Grant: Master's Award: Canada Graduate Scholarships

Irritable bowel syndrome (IBS), a disorder of the gut that causes abdominal pain and altered bowel habits, affects approximately 10% of Canadians and impairs their quality of life. Multiple factors may cause IBS to develop. These mechanisms are not well understood and thus treatment is often unsuccessful. The gut microbiome, a group of bacteria in the gut, is implicated in the development of IBS. However, it is unclear how the microbiome affects the nerves of the gut to cause abdominal pain. Determining how the microbiome affects abdominal pain will lead to more targeted and effective treatments. Recent studies have found the antibiotic Rifaximin improves symptoms in many IBS patients. While it is not certain how this occurs, Rifaximin may change the gut microbiome, the mediators it produces, or act through a mechanism independent of the microbiome. This project seeks to determine the effects of Rifaximin on the gut microbiome, its mediators, and pain nerves in the gut. We hypothesize that Rifaximin treatment will change the gut microbiota and its mediators to a healthier state, which will improve abdominal pain. We will examine the effect of mediators produced by gut bacteria from IBS patients on gut pain nerves and whether this changes after Rifaximin treatment. We will also explore if there is a relationship between the bacterias effect on gut pain nerves and the patients abdominal pain. This research will help us understand how Rifaximin improves abdominal pain and in which IBS patients Rifaximin is most effective. Determining Rifaximins mechanism of action will allow researchers to develop more effective, targeted microbiome treatments beyond a non-specific antibiotic.