FOS increased the number of bifidobacteria and decreased the number of Clostridium difficile cluster XI and Clostridium difficile in the DSS-induced mouse model, in addition to improving the symptoms of colitis, inhibiting proinflammatory factors such as IL-6, promoting IL-10, enhancing the intestinal barrier, and improving the balance of Treg/Th17 cells. This evidence concerns the gene IL6 and colitis.