Gut Microbiota and Interorgan Communication Among the Gut, Brain, and Beyond.

The intestinal tract contains the largest reservoir of lymphoid tissue in the body and it communicates with other organs through metabolites, cytokine activation, and the migration of gut immune cells. In particular, the liver interacts with the gut through the portal vein and bile ducts. Furthermore, the frequent abdominal symptoms reported by patients with neuropsychiatric disorders underscore a strong gut-brain connection. Gut-liver and gut-brain interactions have received increasing attention in recent years, and numerous studies have been performed in the last decade. Research is now being actively conducted to determine the specific bacteria associated with the development and progression of various diseases. This review summarizes recent findings, with a focus on the links between gut immunity and other organs.