CD8A and neoplasm: With the discovery of an increasing number of disorders linked to an imbalance in the gut microbiota, a new era of intestinal probiotics and microbial therapy is fast approaching.25,26 The gut microbiota and their metabolites exert a significant impact on inflammatory signaling pathways, which can directly or indirectly influence the host immune system.27 Early studies demonstrated that the gut microbiota can enhance anti-tumor ability by stimulating CD8+ T cells,28 Th1 cells29 and tumor-associated macrophages30 in the TME.