Airborne particulate matter and a western style diet as potential environmental factors in the pathogenesis of Inflammatory Bowel Disease

Abstract

Inflammatory bowel disease is believed to occure in response to environmental factors resulting in immune dysregulation in genetically predisposed individuals. Such environmental factors include diet, (specifically a “western diet”rich in refined sugars, and fat) and airborne particulate matter (PM) pollution. Normally the gastrointestinal tract maintains tolerance to luminal antigens and the enteric flora, however, it’s proposed that in genetically predisposed individuals, presence of such antigens acts to trigger or exacerbate intestinal inflammation resulting in IBD development. In this thesis, I demonstrate the ability for short-term, oral exposure of PM to initiate an acute intestinal inflammatory response in wild type mice. Next, long term oral PM exposure alters the expression of various Th1/Th2 mediated cytokines microbial composition in WT and IL10-/- mice. Finally, I demonstrate that exposure to a western diet, with or without, PM results in immunosuppression in the colon and significant inflammation in the small intestine of IL10-/- mice.