B. longum strain capable of promoting postoperative liver function recovery and use thereof

Abstract

Disclosed are a B. Longum strain capable of promoting postoperative liver function recovery, and the use thereof. The strain has a deposit number of CCTCC M 20231518, and is deposited in the China Center for Type Culture Collection in Wuhan, Hubei. The 5-HT yield of the strain can reach 10.18 ng / ml, and the GABA yield can reach 12.93 μg / mL, wherein 5-HT is beneficial to promoting liver regeneration, and GABA has an effect of protecting the liver. Upon verification in a mouse model of liver injury, the strain can significantly alleviate postoperative drug-induced liver injury and promote liver function recovery, can be used in the preparation of a product for alleviating liver injury, especially a product for promoting postoperative liver function recovery in a patient with liver cancer, and can be particularly used in the preparation of a probiotic preparation for promoting postoperative liver function recovery in a patient with liver cancer. The strain is beneficial to rapid postoperative liver function recovery in a patient with liver cancer, and is beneficial to relieving the medical burden of a patient for postoperative liver function recovery.

Description

A B. longum strain capable of promoting postoperative liver function recovery and its application

[0001] This application is based on the Chinese patent application with application number 202311144612.3 and application date September 5, 2023, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is incorporated herein by reference. Technical Field

[0002] The present invention belongs to the field of biomedicine, and more particularly relates to a B. longum strain capable of promoting postoperative liver function recovery and an application thereof. Background Art

[0003] Hepatocellular carcinoma (HCC) accounts for approximately 90% of primary liver cancer cases and is the third leading cause of cancer death. According to the guidelines of the European Association for the Study of the liver (EASL) and the China Liver Cancer Staging (CNLC), surgical resection is the recommended treatment for patients with early and some intermediate-stage HCC who retain good liver function. However, postoperative liver function recovery (LFR) remains a challenge. Studies in recent years have shown that multiple factors can affect postoperative liver function recovery, including preoperative liver reserve function, residual liver volume, and underlying liver diseases such as viral hepatitis, steatosis, fibrosis, and drug-induced liver injury. Usually, only rapid recovery of liver function after surgery can ensure the safety of surgery and enable patients to benefit from the surgery. Therefore, identifying and verifying the key factors that promote postoperative liver function recovery in patients with liver cancer is of great clinical value.

[0004] The gut microbiota can regulate liver function through the gut-liver axis, which bidirectionally exchanges bioactive substances, including gut microbiota-derived metabolites to the liver and liver-derived bile acids and intestinal antibodies. Several studies have found an association between gut microbiota dysbiosis and liver dysfunction in humans and mice, supporting the importance of this axis. Furthermore, studies have also reported that many gut microbes themselves contribute to the production of 5-HT, and a clinical study has shown that reduced intraplatelet (IP) 5-HT levels are associated with postoperative liver dysfunction. Recently, Wen et al. demonstrated that portal venous 5-HT levels were elevated during liver regeneration after hepatectomy in wild-type mice compared with transgenic mice (L-33- / - and ST2- / - mice), suggesting that 5-HT plays an important role in liver function recovery. Therefore, screening for probiotics with high 5-HT production from the gut microbiota could be beneficial for promoting liver function recovery after surgery in patients with liver cancer and reducing the medical costs associated with postoperative hepatectomy outcomes.

[0005] Summary of the Invention

[0006] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides a B. longum strain capable of promoting postoperative liver function recovery and its application. The purpose is to use selective culture medium to screen intestinal probiotics, and unexpectedly discovered a B. longum strain that simultaneously produces high levels of 5-HT and GABA, named Bifidobacterium longum JWA3. The strain can produce up to 10.18 ng / ml of 5-HT and 12.93 μg / mL of GABA. Validated in an animal liver injury model, the strain has the effect of significantly improving liver damage and promoting liver function recovery after hepatectomy, thereby solving the technical problem that liver function in patients with existing liver cancer is difficult to recover after surgery and the medical expenses required for postoperative outcomes are high.

[0007] To achieve the above objectives, according to one aspect of the present invention, a B. longum strain having the function of promoting postoperative liver function recovery is provided, whose preservation number is CCTCC M 20231518, named Bifidobacterium longum JWA3, and has been deposited in the China Center for Type Culture Collection, Wuhan, Hubei.

[0008] Preferably, the B. longum strain capable of promoting postoperative liver function recovery can produce 5-HT above 10 ng / ml and GABA above 12 μg / mL.

[0009] According to another aspect of the present invention, there is also provided a use of the B. longum strain according to the present invention in preparing a product for improving liver damage.

[0010] Preferably, the application is used in the preparation of a product for improving drug-induced liver injury.

[0011] Preferably, the application is used to prepare a product that promotes liver function recovery in patients with liver cancer after liver resection.

[0012] Preferably, the application is used to prepare a probiotic preparation for promoting liver function recovery in patients with liver cancer after surgery.

[0013] According to another aspect of the present invention, a probiotic preparation for promoting liver function recovery in patients with liver cancer after surgery is provided. The probiotic preparation comprises the Bifidobacterium longum JWA3 strain according to the present invention.

[0014] Preferably, the probiotic preparation for promoting liver function recovery in patients with liver cancer after surgery has a concentration of Bifidobacterium longum JWA3 strain of 1.0*10 10CFU / ml or 1.0*10 10 CFU / g or above.

[0015] Preferably, the probiotic preparation for promoting liver function recovery in patients with liver cancer after surgery has a concentration of Bifidobacterium longum JWA3 strain of 1.2*10 10 CFU / ml or 1.2*10 10 CFU / g.

[0016] According to another aspect of the present invention, a drug for improving postoperative liver function is provided, wherein the drug comprises the Bifidobacterium longum JWA3 strain according to the present invention.

[0017] In general, the above technical solution conceived by the present invention can achieve the following beneficial effects compared with the prior art, because a B. longum strain that simultaneously produces high levels of 5-HT and GABA has been discovered in the healthy human intestine:

[0018] The present invention provides a Bifidobacterium longum JWA3 strain with a deposit number of CCTCC M 20231518, which has a 5-HT production of more than 10 ng / ml and a GABA production of more than 12 μg / mL. During liver regeneration, 5-HT stimulates DNA synthesis and cell proliferation by activating 5-HT receptors, which is beneficial to liver function recovery. In addition, GABA has a liver-protecting effect. Among other intestinal probiotics, the B. longum strain discovered by the present invention can simultaneously produce high levels of 5-HT and GABA. It has been verified by a mouse liver injury model that it can significantly improve postoperative drug-induced liver injury and promote liver function recovery. It can be used to prepare a product that promotes liver function recovery after surgery in patients with liver cancer, which is beneficial to the rapid recovery of liver function after surgery in patients, and at the same time helps to reduce the medical burden of liver function recovery after surgery in patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a screening result of 64 probiotic strains producing 5-HT isolated and obtained in Example 1;

[0020] FIG2 is a screening result of 64 probiotic strains producing GABA isolated and obtained in Example 1;

[0021] FIG3 is a schematic diagram of the relative weight changes of mice in each group;

[0022] Figure 4 shows the liver / body weight of mice in each group;

[0023] Figure 5 is a comparison of serum ALT, AST, and TB levels in mice of each group;

[0024] Figure 6 is a comparison of serum PTA and TBA levels in mice of various groups;

[0025] FIG7 is HE staining and Masson staining of liver tissues in each group;

[0026] FIG8 shows the results of determination of the abundance of B. longum in the feces of mice in each group. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0028] Based on healthy human fecal samples, the present invention combines bifidobacterium selective screening and high-throughput 5-HT screening, and unexpectedly discovered a Bifidobacterium longum (B.longum) strain that can simultaneously produce high levels of 5-HT and GABA, with 5-HT production reaching 10.18ng / ml and GABA production reaching 12.93μg / mL. Based on this, the present invention provides a B.longum strain that promotes postoperative liver function recovery, with a deposit number of CCTCC M 20231518, named Bifidobacterium longum JWA3, and was deposited in the China Center for Type Culture Collection, Wuhan, Hubei on August 22, 2023.

[0029] The B. longum strain can produce 5-HT above 10 ng / ml and GABA above 12 μg / mL.

[0030] In addition, the present invention also provides an application of the B. longum strain according to the present invention in preparing a product for improving liver damage; the application is used to prepare a product for improving drug-induced liver damage.

[0031] In particular, it is used to prepare products that promote liver function recovery in patients with liver cancer after liver resection;

[0032] In particular, it is used to prepare probiotic preparations for promoting liver function recovery in patients with liver cancer after surgery.

[0033] The present invention also provides a probiotic preparation for promoting liver function recovery in patients with liver cancer after surgery. The probiotic preparation comprises, as an active ingredient, the Bifidobacterium longum JWA3 strain of the present invention.

[0034] Preferably, the concentration of the Bifidobacterium longum JWA3 strain is 1.0*10 10 CFU / ml or 1.0*10 10 CFU / g or more; in some embodiments, the concentration of the Bifidobacterium longum JWA3 strain is 1.2*10 10 CFU / ml.

[0035] The present invention also provides a medicine for improving postoperative liver function recovery, wherein the effective ingredient of the medicine comprises the Bifidobacterium longum JWA3 strain of the present invention.

[0036] The content of Bifidobacterium longum JWA3 strain in the medicine is (1-1.2)*10 9 CFU / ml or (1~1.2)*10 9 CFU / g.

[0037] The following are examples:

[0038] Example 1 Screening and separation of probiotics

[0039] Sample: Feces of healthy adults;

[0040] Bifidobacterium selective medium: MRS basal broth + 50 mg / L mupirocin lithium salt;

[0041] Lactic acid bacteria selective culture medium: MRS basal broth medium + bromocresol purple;

[0042] Culture conditions: 37°C, 182 kPa (1.8 atm) N2 / CO2 (80:20, v / v) under anaerobic conditions.

[0043] Specific implementation steps:

[0044] 1. Separation and screening

[0045] a. Prepare bacterial solution: Mix feces with normal saline and dilute to obtain a dilution solution with a feces concentration of 10 -6g / ml, and the dilution was spread on a bifidobacterium and lactic acid bacteria selective culture medium plate, and cultured anaerobically at 37°C for 3 days.

[0046] b Single colony purification: Single colonies were selected based on colony morphology, color, and size and three lines were drawn on the MRS basal broth medium plate. After multiple selections of single colonies for purification, the obtained single colonies were scraped and subjected to 16-second identification and seed preservation. The probiotic screening results are shown in Table 1:

[0047] Table 1 Probiotic screening results

[0048] In the table, 58 is Lactobacillus paracasei PS23, 59 is Lactobacillus plantarum PS128, which are the same commercially available strains; 60 is Lactobacillus rhamnosus LGG, and 61 is Bifidobacterium animalis BB12.

[0049] Example 2 High-throughput screening of strains producing high 5-HT

[0050] The 64 strains obtained in Example 1 above, stored in glycerol tubes, were removed and thawed. A loopful of culture was streaked onto a plate containing an appropriate culture medium using an inoculating loop and cultured at 37°C until single colonies grew. The colonies on the plate were observed for uniform morphology. A single colony from the plate was inoculated into a 2 mL EP tube containing 1 mL of the appropriate culture medium and cultured at 37°C for approximately 24 hours. The cultured bacterial solution was then inoculated a second time (inoculation volume 3%) and cultured at 37°C for approximately 24 hours. After activation, the supernatant and bacterial cells were collected.

[0051] The 64 strains described above were activated and inoculated at a 2% inoculum into a medium containing 0.2% tryptophan, cultured for 48 h, and the supernatant was collected by centrifugation and filtered through a 0.22 μm filter membrane to obtain the test samples. The samples were spotted onto thin-layer chromatography silica gel plates GF, developed in a chromatography tank with a developing solvent (n-butanol: acetic acid: water = 4:1:5), and developed with a color developer (1 g of p-dimethylaminobenzaldehyde, 9 ml of ethanol, 2.3 ml of hydrochloric acid, and ethanol was added to 100 ml). 5-hydroxytryptamine was used as a control, and the results were observed. The results are shown in Figure 1.

[0052] Compared with the standard spot at the corresponding position of 5-HT, the strain corresponding to No. 28 showed a positive reaction (the standard spot corresponding to No. 28 was lighter in color and not clearly shown in Figure 1), while Nos. 58 and 59 corresponded to commercially available strains, which were used as positive controls.

[0053] The amounts of 5-HT produced by strains corresponding to test numbers 28, 58, and 59 are as follows:

[0054] 5-HT HPLC detection: mobile phase A: 5 mM ammonium formate + 0.1% formic acid in water, B: 0.1% formic acid-acetonitrile;

[0055] Column: Waters BEH C18 2.1x100mmx1.7μm;

[0056] Flow rate: 0.3 mL / min;

[0057] Gradient: 0-1 min (5% B); 1-2 min (90% B); 2-4.5 min (90% B); 4.5-4.6 min (5% B); 4.6-7 min (Stop). The 5-HT detection results are shown in Table 2.

[0058] Table 2 5-HT production determination results

[0059] In the table, 58 and 59 are commercially available strains, used as positive controls.

[0060] As shown in Table 2, the 5-HT production of the screened Bifidobacterium longum corresponding to No. 28 can reach 10.18 ng / ml, while the 5-HT production of the commercially available positive strains is 5.22 ng / ml and 4.96 ng / ml respectively. It can be seen that the 5-HT production of the screened strain is significantly better than that of the commercially available positive strains.

[0061] Furthermore, the above-mentioned bacteria were added with 1% glutamic acid solution according to their wet weight and reacted for 24 hours, and then the supernatant was centrifuged and a mixed acid-base indicator was added. The color reaction was observed, and it was preliminarily determined that the solution turned green and had glutamate decarboxylase (GAD) activity. The results are shown in Figure 2; 4 strains with GAD activity were screened out, and the GABA content of the screened strains was tested respectively. The specific tests were as follows:

[0062] GABA HPLC detection: mobile phase A: 5 mM ammonium formate + 0.1% formic acid in water, mobile phase B: 0.1% formic acid-acetonitrile;

[0063] Column: Waters BEH C18 2.1x100mmx1.7μm;

[0064] Flow rate: 0.3 mL / min;

[0065] Gradient: 0-1 min (5% B); 1-2 min (90% B); 2-4.5 min (90% B); 4.5-4.6 min (5% B); 4.6-7 min (Stop); The results of GABA production by each strain are shown in Table 3.

[0066] Table 3 Determination of GABA content produced by each strain

[0067] As shown in Table 3, among the strains numbered 4, 28, and 36, the Bifidobacterium longum strain corresponding to No. 28 has the highest GABA production, which can reach 13 μg / mL. It is a high-GABA-producing strain among the probiotics isolated and screened.

[0068] Through the above high-throughput screening, it was unexpectedly discovered that the new B. longum strain No. 28 selected can simultaneously produce high levels of GABA and 5-HT. It has now been deposited in the China Center for Type Culture Collection in Wuhan, Hubei, with the deposit number: CCTCC M20231518, and named Bifidobacterium longum JWA3. The strain can produce up to 12.93 μg / mL of GABA and 10.18 ng / ml of 5-HT.

[0069] Among them, in the process of coordinating liver regeneration, 5-HT stimulates DNA synthesis and cell proliferation by activating 5-HT receptors, which is beneficial for liver regeneration and restoration of its function; and gamma-aminobutyric acid (GABA), also known as aminobutyric acid, is an amino acid derivative. It is a non-protein amino acid that has a calming effect on nerves in animals. In animals, it is mainly derived from glutamic acid through decarboxylation. GABA is a central nervous system sedative. Studies have shown that it has the effects of stabilizing, anticonvulsant, lowering blood pressure, enhancing brain activity and nourishing nerve cells, promoting growth hormone, and protecting the liver and kidneys. It is widely used in the current pharmaceutical and food industries. This shows that the B. longum strain provided by the present invention has the potential to improve liver damage and promote liver function recovery.

[0070] Example 3 Bifidobacterium longum (preserved strain) improves LFR in mice after surgery

[0071] Broad-spectrum antibiotics: Vancomycin (0.1g / L), Neomycin (0.2g / L), Ampicillin (0.2g / L), and Metronidazole (0.2g / L). Drinking water containing antibiotics every other day can deplete the symbiotic flora.

[0072] DDC treatment: Mice were continuously treated with 3,5-diethoxycarbonyl-1,4-dihydrochoridine (DDC) for 4 weeks to establish a liver injury mouse model. The mice were then divided into four groups: a blank group (Saline), experimental group 1 (AS-DR-FMT), experimental group 2 (AS-DR-BL), and experimental group 3 (AS-DR-FMT+BL). The specific bacterial solution preparation and oral gavage were as follows:

[0073] Preparation of BL bacterial suspension: The B. longum strain (accession number CCTCC M 20231518) obtained from Example 2 was cultured anaerobically in MRS broth at 37°C for 24 h, then maintained and counted on MRS agar medium before oral gavage. Bacterial cells were collected by centrifugation at 12,000 rpm for 5 min and resuspended in 1 mL of sterile saline solution. 200 μL of the suspension was gavaged to each mouse in divided doses, with a final concentration of 1.2 × 10 10 CFU / ml, according to the ratio of effective dose for mice to adults (10-12):1, the effective dose for adults is (1-1.2)*109 CFU / ml.

[0074] Fecal microbiota transplantation solution: Fecal samples were collected from patients with delayed recovery (DR) at the time of their first postoperative bowel movement. Approximately 1000 mg of fecal sample was suspended in 5 mL of PBS and vortexed for 2 minutes. 200 μL of the suspension was administered orally to each mouse.

[0075] Fecal microbiota transplantation with a mixed solution of preserved strains: Fecal samples were collected from patients with delayed recovery (DR) at the time of their first bowel movement after surgery. Samples from patients with delayed recovery of liver function (AS-DR) and samples of the preserved strains were mixed. Approximately 1000 mg of the mixed sample was suspended in 5 mL of PBS and vortexed for 2 minutes. Each mouse was gavage-administered with 200 μL of the suspension.

[0076] 70% of the liver was removed in each group of mice 4 weeks after DDC induction. Antibiotics (ABx) were used for 3 days starting on the first day after surgery. Subsequently, starting from the second day after surgery, a 3-day gavage was performed. The blank group (Saline) model mice were gavaged with normal saline on the second day after surgery; the experimental group 1 (AS-DR-FMT) model mice were gavaged with fecal microbiota transplantation liquid, and the experimental group 2 (AS-DR-BL) model mice were gavaged with preserved strain liquid; the experimental group 3 (AS-DR-FMT+BL) model mice were gavaged with a mixture of fecal microbiota transplantation and preserved strains. The weight of each group of mice was recorded during the experiment, and the results are shown in Figure 3.

[0077] On the fifth day after surgery, blood and fecal samples were collected. Finally, all mice were killed and liver tissue samples were collected. The hepatosomatic index (HSI) of each group of mice was calculated according to the formula: liver index = (wet liver weight / body weight) × 100%. The results are shown in Figure 4.

[0078] Blood was collected to test liver function, and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB), prothrombin activity (PTA), and total bile acid (TBA) in the serum of each group of mice were determined. The results of ALT, AST, and TB levels are shown in Figure 5, and the results of PTA and TBA levels are shown in Figure 6.

[0079] The liver specimens were weighed, and a portion was embedded in paraffin in Tissue-Tek Compound Medium for hematoxylin-eosin (HE) staining and Masson staining. The staining results are shown in FIG7 .

[0080] Mouse fecal samples were immediately frozen at −80°C after collection and subjected to quantitative PCR (qPCR). The abundance of B. longum in the feces of mice in each group is shown in FIG8 .

[0081] As can be seen from Figure 3, the weight of mice in the BL group increased significantly compared with the mice in the blank control Saline group, while the weight of mice in the AS-DR-FMT group decreased compared with the mice in the blank control Saline group, and the weight of mice in the AS-DR-FMT+BL group increased compared with the mice in the AS-DR-FMT group, indicating that fecal microbiota transplantation solution of patients with delayed recovery (DR) can delay the postoperative recovery of mice, and intragastric administration of the preserved strain solution of the present invention can significantly promote the postoperative recovery of mice, especially the postoperative recovery of patients with delayed recovery.

[0082] As shown in Figure 4 , among the four groups, the liver-body index of mice in the BL group was significantly lower than that in the other groups, and the liver-body index of mice in the AS-DR-FMT+BL group was lower than that in the AS-DR-FMT group.

[0083] Commonly used indicators of liver function tests include ALT, AST, TB, TBA and PTA; among them, ALT and AST are indicators reflecting liver parenchymal damage, and ALT is the most commonly used sensitive indicator. When 1% of liver cells are necrotic, the serum ALT level can increase by 1 times; TB and TBA are indicators reflecting bilirubin metabolism and cholestasis. These indicators will increase when liver cells are degenerated and necrotic, bilirubin metabolism is impaired or intrahepatic cholestasis occurs; PTA is one of the indicators reflecting liver synthetic function. Decreased prothrombin activity indicates that normal liver cells are gradually decreasing, liver cells have poor protein and coagulation factor synthesis function, liver reserve function is reduced, and the prognosis is poor.

[0084] As shown in Figure 5, compared with the blank control group, the serum ALT, AST, and TB levels of mice in the BL group were significantly reduced, while those in the AS-DR-FMT group were increased. This indicates that the AS-DR-FMT group experienced delayed postoperative recovery, and oral administration of the preserved strain significantly reduced serum ALT, AST, and TB levels. As shown in Figure 6, compared with the blank control group, the serum PTA levels of mice in the BL group were significantly increased, while the TBA levels were decreased. However, compared with the blank control group, the PTA levels in the AS-DR-FMT group were significantly decreased, while the TBA levels were increased. This indicates that the BL strain provided by the present invention can significantly improve liver damage and can be used to improve liver function recovery after hepatectomy.

[0085] Further pathological analysis in Figure 7 showed that the liver tissue damage in the AS-DR-FMT+BL group was alleviated compared with the AS-DR-FMT group, indicating that oral administration of the BL strain provided by the present invention can improve liver damage.

[0086] As shown in Figure 8, the abundance of B. longum in the feces of mice in the BL group was the highest among the four groups, and the abundance of B. longum in the AS-DR-FMT+BL group was significantly higher than that in the AS-DR-FMT group, indicating that the BL bacteria intervention provided by the present invention can significantly alleviate DDC-induced liver damage in mice and avoid further deterioration of liver function.

[0087] The Bifidobacterium longum JWA3 (B. longum) provided by this invention is a strain of Bifidobacterium longum JWA3, obtained from the healthy human intestine and screened for its complete human adaptation. It meets the requirements of the U.S. Food and Drug Administration (FDA) for use in general foods. Furthermore, Bifidobacterium longum (BL) probiotics have been shown to regulate the human intestinal tract and improve health. Clinically, this product is often used to treat diarrhea, bloating, and constipation caused by intestinal dysbiosis. It can quickly restore the balance of probiotics in the human body and improve liver function recovery after surgery.

[0088] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A B. longum strain having the ability to promote recovery of liver function after surgery, characterized in that: The accession number is CCTCC M20231518, named Bifidobacterium longum JWA3, and has been deposited in the China Type Culture Collection, Wuhan, Hubei.

2. The B. longum strain having the ability to promote recovery of postoperative liver function according to claim 1, characterized in that: The B. longum strain has a 5-HT production of more than 10 ng / ml and a GABA production of more than 12 μg / mL. 。 3. Use of the B. longum strain as claimed in claim 1 or 2 in preparing a product for improving liver damage.

4. The use according to claim 3, characterized in that: Application in the preparation of products for improving drug-induced liver injury.

5. The use according to claim 3, characterized in that: Used to prepare products that promote liver function recovery in patients with liver cancer after liver resection.

6. The use according to claim 5, characterized in that It is used to prepare probiotic preparations for promoting liver function recovery in patients with liver cancer after surgery.

7. A probiotic preparation for promoting liver function recovery in patients with liver cancer after surgery, characterized in that: The probiotic preparation comprises the Bifidobacterium longum JWA3 strain according to claim 1 or 2.

8. The probiotic preparation for promoting liver function recovery in patients with liver cancer after surgery according to claim 7, characterized in that: The concentration of the Bifidobacterium longum JWA3 strain is 1.0*10 10 CFU / ml or 1.0*10 10 CFU / g and above.

9. The probiotic preparation for promoting liver function recovery after surgery for liver cancer patients according to claim 8, characterized in that: The concentration of Bifidobacterium longum JWA3 strain in the probiotic preparation is 1.2*10 10 CFU / ml or 1.2*10 10 CFU / g.

10. A drug for improving postoperative liver function, characterized in that: The medicament comprises the Bifidobacterium longum JWA3 strain as claimed in claim 1 or 2.

11. The drug according to claim 10, characterized in that The content of Bifidobacterium longum JWA3 strain in the drug is (1-1.2)*10 9 CFU / ml or (1~1.2)*10 9 CFU / g.

12. A method for treating liver damage and / or promoting recovery of liver function after surgery, characterized in that: The method comprises administering the Bifidobacterium longum (B. longum) of claim 1 or 2 to a patient in need, or administering a product or a probiotic preparation or a drug containing the Bifidobacterium longum (B. longum) of claim 1 or 2 to a patient in need.

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