The Impact of Microbiome on Breast Cancer and Regulatory Strategies.

Breast cancer, the most prevalent malignant tumor in women, is closely linked to the human microbiota. The microbiome participates throughout breast cancer pathogenesis, including its occurrence, progression, response to anti-tumor therapies, and treatment-related complications. This review examines the central hypothesis that microbiome-driven inflammatory and immune mechanisms shape breast cancer progression through two key pathways: systemic immune-inflammatory regulation and local tumor microenvironment remodeling. Furthermore, microorganisms and their metabolites modulate systemic treatments by interfering with drug metabolism and altering systemic or local immune-inflammatory environments. Targeting the microbiota represents a promising strategy for enhancing anticancer efficacy and reducing treatment-related complications. This review aims to advance the understanding of the etiology and disease progression of breast cancer from the perspective of microbial-regulated inflammation and immunity, offering new insights for its prevention and treatment.