McMaster University

Medical Sciences
Graduate Program

Scope of Search


Stephen M. Collins

Stephen M. Collins


Professor Emeritus

Research Interests

The Intestinal Microbiota and the Gut-Brain Axis in Health and Disease


Our current research investigates how commensal bacteria shape the physiology of host tissues within and outside the gut, with a particular focus on the brain. Access to germ free and gnotobiotic mice enables us to study how the intestinal microbiota maintains the integrity of gut-brain function and the bidirectional communication between these systems and the microbiota. An understanding of these interactions is relevant to our understanding of chronic intestinal functional and inflammatory bowel disorders (Nature Commun. 2015 PMID: 26218677). We have a particular interest in understanding how the intestinal microbiota influence the expression of intestinal and behavioural symptoms that characterize the Irritable Bowel Syndrome (IBS)  – the most common of all chronic GI conditions. To enable this investigation we have developed a model in which ex-germ free mice are colonized by the microbiota of patients with IBS, with or without psychiatric co-morbidity (Science Transl Med 2017 PMID 28251905). Our work focuses on mechanisms whereby the intestinal microbiota influence gut and brain function in health and in disease with a focus on immunological and metabolic pathways. We have also investigated the ability of selected probiotic bacteria to attenuate intestinal dysfunction and altered behaviour in preclinical models as well as in patients with IBS and psychiatric co-morbidity (Gastroenterology 2018 PMID: 28483500). 




McMaster University
Health Sciences Centre

telephone: (905) 525-9140 ext. 22184


Program Area

Infection & Immunity


Research Focus

Pregnancy Immunology, Tolerance, Cytokines, Transfusion immunomodulation, CD200, fgl2

Selected Publications

  • Bead study: a novel method to measure gastrointestinal transit in mice.Reed DE, Pigrau M, Lu J, Moayyedi P, Collins SM, Bercik P.Neurogastroenterol Motil. 2014 Nov
  • Qualitative multiplatform microanalysis of individual heterogeneous atmospheric particles from high-volume air samples.Conny JM, Collins SM, Herzing AA.Anal Chem. 2014 Oct
  • The effects of inflammation, infection and antibiotics on the microbiota-gut-brain axis.

    Bercik P, Collins SM. Adv Exp Med Biol. 2014