Pathways in gut-brain communication: evidence for distinct gut-to-brain and brain-to-gut syndromes.

Objective: The rich interconnectedness between gut and brain is increasingly being identified. This article reviews the evidence for brain-gut and gut-brain syndromes, particularly recent epidemiological evidence, and animal studies demonstrating bi-directionality at the formative stage of development.

Method: Narrative literature review with selection for relevance and quality.