Treg depletion in Foxp3-DTR mice reversed the differences observed between Veh-treated (WT-Veh) and Dub-colonized WT mice (WT-Dub) in disease phenotypes (Fig. 3d and Supplementary Fig. 4j), histological evaluation (Fig. 3e, f) and proinflammatory cytokine expression (Supplementary Fig. 4k), indicating that Foxp3+ Tregs are essential for the Dub protective effect against DSS-induced colitis. This evidence concerns the gene FOXP3 and colitis.