Garth R. Swanson, M.D., serves as division director and professor in the Division of Gastroenterology and Hepatology within the Department of Medicine at the MUSC College of Medicine. A physician-scientist specializing in inflammatory bowel disease (IBD), he combines patient care with a research program spanning basic, translational and clinical investigation. His research examines the mechanisms that contribute to IBD, with a particular commitment to translating laboratory discoveries into potential improvements in patient care.
Dr. Swanson’s basic research laboratory focuses on two primary areas: understanding the mechanisms of intestinal barrier homeostasis that contribute to IBD and examining how environmental factors, including circadian misalignment and alcohol consumption, affect intestinal barrier permeability. His research group has made several key discoveries related to intestinal barrier function and circadian biology. The group found that disruption of the circadian clock through environmental or genetic models decreases the intestine’s resilience to injurious agents such as alcohol. His research also demonstrated that night shift workers experiencing circadian misalignment have increased alcohol induced intestinal permeability following moderate alcohol consumption, driven in part by decreased serum melatonin. The National Institute on Alcohol Abuse and Alcoholism previously funded his research through a K23 award. The National Institute of Diabetes and Digestive and Kidney Diseases currently supports his work through two R01 grants.
A second major focus of Dr. Swanson’s basic research is chronobiology. His laboratory has shown that individuals with IBD experience greater circadian misalignment than healthy controls, as measured through chronotype questionnaires, rest and wake cycles assessed by actigraphy, and laboratory phase assessments using dim light melatonin onset. His team has also shown that patients with IBD who experience circadian misalignment have worse disease related outcomes, increased intestinal permeability and a proinflammatory microbiota.
The study of chronobiology in IBD may create new treatment pathways, including chronotherapy through the timing of medication and bright light therapy using Retimer, to improve intestinal barrier function. This work also has a distinct mechanistic focus, including tight junction proteins, metabolites such as short chain fatty acids and critical inflammatory pathways such as STAT3.
Dr. Swanson has also played an active role in developing clinical programs for patients with IBD. At Rush University, he established the institution’s first multidisciplinary IBD conference and later developed a multidisciplinary IBD clinic. He served as director of the Crohn’s and Colitis Center and collaborated with researchers in the Rush Center for Integrated Microbiota and Chronobiology. The center received partial funding through an R24 grant for which he served as a co-investigator.
Dr. Swanson’s laboratory also established a robust Digestive Diseases biorepository containing more than 38,000 samples. Beginning in 2010, he served as co-director of the Rush University Digestive Disease Biorepository and helped upgrade its inventory and management system.