A strain of Lactobacillus delbrueckii JNL0010, its application and a microbial agent

Abstract

The present invention discloses a strain of Lactobacillus delbrueckii JNL0010, its application and a microbial agent, belonging to the field of microbial technology. The Lactobacillus delbrueckii JNL0010 was deposited in the China General Microbiological Culture Collection Management Center on June 24, 2024, with a preservation address of No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, with a preservation number of CGMCC NO:31042, and was classified as Lactobacillus delbrueckii subsp.bulgaricus. The strain can produce high indole-3-lactic acid in MRS culture medium. In vitro experimental results showed that the supernatant of the strain significantly inhibited the inflammatory polarization of macrophages and the secretion of inflammatory factors stimulated by lipopolysaccharide. Animal experimental results showed that the strain can significantly inhibit the secretion of inflammatory factors and intestinal barrier damage in colon tissue induced by sodium dextran sulfate, alleviate ulcerative colitis, and show great application value.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and specifically relates to a strain of Lactobacillus delbrueckii JNL0010, an application thereof and a microbial agent. Background Art

[0002] Inflammatory bowel diseases (IBD) are chronic inflammatory diseases that occur in the ileum, cecum, and colorectum. IBD usually occurs in genetically susceptible hosts and is a long-term, recurrent intestinal disease caused by an immune response to specific components of intestinal microorganisms regulated by overactive T cells. Currently, the first-line treatment drugs in clinical practice mainly include aminosalicylicylates, corticosteroids, biological drugs, and immunosuppressants. Not all IBD patients benefit from these treatments, and these drugs also have a considerable risk of side effects.

[0003] The typical feature of IBD is intestinal microecological imbalance. Studies have found that probiotics can inhibit pathogenic bacteria and repair damaged intestinal microecology. Many studies have reported that probiotics have anti-inflammatory effects in vivo and in vitro. Moreover, probiotics colonize in the intestines and can continuously exert therapeutic effects with low side effects. Therefore, there are huge advantages in using probiotics to treat IBD.

[0004] Indole-3-lactic acid (ILA) is an indole compound produced by intestinal microbial metabolism of tryptophan. Studies have shown that ILA can reduce the polarization of T cells to pro-inflammatory Th17 cells, inhibit the inflammatory polarization of macrophages, inhibit the release of pro-inflammatory cytokines, and reduce intestinal inflammatory response. In addition, ILA can be used by intestinal commensal bacteria to produce indole-3-propionic acid, thereby enhancing CD8 + The efficacy of T cell-mediated aPD-1 tumor immunotherapy. Therefore, indole-3-lactic acid can play an anti-inflammatory and anti-tumor role in the body and has great value in drug development.

[0005] At present, the chemical synthesis of ILA may produce toxic by-products, and the preparation conditions are harsh, the process is complicated, and the cost is high. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, the present invention provides a strain of Lactobacillus delbrueckii JNL0010, its application and a microbial agent.

[0007] On the one hand, the present invention provides a strain of Lactobacillus delbrueckii JNL0010, which was deposited in the China General Microbiological Culture Collection Center on June 24, 2024, with a storage address of No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with a storage number of CGMCC NO: 31042, and a classification name of Lactobacillus delbrueckii subsp. bulgaricus.

[0008] The present invention also provides the application of the Lactobacillus delbrueckii JNL0010 in producing indole-3-lactic acid.

[0009] The present invention also provides the use of the Lactobacillus delbrueckii JNL0010 in reducing the proportion of pro-inflammatory M1 macrophages.

[0010] The present invention also provides the use of the Lactobacillus delbrueckii JNL0010 in increasing the proportion of anti-inflammatory M2 macrophages.

[0011] The present invention also provides the use of the Lactobacillus delbrueckii JNL0010 in inhibiting the secretion of pro-inflammatory cytokines IL-6 and TNF-α.

[0012] The present invention also provides the use of the Lactobacillus delbrueckii JNL0010 in preparing a medicine for treating intestinal inflammation.

[0013] The present invention also provides the use of the Lactobacillus delbrueckii JNL0010 in preparing a medicine for treating colitis.

[0014] The present invention also provides a microbial preparation, which contains Lactobacillus delbrueckii JNL0010.

[0015] Furthermore, the microbial preparation also contains an excipient.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention provides a strain of Lactobacillus delbrueckii JNL0010 and its application. The strain can produce high indole-3-lactic acid in MRS culture medium, which is 10-12 times higher than the commercial strain Lacticaseibacillus rhamnosus LGG. The results of in vitro experiments show that the supernatant of Lactobacillus delbrueckii JNL0010 significantly inhibits the inflammatory polarization of macrophages and the secretion of inflammatory factors stimulated by lipopolysaccharide (LPS). The results of animal experiments show that Lactobacillus delbrueckii JNL0010 can significantly inhibit the secretion of inflammatory factors and intestinal barrier damage in colon tissue induced by dextran sulfate sodium (DSS), alleviate ulcerative colitis, and show great application value.

[0018] 2. The present invention provides Lactobacillus delbrueckii JNL0010 to produce indole-3-lactic acid, which overcomes many disadvantages of chemically synthesizing indole-3-lactic acid and uses microbial metabolism of tryptophan to produce indole-3-lactic acid, which has low cost and mild reaction conditions and is suitable for industrial production needs. In addition, the indole-3-lactic acid-producing probiotics can be colonized in the human intestine, can continuously secrete indole-3-lactic acid, and regulate the host intestinal immune microenvironment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] Figure 1 This is the phylogenetic tree of Lactobacillus delbrueckii JNL0010.

[0021] Figure 2 This is the morphological diagram of Lactobacillus delbrueckii strain JNL0010.

[0022] Figure 3 The indole-3-lactic acid production level of Lactobacillus delbrueckii JNL0010 in Example 4 is shown in Figure 4; wherein (a) is the ILA level in the culture medium, and (b) is the level of each OD 600 The level of ILA produced by bacteria.

[0023] Figure 4 The figure is a diagram showing the effect of the supernatant of Lactobacillus delbrueckii JNL0010 in Example 5 on inhibiting the inflammatory polarization of macrophages and the secretion of inflammatory factors; wherein, (a) is the proportion of M1 macrophages, (b) is the proportion of M2 macrophages, (c) is the level of TNF-α in the cell supernatant, and (d) is the level of IL-6 in the cell supernatant; * is p<0.05, ** is p<0.01; *** is p<0.001, **** is p<0.0001.

[0024] Figure 5 The results of bacterial hemolytic analysis in Example 7; wherein (a) is α hemolysis, (b) is β hemolysis, and (c) is γ hemolysis.

[0025] Figure 6 The figure shows the effect of Lactobacillus delbrueckii JNL0010 in alleviating DSS-induced colitis in terms of body weight and disease activity index in Example 8; wherein (a) is body weight, and (b) is disease activity index.

[0026] Figure 7This is a graph showing the effect of Lactobacillus delbrueckii JNL0010 on reducing DSS-induced colitis in terms of colorectal length in Example 8; * indicates p<0.05, ** indicates p<0.01, *** indicates p<0.001, **** indicates p<0.0001.

[0027] Figure 8 This is a diagram showing the effect of Lactobacillus delbrueckii JNL0010 in alleviating DSS-induced colitis in colon tissue H&E staining in Example 8.

[0028] Fig. 9 This is a diagram showing the effect of Lactobacillus delbrueckii JNL0010 in alleviating DSS-induced colitis in terms of the proportion of colonic immune cells and the level of colonic inflammatory factors in Example 8; * is p<0.05, ** is p<0.01; *** is p<0.001, **** is p<0.0001. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. Unless otherwise specified, the experimental methods disclosed in the present invention all adopt conventional techniques in the art, and the reagents and raw materials used in the examples can all be purchased from the market.

[0030] The composition of the MRS culture medium used in the embodiment is as follows:

[0031] Peptone 10.0g / L, beef powder 8.0g / L, yeast powder 4.0g / L, glucose 20.0g / L, dipotassium hydrogen phosphate 2.0g / L, diammonium hydrogen citrate 2.0g / L, sodium acetate 5.0g / L, magnesium sulfate 0.2g / L, manganese sulfate 0.04g / L, Tween 80 1.0g / L. pH value 5.7±0.2 (25℃).

[0032] The Lactobacillus delbrueckii JNL0010 provided by the present invention is separated from fermented yogurt collected in Qinghai Province. The strain can produce high indole-3-lactic acid in MRS culture medium, which is 10-12 times higher than the commercial strain Lactobacillus rhamnosus LGG. The results of in vitro experiments show that the supernatant of Lactobacillus delbrueckii JNL0010 significantly inhibits the inflammatory polarization of macrophages and the secretion of inflammatory factors stimulated by lipopolysaccharide (LPS). The results of animal experiments show that Lactobacillus delbrueckii JNL0010 can significantly inhibit the secretion of inflammatory factors and intestinal barrier damage in colon tissue induced by dextran sulfate sodium (DSS), alleviate ulcerative colitis, and show great application value.

[0033] Example 1, separation and purification

[0034] Prepare MRS medium according to the instructions and sterilize at 118℃ for 20min. Take an appropriate amount of yogurt sample, add physiological saline to dilute it in a gradient, evenly apply it on MRS solid medium, and culture it anaerobically at 37℃ for 48h. Pick a single clone and observe the bacterial morphology by Gram staining. Use primers 27F (5'-AGAGTTTGATCCTGGCT CAG-3') and 1492R (5'-GGCTTACCTTGTTACGACTT-3') to amplify bacterial 16S rRNA. The bacterial 16S rRNA gene sequence is:

[0035] 5’-TAACCTGCCCTTAAGTGGGGGATAACATTTGGAAACAGATGCTAATACCGCATA AATCCAAGAACCGCATGGTTCTTGGCTGAAAGATGGCGTAAGCTATCGCTTTTGGATGGACCCGCGGCGTATTAGCTAGTTGGTGAGGTAACGGCTCACCAAGGCAATGATACGTAGCCGAACTGAGAGGTTGATCGGCCACATTGGGACTGAGACACGGCCCAAACTCCTACGGGAGGCAGCAGTAGGGAATCTTCCACAATGGACGCAAGTCTGATGGAGCAACGCCGCGTGAGTGAAGAAGGCTTTCGGGTCGTAAAACTCTGTTGTTGGAGAAGAATGGTCGGCAGAGTAACTGTTGTCGGCGTGACGGTATCCAACCAGAAAGCCACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTGGCAAGCGTTATCCGGATTTATTGGGCGTAAAGCGAGCGCAGGCGGTTTTTTAAGTCTGATGTGAAAGCCCTCGGCTTAACCGAGGAAGTGCATCGGAAACTGGGAAACTTGAGTGCAGAAGAGGACAGTGGAACTCCATGTGTAGCGGTGAAATGCGTAGATATATGGAAGAACACCAGTGGCGAAGGCGGCTGTCTGGTCTGTAACTGACGCTGAGGCTCGAAAGCATGGGTAGCGAACAGGATTAGATACCCTGGTAGTCCATGCCGTAAACGATGAATGCTAGGTGTTGGAGGGTTTCCGCCCTTCAGTGCCGCAGCTAACGCATTAAGCATTCCGCCTGGGGAGTACGACCGCAAGGTTGAAACTCAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCTTTTGATCACCTGAGAGATCAGGTTTCCCCTTCGGGGGCAAAATGACAGGTGGTGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTATGACTAGTTGCCAGCATTTAGTTGGGCACTCTAGTAAGACTGCCGGTGACAAACCGGAGGAAGGTGGGGATGACGTCAAATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGATGGTA CAACGAGTTGCGAGACCGCGAGGTCAAGCTAATCTCTTAAAGCCATTCTCAGTTCGGACTGTAGGCTGCAACTCGCCTACACGAAGTCGGAATCGCTAGTAATCGCGGATCAGCACGCCGCGGTGAATACGTTCCCGGGCCTTGTACACACCGCCCGTCACACCATGAGAGTTTGTAACACCCGAAGCCGGTGGCGTAACCCTTTTA-3'

[0036] By comparing the NCBI database, a phylogenetic tree was constructed, such as Figure 1 As shown, the alignment result is L. delbrueckii subsp. bulgaricus.

[0037] The Lactobacillus delbrueckii JNL0010 in the present invention was deposited in the China General Microbiological Culture Collection Center on June 24, 2024, with the deposit address at No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with the deposit number CGMCC NO: 31042, and the classification name is Lactobacillus delbrueckii subsp.bulgaricus.

[0038] The morphological characteristics of the Lactobacillus delbrueckii JNL0010 strain are analyzed as follows: Figure 2 As shown, a single colony was picked for Gram staining and observed under a microscope. Lactobacillus delbrueckii JNL0010 was rod-shaped or slightly curved, 3.4-6.9 μm (length) × 0.6-0.8 μm (width), and Gram-positive.

[0039] Example 2, bacterial culture and counting

[0040] Prepare MRS medium according to the instructions for use and sterilize at 118℃ for 20min. After cooling to room temperature, inoculate Lactobacillus delbrueckii JNL0010 at a 1% inoculation rate and culture anaerobically at 37℃ for 24h. After culture, dilute the cultured bacterial solution with physiological saline gradient, take 100μL and evenly apply it on MRS solid medium, and culture anaerobically at 37℃ for 48h. Count the bacterial growth according to the number of colonies grown. OD value of bacterial solution after 24h culture of Lactobacillus delbrueckii JNL0010 600 =0.30, the number of viable bacteria is 2.0×10 7 CFU / mL. OD of bacterial solution after 36h of culture 600 =2.30, OD of 48h bacterial solution 600 =3.05.

[0041] Example 3, bacterial supernatant separation

[0042] The cultured bacteria were centrifuged at 12000 rpm and 4°C for 10 min, and the supernatant was collected and filtered through a 0.22 μm filter membrane.

[0043] Example 4, Analysis of indole-3-lactic acid production levels by probiotics

[0044] Indole-3-lactic acid single standard stock solution was prepared with 50% methanol and gradiently diluted with 10% methanol. 200μL of Lactobacillus delbrueckii JNL0010 supernatant was added with 10% methanol at a final concentration and vigorously shaken and mixed, and centrifuged at 12000rpm for 5min. Standards and bacterial supernatant extract samples were injected and analyzed. TSQ Altis targeted quantitative mass spectrometer was used for analysis.

[0045] The column temperature of HSS T3 chromatographic column was 40°C, and the mobile phases were A-0.1% formic acid water, B-0.1% formic acid methanol. The gradient elution conditions were: 0-1min, 5% B; 1-2min, 5%-50% B; 2-5min, 50%-95% B; 6-8min, 95%-5% B. Mass spectrometry conditions: electrospray ionization (ESI) source, positive ion ionization mode. The ion source temperature was 500°C, the ion source voltage was 5500V, the collision gas was 6psi, the curtain gas was 30psi, and the nebulizer gas and auxiliary gas were both 50psi. Multiple reaction monitoring (MRM) and retention time locking were used for scanning. The concentration of indole-3-lactic acid in the bacterial supernatant of Lactobacillus delbrueckii JNL0010 was quantitatively analyzed according to the ion intensity of the standard.

[0046] The same number of Lactobacillus delbrueckii JNL0010 and Lactobacillus rhamnosus LGG were inoculated into MRS liquid medium and cultured anaerobically at 37°C. The bacterial OD600 and the ILA content in the fermentation broth were detected at 12h, 24h, 36h and 48h. Figure 3As shown in (a) and (b), the results showed that after 48 h of culture, the ILA content in the culture medium of Lactobacillus delbrueckii JNL0010 was 2.66 μg / mL, while the ILA content in the culture medium of Lactobacillus rhamnosus LGG was about 0.23 μg / mL.

[0047] Example 5: Cell experiment analysis of the anti-inflammatory level of probiotic supernatant in vitro

[0048] RAW264.7 cells were seeded into 12-well plates (1×10 6 cells), CO 2 The cells were incubated at 37°C for 12 hours to adhere to the wall. Lipopolysaccharide (LPS) (5 μg / mL) was added to stimulate the inflammatory response of RAW264.7 cells. After 6 hours, 50 μL of blank MRS medium and supernatant of Lactobacillus delbrueckii JNL0010 were added, respectively. 2 Incubate at 37°C in an incubator for 24 h. Mouse TNF-α (Biyuntian, PT512) and IL-6 (Biyuntian, PI326) ELISA kits were used to detect the levels of inflammatory factors TNF-α and IL-6 in the cell supernatant, respectively. Antibodies against mouse F4 / 80, CD206, and CD86 were used to label cells, and flow cytometry was used to analyze cell populations.

[0049] After 6 hours of LPS stimulation of RAW264.7 cells, the bacterial supernatants of Lactobacillus delbrueckii JNL0010 and Lactobacillus rhamnosus LGG were added and incubated for 24 hours. Flow cytometry analysis showed that compared with the LPS treatment group, Lactobacillus delbrueckii JNL0010 significantly reduced the proportion of pro-inflammatory M1 macrophages and significantly increased the proportion of anti-inflammatory M2 macrophages. Figure 4 As shown in (a) and (b). The results of ELISA analysis showed that Lactobacillus delbrueckii JNL0010 significantly inhibited the secretion of pro-inflammatory cytokines IL-6 and TNF-α. Figure 4 As shown in (c) and (d). Moreover, Lactobacillus delbrueckii JNL0010 has a better inhibitory effect on inflammation than Lactobacillus rhamnosus LGG.

[0050] Example 6, bacterial antibiotic sensitivity analysis

[0051] Lactobacillus delbrueckii JNL0010 was inoculated in liquid MRS medium and cultured anaerobically at 37°C for 24 hours to obtain seed liquid. The bacterial liquid was diluted to 0.5 McFarland turbidity with 0.85% saline, 100 μL of bacterial liquid was accurately aspirated and evenly spread on the surface of MRS agar medium. After the surface bacterial liquid was dried, a drug-sensitive paper was placed on the surface of the culture medium. The sensitivity of Lactobacillus delbrueckii JNL0010 to six antibiotics, including ampicillin (10 μg / piece), gentamicin (10 μg / piece), kanamycin (30 μg / piece), streptomycin (10 μg / piece), clindamycin (2 μg / piece) and chloramphenicol (30 μg / piece), was detected by KB paper diffusion method. The sensitivity of each bacterial strain to each antibiotic was repeated three times. Cultured anaerobically at 37°C for 24 hours. The diameter of the inhibition zone was measured and recorded, and compared with the diameter of the inhibition zone of the reference strain in the instruction manual. The results are shown in Table 1.

[0052] Table 1 Antibiotic inhibition zone of Lactobacillus delbrueckii JNL0010

[0053]

[0054] Example 7, Bacterial Hemolytic Analysis

[0055] Prepare Columbia blood agar plates: 23.0g animal tissue hydrolysate, 1.0g starch, 5.0g NaCl, 15g agar, 1000mL distilled water, pH7.3. Sterilize at 121℃ for 15min. When cooled to 50℃, add 5% defiberized sheep blood. Cool and set aside. Keep at room temperature for no more than 4h, and store at 4℃ for no more than 7d. Streak Lactobacillus delbrueckii JNL0010 and control strains on Columbia blood agar plates. Incubate anaerobically at 37℃ for 18-24h, and observe the colony morphology. α-hemolysis is manifested as a narrow, grass-green hemolysis ring; β-hemolysis is manifested as a wide, well-defined, completely transparent hemolysis ring; γ-hemolysis is non-hemolysis, that is, no hemolysis ring appears. Figure 5 As shown in (a), (b), and (c), the light green balloon bacteria were used as the α-hemolytic control strain, the Streptococcus pyogenes CICC10373 was used as the β-hemolytic control strain, and Lactobacillus delbrueckii JNL0010 did not show a hemolytic ring.

[0056] Example 8: Animal Experiment Analysis of the Therapeutic Effect of Probiotics on DSS-Induced Colitis

[0057] After 1 week of adaptive feeding, 6-8 week old male C57Bl / 6N mice were allowed to drink freely 2.5% DSS (molecular weight 36,000-50,000Da) aqueous solution to induce colitis mouse model. Lactobacillus delbrueckii JNL0010 cultured for 24 hours was centrifuged at 5000rpm and 4℃ for 5 minutes, the supernatant was discarded, and the cells were resuspended in physiological saline. The daily oral dose for each mouse was 2×10 9 CFU. 5-Amino Salicylic Acid (5-ASA, 100 mg / kg / d) was used as a positive control drug. The experimental period was 7 days, during which the weight, diarrhea, bloody stools and activity status of the mice were monitored daily. The mice were anesthetized and killed by cervical dislocation, and the colon tissues were collected and analyzed by hematoxylin-eosin (H&E) staining. Flow cytometry was used to analyze the proportion of regulatory T cells (Treg) and macrophages in the colon tissue of mice, and RT-qPCR was used to detect the transcription levels of inflammatory factors IL-β, IL-6 and TNF-α in the colon tissue of mice.

[0058] The scoring criteria for the disease activity index (DAI) of colitis mice are shown in Table 2:

[0059] Table 2 DAI scoring criteria for colitis model mice

[0060]

[0061] The DAI score is the sum of the scores of weight loss, diarrhea, and blood in stool.

[0062] The colitis mouse model was induced by DSS aqueous solution, and 2×10 9 CFU of Lactobacillus delbrueckii JNL0010 or Lactobacillus rhamnosus LGG. Lactobacillus delbrueckii JNL0010 significantly slowed down the weight loss of colitis mice and reduced the disease activity index of mice, such as Figure 6 As shown in (a) and (b). The improvement effects of Lactobacillus rhamnosus LGG and 5-ASA on the body weight and disease activity index of mice were weak. Treatment with Lactobacillus delbrueckii JNL0010 could improve the colon shortening caused by DSS, significantly enhance the integrity of the intestinal barrier, and inhibit the infiltration of inflammatory cells in the colon tissue and the destruction of the mucosa, as shown in (a) and (b). Figure 7 and Figure 8As shown. 5-ASA can inhibit colonic inflammatory cell infiltration and protect the integrity of the intestinal barrier, but Lactobacillus rhamnosus LGG has a weaker protective effect on the intestinal tissue structure. Flow cytometry analysis results showed that Lactobacillus delbrueckii JNL0010 increased the proportion of M2 macrophages (anti-inflammatory) in the intestinal lamina propria, reduced the proportion of M1 macrophages (pro-inflammatory), and had a trend of upregulating the Treg immune cell population. RT-qPCR analysis results showed that JNL0010 can significantly inhibit the levels of proinflammatory cytokines IL-1β, IL-6 and TNF-α in colon tissue, indicating that Lactobacillus delbrueckii JNL0010 can effectively inhibit intestinal tissue inflammation, such as Fig. 9 As shown in the figure, the inhibitory effect of Lactobacillus rhamnosus LGG on intestinal inflammation is weaker than that of Lactobacillus delbrueckii JNL0010.

[0063] Example 9, a microbial preparation

[0064] The supernatant containing Lactobacillus delbrueckii JNL0010 prepared in Example 3 can be used to prepare drugs.

[0065] As an embodiment, in the medicine, Lactobacillus delbrueckii JNL0010 is the only effective active ingredient.

[0066] The supernatant may be freeze-dried to prepare a lyophilized powder.

[0067] It can also be combined with solvents or other excipients for the treatment of colitis. When combined with solvents, injections can be prepared. When combined with other solid excipients, other conventional dosage forms such as tablets and capsules can be prepared.

[0068] Alternatively, as another embodiment, Lactobacillus delbrueckii JNL0010 is combined with other active ingredients for treating colitis.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A strain of Lactobacillus delbrueckii JNL0010, characterized in that: The Lactobacillus delbrueckii JNL0010 was deposited in the China General Microbiological Culture Collection Center on June 24, 2024, with the deposit address at No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with the deposit number CGMCC NO: 31042, and the classification name is Lactobacillus delbrueckii subsp. bulgaricus.

2. Use of the Lactobacillus delbrueckii JNL0010 described in claim 1 in producing indole-3-lactic acid.

3. Use of the Lactobacillus delbrueckii JNL0010 according to claim 1 in the preparation of a medicine for treating colitis.

4. A microbial preparation, characterized in that: The method comprises the Lactobacillus delbrueckii JNL0010 according to claim 1.

5. The microbial preparation according to claim 4, characterized in that Also included are excipients.

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