The role of human microbiota in breast cancer pathogenesis and treatment.

The human microbiota contributes to breast cancer pathogenesis and treatment response through interactions involving the oral, gut, and breast microbial niches. (Left) Multi-site dysbiosis is characterized by altered microbial composition and abundance across different anatomical sites. (Middle) Microbial components and metabolites influence tumor progression and the tumor microenvironment through mechanisms including immune, metabolic, and inflammatory regulation. (Right) The microbiota and their metabolites further affect therapeutic efficacy and toxicity in immunotherapy, chemotherapy, endocrine therapy, and human epidermal growth factor receptor 2 (HER2)-targeted therapy, highlighting the translational potential of microbiota-targeted strategies in breast cancer.