The gastrointestinal tract (GIT) is the largest immune organ and maintains systemic immune homeostasis in the presence of bacterial challenge. Immune elimination and immune escape are hallmarks of cancer, both of which can be partly bacteria dependent in shaping immunity by mediating host immunomodulation. In addition, host immunity regulates the microbiome by altering bacteria-associated signaling to influence tumor surveillance. Cancer immunotherapy, including immune checkpoint blockade (ICB), appears to have heterogeneous therapeutic effects in different individuals, partially attributed to the microbiota. Thus, the microbiome signature can predict clinical outcomes, prognosis, and immunotherapy responses. In this review, we summarize the intricate crosstalk among the gut microbiome, cancer immune response, and immunotherapy. Interactive modulation of the host microbiota provides new therapeutic strategies to promote anticancer therapy efficacy and/or reduce toxicity.

胃肠道 (GIT) 是最大的免疫器官，在存在细菌挑战的情况下维持全身免疫稳态。免疫消除和免疫逃逸是癌症的标志，这两者在通过介导宿主免疫调节来塑造免疫方面可能部分依赖于细菌。此外，宿主免疫通过改变细菌相关信号来影响肿瘤监测来调节微生物组。癌症免疫疗法，包括免疫检查点阻断 (ICB)，似乎在不同个体中具有不同的治疗效果，部分归因于微生物群。因此，微生物组特征可以预测临床结果、预后和免疫治疗反应。在这篇综述中，我们总结了肠道微生物组、癌症免疫反应和免疫治疗之间错综复杂的相互作用。