Organic selenium ameliorates non-alcoholic fatty liver disease through 5-hydroxytryptamine/bile acid enterohepatic circulation in mice

To investigate the effects of organic selenium (L-selenocystine, L-selenomethionine, and L-selenomethylcysteine) on non-alcoholic fatty liver disease (NAFLD), the NAFLD mice model with hepatic steatosis and fibrosis was established via feeding with a Western diet and CCl4 injection. Compared with the model group, the intervention groups with organic selenium experienced a reduction in hepatic 5-hydroxytryptophan (5-HT) contents and downregulation in the expression of tryptophan hydroxylase 1 (TPH1) and 5-HT receptor 2A/2B/3A. Similar results were observed on TPH1/5-HT in the duodenum. In addition, organic selenium decreased the bile acid (BA) concentrations in gut contents, downregulated the expression of hepatic CYP7A1, and upregulated the expression of hepatic Farnesoid X-activated receptor (FXR). In conclusion, our findings suggest that organic selenium ameliorates NAFLD through 5-HT/BA enterohepatic circulation in mice with NAFLD.