A collection of articles on the gut-brain axis....
"This relationship, commonly dubbed the gut–brain axis (or the microbiota–gut–brain axis), involves various afferent and efferent pathways such as the vagus nerve and the hypothalamic-pituitary-adrenal pathway to regulate aspects of homeostasis such as satiety and hunger, and inflammation. Disruption of the gut–brain axis has been shown to be involved in the pathogenesis of a diverse range of diseases, including Parkinson disease and irritable bowel syndrome. Although the majority of data to-date is from animal models, this emerging area of research is evolving quickly and with promising translational value"
http://www.nature.com/collections/dyhbndhpzv

Collection of articles from the Nature Research journals covering the gut-brain axis