Paul O’Toole is Professor of Microbial Genomics and Head of Microbiology at University College Cork, Ireland. He is a Principal Investigator in APC Microbiome Ireland (apc.ucc.ie), in which he leads projects on gut microbiota as a modulator of health and disease risk. His main research programme is on the functional genomics of gastrointestinal bacteria in humans with emphasis on lactobacillus genomics and phylogeny, gut microbiota in ageing, colorectal cancer and in IBS. He has co-ordinated and participated in several major national and international projects that examined the composition and function of the gut microbiota, its reaction to habitual diet, and its relationship to health, functional gastrointestinal disorders, and ageing. The ultimate aim of these investigations is to understand and control host-microbiome interactions, especially in the context of multi-factorial disease. Research in his lab is supported by Science Foundation Ireland, Dept. Agriculture Fisheries and Marine (Govt. Ireland), the Health Research Board Ireland, and the European Union.