The Division of Pediatric Gastroenterology at National Taiwan University Children’s Hospital specializes in the investigation of (1) diagnosis of common pediatric gastrointestinal diseases; (2) prevalence and mechanisms of hepatitis B virus and related hepatitis and hepatocellular carcinoma, maternal transmission and vaccine efficacy; (3) pathogenic genes and mechanisms involving hepatoblastoma, biliary atresia, cholestasis, allergic and related liver diseases; (4) gut microbiota-based therapeutic strategies in pediatric gastrointestinal diseases.