Grant: DRA : Canada Graduate Research Scholarship - Doctoral Program (CGRS D)

The human gut is home to trillions of microbes that play a central role in health and disease. These microbes must adapt to constant stress, including exposure to bile acids, which aid in fat digestion but can also act as powerful antimicrobial agents. In inflammatory bowel disease (IBD), bile acid balance is disrupted, leading to changes in microbial communities that can worsen disease. Recent work has shown that Enterocloster bolteae, a common gut bacterium associated with IBD, forms robust biofilms-specialized and structured bacterial communities-in response to bile acids. Biofilms may allow E. bolteae to survive stress and compete with other microbes within the gut, but the underlying mechanisms and ecological consequences are poorly understood. This project aims to identify the genes that enable E. bolteae to form biofilms under bile stress and to determine whether this response enhances its ability to colonize and survive in the gut. Genetic tools, bioinformatics, and high-throughput assays will be used to uncover key biofilm genes, while germ-free (microbe-less) mouse models will test whether biofilm formation provides a competitive advantage in bile-rich environments, including those characteristic of IBD. Overall, the findings from this study will clarify how a core gut microbe adapts to bile acid stress and will advance our understanding of how microbial stress responses shape gut ecosystems in health and disease.