Gut Microbiota and Anxiety: An Exploration of Key Findings

Abstract

There is a growing body of evidence linking the intestinal microbiota with anxiety disorders. Studies using germ free (GF) rodent models have demonstrated that bacterial colonization of the gut is crucial to the development of the central nervous system (CNS), enteric nervous system (ENS), and the hypothalamic-pituitary-adrenal (HPA) axis. Furthermore, evidence points towards the important role of gut microbiota in the induction of the anxiety response, with a disrupted gut microbiome leading to aberrations in stress-related behaviors and anxiety. In human subjects, ingestion of probiotics has been shown to reduce anxiety symptoms, thereby further strengthening the link between gut microbiome and anxiety. In this article, we review studies examining the relationship between gut microbiota and anxiety, and discuss proposed mechanisms and future direction of research.