Transfer fecal microbiota from IBD patients to germ-free mice induced colitis through perturbing the balance of Treg/Th2/Th17 [8], and while transplanting fecal flora from healthy people to mice with experimental colitis significantly improved the immune-inflammatory state of mice, reshaping Th1/Th17/Treg balance, downregulating the level of pro-inflammatory cytokines, including TNF-α, IFN-γ, IL-1β and increasing the level of IL-10 [9]. The gene discussed is IFNG; the disease is colitis.