近年来，我们对微生物群如何通过调节肿瘤微环境和全身免疫系统来影响癌症治疗反应和失败之间的平衡的理解迅速发展。针对癌症患者的微生物群干预措施是一个深入研究的领域。令人鼓舞的是，I-II 期临床试验表明，粪便微生物群移植等干预措施可以克服​​黑色素瘤患者对免疫检查点阻断的抵抗力，改善初治患者的治疗结果，并减少治疗引起的免疫毒性。在这里，我们综合了证据，表明微生物群是癌症治疗效果和治疗引起的急性和长期毒性的重要决定因素，并讨论了所涉及的复杂且相互关联的机制。我们还评估了微生物群靶向干预措施（包括细菌工程和噬菌体疗法）的潜力，以优化癌症治疗的反应和恢复。© 2023。Springer Nature Limited。

Our understanding of how the microbiota affects the balance between response to and failure of cancer treatment by modulating the tumour microenvironment and systemic immune system has advanced rapidly in recent years. Microbiota-targeting interventions in patients with cancer are an area of intensive investigation. Promisingly, phase I-II clinical trials have shown that interventions such as faecal microbiota transplantation can overcome resistance to immune checkpoint blockade in patients with melanoma, improve therapeutic outcomes in treatment-naive patients and reduce therapy-induced immunotoxicities. Here, we synthesize the evidence showing that the microbiota is an important determinant of both cancer treatment efficacy and treatment-induced acute and long-term toxicity, and we discuss the complex and inter-related mechanisms involved. We also assess the potential of microbiota-targeting interventions, including bacterial engineering and phage therapy, to optimize the response to and recovery from cancer therapy.© 2023. Springer Nature Limited.