Research Advances in the Association between Gut Microbiota and HER2-Positive Breast Cancer

人表皮生长因子受体2 (HER2)阳性乳腺癌作为侵袭性强、预后较差的乳腺癌亚型，其治疗耐药性与复发转移问题亟待突破。近年来，肠道菌群与肿瘤微环境的交互作用成为研究热点，其通过调控药物代谢、重塑免疫应答及调节炎症微环境等机制，显著影响HER2阳性乳腺癌的发生发展与治疗反应。本文将从肠道菌群与HER2阳性乳腺癌的关系、肠道菌群与HER2阳性乳腺癌的化学治疗、肠道菌群与抗HER2靶向治疗、肠道菌群在HER2阳性乳腺癌中的潜在应用等方面进行文献综述。Human epidermal growth factor receptor 2 (HER2)-positive breast cancer, an aggressive subtype with poor prognosis, presents a critical challenge due to therapeutic resistance, recurrence, and metastasis. In recent years, the interaction between the gut microbiota and the tumor microenvironment has emerged as a significant area of research. The gut microbiota significantly influences the development, progression, and treatment response of HER2-positive breast cancer through mechanisms such as modulating drug metabolism, reshaping immune responses, and regulating the inflammatory microenvironment. This review aims to provide an overview of the relationship between the gut microbiota and HER2-positive breast cancer, its impact on chemotherapy, its role in anti-HER2 targeted therapy, and the potential applications of gut microbiota in HER2-positive breast cancer.