For examples, mice receiving anti-CTLA-4 with superimposed DSS colitis also receiving a cocktail of Bifidobacterium bifidum, Bifidobacterium longum, Bifidobacterium lactis, and Bifidobacterium breve show less colitis compared to no bacteria controls without impacting anti-tumor efficacy against B16F10 melanoma.138 Tregs are required for this protective effect as it is abrogated in Treg-depleted mice. Here, CTLA4 is linked to colitis.