MUC2 and infection: It was proved in the mouse model that animals fed a fiber-free diet presented decreased thickness of mucus layer that increased their susceptibility towards infection with C. rodentium and that effect was similar to the MUC2−/− mouse model, where the colon inner mucus layer was thinner, the proximity of gut microbiota to the epithelial cells was smaller, and as a consequence, the development of spontaneous colitis was observed [31,37,144,169].