L. rhamnosus activates colonic CD8+T to reduce CRC burden L. acidophilus decreased cellular proliferation and carcinogenesis. Stimulated the secretion of anti-inflammatory cytokines and upregulation of Treg and Th2 response-related gene expression. L. plantarum reduced the tumor growth and increased PD-L1 blocking antibody against cancers. Here, CD8A is linked to neoplasm.