PDCD1 and colitis: These effects were shown to alleviate tissue injury in colitis GF mice.[72]Bifidobacterium infantis enhanced the expression of Foxp3 on Tregs, increased the protective colonic programmed cell death ligand 1 (PD‐L1) as well as programmed cell death 1 (PD‐1) levels and promoted the immunosuppressive cytokine (IL‐10 and TGF‐β1) levels in an experimental acute IBD murine model.[73] However, VacA from H. pylori activates peripheral Tregs.