Studies show that an important role in the pathogenesis of NAFLD is played by the farnesoid X receptor (FXR), a nuclear receptor preferentially activated by primary bile acids and expressed in the intestinal epithelium and liver, which has a role in protecting the integrity of the intestinal barrier, regulating carbohydrate, lipid and amino acid metabolism, and producing antimicrobial peptides [24]. This evidence concerns the gene NR1H4 and metabolic dysfunction-associated steatotic liver disease.