CD4 and colitis: Administering these bacterial strains in the DSS-induced colitis model showed that while L. rhamnosus had little effect on disease severity, B. breve ameliorated DSS-induced colitis, increased Treg- and Th2-associated responses and locally reduced CD4+RORγt+Foxp3- T cells while simultaneously increasing CD4+ RORγt-Foxp3+ T cells.