RT Journal Article SR Electronic T1 Exercise and associated dietary extremes impact on gut microbial diversity JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 1913 OP 1920 DO 10.1136/gutjnl-2013-306541 VO 63 IS 12 A1 Siobhan F Clarke A1 Eileen F Murphy A1 Orla O'Sullivan A1 Alice J Lucey A1 Margaret Humphreys A1 Aileen Hogan A1 Paula Hayes A1 Maeve O'Reilly A1 Ian B Jeffery A1 Ruth Wood-Martin A1 David M Kerins A1 Eamonn Quigley A1 R Paul Ross A1 Paul W O'Toole A1 Michael G Molloy A1 Eanna Falvey A1 Fergus Shanahan A1 Paul D Cotter YR 2014 UL http://gut.bmj.com/content/63/12/1913.abstract AB Objective The commensal microbiota, host immunity and metabolism participate in a signalling network, with diet influencing each component of this triad. In addition to diet, many elements of a modern lifestyle influence the gut microbiota but the degree to which exercise affects this population is unclear. Therefore, we explored exercise and diet for their impact on the gut microbiota. Design Since extremes of exercise often accompany extremes of diet, we addressed the issue by studying professional athletes from an international rugby union squad. Two groups were included to control for physical size, age and gender. Compositional analysis of the microbiota was explored by 16S rRNA amplicon sequencing. Each participant completed a detailed food frequency questionnaire. Results As expected, athletes and controls differed significantly with respect to plasma creatine kinase (a marker of extreme exercise), and inflammatory and metabolic markers. More importantly, athletes had a higher diversity of gut micro-organisms, representing 22 distinct phyla, which in turn positively correlated with protein consumption and creatine kinase. Conclusions The results provide evidence for a beneficial impact of exercise on gut microbiota diversity but also indicate that the relationship is complex and is related to accompanying dietary extremes.