Dorsal bacteria EMF18-06B1D and its use

Abstract

The present invention relates to the field of microbial medicine technology, and specifically discloses Dorsalella EMF18-06B1D and its use. Dorea phocaensis )EMF18‑06B1D, which was deposited in Guangdong Provincial Microbial Culture Collection Center on September 2, 2024, with a deposit number of GDMCC No: 65085. The present invention proves through a mouse model that Dorea sp. EMF18‑06B1D can significantly improve the disease activity index (DAI) of mice with ulcerative colitis induced by sodium dextran sulfate, alleviate the weight loss trend and colon shortening degree of mice with ulcerative colitis, and help restore intestinal barrier function and reduce intestinal inflammatory response.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial medicine, and specifically relates to Dorsal sp. EMF18-06B1D and uses thereof. Background Art

[0002] Inflammatory bowel disease (IBD) is a type of inflammatory disease characterized by chronic, recurrent intestinal inflammation, including two subtypes: Crohn's disease (CD) and ulcerative colitis (UC). The global incidence of IBD is on the rise, especially in industrialized countries. Although the exact cause of IBD has not yet been fully revealed, it is generally believed that it is the result of a complex network of interactions between genetic background, immune response, environmental influences, and intestinal microbial communities.

[0003] In recent years, the rapid development of metagenomics and microbiome has revealed the close connection between intestinal microecology and human health. In particular, the balance of intestinal flora plays an important role in the prevention and treatment of inflammatory diseases such as inflammatory bowel disease. Some specific probiotic strains may have a positive effect on intestinal barrier function by regulating the intestinal environment and host metabolic pathways.

[0004] Currently, commonly used methods for treating inflammatory bowel disease (IBD) include salicylates, glucocorticoids, immunosuppressants, and biologics. Although these treatments are effective to a certain extent, they may cause side effects, the cost of treatment may also be high, and the effects vary from person to person. Therefore, probiotics are receiving more and more research attention as a possible alternative or complementary treatment. Probiotics are a class of live bacteria that can provide health benefits to the host. However, there are relatively few strategies in the prior art for using probiotics to prevent and treat inflammatory bowel disease. Summary of the invention

[0005] The purpose of the present invention is to provide a Dorea sp. EMF18-06B1D and its use in view of the above-mentioned deficiencies in the prior art. The Dorea sp. EMF18-06B1D can significantly improve the disease activity index (DAI) of UC mice induced by DSS (dextran sulfate sodium), control the weight loss and colon shortening of UC mice, improve the intestinal barrier function and reduce the inflammatory response, and compared with the existing therapeutic drugs, it shows a better therapeutic effect, providing new insights and strategies for the treatment of IBD.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] The first object of the present invention is to provide Dorea sp. EMF18-06B1D, which was deposited in Guangdong Provincial Microbiological Culture Collection Center on September 2, 2024. The address of the depository is 5th Floor, Building 59, No. 100, Xianlie Middle Road, Guangzhou, and the taxonomic name is Dorea phocaeensis, The deposit number is GDMCC No:65085.

[0008] The second object of the present invention is to provide a composition, comprising Doreae sp. with a deposit number of GDMCC No:65085.

[0009] The amount of live bacteria of Dorea sp. EMF18-06B1D contained in the above composition is (1~10000)×10 6 cfu / g.

[0010] The third object of the present invention is to provide the use of the above-mentioned Dorea sp. EMF18-06B1D or the composition in the preparation of drugs for preventing and alleviating inflammatory bowel disease.

[0011] Furthermore, the inflammatory bowel disease is ulcerative colitis or Crohn's disease.

[0012] Furthermore, the Dorea sp. EMF18-06B1D can significantly improve the disease activity index of ulcerative colitis induced by sodium dextran sulfate in a mouse model.

[0013] Furthermore, the Dorea sp. EMF18-06B1D was able to control colon shortening and reduce inflammatory response in a mouse model.

[0014] Furthermore, the Dorea sp. EMF18-06B1D can enhance the intestinal barrier function in a mouse model.

[0015] The fourth object of the present invention is to provide a medicine, which comprises the above-mentioned Dorea sp. EMF18-06B1D bacteria or composition, and pharmaceutically acceptable excipients.

[0016] The Dorsal bacteria EMF18-06B1D or fermentation liquid or composition can be used as the only active ingredient with the function of relieving colitis, or it can contain other active ingredients. The drug provided by the present invention can be used alone or in combination with other products with the function of relieving colitis. The present invention does not specifically limit the concentration of live Dorsal bacteria in the colitis relieving product, and it can be conventionally selected according to actual needs. The live Dorsal bacteria concentration in the product is 1×10 8 ~1×10 10 CFU / mL. As an embodiment, the colitis is relieved.

[0017] The dosage form of the drug can be solution, powder, granules, capsule or tablet.

[0018] The fifth object of the present invention is to provide a bacterial agent, wherein the above-mentioned Dorsalella EMF18-06B1D strain is inoculated into an MRS anaerobic broth culture medium for activation and fermentation culture in sequence to obtain a fermentation liquid; the fermentation liquid is centrifuged, mixed with a protective agent, and then freeze-dried to obtain Dorsalella EMF18-06B1D strain powder; the Dorsalella EMF18-06B1D strain powder is prepared according to the ratio of live bacteria count to obtain the bacterial agent.

[0019] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0020] The present invention isolates and screens a strain of microorganisms from adult feces samples, and the taxonomic name is Dorea phocaeensis The strain Dorsachinensis EMF18-06B1D was deposited in the Guangdong Provincial Microbial Culture Collection Center on September 2, 2024, with the deposit number GDMCC No: 65085. The strain Dorsachinensis EMF18-06B1D can effectively reduce the inflammatory response and show a relieving effect in the treatment of intestinal inflammatory bowel disease. Specifically, Dorsachinensis EMF18-06B1D can significantly reduce the disease activity index (DAI) of the ulcerative colitis (UC) mouse model induced by DSS (dextran sulfate sodium). In addition, it can effectively control the weight loss and colon shortening of UC mice, while improving the intestinal barrier function and reducing the occurrence of inflammatory response. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the genome circular map information of Dorea sp. EMF18-06B1D provided in an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of the KEGG metabolic pathway annotation provided in an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of weight monitoring results provided by an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of the DAI score of the Dorea sp. EMF18-06B1D group provided in an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of the length of colon tissue provided by an embodiment of the present invention;

[0026] Figure 6A schematic diagram of the statistical analysis of colon length provided by an embodiment of the present invention;

[0027] Figure 7 Representative micrographs of H&E staining of colon tissues of four groups of mice provided in the embodiments of the present invention;

[0028] Figure 8 A schematic diagram of histopathological scoring provided by an embodiment of the present invention;

[0029] Fig. 9 Schematic diagram of the effect of ELISA on the expression of inflammatory factor IL-6 in colon tissue;

[0030] Fig.10 Schematic diagram of the effect of ELISA on the expression of anti-inflammatory factor TGF-β1 in colon tissue;

[0031] Fig.11 Schematic diagram of the effect of qRT-PCR technology on the expression of inflammatory factor IL-1β in colon tissue;

[0032] Fig.12 Schematic diagram of the effect of qRT-PCR technology on the expression of inflammatory factor TNF-α in colon tissue;

[0033] Fig.13 Schematic diagram of the effect of qRT-PCR technology on the expression of inflammatory factor IL-6 in colon tissue;

[0034] Fig.14 Schematic diagram of the effect of qRT-PCR technology on the expression of anti-inflammatory factor IL-10 in colon tissue;

[0035] Fig.15 A schematic diagram of the effect of Doreae EMF18-06B1D on intestinal tight junction protein ZO-1 provided in an embodiment of the present invention;

[0036] Fig.16 A schematic diagram of the effect of Doreae EMF18-06B1D on the intestinal tight junction protein Occludin provided in an embodiment of the present invention;

[0037] Fig.17 A schematic diagram of the effect of Doreae EMF18-06B1D on the intestinal tight junction protein Claudin-2 provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are further described in detail below in conjunction with specific examples and drawings. If no specific technology or conditions are specified in the examples, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained commercially.

[0039] The present invention isolates a new strain of Dorea EMF18-06B1D from fecal samples of healthy adults. The strain can effectively reduce inflammatory response and show a relieving effect in the treatment of intestinal inflammatory bowel disease. Dorea EMF18-06B1D was deposited in the Guangdong Provincial Microbiological Culture Collection Center on September 2, 2024. The address of the depository is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, and the deposit number is GDMCC No: 65085.

[0040] Example 1

[0041] Origin, isolation and identification of Dorea sp. EMF18-06B1D.

[0042] (1) Sample collection

[0043] Fecal samples from healthy adults were collected and transferred to sample tubes under sterile conditions and brought back to the laboratory for processing within 1 hour. All subjects were informed of the nature of the sampling and experiment and their consent was obtained. The samples were strictly screened, and samples from patients with the following conditions were excluded: patients with a history of other types of cancer, other serious systemic diseases or digestive system diseases, chronic viral infections, bacterial infections before surgery, and those who had received immunosuppressive therapy (such as chemotherapy, oral steroids, etc.) or other cancer-related treatments before surgery.

[0044] (2) Isolation and purification of Doerrella

[0045] 0.2g of fecal sample was mixed in 1ml of sterile PBS, spread on the culture medium after gradient dilution, and cultured at 37℃ for 72 hours under anaerobic conditions; a single, moist, raised round colony was picked for Gram staining and the colony morphology was recorded. Three rounds of purification were performed on the three-zone line and cultured anaerobically at 37℃ for 3 days to enrich anaerobic Gram-positive bacteria, and a single colony was picked and identified by PCR sequencing, that is, the strain was isolated and screened.

[0046] (3) Preservation of bacterial strains

[0047] The purified strain was cultured to a concentration of about 1×10 9 cfu / ml, and after adding 20% ​​glycerol, they were stored at -80°C for long term storage.

[0048] (4) Genomic DNA extraction and 16S rDNA identification

[0049] Genomic DNA was extracted using a commercial kit and amplified by PCR using universal 16S rDNA primers. The strain was sequenced and compared with the Genebank database. Dorea phocaeensis , Sequencing sequence see SEQ ID NO.1

[0050] Example 2

[0051] Analysis of the genomic characteristics of Dorea sp. EMF18-06B1D.

[0052] (1) Whole genome sequencing and assembly

[0053] like Figure 1-Figure 2 As shown, the whole genome of Dorea sp. EMF18-06B1D was sequenced using high-throughput sequencing technology, and 37 sequences with a total length of 2,242,707 bp were obtained. The GTDB-Tk tool was used for genome classification, and 1,803 coding DNA sequences (CDS) were predicted, including 4 rRNA genes, 53 tRNA genes, and 1 tmRNA gene.

[0054] (2) Metabolic pathway analysis

[0055] Metabolic pathway annotation was performed using eggNOG-mapper and the KEGG database, and it was found that the strain had strong metabolic functions and environmental adaptability.

[0056] Example 3

[0057] Safety evaluation of Dorea sp. EMF18-06B1D.

[0058] (1) Antibiotic resistance gene detection

[0059] The antibiotic resistance genes were predicted using the RGI tool and the CARD database, and genes such as rpoB mutant, tet(W), dfrF, and ErmX were found. The genes associated with antibiotic resistance are shown in Table 1.

[0060] Table 1.

[0061]

[0062] (2) Virulence factor gene detection

[0063] The VFDB database was used to predict virulence factor genes, and genes related to bacterial adhesion, immune regulation, anti-phagocytosis, and nutritional / metabolic factors were discovered.

[0064] Table 2. Virulence factor genes

[0065]

[0066] Example 4

[0067] Study on the therapeutic effect of Dorea sp. EMF18-06B1D on colitis mouse model.

[0068] (1) Establishment of animal model

[0069] The animal experiment in this embodiment selected 37 6-8 week SPF healthy C57BL / 6 mice with an average body weight of 18-22g. The mice were adaptively raised in an SPF-grade laboratory environment for one week and randomly assigned to four different experimental groups. The grouping is as follows: normal control group, dextran sulfate sodium (DSS) treatment group, mesalazine (5-ASA) treatment group and EMF18 treatment group (Doleella EMF18-06B1D), and the specific grouping is shown in Table 3.

[0070] From day 1 to day 14, mice in the EMF18-treated group received 1×10 -9 The mice in the DSS-treated group and the normal control group were gavaged with an equal amount of phosphate buffered saline (PBS). From the 8th to the 14th day, except for the normal control group, the mice in other groups drank 2.5% dextran sulfate sodium (DSS) solution freely for 7 days. All the mice in each group had diarrhea (100%), decreased food intake, decreased weight, decreased fur gloss, and the inflammatory bowel disease model was successfully established.

[0071] Table 3. Mouse experiment design table

[0072]

[0073] (2) Observation and detection indicators and treatment:

[0074] ① During the modeling and oral gavage, the weight changes, food and water intake, hair gloss, mental state, activity and death of mice were observed, and the severity of enteritis in mice was determined according to the disease activity index (DAI). DAI includes the percentage of weight loss, the degree of fecal diarrhea and blood in the stool. The specific calculation method is: the sum of the scores of the percentage of weight loss, the degree of fecal diarrhea and blood in the stool; among them, the percentage of weight loss score: 0 = no weight loss; 1 = 1-5%; 2 = 5-10%; 3 = 10-20%; 4 = more than 20%; feces score: 0 = solid feces pellets; 1 = solid feces pellets, easy to deform; 2 = unformed stool; 3 = loose stool; 4 = liquid stool; blood in the stool score: 0 = occult blood; negative test; 1 = occult blood test 1+, no visible blood in the stool; 2 = occult blood test 2+; 3 = occult blood test 3+, visible blood in the stool; 4 = severe blood in the stool. The specific DAI scoring criteria are shown in Table 4.

[0075] Table 4. DAI scoring criteria

[0076]

[0077] Note: DAI = (weight loss score + stool characteristics score + blood in stool score) / 3; the comprehensive score of DAI is between 0 and 4, with 0 representing normal and 4 representing the highest inflammatory activity.

[0078] ②On the 15th day of the experiment, the mice were weighed, blood was collected from their eyes after anesthesia, and the mice were killed by cervical dislocation. Subsequently, the collected blood samples were centrifuged to separate the serum and stored at -80°C for subsequent biochemical index testing. The length of the mouse colon was measured, and samples were taken for tissue sections. Some colon samples were used to make pathological sections for histological analysis under a microscope. The remaining colon tissue was frozen and stored at -80°C for future experimental studies.

[0079] ③ The distal colorectal tissue (about 2 cm away from the anus) was made into a Swiss roll and fixed with 4% paraformaldehyde before routine paraffin embedding and sectioning to obtain colon tissue sections. Hematoxylin-eosin (H&E) staining was performed to detect the pathological condition and score the score. The criteria were as follows: Pathological score included epithelial loss, crypt damage, goblet cell reduction and inflammatory cell infiltration; epithelial loss: 0 = no pathological change; 1 = 0-5% epithelial loss; 2 = 5-10% epithelial loss; 3 = more than 10% epithelial loss; crypt damage: 0 = crypt intact; 1 = 0-10% crypt damaged; 2 = 10-20% crypt damaged; 3 = more than 20% crypt damaged; goblet cell reduction: 0 = none; 1 = mild; 2 = moderate; 3 = severe; inflammatory cell infiltration; 0 = no infiltration; 1 = increased inflammatory cells in the lamina propria; 2 = inflammatory cells extending to the submucosal layer; 3 = transmural inflammatory cell infiltration. The specific histopathological scoring criteria are shown in Table 5.

[0080] Table 5. Pathological histological scoring criteria

[0081]

[0082] ④Intestinal barrier function analysis

[0083] The mRNA expression levels of tight junction proteins (ZO-1, Occludin, and Claudin-2) were evaluated by qRT-PCR, and the expression of tight junction proteins (ZO-1, Occludin, and Claudin-2) was analyzed by western blot to evaluate the recovery of intestinal barrier function.

[0084] ⑤ Cytokine level determination

[0085] ELISA was used to determine the levels of inflammatory factor IL-6 and anti-inflammatory factor TGF-β1 in colon tissue; and qRT-PCR technology was used to determine the levels of inflammatory factors (IL-6, IL-1β and TNF-α) and anti-inflammatory factor (IL-10) in colon tissue.

[0086] Monitor the initial body weight (0 day) and the body weight after 14 days of intervention, and calculate the body weight change rate. Figure 3 . It can be seen that, except for the control group, the other three groups all showed weight loss under DSS induction; after continuous intragastric administration of EMF18 bacterial solution for 14 days, compared with the DSS group, the Dorea group could significantly improve the weight loss of DSS mice (P<0.05); compared with the 5-ASA group, the results of improving the weight loss of mice in the Dorea group were no different from those in the 5-ASA group. The results show that the bacterial solution of the Dorea group can effectively reduce the weight loss symptoms caused by inflammatory bowel disease.

[0087] The disease activity index (DAI) scores of the four different treatment groups were detected and recorded. The DAI scores after the initial administration of 2.5% DSS (7 days) and the final administration of 2.5% DSS (14 days) were monitored. Figure 4 As shown. It can be seen that the disease activity index of the other three groups except the control group increased under DSS induction; compared with the DSS group, the Dorea group and the 5-ASA group could significantly reduce the disease activity index of DSS mice (P<0.0001); compared with the 5-ASA group, the results of the Dorea group in reducing the disease activity index of mice were no different from those of the 5-ASA group. The results show that the bacterial solution of the Dorea group can effectively reduce the activity index caused by inflammatory bowel disease.

[0088] like Figure 5 The image shown is the length of colon tissue. It can be seen from the figure that the Dorea group bacterial solution can significantly improve the shortening of the colon in DSS-treated mice.

[0089] like Figure 6 Figure 2 shows the results of statistical analysis of colon length. The colon length of the DSS group (5.21±0.34 cm) was significantly shorter than that of the control group (7.33±0.71 cm) (P<0.0001). The colon length of the EMF18 group (6.319±0.66 cm) was significantly longer than that of the DSS group (P<0.05), indicating that EMF18 may reduce colon shortening in DSS-induced colitis mice.

[0090] like Figure 7 The following are representative micrographs of H&E staining of colon tissues of mice in the four groups. The colon tissue structure of mice in the control group was clear and intact; the colon tissue of mice in the mesalazine group and the Dorea group was damaged to a certain extent, but some structures were still retained; the colon tissue structure of mice in the sodium dextran sulfate group was severely damaged, and the inflammatory response was obvious.

[0091] like Figure 8 The results of colon histopathology scores are shown in the figure. It can be seen that the colon histopathology scores of the other three groups, except the control group, increased under the induction of sodium dextran sulfate. Compared with the sodium dextran sulfate group, the colon histopathology scores of mice induced by sodium dextran sulfate were significantly reduced in the Dorea group and the mesalazine group (P<0.0001). Compared with the mesalazine group, the colon histopathology scores of mice in the Dorea group were not significantly different from those in the mesalazine group. The results show that the bacterial solution of the Dorea group can effectively reduce the pathological changes in the colon tissue of mice caused by inflammatory bowel disease.

[0092] like Figure 9-14The results of cellular inflammatory factor expression are shown in Figure 2. It can be seen that under the induction of sodium dextran sulfate, the expression of proinflammatory factors (IL-6, IL-1β and TNF-α) in the other three groups of mice except the control group increased, and the expression of anti-inflammatory factors (TGF-β1 and IL-10) decreased. Compared with the sodium dextran sulfate group, the Dorea group and the mesalazine group could significantly reduce the expression of proinflammatory factors (IL-6, IL-1β and TNF-α) in mice (P<0.0001). In addition, the Dorea group was equivalent to the mesalazine group in reducing the expression of proinflammatory factors (IL-6, IL-1β and TNF-α) in mice. These results show that the bacterial solution of the Dorea group can effectively reduce the expression level of proinflammatory factors in mice caused by inflammatory bowel disease and increase the expression level of anti-inflammatory factors.

[0093] like Figure 15-17 As shown in the figure, it is the result of enhancing the intestinal barrier function. It can be seen that under the condition of sodium dextran sulfate induction, except for the sodium dextran sulfate group, the intestinal tight junction proteins of the other three groups of mice were expressed. Specifically, compared with the control group, the expression of ZO-1 protein and Claudin-2 protein in the Dorea group and mesalazine group increased significantly under the influence of inflammation (P<0.0001), and the expression of occludin protein was relatively reduced; however, the three tight junction proteins were almost not expressed in the sodium dextran sulfate group (P<0.0001). This shows that the bacterial solution of the Dorea group can effectively increase the expression of colon tight junction proteins and maintain the integrity of epithelial cells.

[0094] Example 5

[0095] Preparation of microecological solution preparation containing Dorea sp. EMF18-06B1D.

[0096] (1) Preparation of probiotic suspension

[0097] A single colony of Dorea sp. EMF18-06B1D was inoculated into MRS anaerobic broth medium and cultured anaerobically at 37°C until the growth plateau phase, and the bacterial suspension of Dorea sp. EMF18-06B1D was collected. The bacterial suspension was centrifuged at 3000×g and 4°C for 10 minutes, the supernatant was removed, the bacterial cells were collected and resuspended with physiological saline to a concentration of 1×10 9 CFU / mL, and the suspension of Dorea sp. EMF18-06B1D was obtained.

[0098] (2) Microecological preparation formula

[0099] The suspension of Doreae EMF18-06B1D is mixed with a protective agent, a nutritional supplement, etc. according to the number of live bacteria to prepare a microecological preparation suitable for oral administration. Among them, the protective agent is selected from any one of milk powder, cyclodextrin, maltose, glucose, glycerol, sodium glutamate, mannose, galactose, mannitol or methylcellulose, and the nutritional supplement is not limited to meet the food or drug testing standards according to the product design. The ratio of live bacteria to protective agent is a conventional choice for common processes of microecological preparations. The protective agent is generally calculated by mass volume ratio, and the addition amount is 1%~10%.

[0100] (3) Preparation stability test

[0101] The prepared microecological preparations are subjected to stability tests to ensure the activity of probiotics during storage and use.

[0102] Example 6

[0103] Preparation of microecological freeze-dried bacterial powder preparation containing Dole's EMF18-06B1D.

[0104] (1) Probiotic culture

[0105] A single colony of Dorea sp. EMF18-06B1D was inoculated into MRS anaerobic broth medium and cultured anaerobically at 37°C until the growth plateau phase, and the bacterial suspension of Dorea sp. EMF18-06B1D was collected. The bacterial suspension was centrifuged at 3000×g and 4°C for 10 minutes, the supernatant was removed, the bacterial cells were collected and resuspended with physiological saline to a concentration of 1×10 9 The CFU / mL was mixed with a protective agent and then freeze-dried to obtain the powder of Dorea sp. EMF18-06B1D strain, wherein the protective agent is selected from any one of milk powder, cyclodextrin, maltose, glucose, glycerol, sodium glutamate, mannose, galactose, mannan or methylcellulose. The protective agent is generally calculated according to the mass volume ratio, and the conventional selected addition amount is 1% to 10%.

[0106] (2) Microecological preparation formula

[0107] The powder of EMF18-06B1D strain of Doreae is mixed with protective agents, nutritional supplements, etc. according to the number of live bacteria to prepare a microecological freeze-dried powder preparation suitable for oral administration. Among them, the protective agent is selected from any one of milk powder, cyclodextrin, maltose, glucose, glycerol, sodium glutamate, mannose, galactose, mannitol or methylcellulose, and the nutritional supplement is not limited to meet the food testing standards according to the product design. The ratio of live bacteria to protective agent is a conventional choice for common processes of microecological preparations. The protective agent is generally added in an amount of 1% to 10% according to the mass volume ratio.

[0108] (3) Preparation stability test

[0109] The prepared microecological preparations are subjected to stability tests to ensure the activity of probiotics during storage and use.

[0110] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Dorsal bacteria EMF18-06B1D, which was deposited in Guangdong Microbial Culture Collection Center on September 2, 2024. The address of the depository is 5th Floor, Building 59, No. 100, Xianlie Middle Road, Guangzhou. The taxonomic name is Dorea phocaeensis , the deposit number is GDMCC No:65085.

2. A composition, characterized in that The composition comprises Doreae bacteria with a deposit number of GDMCC No:65085.

3. Use of the Dorea sp. EMF18-06B1D according to claim 1 or the composition according to claim 2 in the preparation of a medicament for relieving ulcerative colitis.

4. A drug, characterized in that The drug comprises the bacteria of Dorea sp. EMF18-06B1D according to claim 1 or the composition according to claim 2, and pharmaceutically acceptable excipients.

5. A bacterial agent, characterized in that: The Doreae EMF18-06B1D strain of claim 1 is inoculated into an MRS anaerobic broth medium for activation and fermentation culture in sequence to obtain a fermentation broth; the fermentation broth is centrifuged, mixed with a protective agent, and freeze-dried to obtain a Doreae EMF18-06B1D strain powder; The bacterial powder of Dorea sp. EMF18-06B1D strain is prepared according to the ratio of viable bacteria count to obtain the bacterial agent.

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