Clinical Connections Between the Microbiota and Breast Cancer (Onset, Progression and Management)

The microbiota is recognized as one of the major players in human malignancies, including breast cancer (BC). Beside the role that microbiota plays in immune modulation and metabolism, affecting chronic inflammation and other drivers of cancer, specific gut bacterial genes (estrobolome) influence the sexual hormonal balance and subsequently may affect the onset, progression and treatment of hormonal dependent cancers. Moreover, specific microbes display unique features in a number of extraintestinal body sites, including the breast tissue, which can result in an increased risk of cancer, even though a clear link between microbiota composition and BC genesis is still to be confirmed. Based on these premises, in a new “oncobiotic” perspective, the individual microbiome is becoming a predictive tool and a potential target, in order to better tailor antitumoral treatments as well as to lower their toxicity.