Gerard Clarke is Professor of Neurobehavioural Science in the Department of Psychiatry and Neurobehavioural Science and a Principal Investigator in APC Microbiome Ireland at University College Cork. His research interests include the impact of the gut microbiome on brain and behaviour, microbial regulation of tryptophan metabolism and translational biomarkers of stress-related neuropsychiatric disorders. Target human populations of his research include major depression and anxiety as well as gastrointestinal disorders with high psychiatric comorbidities such as irritable bowel syndrome. He has recently co-authored a book titled Microbiota Brain Axis: A Neuroscience Primer.