms, meaning including but not limited to.

Isolation screening and identification of embodiment 1 bacterial strain

1. Preparation of culture medium:

MRS liquid medium: glucose 20.0g/L; peptone 10.0g/L; yeast extract 5g/L; beef extract powder 5.0g/L; dipotassium hydrogen phosphate 2.0g/L; sodium acetate 5.0g/L; citric acid Triammonium 2.0g/L; Tween-80 1.0mL.

Improved MRS liquid medium: glucose 20.0g/L; peptone 10.0g/L; yeast extract 5g/L; beef extract powder 5.0g/L; dipotassium hydrogen phosphate 2.0g/L; sodium acetate 5.0g/L; lemon Ammonium triammonium 2.0g/L; Tween-80 1.0mL; bromocresol purple (acid-base indicator) 0.01g/L.

For solid medium, 2% agar powder was added on the basis of liquid medium, and all medium was sterilized at 115°C for 25 minutes.

2. Strain isolation and screening:

Take 2 g of fresh feces from healthy infants and place them in 100 mL of pre-sterilized modified MRS liquid medium. After standing for 12 hours, take 1 mL of culture liquid for gradient dilution and spread the improved MRS plate. After the plate was cultured at 37°C for 48 hours, yellow colonies (bromocresol purple turns yellow under acidic conditions) were selected for streak isolation and culture, and a total of 15 colonies were selected. The obtained single colony was transferred to 100mL MRS modified liquid medium and cultured at 37°C for 24 hours, and the pH value of the culture medium was measured.

The acid production rate of the strain Lactobacillus rhamnosus BY-02 was the fastest, and the pH value of the culture solution dropped to 4.15 after 24 hours of cultivation at 37°C.

The acid production rate of the strain Lactobacillus plantarum BY-05 was faster, and the pH value of the culture solution dropped to 4.20 after 24 hours of cultivation at 37°C.

Biochemical identification of strain BY-02:

The strain is long rod-shaped, without spores. The colonies on the MRS-modified solid medium were light yellow, round, with neat edges (Figure 1). Physiological and biochemical identification strain BY-02 is facultatively anaerobic, does not reduce nitrate, does not liquefy gelatin, and is negative for catalase and oxidase.

Biochemical identification of strain BY-05:

The strain is long rod-shaped, without spores. The colony on the MRS modified solid medium was light yellow, round and neat. Physiological and biochemical identification strain BY-05 is facultatively anaerobic, does not reduce nitrate, does not liquefy gelatin, and is negative for catalase and oxidase.

16S rDNA identification of the strain: A single colony of BY-02 was picked and amplified with universal primers, and the amplified products were analyzed by 16S rDNA sequencing. The sequencing results are as follows (SEQ ID No.1):

GGTGGGGATGTGTCTATGATGGGCGTCGTATGAGTTCTGTTTATTGCCGGGTGCTTGCCTCTTGATTTATTTTTCGCGGATCGGTGGACGGCGGAAGCTTCGTGGGTAACCTGCCCTTAACTGGGGGATTACTTTTGGAAACCGATGCTAATACCGGATAAATCCTGTAACCGCATGGTTCTTGGCTGAAAGATGGCGTAAGCTATC GCTTTTGGATGGACCCGCGGCGTATTAGCTAGTTGGTGAGGTAACGGCTCACCAAGGCAATGATACGTAGCCGAACTGAGAGGTTGATCGGCCACATTGGGACTGAGACACGGCCCAAACTCCTACGGGAGGCAGCAGTAGGGAATCTTCCACAATGGACGCAAGTCTGATGGAGCAACGCCGCGTGAGTGAAGAAGGCTTTCGGGTCGTAA AACTCTGTTGTTGGAGAAGAATGGTCGGCAGAGTAACTGTTGTCGGCGTGACGGTATCCAACCAGAAAAGCCACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTGGCAAGCGTTATCCGGATTTATTGGGCGTAAAGCGAGCGCAGGCGGTTTTTAAGTCTGATGTGAAAGCCCTCGGCTTAACCGAGGAAGTGCATCGGAAACTG GGAAACTTGAGTGCAGAAGAGGACAGTGGAACTCCATGTGTAGCGGTGAAATGCGTAGATATGGAAGAACACCAGTGGCGAAGGCGGCTGTCTGGTCTGTAACTGACGCTGAGGCTCGAAAGCATGGGTAGCGAACAGGATTAGATACCCTGGTAGTCCATGCCGTAAACGATGAATGCTAGGTGTTGGAGGGTTTCCGCCCTTCAGTGCCG CAGCTAACGCATTAAGCATTCCGCCTGGGGAGTACGACCGCAAGGTTGAAACTCAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCTTTTGATCACCTGAGAGATCAGGTTTCCCCTTCGGGGGCAAAATGACAGGTGGTGCATGGTTGTCGTCAGCTCGTG TCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTATGACTAGTTGCCAGCATTTAGTTGGGCACTCTAGTAAGACTGCCGGTGACAAACCGGAGGAAGGTGGGGATGACGTCAAATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGATGGTACAACGAGTTGCGAGACCGCGAGGTCAAGCTAATCTCTTAAAGC CATTCTCAGTTCGGACTGTAGGCTGCAACTCGCCTACACGAAGTCGGAATCGCTAGTAATCGCGGATCAGCACGCCGCGGTGAATACGTTCCCGGGCCTTGTACACACCGCCCGTCACACCCATGAGAGTTTGTAACACCCGAAGCCGGTGGCGTAACCCTTTTAGGGAGCGAGCCGTCTAAGGTCACAAAGAA.

16S rDNA identification of strains: A single colony of BY-05 was picked and amplified with universal primers, and the amplified products were analyzed by 16S rDNA sequencing. The sequencing results are as follows (SEQ ID No.2):

GCGATGCGCCACGGTGGGGTCGTATCATTTCTGTGGTGGGTTGTTGCTTGCTCTTGAGTTACTTCGCCGCGAGAGGTCAACTGGTGATTGCCGAAGGGGTCATCTGCCCACAAGCGGTGGATACCACGTGGAAACGGATGCTAATACCGCGTAACAACTTGGACCGCATGGCCCGAGTTTGAAAGATGGCTTCGGCTATCACTTTTG GATGGTCCCGCGGCGTATTAGCTAGATGGTGGGGTAACGGCTCACCATGGCAATGATACGTAGCCGACCTGAGAGGGTAATCGGCCACATTGGGACTGAGACACGGCCCAAACTCCTACGGGAGGCAGCAGTAGGGAATCTTCCACAATGGACGAAAGTCTGATGGAGCAACGCCGCGTGAGTGAAGAAGGGTTTCGGCTCGTAACT CTGTTGTTAAAGAAGAACATATCTGAGAGTAACTGTTCAGGTATTGACGGTATTTAACCAGAAAAGCCACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTGGCAAGCGTTGTCCGGATTTATTGGGCGTAAAGCGAGCGCAGGCGGTTTTTTTAAGTCTGATGTGAAAGCCTTCGGCTCAACCGAAGAAGTGCATCGGAAACTGGGAAACTTGAGT GCAGAAGAGGACAGTGGAACTCCATGTGTAGCGGTGAAATGCGTAGATATGGAAGAACACCAGTGGCGAAGGCGGCTGTCTGGTCTGCAACTGACGCTGAGGCTCGAAAGTATGGGTAGCAAACAGGATTAGATACCCTGGTAGTCCATACCGTAAACGATGAATGCTAAGTGTTGGAGGGTTTCCGCCCTTCAGTGCTGCAGCTAACGCATTAAG CATTCCGCCTGGGGAGTACGGCCGCAAGGCTGAAACTCAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCTACGCGAAGAACCTTACCAGGTCTTGACATACTATGCAAATCTAAGAAGATTAGAACGTTCCCTTCGGGGACATGGAATACAGGTGGTGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGT TGGGTTAAGTCCCGCAACGAGCGCAACCCTTATTATCAGTTGCCAGCATTAAGTTGGGCACTCTGGTGAGACTGCCGGTGACAAACCGGAGGAAGGTGGGGATGACGTCAAATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGATGGTACAACGAGTTGCGAACTCGCGAGAGTAAGCTAATCTCTTAAAGCATTCAGTTC GGATTGTAGGCTGCAACTCGCCTACATGAAGTCGGAATCGCTAGTAATCGCGGATCAGCATGCCGCGGTGAATACGTTCCCGGGCCTTGTACACACCGCCCGTCACACCCATGAGAGTTTGTAACACCCAAAGTCGGTGGGGTAACCTTTTAGGAACCAGCCGCCTAAGGTCACAGAGTA.

The results showed that the sequence of SEQ ID No.1 had the highest similarity with the 16S rDNA sequence of Lactobacillus rhamnosus, reaching 97.86%. The strain could be identified as Lactobacillus rhamnosus and named Lactobacillus rhamnosus BY-02. The strain has been deposited in the China Center for Type Culture Collection (CCTCC) on April 1, 2022, with a classification name: Lactobacillus rhamnosus BY-02, a deposit number: CCTCC NO: M 2022363, and an address: Wuhan University, Wuhan, China.

The results showed that the sequence of SEQ ID No.2 had the highest similarity with Lactobacillus plantarum 16S rDNA sequence, reaching 97.38%. The strain could be identified as Lactobacillus plantarum and named Lactobacillus plantarum BY-05.

The strain has been deposited in the China Center for Type Culture Collection (CCTCC) on April 1, 2022, with a classification name: Lactobacillus plantarum BY-05, a deposit number: CCTCC NO: M 2022364, and an address: Wuhan University, Wuhan, China.

Example 2

Probiotic performance test of Lactobacillus rhamnosus BY-02:

The culture solution of Lactobacillus rhamnosus BY-02 grown to the late logarithmic phase was centrifuged, washed twice with sterile water, resuspended, inoculated into artificial gastric juice at pH 3.0 at 10 ⁸ CFU/mL, and incubated at 37 After incubating in a water bath at ℃ for 2 hours, samples were taken, diluted and spread on an MRS plate to determine the number of viable bacteria.

The results showed that when the Lactobacillus rhamnosus BY-02 tolerated the artificial gastric juice of pH 3.0 for 2 hours, the survival rate was 75.61%.

Centrifuge the culture solution of Lactobacillus rhamnosus BY-02 that has grown to late logarithm, wash it twice with sterile water, resuspend it, inoculate it into artificial intestinal juice at 10 ⁸ CFU/mL, and place it in a water bath at 37°C. After incubation for 6 hours, samples were taken, diluted and spread on MRS plates to determine the number of viable bacteria.

The results showed that the survival rate of the Lactobacillus rhamnosus was 62.18% after being treated with the artificial intestinal fluid for 6 hours.

The culture medium of Lactobacillus rhamnosus BY-02 grown to the late logarithmic phase was centrifuged, washed twice with sterile water, resuspended, and inoculated into 0.3% pig bile salt environment at an amount of 10 ⁸ CFU/mL. After incubating in a water bath at 37°C for 3 hours, samples were taken, diluted and spread on an MRS plate to determine the number of viable bacteria.

The result showed that the Lactobacillus rhamnosus BY-02 was incubated in 0.3% pig bile salt for 3 hours, and the survival rate was 55.27%.

Probiotic performance test of Lactobacillus plantarum BY-05:

Centrifuge the Lactobacillus plantarum BY-05 culture solution that has grown to late logarithm, wash twice with sterile water, resuspend, inoculate 10 ⁸ CFU/mL into artificial gastric juice of pH 3.0, and place in a 37°C water bath After incubating in the pot for 2 hours, samples were taken, diluted and spread on MRS plates to determine the number of viable bacteria.

The results showed that when the plantarum BY-05 tolerated the artificial gastric juice of pH 3.0 for 2 hours, the survival rate was 73.28%.

Centrifuge the Lactobacillus plantarum BY-05 culture solution that has grown to late logarithm, wash twice with sterile water and resuspend, inoculate 10 ⁸ CFU/mL into artificial intestinal juice, and incubate in a water bath at 37°C After 6 hours, samples were taken and diluted to spread on MRS plates to determine the number of viable bacteria.

The results showed that the survival rate of the plantarum lactobacillus was 60.69% after being treated with the artificial intestinal juice for 6 hours.

Centrifuge the Lactobacillus plantarum BY-05 culture medium that has grown to late logarithm, wash twice with sterile water and resuspend, inoculate 10 ⁸ CFU/mL into 0.3% pig bile salt environment, and incubate at 37°C After incubating in a water bath for 3 hours, samples were taken, diluted and spread on an MRS plate to determine the number of viable bacteria.

The results showed that the plantarum BY-05 was incubated in 0.3% pig bile salt for 3 hours, and the survival rate was 52.36%.

Example 3

Effect of Lactobacillus rhamnosus BY-02 and its combined culture with Lactobacillus plantarum BY-05 on experimental colitis in mice

Select 50 healthy male C57 mice, weighing 20±2g, purchased from the Experimental Animal Center of Huazhong Agricultural University, raised in SPF grade animal room, randomly divided into 5 groups, 10 mice in each group, and all mice were adaptively fed for 7 days before the experiment. sky.

1. Experimental animal model and grouping:

Using 3% DSS (dextran sulfate sodium, DSS, purchased from Shanghai Yuanye Biotechnology Co., Ltd.) solution to induce acute colitis in mice, 50 mice were randomly divided into 5 groups: normal control group, model group, rhamnose milk Bacillus BY-02 group, Lactobacillus plantarum BY-05 group and the combination of BY-02 and BY-05 strains. Animal grouping and treatment are shown in Table 1:

Table 1

group modeling number of animals normal control group no 10 model group yes 10 BY-02 group yes 10 BY-05 group yes 10 BY-02 and BY-05 joint group yes 10

Add 30g of DSS into 1L of ultrapure water, fully dissolve and prepare a 3% DSS solution, which is freshly prepared every day. The mice drank 3% DSS solution freely for 7 days, and drank water normally for 7 days, and the above 14 days were the modeling and experiment period. After the administration of DSS, intragastric administration was started, once a day at a fixed time, for 14 consecutive days. The normal control group and the model group were fed with 0.2mL ultrapure water every day;

The BY-02 group, BY-05 group and the combination group were intragastrically administered with a fixed amount of viable bacteria solution every day, and the dosage was: 6×10 ⁸ CFU/bird in both the BY-02 group and BY-05 group; the combination group was 6 ×10 ⁸ CFU/piece (BY-02 and BY-05 each 3×10 ⁸ CFU/piece).

2. Changes in body weight of mice:

Since the start of gavage, the mice were weighed at a fixed time every day:

(1) The body weight of the mice in the normal group increased gradually during the 14 days of the experiment;

(2) The mice in the DSS group all lost weight;

(3) The mice in the BY-02, BY-05 group and the combination group also lost weight in the first 10 days of the experiment, but gradually gained weight on the 11th day, and the weight at the end of the experiment was significantly higher than that of the model group.

The above results show that the supplementation of BY-02 and the combined use of BY-02 and BY-05 can effectively alleviate the symptoms of DSS-induced weight loss (see Figure 2).

3. Calculation of Mouse Disease Activity Integral (DAI):

Since the start of gavage, the body weight, stool properties and occult blood of the mice were observed daily, and the disease integral activity (DAI) score of each mouse was calculated to evaluate the degree of colitis activity. The result is as follows:

(1) The DAI score of mice in the normal group has been stable at zero level;

(2) The DAI score of the mice in the BY-02, BY-05 group and the combination group also gradually increased in the first 10 days of the experiment, and the DAI gradually decreased after the 11th day;

(3) During the experimental period, the DAI of the mice in the BY-02 combination group was significantly lower than that in the model group.

The above results show that supplementation of BY-02 and combined use of BY-02 and BY-05 can effectively alleviate the diarrhea and bloody stools caused by intestinal inflammation in mice, and the combination group has the best effect on relieving enteritis (see Figure 3).

4. On the 14th day of gavage, blood was collected from the tail vein of the mice, and the TNF-α content in the serum was detected with an ELISA kit (purchased from Wuhan Beiyinlai Biotechnology Co., Ltd.). The result is as follows:

(1) After the experiment, the concentration of TNF-α in the serum of the model group was significantly higher than that of the normal group;

(2) Compared with the model group, the concentration of TNF-α in the serum of the mice in the BY-02, BY-05 group and the combined group decreased to varying degrees.

The above results show that the supplementation of BY-02 and the combined use of BY-02 and BY-05 can effectively alleviate the systemic inflammatory response induced by DSS (see Figure 4).

5. On the 14th day of gavage, the mice were killed by cervical dislocation, the colon of the mice was taken out, and its length was measured. The results indicated:

(1) After the experiment, the colon length of the mice in the model group was significantly shorter than that in the normal group;

(2) Compared with the model group, the length of the colon of the mice in the BY-02, BY-05 group and the combination group increased to varying degrees.

The above results show that the supplementation of BY-02 and the combined use of BY-02 and BY-05 can effectively alleviate the shortening of the colon caused by the intestinal tract (see Figure 5).

The above-mentioned embodiments are only to describe the preferred mode of the present invention, not to limit the scope of the present invention. Without departing from the design spirit of the present invention, those skilled in the art may make various Variations and improvements should fall within the scope of protection defined by the claims of the present invention.

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cagctaacgc attaagcatt ccgcctgggg agtacggccg caaggctgaa actcaaagga 900

attgacgggg gcccgcacaa gcggtggagc atgtggttta attcgaagct acgcgaagaa 960

ccttaccagg tcttgacata ctatgcaaat ctaagaagat tagaacgttc ccttcgggga 1020

catggaatac aggtggtgca tggttgtcgt cagctcgtgt cgtgagatgt tgggttaagt 1080

cccgcaacga gcgcaaccct tattatcagt tgccagcatt aagttgggca ctctggtgag 1140

actgccggtg acaaaccgga ggaaggtggg gatgacgtca aatcatcatg ccccttatga 1200

cctgggctac acacgtgcta caatggatgg tacaacgagt tgcgaactcg cgagagtaag 1260

ctaatctctt aaagccattc tcagttcgga ttgtaggctg caactcgcct acatgaagtc 1320

ggaatcgcta gtaatcgcgg atcagcatgc cgcggtgaat acgttcccgg gccttgtaca 1380

caccgcccgt cacaccatga gagtttgtaa cacccaaagt cggtggggta accttttagg 1440

aaccagccgc ctaaggtcac agagta 1466

Claims (7)

1. A lactic acid bacteria composition, wherein the lactic acid bacteria composition comprises Lactobacillus rhamnosus (L.) (Lactobacillus rhamnosus) BY-02 AND Lactobacillus plantarum (F.)Lactobacillus plantarum) BY-05, wherein the preservation number of the lactobacillus rhamnosus BY-02 is CCTCC NO: m2022363, the preservation number of the lactobacillus plantarum BY-05 is CCTCC NO: m2022364.

2. The lactic acid bacterium composition according to claim 1,it is characterized in that the total viable count of the lactobacillus composition is more than or equal to 1.0 multiplied by 10 ¹⁰ CFU/g。

3. The lactic acid bacteria composition according to claim 2, wherein the ratio of viable bacteria of lactobacillus plantarum BY-05 and lactobacillus rhamnosus BY-02 in the lactic acid bacteria composition is 0.5-2:0.5-2.

4. Use of a lactic acid bacteria composition according to any of claims 1-3 for the preparation of a medicament for the prevention and/or treatment of inflammatory bowel disease.

5. The use according to claim 4, wherein the inflammatory bowel disease is ulcerative colitis or Crohn's disease.

6. The use according to claim 4, wherein the effective dose of the active ingredient of the medicament is not less than 1.0 x 10 ¹⁰ CFU/g。

7. The use of claim 4, wherein the medicament further comprises a pharmaceutically acceptable carrier.

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