A recent clinical trial (NCT02443116) showed that aldafermin, a FGF19 analog, suppressed bile acid synthesis, led to an enrichment of Veillonella and corresponding changes in serum bile acids in patients with NASH (41). Obeticholic acid (OCA), a FXR agonist, has shown effectiveness in altering the intestinal microbiota, and effectively improves hepatic histological characteristics in patients with NASH (42, 43). This evidence concerns the gene NR1H4 and metabolic dysfunction-associated steatohepatitis.