癌症通常被定义为一种衰老疾病。随着衰老，肠道微生物群的组成、多样性和功能特征发生变化，内在和外在因素（例如饮食、药物和慢性健康状况）引发有益共生微生物的减少。如今，肠道微生物群失调被认为是癌症的一个标志。与此同时，衰老还伴随着先天性和适应性免疫的变化（称为免疫衰老），以及慢性低度炎症（称为炎症）。老年人癌症发病率和死亡率的升高与衰老相关的肠道微生物群变化有关，肠道微生物群的变化会引起全身代谢变化，导致免疫失调，从而产生潜在的致瘤作用。肠道微生物群和免疫衰老可能都会影响癌症患者对治疗的反应。深入了解与年龄相关的肠道微生物群和免疫力的变化将有助于了解老年人癌症发生和进展的风险。在这里，我们描述了癌症中肠道微生物群与衰老相关的变化，并回顾了对肠道微生物群靶向干预策略的不断发展的理解。此外，我们总结了免疫衰老的细胞和分子机制及其对癌症影响的知识。最后，我们讨论有关肠道微生物群与免疫衰老之间关系的最新知识，以及对癌症治疗的影响。针对肠道微生物群的干预策略可以减轻炎症并恢复免疫功能，从而为老年患者提供抗肿瘤益处。版权所有 © 2024 Elsevier Ltd. 保留所有权利。

Cancer is generally defined as a disease of aging. With aging, the composition, diversity and functional characteristics of the gut microbiota occur changes, with a decline of beneficial commensal microbes triggered by intrinsic and extrinsic factors (e.g., diet, drugs and chronic health conditions). Nowadays, dysbiosis of the gut microbiota is recognized as a hallmark of cancer. At the same time, aging is accompanied by changes in innate and adaptive immunity, known as immunosenescence, as well as chronic low-grade inflammation, known as inflammaging. The elevated cancer incidence and mortality in the elderly are linked with aging-associated alterations in the gut microbiota that elicit systemic metabolic alterations, leading to immune dysregulation with potentially tumorigenic effects. The gut microbiota and immunosenescence might both affect the response to treatment in cancer patients. In-depth understanding of age-associated alterations in the gut microbiota and immunity will shed light on the risk of cancer development and progression in the elderly. Here, we describe the aging-associated changes of the gut microbiota in cancer, and review the evolving understanding of the gut microbiota-targeted intervention strategies. Furthermore, we summarize the knowledge on the cellular and molecular mechanisms of immunosenescence and its impact on cancer. Finally, we discuss the latest knowledge about the relationships between gut microbiota and immunosenescence, with implications for cancer therapy. Intervention strategies targeting the gut microbiota may attenuate inflammaging and rejuvenate immune function to provide antitumor benefits in elderly patients.Copyright © 2024 Elsevier Ltd. All rights reserved.