MOOD AND ANXIETY DISORDERS: Edited by Gordon Parker and Sidney H. KennedyThe gut microbiome and diet in psychiatry focus on depressionDash, Saraha; Clarke, Gerardb,c; Berk, Michaela,d,e,f; Jacka, Felice N.a,b,g,hAuthor Information aIMPACT Strategic Research Centre, Deakin University, Geelong bDepartment of Psychiatry cAlimentary Pharmabiotic Centre, University College Cork, Cork, Ireland dDepartment of Psychiatry, The University of Melbourne eThe Florey Institute of Neuroscience and Mental Health, At Genetics Lane, Royal, Parade, The University of Melbourne fOrygen Youth Health Research Centre, Parkville, Victoria gCentre for Adolescent Health, Murdoch Children's Research Institute, Melbourne, Victoria hBlack Dog Institute, Sydney, New South Wales, Australia Correspondence to Dr Felice Jacka, IMPACT Strategic Research Centre, School of Medicine, Deakin University, Kitchener House, Ryrie Street, Geelong, 3220, Victoria, Australia. Tel: +61 4 2219 4218; fax: +61 3 4215 3491; e-mail: firstname.lastname@example.org Current Opinion in Psychiatry: January 2015 - Volume 28 - Issue 1 - p 1-6 doi: 10.1097/YCO.0000000000000117 Buy Metrics Abstract Purpose of review With depressive disorders the leading source of disability globally, the identification of new targets for prevention and management is imperative. A rapidly emerging field of research suggests that the microbiome–gut–brain axis is of substantial relevance to mood and behaviour. Similarly, unhealthy diet has recently emerged as a significant correlate of and risk factor for depression. This review provides evidence for the gut microbiota as a key factor mediating the link between diet and depressive illness. Recent findings The development of new technologies is affording a better understanding of how diet influences gut microbiota composition and activity and how this may, in turn, influence depressive illness. New interventions are also suggesting the possible utility of pre and probiotic formulations and fermented food in influencing mental health. Summary Although in its early stages, the emerging field of research focused on the human microbiome suggests an important role for the gut microbiota in influencing brain development, behaviour and mood in humans. The recognition that the gut microbiota interacts bidirectionally with other environmental risk factors, such as diet and stress, suggests promise in the development of interventions targeting the gut microbiota for the prevention and treatment of common mental health disorders. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.