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). The gene discussed is FGF19; the disease is metabolic dysfunction-associated steatohepatitis.