FOXP3 and inflammatory bowel disease: Our research group previously found that Bifidobacterium infantis (B. infantis) can promote the expression of Foxp3 in Tregs by upregulating PD-L1, thereby promoting cell proliferation and improving the anti-inflammatory function of these cells, so as to inhibit the intestinal immune response, and this provided new clues for the immunosuppressive treatment of IBD (7).