New applications of Lactobacillus delbrueckii surface proteins

Abstract

The present invention belongs to the field of biomedicine technology, and specifically discloses the application of Lactobacillus delbrueckii surface protein in the preparation of products that improve intestinal inflammation. The new use of Lactobacillus delbrueckii surface protein provided by the present invention, including the application in the preparation of a medicine for preventing and / or treating ulcerative colitis. Cell and animal experimental results show that Lactobacillus delbrueckii surface protein can alleviate DSS-induced ulcerative colitis in mice, improve weight loss, shortened colon length and colon mucosal damage, reduce proinflammatory cytokine (such as IL-1β, IL-6) content in the colon, increase anti-inflammatory cytokine (such as IL-10) content, reduce proinflammatory macrophage ratio in spleen and colon, inhibit macrophage proinflammatory phenotype, can be used for the preparation of products that improve intestinal inflammation, and has good application prospects and potential clinical treatment value.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine technology, and particularly relates to the application of Lactobacillus delbrueckii surface protein in the preparation of products for improving intestinal inflammation. Background Art

[0002] Intestinal homeostasis is strictly controlled by regulatory immune mechanisms, which are established by the interaction between commensal / probiotics and host PRRs (including CLRs and TLRs). Disruption of this regulatory mechanism may lead to chronic intestinal inflammation. Many studies have revealed that surface proteins play an important role in host-probiotic interactions mediated by intestinal cells. For example, the anti-inflammatory effect of Lactobacillus helveticus MIMLh5 on Caco-2 cells is mediated by its surface layer protein A and can reduce the activation of NF-κB (Taverniti, V., Stuknyte, M., Minuzzo, M., Arioli, S., De Noni, I., Scabiosi, C., et al. (2013). S-layer protein mediates the stimulatory effect of Lactobacillus shelveticus MIMLh5 on innate immunity. Appl. Environ. Microbiol. 79, 1221-1231.). Lactobacillus acidophilus interacts with PRRs through surface proteins and regulates immune responses. Lactobacillus acidophilus surface protein can also reduce the secretion of the proinflammatory factor interleukin 8 in Caco-2 cells stimulated by Salmonella typhimurium (Li, P., Yu, Q., Ye, X., Wang, Z., and Yang, Q. (2011). Lactobacillus S-layer protein inhibition of Salmonella-induced reorganization of the cytoskeleton and activation of MAPK signaling pathways in Caco-2 cells. Microbiol. Read. Engl. 157, 2639-2646.). In addition to interacting with primary intestinal epithelial cells, surface proteins also interact with antigen-presenting cells, which are located in Peyer's patches, lamina propria, and mesenteric lymph nodes.Furthermore, SlpA of Lactobacillus acidophilus imparts anti-inflammatory properties to the strain. It can bind to the C-type lectin SIGNR3, inducing regulatory signals that can alleviate colitis (Lightfoot, YL, Selle, K., Yang, T., Goh, YJ, Sahay, B., Zadeh, M., et al. (2015). SIGNR3-dependent immune regulation by Lactobacillus acidophilus surface layer protein A in colitis. EMBO J. 34, 881-895.). These studies suggest that probiotics can play a role in the prevention and treatment of intestinal diseases. However, their use also has limitations: first, the quality of the inoculum is difficult to guarantee, and its effectiveness depends on a sufficient number of viable bacteria; second, they can easily cause adverse reactions in the body, such as bacterial and fungal sepsis, harmful metabolic activity, and excessive immune and gastrointestinal stimulation. In certain special populations (such as premature infants and those with compromised immune systems), vigilance against serious adverse reactions is also warranted. The European Food Safety Authority (EFSA) also believes that the health claims of most probiotic products are insufficient in terms of strain characteristics (Scientific Opinion on the substantiation of health claims related to noncharacterized microorganisms pursuant to Article 13(1) of Regulation (EC) No 1924 / 2006, 2009). Therefore, it is particularly important to reveal the probiotics and identify the effector molecules in probiotics that exert their probiotic effects.

[0003] Chinese patent application CN116178509A (Northeast Agricultural University) discloses a method for preparing a bifidobacterium surface protein, using bifidobacterium DNG6 as a fermentation strain and 2'-FL as the sole carbon source. After fermentation and cultivation, LiCl solution is added for incubation, and the supernatant is collected by centrifugation. The supernatant is passed through a hydrophilic microporous filter membrane, and the filtrate is placed in a dialysis bag for dialysis. The liquid after dialysis is collected and freeze-dried to obtain the bifidobacterium surface protein. Experimental results show that the bifidobacterium surface protein can inhibit the growth and adhesion of pathogens, inhibit the activation of inflammation-related pathways, and thus reduce inflammatory reactions. Lactobacillus delbrueckii is a widely used probiotic with good anti-inflammatory properties, but the function of its surface protein has not yet been discovered. If the Lactobacillus delbrueckii surface protein can be extracted and its alleviating effect on intestinal inflammation is explored, it will contribute to the development of new probiotic products and have potential application value for alleviating intestinal inflammation. Summary of the Invention

[0004] The main technical problem solved by the present invention is to provide a new use of Lactobacillus delbrueckii surface protein, specifically the use of Lactobacillus delbrueckii surface protein in the preparation of products for improving intestinal inflammation.

[0005] Secondly, the present invention provides a drug for preventing and / or treating intestinal inflammation.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A new use of Lactobacillus delbrueckii surface protein, which is the use of Lactobacillus delbrueckii surface protein in the preparation of products for improving intestinal inflammation.

[0008] Specifically, the preparation method of the Lactobacillus delbrueckii surface protein is as follows: after fermentation and culture of Lactobacillus delbrueckii, lithium chloride solution is added for incubation; after incubation, the sterile clear fluid is collected for dialysis, and the dialyzate is filtered and sterilized to obtain a surface protein solution.

[0009] Specifically, the Lactobacillus delbrueckii includes but is not limited to commercially available strains such as Lactobacillus delbrueckii subsp. Indicus and Lactobacillus delbrueckii subspecies bulgaricus, or isolated strains, for example, Lactobacillus delbrueckii Mafic1501 disclosed in patent application CN116676214A, deposit number: CGMCC No. 26198, deposit unit: General Microbiology Center of China Culture Collection Administration, deposit address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, deposit date: December 14, 2022.

[0010] Specifically, the fermentation culture uses MRS culture medium containing 0.1-2 g / L cysteine.

[0011] Specifically, the fermentation culture conditions are: temperature 30°C-45°C, time 10-16 hours.

[0012] Specifically, the concentration of the lithium chloride solution is 3-8 M, and the amount used is 3-8 times the volume of the bacterial cells.

[0013] Specifically, the incubation conditions are: rotation speed 100-300 rpm, temperature 30° C.-45° C., and time 10-60 min.

[0014] Specifically, the dialysis conditions are: the molecular weight cut-off of the dialysis device is 500-2000D, and the time is 18-30 hours.

[0015] Specifically, the pore size of the filter membrane used for filtration sterilization is 0.22 μm.

[0016] As a preferred embodiment of the present invention, the product includes but is not limited to medicines.

[0017] Specifically, the use is: use of Lactobacillus delbrueckii surface protein in the preparation of a drug for preventing and / or treating intestinal inflammation (such as ulcerative colitis).

[0018] As a preferred embodiment of the present invention, the intestinal inflammation includes but is not limited to ulcerative colitis.

[0019] As a preferred embodiment of the present invention, the improvement of intestinal inflammation includes at least one of the following aspects:

[0020] (1) Improve weight loss;

[0021] (2) Improvement of colon length shortening;

[0022] (3) Improve colon mucosal damage;

[0023] (4) reduce the levels of pro-inflammatory cytokines in the colon;

[0024] (5) increase the content of anti-inflammatory cytokines in the colon;

[0025] (6) reduce the proportion of pro-inflammatory macrophages in the spleen;

[0026] (7) reduce the number of pro-inflammatory macrophages in the colon;

[0027] (8) Increase the number of anti-inflammatory macrophages in the colon;

[0028] (9) Inhibit the pro-inflammatory phenotype of macrophages.

[0029] As a preferred embodiment of the present invention, the inhibition of macrophage pro-inflammatory phenotype includes at least one of the following aspects:

[0030] (1) downregulating the expression of proinflammatory cytokines (such as IL-1β, IL-6, and / or TNF-α) in macrophages;

[0031] (2) inhibiting the expression of genes related to the Mincle signaling pathway in macrophages;

[0032] (3) Reduce the expression of Mincle, Malt1 and / or P50 in macrophages.

[0033] A medicine for preventing and / or treating intestinal inflammation, wherein the active ingredient of the medicine comprises the Lactobacillus delbrueckii surface protein prepared by the above method.

[0034] As a preferred embodiment of the present invention, the content of Lactobacillus delbrueckii surface protein in the drug is the effective amount, which can be in the range of 0.01wt%-99.99wt%.

[0035] As a preferred embodiment of the present invention, the drug further comprises other medicinal ingredients, including but not limited to medicinal ingredients for assisting in preventing and / or treating intestinal inflammation.

[0036] As a preferred embodiment of the present invention, the drug further comprises pharmaceutically acceptable carriers or excipients, including but not limited to excipients, preservatives, stabilizers, wetting agents, emulsifiers, salts for regulating osmotic pressure, buffers, and the like.

[0037] As a preferred embodiment of the present invention, the dosage form of the drug is a pharmaceutically acceptable dosage form, including but not limited to powder injection, injection, tablet, pill, capsule, spray, dispersion, etc.

[0038] As a preferred embodiment of the present invention, the dosage of the drug is a pharmaceutically acceptable dosage.

[0039] Beneficial effects of the present invention:

[0040] The present invention provides a method for preparing a product that improves intestinal inflammation, including a method for preparing a drug for preventing and / or treating ulcerative colitis. Cell and animal experimental results show that the Lactobacillus delbrueckii surface protein can alleviate DSS-induced ulcerative colitis in mice, improve weight loss, shortened colon length, and colonic mucosal damage, reduce the levels of proinflammatory cytokines (such as IL-1β and IL-6) in the colon, increase the levels of anti-inflammatory cytokines (such as IL-10), reduce the proportion of proinflammatory macrophages in the spleen and colon, and inhibit the proinflammatory phenotype of macrophages. The protein can be used to prepare a product that improves intestinal inflammation.

[0041] The product (medicine) for improving intestinal inflammation provided by the present invention, in addition to containing an effective amount of Lactobacillus delbrueckii surface protein, also contains a formulation / pharmaceutically acceptable carrier or excipient, which is used to make a dosage form that is easy to carry, store or use, and has good application prospects and potential clinical therapeutic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the effect of SP treatment on the body weight of mice with DSS-induced colitis in the experimental example.

[0043] Figure 2 This is the effect of SP treatment on the colon length of mice with DSS-induced colitis in the experimental example.

[0044] Figure 3This is the effect of SP treatment on the colon morphology of mice with DSS-induced colitis in the experimental example.

[0045] Figure 4 This is the effect of SP treatment on the levels of IL-1β, IL-6 and IL-10 in the mouse colon in the experimental example.

[0046] Figure 5 This is the effect of SP treatment on the typing of mouse spleen macrophages in the experimental example.

[0047] Figure 6 This is the effect of SP treatment on the typing of mouse colon macrophages in the experimental example.

[0048] Figure 7 This is the effect of different concentrations of SP treatment on the viability of RAW264.7 cells in the experimental example.

[0049] Figure 8 This is the effect of SP treatment on LPS-induced proinflammatory cytokine expression in macrophages in the experimental example.

[0050] Figure 9 This is the effect of SP treatment on the gene expression profile of macrophages in the experimental example.

[0051] Figure 10 This is the effect of SP treatment on the expression of Mincle receptor pathway genes and proteins in the experimental example.

[0052] To more clearly illustrate the technical solutions to be protected by the present invention, the drawings in the embodiments or experimental examples are briefly introduced above. It should be understood that the above drawings should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can also derive other relevant drawings based on these drawings without inventive effort. DETAILED DESCRIPTION

[0053] The technical solution of the present invention will be clearly and completely explained below with reference to specific embodiments and experimental examples.

[0054] Those skilled in the art should understand that the following embodiments and experimental examples are intended only to illustrate the technical solutions and effects of the present invention and should not be construed as limiting the scope of protection of the present invention. Based on the following embodiments, other technical solutions obtained by those skilled in the art without inventive effort, such as those obtained through modification, deformation, or simple substitution, are also within the scope of protection of the present invention.

[0055] Unless otherwise specified, the raw materials, reagents, and equipment used in the examples or experimental examples are all commercially available products.

[0056] Example 1

[0057] This embodiment provides a new use of a Lactobacillus delbrueckii surface protein, specifically, the use of a Lactobacillus delbrueckii surface protein in preparing a product for improving intestinal inflammation, wherein the improvement of intestinal inflammation includes at least one of the following aspects:

[0058] (1) Improve weight loss;

[0059] (2) Improvement of colon length shortening;

[0060] (3) Improve colon mucosal damage;

[0061] (4) reduce the levels of pro-inflammatory cytokines in the colon;

[0062] (5) increase the content of anti-inflammatory cytokines in the colon;

[0063] (6) reduce the proportion of pro-inflammatory macrophages in the spleen;

[0064] (7) reduce the number of pro-inflammatory macrophages in the colon;

[0065] (8) Increase the number of anti-inflammatory macrophages in the colon;

[0066] (9) Inhibit the pro-inflammatory phenotype of macrophages, including downregulating the expression of pro-inflammatory cytokines (such as IL-1β, IL-6 and / or TNF-α) in macrophages, inhibiting the expression of genes related to the Mincle-related signaling pathway in macrophages, and reducing the expression of Mincle, Malt1 and / or P50 in macrophages.

[0067] The preparation method of the Lactobacillus delbrueckii surface protein comprises the following steps:

[0068] (1) Lactobacillus delbrueckii Mafic1501 (deposit number: CGMCC No. 26198, deposited at the General Microbiology Center of China Culture Collection Administration, deposit address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, deposit date: December 14, 2022) was used as the fermentation strain and inoculated into MRS medium (containing 0.5 g / L cysteine) and cultured at 37°C for 12 h to the logarithmic phase;

[0069] (2) Centrifugation at 10,000 rpm and 4°C for 5 min to collect Lactobacillus delbrueckii cells;

[0070] (3) Discard the culture supernatant, add PBS to wash the cells, centrifuge at 10,000 rpm and 4°C for 5 min, discard the PBS, and repeat once;

[0071] (4) Add 5 times the volume of the cells to lithium chloride solution (5 M) to resuspend the cells and incubate them on a shaker at 200 rpm, 37°C, and 30 min.

[0072] (5) After incubation, centrifuge at 10,000 rpm and 4°C for 20 min, and collect the supernatant;

[0073] (6) The supernatant was transferred to a dialysis bag (specification: molecular weight cut-off 1000D), and the dialysis bag was placed in sterile PBS for 24 h. New sterile PBS was replaced at 2 h, 6 h, and 12 h respectively;

[0074] (7) After dialysis, the liquid was aspirated from the dialysis bag and filtered through a hydrophilic microporous filter membrane with a pore size of 0.22 μm to obtain a surface protein solution. The surface protein concentration was determined using a BCA assay kit.

[0075] Example 2

[0076] This example provides a use of a Lactobacillus delbrueckii surface protein (prepared using the method of Example 1) in the preparation of a drug for preventing and / or treating ulcerative colitis.

[0077] This embodiment also provides a drug for preventing and treating ulcerative colitis, comprising a pharmaceutically effective amount of Lactobacillus delbrueckii surface protein, as well as pharmaceutically acceptable carriers and excipients (such as excipients, preservatives and stabilizers), for preparing the drug into an injection.

[0078] In other embodiments of the present invention, the fermentation strain is commercially available Lactobacillus delbrueckii subspecies bulgaricus, and the effect of the obtained surface protein solution on improving intestinal inflammation is the same as that in Example 1 and the experimental example.

[0079] In other embodiments of the present invention, the fermentation strain used is the commercially available Lactobacillus delbrueckii subsp. Indicus, and the effect of the obtained surface protein solution on improving intestinal inflammation is the same as that in Example 1 and the experimental example.

[0080] Experimental example

[0081] 1. Lactobacillus delbrueckii surface protein (SP) alleviates dextran sulfate sodium (DSS)-induced ulcerative colitis in mice

[0082] Experimental method: 24 SPF-grade ICR male mice were randomly divided into 5 groups, namely CON group, DSS group, and SP+DSS group. SP protein (prepared in Example 1) was administered to mice daily by intraperitoneal injection (35 μg / d). The CON group and DSS group were injected with equal volumes of PBS every day. After 14 days of treatment, 3% DSS was added to the drinking water to induce ulcerative colitis. The CON group maintained normal drinking water, and body weight was recorded every day. The mice were killed after 22 days, and the spleen was collected for flow cytometry detection of macrophage typing. The colon was collected to measure the length, and a small section was taken for H&E staining and immunofluorescence staining. Another small section was used to extract proteins for detection of IL-1β, IL-6 and IL-10. The results are shown in the table. Figure 1-6 .

[0083] 1. Effect of SP treatment on body weight of mice with DSS-induced colitis

[0084] The degree of weight change was assessed by the percentage change of the mice's weight during the experiment compared to their initial weight ( Figure 1 At the end of the experiment, the CON group had a higher body weight percentage compared to their initial weight, indicating normal food and water intake, good growth and development, and a natural growth pattern. The DSS group had a significantly lower body weight percentage than the CON group (P < 0.001), and SP treatment significantly attenuated DSS-induced weight loss.

[0085] 2. Effect of SP treatment on colon length in mice with DSS-induced colitis

[0086] from Figure 2 As can be seen, the colon length of mice in the CON group was approximately 10 cm, with formed feces and normal intestinal mucosal morphology, without congestion or swelling. Compared with the CON group, the colon length of mice in the DSS group was significantly shorter (P < 0.0001), reaching only approximately 7 cm. After SP treatment, the colon length of mice was significantly increased compared with the DSS group (P < 0.01).

[0087] 3. Colon histopathological examination

[0088] The severity of colon inflammation was assessed by H&E staining. Figure 3 ). Histopathological changes observed under a light microscope using H&E staining: Colon specimens from the control group showed normal histological morphology of the mouse colon, with intact and continuous colonic mucosal epithelium, neatly arranged glands, normal crypt structure, and little inflammatory cell infiltration. Colon sections from the DSS group showed typical inflammatory changes, such as loss of crypt and surface epithelial cells, infiltration of inflammatory cells, and spread of inflammation to the mucosa, muscularis mucosae, and submucosa. Compared with the DSS group, the degree of colon damage in the SP+DSS group was significantly reduced. Although the crypt morphology was still altered and the mucosal epithelium was locally discontinuous, the inflammatory cell infiltration was reduced and the mucosal structural integrity was higher.

[0089] 4. Effects of SP treatment on IL-1β, IL-6, and IL-10 levels in colon tissue

[0090] ELISA kits were used to detect the levels of IL-1β, IL-6 and IL-10 in mouse colon tissue ( Figure 4 The results showed that compared with the CON group, the levels of pro-inflammatory cytokines IL-1β and IL-6 in the colon of mice in the DSS group were significantly increased (P<0.001), while the level of the anti-inflammatory cytokine IL-10 was decreased. SP treatment significantly decreased IL-6 levels and significantly increased IL-10 levels (P<0.001).

[0091] 5. Effect of SP treatment on the phenotype of splenic macrophages

[0092] Mononuclear cells were obtained from the spleen using a spleen mononuclear cell isolation kit, and CD45 was used to mark leukocytes, F4 / 80 and CD11b to mark macrophages, and CD16 / 32 to mark pro-inflammatory macrophages for flow cytometry analysis (see Figure 5 The results showed that compared with the DSS group, SP treatment significantly reduced the proportion of pro-inflammatory macrophages (P<0.01).

[0093] 6. Effects of SP treatment on the phenotype of colonic macrophages

[0094] Immunofluorescence staining was performed using CD68 to label pro-inflammatory macrophages and CD206 to label anti-inflammatory macrophages in the mouse colon (see Figure 6 The results showed that compared with the CON group, the DSS group had an increase in pro-inflammatory macrophages and a decrease in anti-inflammatory macrophages in the colon. SP treatment reversed this phenomenon, reducing pro-inflammatory macrophages and increasing anti-inflammatory macrophages.

[0095] 2. Effect of SP on Cell Viability

[0096] RAW264.7 cells were seeded into 96-well plates at 25,000 cells per well in high-glucose DMEM (10% fetal bovine serum). After overnight culture, the cells were treated with 1, 5, 10, and 25 μg / mL of SP, respectively. After 12 hours, 10 μL of CCK reagent was added to each well for incubation. After 2 hours, the absorbance was measured at 450 nm using a microplate reader and the relative cell viability was calculated. The results are shown in Table 1. Figure 7 .

[0097] from Figure 7 It can be seen that SP can significantly improve macrophage viability in the concentration range of 1-25 μg / mL.

[0098] 3. Inhibitory effect of SP on LPS-induced pro-inflammatory phenotype of macrophages

[0099] RAW264.7 cells were seeded into 12-well plates at 250,000 cells per well in high-glucose DMEM (10% fetal bovine serum). After overnight culture, the cells were treated with 25 μg / mL of SP. After 12 hours, the medium was replaced and 100 ng / mL of lipopolysaccharide (LPS) was used to induce a pro-inflammatory phenotype in RAW264.7 cells. After 12 hours of induction, the medium was aspirated and the cells were collected for RNA and protein extraction. The results are shown in Table 1. Figure 8-10 .

[0100] from Figure 8 It can be seen that SP significantly inhibited the gene expression of IL-1β, IL-6 and TNF-α. Transcriptome analysis showed that SP treatment of macrophages also inhibited the expression of genes related to the Mincle-related signaling pathway ( Figure 9 ). RT-qPCR and protein identification confirmed that SP pretreatment significantly reduced the expression of Mincle, Malt1, and P50 compared with the LPS group ( Figure 10 These results indicate that SP inhibits LPS-induced proinflammatory phenotype of macrophages by regulating Mincle receptor-related signaling pathways.

[0101] Although the technical solutions and technical effects of the present invention have been described in detail above using general descriptions, specific embodiments and experimental examples, for those skilled in the art, any modifications, replacements or improvements made without departing from the spirit of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A new use of Lactobacillus delbrueckii surface protein, characterized in that: The application is: application of Lactobacillus delbrueckii surface protein in the preparation of medicine for preventing and / or treating ulcerative colitis; The preparation method of the Lactobacillus delbrueckii surface protein comprises the following steps: (1) Lactobacillus delbrueckii was used as the fermentation strain and inoculated into MRS medium containing 0.5 g / L cysteine ​​and cultured at 37°C for 12 h until the logarithmic phase; (2) Centrifugation at 10,000 rpm and 4°C for 5 min to collect Lactobacillus delbrueckii cells; (3) Discard the culture supernatant, add PBS to wash the cells, centrifuge at 10,000 rpm and 4°C for 5 min, discard the PBS, and repeat once; (4) Add 5 times the volume of the bacterial cells to a 5 M lithium chloride solution to resuspend the cells and incubate in a shaker at 200 rpm, 37°C, and 30 min. (5) After incubation, centrifuge at 10,000 rpm and 4°C for 20 min, and collect the supernatant; (6) The supernatant was transferred to a dialysis bag with a molecular weight cutoff of 1000 D, and the dialysis bag was placed in sterile PBS for 24 h. New sterile PBS was replaced at 2 h, 6 h, and 12 h respectively; (7) After dialysis, the liquid was aspirated from the dialysis bag and filtered through a hydrophilic microporous filter membrane with a pore size of 0.22 μm to obtain a surface protein solution; The Lactobacillus delbrueckii is Lactobacillus delbrueckii Mafic1501, with a preservation number of CGMCC No.26198.

2. The novel use according to claim 1, characterized in that: The prevention and / or treatment of ulcerative colitis includes at least one of the following aspects: (1) Improve weight loss; (2) Improvement of colon length shortening; (3) Improve colon mucosal damage; (4) reduce the levels of pro-inflammatory cytokines in the colon; (5) increase the content of anti-inflammatory cytokines in the colon; (6) reduce the proportion of pro-inflammatory macrophages in the spleen; (7) reduce the number of pro-inflammatory macrophages in the colon; (8) Increase the number of anti-inflammatory macrophages in the colon; (9) Inhibit the pro-inflammatory phenotype of macrophages.

3. A drug for preventing and / or treating intestinal inflammation, characterized in that: The active ingredient of the drug comprises Lactobacillus delbrueckii surface protein; The preparation method of the Lactobacillus delbrueckii surface protein comprises the following steps: (1) Lactobacillus delbrueckii was used as the fermentation strain and inoculated into MRS medium containing 0.5 g / L cysteine ​​and cultured at 37°C for 12 h until the logarithmic phase; (2) Centrifugation at 10,000 rpm and 4°C for 5 min to collect Lactobacillus delbrueckii cells; (3) Discard the culture supernatant, add PBS to wash the cells, centrifuge at 10,000 rpm and 4°C for 5 min, discard the PBS, and repeat once; (4) Add 5 times the volume of the bacterial cells to a 5 M lithium chloride solution to resuspend the cells and incubate in a shaker at 200 rpm, 37°C, and 30 min. (5) After incubation, centrifuge at 10,000 rpm and 4°C for 20 min, and collect the supernatant; (6) The supernatant was transferred to a dialysis bag with a molecular weight cutoff of 1000 D, and the dialysis bag was placed in sterile PBS for 24 h. New sterile PBS was replaced at 2 h, 6 h, and 12 h respectively; (7) After dialysis, the liquid was aspirated from the dialysis bag and filtered through a hydrophilic microporous filter membrane with a pore size of 0.22 μm to obtain a surface protein solution; The Lactobacillus delbrueckii is Lactobacillus delbrueckii Mafic1501, with a preservation number of CGMCC No.26198.

4. The drug according to claim 3, characterized in that: The content of the Lactobacillus delbrueckii surface protein in the medicine is the effective amount, which is within the range of 0.01wt%-99.99wt%.

5. The drug according to claim 4, characterized in that: The drug may further comprise other pharmacological ingredients, including but not limited to pharmacological ingredients that assist in preventing and / or treating intestinal inflammation; And / or, the dosage form of the drug is a pharmaceutically acceptable dosage form, including but not limited to powder injection, injection, tablet, pill, capsule, spray, dispersion.

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