Potential Beneficial Effect of Rifaximin in the Prevention of Hepatocellular Carcinoma through the Modulation of the Microbiota in an Experimental Model of Non-alcoholic Fatty Liver Disease

Abstract

Summary Aim. To evaluate the effects of rifaximin through microbiota modulation in a model of hepatocellular carcinoma secondary to non-alcoholic fatty liver disease. Methods. Three groups of 8 adult male Sprague-Dawley rats each were divided as follows: the HCC group: rats fed a high-fat and choline-deficient diet plus diethylnitrosamine as a carcinogen, the hepatocellular carcinoma treated group: rats fed a high-fat and choline-deficient diet plus diethylnitrosamine and treated with rifaximin and the control group: animals fed standard diet and water. The rats were euthanized after 16 weeks. We performed analyses of liver pathology for non-alcoholic fatty liver disease severity and cancer grading, gene expression in intestinal and hepatic tissues and fecal microbiota. Results. All animals in the hepatocellular carcinoma group had non-alcoholic fatty liver disease and developed hepatocellular carcinoma lesions. Rifaximin animals showed less intense non-alcoholic fatty liver disease (assessed by non-alcoholic fatty liver disease activity score [NAS]) compared to the hepatocellular carcinoma group. Both the hepatocellular carcinoma and hepatocellular carcinoma + rifaximin groups showed areas of fibrosis as assessed by picrosirius red. Three animals in the rifaximin group did not develop cancerous lesions. Gut microbiota analyses revealed differences in diversity and composition in the control group vs hepatocellular carcinoma and rifaximin groups. Twelve differentially abundant genera were identified between the hepatocellular carcinoma and rifaximin groups. In the rifaximin group, gene expression of intestinal tight junctions decreased. Conclusions. In a rodent model of non-alcoholic fatty liver disease-related hepatocellular carcinoma, rifaximin reduces the histological severity of non-alcoholic fatty liver disease and the occurrence of hepatocellular carcinoma, probably by modulating the gut microbiota independently of markers of intestinal permeability.