Currently, immunotherapies for CRC such as programmed cell death protein 1 (PD-1) or cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) blockers act mainly through T cells (Makaremi, et al., 2021), while beneficial bacteria act synergistically with immune checkpoint blockade (ICB) by activating immune cells and regulating cytokine secretion. Here, PDCD1 is linked to colorectal carcinoma.