Grant: Doctoral Award - Frederick Banting and Charles Best Canada Graduate Scholarships

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that affects 1 in 150 Canadians. The incidence continues to rise, yet prevention and treatment options are limited. Diet plays a key role in our immune system through changes to the gut microbiome. For example, what we eat encourages the growth of beneficial and harmful bacteria in our gut. An imbalance in the bacteria, called dysbiosis, is linked to chronic diseases like UC. Scientists agree that high fat diets promote dysbiosis, however recent evidence suggests that the type of fat we consume may contribute to inflammation and lead to dysbiosis in our gut. The Gibson lab has demonstrated that monounsaturated fats (olive oil) are beneficial to gut inflammation while n-6 polyunsaturated fats (corn oil) are harmful, and n-3 polyunsaturated fats (fish oil) are beneficial when combined with saturated fats (dairy). Based on these results, the blend of fats in the Mediterranean Diet (MD) is believed to be beneficial to colitis. I hypothesize that a MD will reduce clinical disease activity in UC and reduce the development of colitis in mice. I will perform a diet study where patients with UC in remission will receive a MD or control diet for 12 weeks. Disease activity, symptoms and quality of life will be assessed through questionnaires taken at various time points. To evaluate changes to the gut microbiome, stool samples will be collected/analyzed. To understand if the MD influences colitis in mice, the mice will be fed a high fat diet (40% total fat) where the fat is derived from either corn oil, olive oil, milk fat or MD (blend of fat) for 5 weeks. Tissues and stool will be obtained from the mice and examined for immune responses and dysbiosis. Little is known about how dietary fat impacts the immune system and the gut microbiome. Understanding the relationship between diet and the gut microbiome will inform new dietary treatments and create novel strategies for managing IBD.