Abstract
Functional dyspepsia (FD) is a common functional gastrointestinal disorder characterized by upper abdominal discomfort without structural abnormalities. Traditionally, the FD pathophysiology has focused on impaired gastric emptying, accommodation, and visceral hypersensitivity. Nevertheless, recent studies have highlighted the importance of duodenal factors such as increased mucosal permeability, low-grade inflammation, and microbial dysbiosis. These duodenum-centered approaches, along with altered gut-brain interactions, offer a novel framework to explain FD symptoms beyond the gastric mechanisms. This review summarizes the emerging evidence and explores new diagnostic and therapeutic strategies for the duodenal microenvironment.