Microbial Metabolites as Potential Modulators of Tumor Microenvironment in Breast Cancer

The tumor microenvironment (TME) plays a pivotal role in the initiation, progression, and metastasis of breast cancer. Recent advances in microbiome research have unveiled the intricate interactions between microbial communities and host physiology, suggesting that microbial-derived metabolites can significantly influence cancer biology. These small molecules, including short-chain fatty acids (SCFAs), secondary bile acids, polyamines, and tryptophan-derived indoles, serve as biochemical messengers that modulate inflammation, immune responses, angiogenesis, and epithelial-mesenchymal transition (EMT) within the TME. Accumulating evidence indicates that specific microbial signatures are associated with distinct breast cancer subtypes, and their metabolic outputs may either promote or suppress tumorigenesis.