KLF5 and duodenogastric reflux: DCA is defined as the main bile acid component of duodenogastric reflux, and long-term increment of DCA level leads to abnormal BA metabolism and microbial dysbiosis in the stomach, resulting in gastric inflammation and intestinal meta-plasia development by promoting nuclear STAT3 phos-phorylation and KLF5 upregulation [48].