ABSTRACT
This chapter reviews the impact of nonalcoholic fatty liver disease (NAFLD) on the gastrointestinal tract outside the parenchymal liver. NAFLD is a multisystem disease associated with a myriad of extrahepatic gastrointestinal manifestations. Multiple studies have shown that NAFLD is independently associated with an increased risk of gastroesophageal reflux disease symptoms as well as erosive esophagitis. The possible association between Helicobacter pylori (HP) infection and NAFLD initially stemmed from the isolation of HP in the livers of patients with NAFLD. A possible direct link between NAFLD and gastric cancer has been suggested in a few studies. NAFLD patients have a higher incidence of celiac disease compared to the general population, despite celiac patients having a lower risk for metabolic syndrome before the start of a gluten-free diet. As the gut microbiome is altered in NAFLD, small intestinal bacterial overgrowth may also contribute to the pathogenesis of NAFLD.
