MUC2 and colitis: Immunohistochemistry (IHC) staining of Mucin 2 (Muc2), which is a key component of the mucous layer and plays a role in the protection of the gut barrier [19] also showed that C. sinensis infection in the DSS-induced colitis increased the expression of Muc2 in the cells that are positive by PAS-Alcian Blue in the intestine, compared with non-infected mice with DSS treatment (Fig. 2b, P < 0.05).