A Prevotella bivia strain and its application in preparing products for improving metabolism-related fatty liver disease

Abstract

The present application relates to the field of biotechnology, and specifically discloses a strain of Prevotella bivia and its application in the preparation of products for improving metabolic-related fatty liver disease. The Prevotella bivia strain used in the present application has a good therapeutic effect on metabolic-related fatty liver disease, and has a significant inhibitory effect on the liver's involvement in inflammatory response, which is specifically manifested in the reduction of inflammatory factors such as ALT, AST, TG, CHO and LDL; the present application clarifies the therapeutic effect of the Prevotella bivia strain in metabolic-related fatty liver disease, thereby providing an effective clinical drug for the treatment of metabolic-related fatty liver disease, which has a good application prospect.

Description

Technical Field

[0001] The present application relates to the field of biotechnology, in particular to a strain of Prevotella bivia and its application in preparing a product for improving metabolism-related fatty liver disease. Background Art

[0002] With the changes in dietary structure and lifestyle, metabolic-associated fatty liver disease (MAFLD) is characterized by fat deposition in the liver and diffuse macrovesicular fatty degeneration of hepatocytes. Accompanied by inflammatory response and damage repair, it can further develop into metabolic-associated steatohepatitis (MASH), and even cirrhosis and liver cancer. When the disease progresses to the MASH stage, it can also cause extrahepatic diseases such as type 2 diabetes, chronic kidney disease, colorectal cancer, and high-risk cardiovascular diseases such as stroke and myocardial infarction. Therefore, finding effective targets for the treatment of MASH has become a hot spot and urgent need for global drug research and development.

[0003] Prevotella is a Gram-negative bacterium, Prevotellaceae, Bacteroidales, and is one of the most important genera of keystone bacteria in the intestine. As a large genus, Prevotella includes more than 50 different species, such as Prevotella copri, Prevotella bivia, Prevotella intestinalis, etc. Due to the great genetic differences between different species, the functions of each strain are also different. Studies have shown that Prevotella is associated with a variety of inflammatory and metabolic diseases, and children diagnosed with autism have a lower abundance of Prevotella; Prevotella histicola is lacking in the intestinal microbiota of patients with multiple sclerosis, while treatment of transgenic mice with Prevotella histicola alone or in combination with the multiple sclerosis drug Copaxone reduces the pro-inflammatory response associated with the disease. In patients with MAFLD, the abundance of Prevotella is relatively reduced. This suggests that changes in the intestinal microbiota have a certain impact on the progression of the disease during the development of MAFLD. However, it is unknown whether Prevotella can be used to treat MAFLD. Summary of the invention

[0004] The purpose of the present application is to overcome the deficiencies of the above-mentioned prior art and to provide a Prevotella bivia strain and its use in preparing a product for improving metabolism-related fatty liver disease.

[0005] To achieve the above purpose, the technical solution adopted by this application is:

[0006] The present application provides a Prevotella bivia strain, which is named Prevotella biviaGZSY0524, and has been deposited in the Guangdong Provincial Microbiological Culture Collection Center on August 7, 2024, with a collection number of GDMCCNo: 64991, a classification name of Prevotella bivia, and a collection address of 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0007] The present application obtains a Prevotella bivia strain (Prevotella bivia) through screening and isolation. The Prevotella bivia strain of the present application has a good therapeutic effect in the treatment and / or prevention of metabolic-related fatty liver disease, and has a significant inhibitory effect on the liver's involvement in inflammatory response.

[0008] The present application clarifies the therapeutic effect of the Prevotella bivia strain in metabolism-related fatty liver disease, thereby providing an effective drug for the clinical treatment of metabolism-related fatty liver disease.

[0009] As a preferred embodiment of the Prevotella bivia strain described in the present application, the sequence of 16s rDNA of the Prevotella bivia strain is shown as SEQ ID NO:1.

[0010] The colony diameter of the Prevotella bivia strain of the present application is 1-2 mm, round, with neat edges, opaque, milky white on the front, convex in the middle, smooth, bright on the surface, moist in texture, and easy to pick up.

[0011] The Prevotella bivia strain of the present application is a Gram-negative bacterium, an anaerobic bacterium, and grows at 37°C.

[0012] The present application also provides a bacterial agent, which includes the above-mentioned Prevotella bivia strain.

[0013] As a preferred embodiment of the bacterial agent of the present application, the concentration of the Prevotella bivia strain in the bacterial agent is 0.5~6×10 9 CFU / mL.

[0014] The present application also provides a method for preparing the above-mentioned bacterial agent, characterized in that the method comprises the step of culturing the above-mentioned Prevotella bivia strain.

[0015] As a preferred embodiment of the method for preparing the bacterial agent of the present application, the step of culturing the above-mentioned Prevotella bivia strain comprises:

[0016] 1) Inoculate the glycerol culture of the above-mentioned Prevotella bivia strain into FAB liquid medium, and culture it statically at 35-37°C for 15-16 hours under anaerobism to obtain seed solution;

[0017] 2) The seed solution obtained in step 1) is inoculated into FAB liquid culture medium, and cultured at 35-37° C. for 8-10 hours under anaerobism to obtain a bacterial agent.

[0018] As a preferred embodiment of the method for preparing the bacterial agent of the present application, the FAB liquid culture medium comprises the following components:

[0019] Peptone, sodium chloride, soluble starch, sodium bicarbonate, glucose, soluble pyrophosphate, sodium pyruvate, cysteine ​​hydrochloride, hemin, vitamin K, L-arginine and sodium succinate.

[0020] In some specific embodiments, the FAB liquid medium comprises the following components by weight:

[0021] Mix 23.0 g / L peptone, 5.0 g / L sodium chloride, 1.0 g / L soluble starch, 0.4 g / L sodium bicarbonate, 1.0 g / L glucose, 0.25 g / L soluble pyrophosphate, 1.0 g / L sodium pyruvate, 0.5 g / L cysteine ​​hydrochloride, 0.01 g / L hemin chloride, 0.001 g / L vitamin K, 1.0 g / L L-arginine and 0.5 g / L sodium succinate, and sterilize at 121°C for 15 min.

[0022] The bacterial agent containing the Prevotella bivia strain obtained by culture can be prepared as a liquid bacterial agent directly or by adding auxiliary materials permitted in the field of microbial preparations. The bacterial bodies in the bacterial liquid can also be collected and mixed with auxiliary materials permitted in the field of microbial preparations such as freeze-drying protective agents and then prepared as a dry powder bacterial agent through vacuum freeze-drying.

[0023] Based on the function of the Prevotella bivia strain, the present application provides the following applications of the strain:

[0024] The present application also provides the use of the above-mentioned Prevotella bivia strain or the above-mentioned bacterial agent in the preparation of medicines.

[0025] The present application also provides the use of the above-mentioned Prevotella bivia strain or the above-mentioned bacterial agent in the preparation of a product for preventing, improving or treating metabolism-related fatty liver disease.

[0026] In the technical solution of the present application, the Prevotella bivia strain can reduce the body weight and liver weight of mice with metabolic-associated fatty liver disease, and improve the liver tissue lesions of mice with metabolic-associated fatty liver disease.

[0027] As a preferred embodiment of the application described in the present application, the metabolism-related fatty liver disease includes the metabolism-related fatty liver disease caused by applying high fat, high sugar and high cholesterol to type 2 diabetes samples.

[0028] This application also uses two typical metabolic-associated fatty liver disease (MAFLD) and metabolic-associated steatohepatitis (MASH) animal models for experiments, namely (1) spontaneous type 2 diabetic mice (db / db) given a high-fat, high-sugar, and high-cholesterol Western diet; and (2) a high-fat, methionine, and trace choline-deficient diet (HFMRCD), which can better simulate the disease progression of metabolic-associated fatty liver disease or metabolic-associated steatohepatitis.

[0029] Animal experiments show that compared with the commercial strain Prevotella copri (Pc) group mice, the weight of the Prevotella bivia strain group mice in the present application decreased significantly (P<0.001), and the mouse liver weight / body weight ratio decreased significantly (P<0.05), indicating that the use of the Prevotella bivia strain of the present application can significantly reduce the weight and liver weight of mice, and the fatty degeneration of the liver cells of mice can be alleviated, the liver tissue lesions can be improved, and the ballooning of liver cells is reduced. It shows that the Prevotella bivia strain of the present application can significantly improve the fatty degeneration and inflammatory response of the liver of MAFLD mice induced by Western diet. The Prevotella bivia strain of the present application can also effectively inhibit the fatty degeneration of liver cells, ballooning of liver cells and fibrosis of mice induced by HFMRCD diet, reduce the levels of ALT, AST, TG, CHO and LDL in mice, and has the effect of improving MASH, and the improvement effect of the Prevotella bivia strain on MASH is better than that of the commercial strain Prevotella copri (Pc).

[0030] The above results indicate that Prevotella bivia strain can significantly improve hepatic steatosis and inflammatory response in MAFLD mice induced by Western diet.

[0031] As a preferred embodiment of the application described in the present application, the product includes a medicine.

[0032] The product may be a capsule, a lyophilized powder or a bacterial liquid preparation. The dosage form of the product in this application is not limited to the above types, but also includes common dosage forms in the art.

[0033] The product comprises one or more pharmaceutically acceptable excipients or carriers.

[0034] Acceptable carriers or diluents for therapeutic use are examples of suitable carriers well-known in pharmaceutical technology, including lactose, starch, glucose, methylcellulose, magnesium stearate, mannitol, sorbitol, etc. Examples of suitable diluents include ethanol, glycerol and water. The selection of pharmaceutical carriers, excipients or diluents can be selected for the expected route of administration and standard pharmaceutical practice. The pharmaceutical composition can include any suitable adhesive, lubricant, suspending agent, coating agent, solubilizer as a carrier, excipient or diluent or can include the substance except the carrier, excipient or diluent. Examples of suitable adhesives include starch, gelatin, natural sugars (such as glucose, anhydrous lactose, free-flowing lactose, β-lactose, corn sweeteners), natural and synthetic gums (such as gum arabic, tragacanth) or sodium alginate, carboxymethyl cellulose and polyethylene glycol. Examples of suitable lubricants include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride, etc. Preservatives, stabilizers, dyes and even flavoring agents may be provided in the pharmaceutical composition. Examples of preservatives include sodium benzoate, sorbic acid and parabens. Antioxidants and suspending agents may also be used.

[0035] In certain embodiments, the product of the present application contains a single bacterial strain or species and does not contain any other bacterial strains or species. Such products may contain only minimal amounts or biologically irrelevant amounts of other bacterial strains or species. Such products may be cultures that are substantially free of other organism species. Therefore, in some embodiments, the present application provides a strain of Prevotella bivia that does not contain bacteria from any other species or contains only minimal amounts or biologically irrelevant amounts of bacteria from another species, and is used in treatment.

[0036] The present application also provides the use of the above-mentioned Prevotella bivia strain or the above-mentioned bacterial agent in the preparation of a product for reducing liver function indicators and blood lipid factor levels.

[0037] As a preferred embodiment of the application described in the present application, the liver function index and blood lipid factors include at least one of ALT, AST, TG, CHO and LDL.

[0038] Compared with the mice in the db / db-WD group, the ALT, AST, TG, CHO and LDL of the mice treated with the bacterial agent containing the Prevotella bivia strain of the present application were significantly decreased (P<0.05).

[0039] The present application also provides the use of the above-mentioned Prevotella bivia strain or the above-mentioned bacterial agent in the preparation of a drug for improving the phenotype of metabolism-related fatty liver disease.

[0040] The present application uses the Prevotella bivia strain to intervene and effectively inhibit HFMRCD diet-induced fatty degeneration, ballooning degeneration and fibrosis of hepatocytes in mice. In addition, intervention with Prevotella bivia can reduce the levels of serum ALT, AST, TG, CHO and LDL, indicating that the strain can significantly improve the liver function indicators of mice with metabolic-related fatty hepatitis.

[0041] Compared with the prior art, this application has the following beneficial effects:

[0042] The present application provides a Prevotella bivia strain and its use in the preparation of a product for improving metabolism-related fatty liver disease. The Prevotella bivia strain used in the present application has a good therapeutic effect on metabolism-related fatty liver disease. Using the Prevotella bivia strain of the present application to treat metabolic-related fatty liver disease or metabolic-related fatty hepatitis animal models can improve liver tissue lesions, alleviate fatty degeneration of hepatocytes, reduce ballooning of hepatocytes, and has a significant inhibitory effect on the involvement of the liver in inflammatory responses (specifically manifested in the reduction of inflammatory factors such as ALT, AST, TG, CHO and LDL). The present application clarifies the therapeutic effect of the Prevotella bivia strain in metabolism-related fatty liver disease, thereby providing an effective clinical drug for the treatment of metabolism-related fatty liver disease, which has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The morphological diagram of the Prevotella bivia strain (Prevotella biviaGZSY0524);

[0044] Figure 2 is the evolutionary tree of the Prevotella bivia strain (Prevotella biviaGZSY0524);

[0045] Figure 3The results of treatment with a low-fat, low-sugar control diet (CD) for WT mice and a low-fat, low-sugar control diet (CD) or a Western diet (WD) for db / db mice, and the bacterial agent prepared in Example 2 (containing the Prevotella bivia strain, referred to as Pb) or the commercial strain Prevotella copri (referred to as Pc) are shown in Figure 2. Figure 3 A in the middle is a graph showing the weight gain of mice in each group; Figure 3 Middle B is the liver / body weight ratio of mice in each group; Figure 3 Middle C shows the HE staining and Oil Red staining of liver tissues of mice in each group; compared with db / db-WD, * P<0.05, ** P<0.01, *** P<0.001);

[0046] Figure 4 The results of serum ALT, AST, CHO, TG, and LDL levels in mice in each group after WT mice were treated with a low-fat, low-sugar control diet (CD), db / db mice were treated with a low-fat, low-sugar control diet (CD), a Western diet (WD), and the bacterial agent prepared in Example 2 (containing the Prevotella bivia strain, referred to as Pb) or the commercial strain Prevotella copri (referred to as Pc) (ALT, alanine aminotransferase; AST, aspartate aminotransferase; CHO, total cholesterol; TG, triglycerides; LDL, low-density lipoprotein; compared with db / db-WD, * P<0.05, ** P<0.01, *** P<0.001);

[0047] Figure 5 The treatment results of WT mice treated with a control diet (MCS), a high-fat methionine trace choline deficient diet (HFMRCD), and the bacterial agent prepared in Example 2 (containing the Prevotella bivia strain, referred to as Pb) or the commercial strain Prevotella copri (referred to as Pc) are shown in Figure ( Figure 5 A in the middle shows the HE staining and oil red staining of liver tissues of mice in each group; Figure 5 Figure BD shows the serum ALT, AST, and LDL levels of mice in each group. ALT: alanine aminotransferase; AST: aspartate aminotransferase; LDL: low-density lipoprotein; compared with HFMRCD, * P<0.05, ** P<0.01, *** P<0.001). DETAILED DESCRIPTION

[0048] In order to better illustrate the purpose, technical solutions and advantages of the present application, the present application will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0049] In the following examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified, and the components and raw materials used in each parallel experiment are of the same type.

[0050] The Prevotella bivia strain appearing in the following examples is referred to as Pb.

[0051] The commercial strain Prevotella copri was purchased from Beijing Beina Chuanglian Biotechnology Research Institute, #BNCC337399, referred to as Pc.

[0052] FAB liquid medium includes the following components by weight:

[0053] Mix 23.0 g / L peptone, 5.0 g / L sodium chloride, 1.0 g / L soluble starch, 0.4 g / L sodium bicarbonate, 1.0 g / L glucose, 0.25 g / L soluble pyrophosphate, 1.0 g / L sodium pyruvate, 0.5 g / L cysteine ​​hydrochloride, 0.01 g / L hemin chloride, 0.001 g / L vitamin K, 1.0 g / L L-arginine and 0.5 g / L sodium succinate, and sterilize at 121°C for 15 min.

[0054] BBL thioglycolate medium was obtained from Beijing Solarbio Lifescience Co., Ltd. (Solarbio Lifescience), catalog number: LA8740.

[0055] Example 1: Isolation and screening of Prevotella bivia strains

[0056] This example provides the isolation and screening steps of the Prevotella bivia strain (Prevotella bivia GZSY0524):

[0057] Feces from healthy donors were collected, homogenized in BBL thioglycolate medium, and further processed in an anaerobic workstation using the following gas mixture: 70% nitrogen, 20% carbon dioxide, and 10% hydrogen. Feces were serially diluted 10-fold to 10 -6 and 10 -7 The content was dissolved in brain heart infusion broth (BHI) supplemented with 10% serum (FBS) and 0.5 g / L vitamin K3 (BHI-S) and cultured in sterile 96-well plates at 37°C for 2 days. Prevotella-positive wells were enriched in BHI-S medium containing vancomycin (6 μg / ml) and selected on BHI-S blood agar (defibrinated sheep blood, 5% v / v) plates. Colonies were picked and streaked on agar plates three times before obtaining pure cultures.

[0058] The isolates were confirmed by sequencing the complete 16s rDNA gene, and the amplified 16s rDNA sequence data were submitted to GenBank. Homology alignment was performed using the online software Blast on the NCBI website. The phylogenetic tree was constructed using the Maximum likelihood method in the bioinformatics analysis software MEGA-X, and it was identified as a known Prevotella genus (blastn>90% similarity).

[0059] The strain isolated and screened above (Prevotella bivia strain) was preserved, and the Prevotella bivia strain was named Prevotella biviaGZSY0524, which was deposited in Guangdong Provincial Microbiological Culture Collection Center on August 7, 2024, with a collection number of GDMCCNo: 64991, a classification name of Prevotella bivia, and a collection address of 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0060] The colony diameter of the Prevotella bivia strain (Prevotella biviaGZSY0524) of the present application is 1-2mm, round, with neat edges, opaque, milky white on the front, convex in the middle, smooth, bright on the surface, moist in texture, and easy to pick up. The Prevotella bivia strain of the present application belongs to Gram-negative bacteria, anaerobic bacteria, grows at 37°C, and has a morphology like Figure 1 shown.

[0061] The sequence of 16s rDNA of the Prevotella bivia strain (Prevotella biviaGZSY0524) is shown in SEQ ID NO: 1. The evolutionary tree of the Prevotella bivia strain (Prevotella biviaGZSY0524) is shown in Figure 2 shown.

[0062] SEQ ID NO: 1 is:

[0063]

[0064] Example 2: Bacterial agent containing Prevotella bivia strain

[0065] This embodiment provides a method for preparing a bacterial agent containing the Prevotella bivia strain, the preparation method comprising the following steps:

[0066] 1) 1 mL of the glycerol culture of the Prevotella bivia strain of Example 1 was inoculated into a deoxygenated FAB liquid medium at a 10% inoculation rate, and statically cultured at 37° C. for 15 to 16 hours under anaerobism to obtain a seed solution;

[0067] 2) Determine the OD of the seed solution before inoculation 600 The value is about 0.7~0.8. The seed solution obtained in step 1) is inoculated at a rate of 10% into 30 mL of deoxygenated FAB liquid culture medium, and cultured at 37°C under anaerobism for 8~10 hours to obtain a bacterial agent.

[0068] The bacterial concentration of the Prevotella bivia strain in the bacterial agent is 4×10 9 CFU / mL.

[0069] Example 3: Experiment on the effect of Prevotella bivia on improving metabolic-related fatty liver disease

[0070] 1. In this example, 8-week-old spontaneously diabetic mice (db / db) of the BSK strain were selected and fed with a western diet to construct a MAFLD model. At the same time, the bacterial agent prepared in Example 2 (containing Prevotella bivia, with a dose of 1×10 8 CFU / unit) or a bacterial agent containing the strain Prevotella copri (Prevotella copri is referred to as PC, and the bacterial agent is obtained by resuspending the Prevotella copri cells in PBS buffer. The dosage of the bacterial agent is 1×10 8 CFU / mouse), gavage was performed every other day, body weight was measured every 3 days, and the experiment was terminated after 30 days.

[0071] like Figure 3As shown, WT mice were fed a low-fat, low-sugar control diet (CD), and db / db mice were fed a low-fat, low-sugar control diet (CD), a Western diet (WD), and treated with the bacterial agent prepared in Example 2 (containing the Prevotella bivia strain) and the bacterial agent containing the strain Prevotella copri, constituting the following groups: WT-CD, db / db-CD, db / db-WD, db / db-WD-Pb, and db / db-WD-Pc.

[0072] Figure 3 A in the middle is a graph showing the weight gain of mice in each group; Figure 3 Middle B is the liver / body weight ratio of mice in each group; Figure 3 Middle C shows the HE staining and Oil Red staining of liver tissues of mice in each group. Compared with db / db-WD, * P<0.05, ** P<0.01, *** P<0.001.

[0073] Depend on Figure 3 The results showed that compared with the db / db-WD group, the body weight of the db / db-WD- Pb group mice decreased significantly from day 12 (P<0.001), and the liver weight / body weight ratio of the mice was significantly reduced (P<0.05). Liver H&E staining and Oil Red O staining showed that compared with the WT-CD group, the db / db-WD group mice had severe diffuse fatty degeneration of hepatocytes, with a large number of fat vacuoles, widespread ballooning of hepatocytes, and diffuse red lipid droplets by Oil Red O staining; after administration of the bacterial agent containing the Prevotella bivia strain, the fatty degeneration of hepatocytes in the db / db-WD- Pb group mice was alleviated, and the ballooning of hepatocytes was reduced; in addition, the strain Prevotella copri had almost no improvement on Western diet-induced MAFLD.

[0074] The above results show that Prevotella bivia strain can significantly improve the fatty degeneration and inflammatory response of the liver of MAFLD mice induced by Western diet. Prevotella bivia strain can reduce the body weight and liver weight of MAFLD mice and improve the liver tissue lesions of MAFLD mice.

[0075] 2. In order to study the effect of Prevotella bivia strain on the liver function of MAFLD mice, this application detected the indicators of ALT (alanine amiotransferase), AST (aspartate aminotransferase), CHO (total cholesterol), TG (triglyceride) and LDL (low-density lipoprotein) in the serum of mice.

[0076] WT mice were fed a low-fat, low-sugar control diet (CD), and db / db mice were fed a low-fat, low-sugar control diet (CD), a Western diet (WD), and treated with the bacterial agent prepared in Example 2 (containing the Prevotella bivia strain) and the bacterial agent containing the strain Prevotella copri to form the following groups: WT-CD, db / db-CD, db / db-WD, db / db-WD-Pb, and db / db-WD-Pc. The serum ALT (alanine aminotransferase), AST (aspartate aminotransferase), CHO (total cholesterol), TG (triglycerides), and LDL (low-density lipoprotein) levels of mice in each group were detected. Figure 4 shown.

[0077] Figure 4 It can be seen that compared with the WT-CD group, the ALT, AST, TG and LDL of the db / db-WD group mice were increased, indicating that the db / db-WD group mice had serious liver function and lipid metabolism abnormalities; after administration of the bacterial agent containing the Prevotella bivia strain, compared with the db / db-WD group mice, the ALT, AST, TG, CHO and LDL of the db / db-WD-Pb group mice were significantly decreased (P<0.05). Moreover, compared with the commercial strain Prevotella copri, the liver function indicators ALT, AST, TG, CHO and LDL after treatment with the Prevotella bivia strain of the present application decreased more significantly (P<0.05).

[0078] The results (average values) of different groups in the db / db WD model are shown in Table 1:

[0079] Table 1

[0080]

[0081] 3. In order to further demonstrate the effect of Prevotella bivia in improving MAFLD, the present application selected 8-week-old wild-type C57 mice and fed them with a high-fat methionine trace-choline deficient diet (HFMRCD) to construct a MASH model. After 14 days of modeling, the bacterial agent prepared in Example 2 (containing Prevotella bivia at a dose of 1×10 8 CFU / unit) or a bacterial agent containing the strain Prevotella copri (Prevotella copri is referred to as PC, and the bacterial agent is obtained by resuspending the Prevotella copri cells in PBS buffer. The dosage of the bacterial agent is 1×10 8 CFU / mouse), gavage was performed every other day, and body weight was measured every 3 days to form the following groups: MCS, HFMRCD, HFMRCD-Pb, and HFMRCD-Pc. The experiment was terminated after 30 days.

[0082] like Figure 5 As shown, the treatment results of WT mice using a control diet (MCS), a high-fat methionine trace choline deficient diet (HFMRCD), the bacterial agent prepared in Example 2, and the bacterial agent containing the strain Prevotella copri ( Figure 5 A in the middle shows the HE staining and oil red staining of liver tissues of mice in each group; Figure 5 Figure BD shows the serum ALT, AST, and LDL levels of mice in each group. ALT: alanine aminotransferase; AST: aspartate aminotransferase; LDL: low-density lipoprotein; compared with HFMRCD, * P<0.05, ** P<0.01, *** P<0.001).

[0083] The results (average values) of different groups in the MASH model are shown in Table 2:

[0084] Table 2

[0085]

[0086] From Table 2 and Figure 5 It can be seen that the bacterial agent intervention containing the Prevotella bivia strain in the present application can reduce the levels of serum ALT, AST and LDL, indicating that the Prevotella bivia strain can significantly improve the liver function indicators of MASH mice.

[0087] This application uses two typical MAFLD animal models for experiments, namely, spontaneous type 2 diabetic mice (db / db) given a high-fat, high-sugar, and high-cholesterol Western diet, and a methionine-choline deficient diet (HFMRCD) to construct MASH, which can better simulate the disease progression of MAFLD.

[0088] The Prevotella bivia provided in the present application has a good therapeutic effect in the treatment of MAFLD and has a significant inhibitory effect on the inflammatory response of the liver.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application rather than to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present application.

Claims

1. A strain of Prevotella bivia, characterized in that The Prevotella bivia strain was deposited in the Guangdong Provincial Microbiological Culture Collection Center on August 7, 2024, with the deposit number GDMCC No: 64991, and the deposit address is: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

2. The Prevotella bivia strain according to claim 1, characterized in that The sequence of 16s rDNA of the Prevotella bivia strain is shown in SEQ ID NO:

1.

3. A bacterial agent, characterized in that: The bacterial agent comprises the Prevotella bivia strain as claimed in claim 1 or 2.

4. The bacterial agent according to claim 3, characterized in that The concentration of the Prevotella bivia strain in the bacterial agent is 0.5~6×10 9 CFU / mL.

5. The method for preparing the bacterial agent according to claim 3, characterized in that: The method comprises the step of culturing the Prevotella bivia strain as claimed in claim 1 or 2.

6. The method for preparing the bacterial agent according to claim 5, characterized in that: The step of culturing the Prevotella bivia strain according to claim 1 or 2 comprises: 1) inoculating the glycerol culture of the Prevotella bivia strain as claimed in claim 1 or 2 into FAB liquid culture medium, and culturing it statically at 35-37° C. for 15-16 hours under anaerobic conditions to obtain a seed solution; 2) The seed solution obtained in step 1) is inoculated into FAB liquid culture medium, and cultured at 35-37° C. for 8-10 hours under anaerobism to obtain a bacterial agent.

7. The method for preparing the bacterial agent according to claim 6, characterized in that: The FAB liquid culture medium comprises the following components: Peptone, sodium chloride, soluble starch, sodium bicarbonate, glucose, soluble pyrophosphate, sodium pyruvate, cysteine ​​hydrochloride, hemin, vitamin K, L-arginine and sodium succinate.

8. Use of the Prevotella bivia strain as claimed in claim 1 or 2 or the bacterial agent as claimed in claim 3 in preparing a medicine.

9. Use of the Prevotella bivia strain according to claim 1 or 2 or the bacterial agent according to claim 3 in preparing a product for preventing, improving or treating metabolism-related fatty liver disease.

10. The use according to claim 9, wherein the metabolism-related fatty liver disease comprises the metabolism-related fatty liver disease caused by applying high fat, high sugar and high cholesterol to a type 2 diabetes sample.

11. The use according to claim 9, wherein the product comprises a medicine.

12. Use of the Prevotella bivia strain according to claim 1 or 2 or the bacterial agent according to claim 3 in preparing a product for reducing liver function indexes and blood lipid factor levels, characterized in that: The liver function index and blood lipid factor include at least one of ALT, AST, TG, CHO and LDL.

13. Use of the Prevotella bivia strain according to claim 1 or 2 or the bacterial agent according to claim 3 in the preparation of a medicament for improving the phenotype of metabolism-related fatty hepatitis.

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