免疫检查点抑制剂对晚期恶性肿瘤患者的治疗领域产生了显著的革命。最近的有力证据显示肠道微生物群对人类免疫系统具有重要影响。由于肠道微生物群、宿主免疫力和癌症之间的复杂联系，肠道微生物群的变异可能会影响免疫检查点抑制剂的疗效。事实上，已有一些细菌种类被报道为免疫检查点抑制剂治疗患者的癌症预后的预测因子。尽管免疫检查点抑制剂目前被证明是一种有效的抗肿瘤治疗方法，但它们可能引发一种称为免疫相关不良事件的明显毒性。免疫相关结肠炎是免疫检查点抑制剂常见的毒性之一，并且在严重或难治病例中可能妨碍癌症治疗。通过粪菌移植或益生菌的使用来调节肠道微生物群已被提议作为增强抗肿瘤效果和降低免疫相关结肠炎风险的一种方法。在这里，我们回顾了肠道微生物群在免疫检查点抑制剂治疗中的作用以及随之而来的免疫相关结肠炎，为更好的抗癌治疗提供了新的见解。

Immune checkpoint inhibitors have dramatically revolutionized the therapeutic landscape for patients with advanced malignancies. Recently, convincing evidence has shown meaningful influence of gut microbiome on human immune system. With the complex link between gut microbiome, host immunity and cancer, the variations in the gut microbiota may influence the efficacy of immune checkpoint inhibitors. Indeed, some bacterial species have been reported to be predictive for cancer outcome in patients treated with immune checkpoint inhibitors. Although immune checkpoint inhibitors are currently proven to be an effective anti-tumor treatment, they can induce a distinct form of toxicity, termed immune-related adverse events. Immune-related colitis is one of the common toxicities from immune checkpoint inhibitors, and it might preclude the cancer therapy in severe or refractory cases. The manipulation of gut microbiome by fecal microbiota transplantation or probiotics administration has been suggested as one of the methods to enhance anti-tumor effects and decrease the risk of immune-related colitis. Here we review the role of gut microbiome on immune checkpoint inhibitor therapy and consequent immune-related colitis to provide a new insight for better anti-cancer therapy.