The Role Of Intestinal Microbiota In The Clearance Of Surface Antigen In Hepatitis B Mouse Model

ObjectiveWith the current antiviral therapy for chronic hepatitis B,it is hard to achieve the goal of functional cure.Recent studies have shown that intestinal microbiota can affect liver immunity through "gut-liver" axis and play an important role in a variety of liver diseases.The purpose of this study was to investigate the role of intestinal microbiota in HBsAg clearance and its mechanism by HBV mouse model.Methods1.High pressure tail vein injection technique was used to inject pAAV/HBV 1.2 plasmid into C57BL/6 mice.The blood samples were collected at different time points to monitor the dynamic changes of serum HBsAg,HBeAg,ALT and HBV DNA.The fecal samples of each mouse were collected daily and frozen at-80℃ for fecal microbiota transplantation and sequencing.2.According to the decline rate of HBsAg,the mice were divided into rapid decline group,medium decline group and slow decline group.The feces of the rapid decline group and the slow decline group were transplanted to a new batch of mice respectively.The decline rate of surface antigen in mice receiving different fecal bacteria transplantation was observed.Results1.After infection with pAAV/HBV 1.2,the decline rate of HBsAg was different among mice.Twenty percent(8/40)of mice could clear HBsAg 21 days after infection,while 20%(8/40)mice had less than 1 log10 IU/mL decline of surface antigen from the 7th day to the 21st day after infection;2.After fecal microbiota transplantation,the decline of HBsAg was faster in mice receiving the feces of mice with rapid decline of HBsAg,and slower in mice receiving the feces of mice with slow decline of HBsAg;3.The structure of intestinal microbiota in mice with rapid decline of HBsAg was different from that in mice with slow decline of HBsAg.There was significant difference in β diversity(P<0.05),but there was no difference in the content of akkermansia between the two groups.Linear discriminant analysis coupled with effect size measurements(LEfSe)identified 28 characteristic bacteria in the rapid decline group and 1 Characteristic bacteria in the slow decline group.Fecal metabonomics showed that the contents of hexanoic acid,citric acid and dihydrocaffeic acid in fecal samples of the rapid decline group were higher than those of the slow decline group,while the contents of glucose,serine,N-acetylglucosamine,indoleacetic acid,histidine and ursolic acid were lower than those of the slow decline group.Conclusions1.There was a large variation in the rate of decline of HBsAg in C57BL/6J mice infected with pAAV/HBV 1.2 plasmid.;2.Fecal microbiota transplantation can affect the decline rate of surface antigen in C57BL/6J mice;3.Mice with different surface antigen decline rate have different intestinal microbiota structure and different intestinal metabolites.