Dr. Leo Dieleman


Department of Medicine

Division of Gastroenterology
    Contact details are for academic matters only.

About Me

Personal Statement:

My research and clinical interests have been internationally recognized in the understanding, management and prevention of Inflammatory Bowel Disease (IBD) through diet and/or dietary supplements that change gut bacteria. I investigate the mechanisms involved in chronic inflammation of the gut mediated by the gut microbiome with the goal of developing and testing personalized therapeutics that can reduce or prevent inflammatory bowel disease. 

Dr. Leo Dieleman received his medical degree in 1983 from the University of Nijmegen, The Netherlands, after which he trained in internal medicine and gastroenterology in the Netherlands. In 1989 he received an International Fogarty Research Fellowship from National Institutes of Health that led him to pursue doctoral studies on the role of cytokines in experimental and human inflammatory bowel disease (IBD) with Dr. Charles Elson at University of Alabama in Birmingham, USA. He then went on to complete a Clinical Fellowship in Gastroenterology and also received a PhD degree in 1995 at the Free University of Amsterdam, The Netherlands. In 1996 he returned to the USA to join the faculty as assistant professor (clinical and research) at the University of North Carolina  in Chapel Hill. In 2003 Dr. Dieleman was recruited as Associate Professor to the University of Alberta where he became Full Professor in 2013.

Dr. Dieleman is an internationally recognized expert in the gut microbiome whose research is supported by provincial, national and international funding agencies.

Leadership and Collaborations:

Dr. Dieleman is the Co-Director of the Inflammatory Bowel Disease Unit at the Division of Gastroenterology. He is also a team leader (diets) in the CIHR-funded IMAGINE study, as well as a member of the Steering Committee of the GEM study in healthy first degree relatives of Crohn’s patients. He is also a member of the Centre of Excellence for Gastrointestinal Inflammation and Immunity Research. In addition, he is a member of the scientific board of the Biocodex Microbiota Foundation.  His interest in new therapies for IBD have also led to his involvement with the Edmonton-based company BioImmuno Designs as a co-scientific director. He is currently an Associate Editor with the Journal of the Canadian Association of Gastroenterology and Frontiers in Medicine and a reviewer for numerous international scientific journals and grant agencies in his field. Dr. Dieleman is also Principal Investigator in several novel drug therapies in IBD.


Dr. Dieleman supervises clinical and research trainees and residents and provides classroom instruction for the medical students. He also participates in continuing medical education sessions for physicians and other health care providers.


Dr. Dieleman’s research interests are intestinal bacteria, probiotics, prebiotics, dietary therapy for the treatment of inflammatory bowel disease, and management of reproductive issues in IBD. His research funders included the National Institutes of Health (US), the Canadian Institutes of Health Research, Crohn’s and Colitis Canada, Alberta Innovates and Women & Children’s Health Research Institute. He has published more than 100 original scientific articles and book chapters in peer-reviewed journals and is a frequent presenter at international, national and regional scientific conferences, mostly focused on IBD.

Research Keywords

Crohn's disease, diets, gut bacteria, prebiotics, probiotics, ulcerative colitis