The Role That Food and Bacteria Play in Generating Abdominal Pain

Irritable Bowel Syndrom (IBS) affects up to five percent of Canadians and has proven difficult to treat. Our research will explore how a type of dietary carbohydrate, called FODMAPS, contributes to chronic abdominal pain in irritable bowel syndrome (IBS). FODMAPs, are poorly digested carbohydrates and removing FODMAPs from the diet relieves abdominal pain in approximately half of IBS patients. Unfortunately, FODMAPs are contained in many foods, which makes it challenging for patients to remain on a low FODMAP diet for extended periods. Our proposed research will identify which subtypes of FODMAPs are most responsible for increasing pain and will tease apart whether the pain-causing effects of FODMAPs rely on the gut microbiota or not. To identify which specific type of FODMAP causes pain, IBS patients will adopt a low FODMAP diet and then individual FODMAP subtypes will be added back to their diet while monitoring changes to their pain. Stool samples will be collected from the participants to determine whether the composition of the gut microbiota or the chemicals that it produces are changed when symptoms are improved or exacerbated by manipulating FODMAP availability. In parallel studies, the microbiota of each IBS patient will be grown in specialized conditions to mimic the environment of the gut. These patient microbial communities will be exposed to the same FODMAP manipulations as the patients themselves experience. This will allow us to test whether the changes in gut microbiota composition and the chemicals produced that occur in IBS patients in response to FODMAP manipulations also occur when only the microbiota is exposed to these manipulations. Together, these studies will aim to optimize a dietary therapy for a common chronic pain condition and will provide novel insights into how diet affects the chemicals the gut microbiota produces that contribute to abdominal pain.