MPO and colitis: In line with previous findings13,19, disease activity index (DAI; DSS main effect: F(1, 28) = 195.6; p < 0.001)) and the colonic content of myeloperoxidase (MPO), a marker of colonic leukocyte infiltration, was significantly increased in DSS-treated mice (DSS main effect: F (1, 28) = 95.5; p < 0.001), which confirms the presence of colitis in response to DSS.