Dr. Brennan [Dennis and Marsha Dammerman Fellow] studies colorectal cancer and its connection to the human microbiota--the collection of bacteria and other microbes found associated with the body in both healthy and disease states. One such organism is Fusobacterium nucleatum, a bacterium that is naturally found in the mouths and gastrointestinal tract of healthy individuals. This bacterium is also observed in high abundance in some colorectal tumors relative to healthy colon tissue within the same person; experimental studies have demonstrated that this bacterium actively promotes tumor development. Her research will investigate how Fusobacterium signals to both the immune system and other microbes in the developing tumor environment, offering insight into the potential utility of Fusobacterium as a diagnostic or therapeutic target for colorectal cancer.