Dr. Zhao's long-term research interest and area of expertise are the host-microbiota relationship, especially the dynamic interactions between the host immune system and mucus-associated Lachnospiraceae bacteria and their impact on the pathogenesis of Crohn’s disease. This includes, but is not limited to, the role of microbiota-specific CD4+ T cell and B cell responses in intestinal inflammation, bacterial flagellin-directed reactivities by innate Toll-like receptors in health and disease, and therapeutic interventions for inflammatory bowel diseases via targeting the host immune system.