Palm oil-containing high-fat diet with LPS and CCl4 C57BL/6J mouse model induces the progression of NASH/liver fibrosis and remodels the gut microbiota and its function

Abstract Animal models of non-alcoholic steatohepatitis (NASH) and liver fibrosis are essential for preclinical research of novel drugs. A high-fat diet (HFD) animal model has an indispensable role in the research of gut-liver axis by generating an imbalance of gut microbiota and intestinal leakage, resulting in translocation of harmful bacterial metabolites and lipopolysaccharides (LPSs) to the liver, triggering hepatic immune responses, and stimulating NASH and liver fibrosis. Replacing trans-fat with palm oil in HFDs is an emerging animal model with human translatability in terms of liver biopsy phenotype and transcriptome changes. We developed the NASH and fibrosis C57BL/6J mouse model using a palm oil-containing high-fat diet (P-HFD) combined with LPS to simulate gut dysbiosis and endotoxemia and examined the role of carbon tetrachloride (CCl4) on the gut-liver axis. We developed the mouse models, and the mice were fed P-HFD with or without intraperitoneal LPS/CCl4 injections. NASH/fibrosis progression and gut microbiota shift were examined at 4, 8, 12, 16, 20, and 24 weeks (n=192). The animal model showed obesogenic and metabolic changes, hepatomegaly, increased hepatic lipid levels, NASH phenotype, increased gut dysbiosis, changes in gut microbiota and its function, reduced beneficial bacteria, increased pathogenic related microbiome, intestinal leakage, and endotoxemia. P-HFD with LPS supplementation resulted in comparable NASH, intestinal leakage, and endotoxemia phenotypes compared with the P-HFD group, but worsened the degree of intestinal microbiota dysbiosis by increasing the occurrence of pathogenic bacteria and reducing beneficial microbiota. P-HFD with CCl4 resulted in a liver fibrosis phenotype and produced a more severe gut microbiota shift. These mouse models could be informative for a researcher focused on the gut-liver axis and could be used as valuable tool for preclinical drug testing.