The Ileal Microbiome Shapes the Immunosurveillance and Prognosis of Proximal Colon Cancer

The prognosis of colon cancer is dictated by tumor infiltrating lymphocytes, in particular follicular T helper cells (FTH), as well as by the efficacy of chemotherapy-induced anticancer immune responses. While distinct gut microbes may promote colorectal carcinogenesis, the beneficial role of commensals in tumor immunosurveillance remains unclear. Here, we show that the ileal microbiota determines the balance between tolerogenic versus immunogenic activity of dying intestinal epithelial cells.