Grant: CIHR Fellowship

The mucosal immune system protects the host from a steady barrage of bacterial, fungal, and viral pathogens that it encounters. Recent advances have identified that proper functioning of the mucosal immune system requires continual stimulation from good bacteria that reside in our gastrointestinal tract. When these good bacteria are absent as a consequence of antibiotic therapy or other disturbances, such as Crohn's disease, the mucosal immune system fails to control pathogens allowing the host to become sick. However, relatively little is known about what changes in mucosal immunity occur as a consequence of a disrupted gut bacterial population, or which bacteria are responsible for these changes. There are many components to the mucosal immune system and it would appear that each bacterium affects the immune system in a different way. We endeavor to identify the changes in mucosal antimicrobial immunity that result from antibiotic-induced microbial disruption, which bacteria are responsible and how these changes impact susceptibility to disease. Understanding the changes in mucosal immunity and how they relate to deviations in gut bacteria will be important in the development of strategies to bolster the mucosal immune system and promote intestinal health. Future applications of this research could include the administration of immune stimulatory molecules in cases where gut bacteria are disrupted so as to protect the host from infection.