In prostate cancer, dysbiosis involving androgen-producing microbes are able to degrade androgen deprivation therapy.255,256 In ER positive breast cancers, differences were noted in the gut microbial composition of good responders to adjuvant aromatase inhibitor therapy compared to poor responders, with poor responders demonstrating higher gut microbiome diversity and elevated levels of Veillonella. This evidence concerns the gene CYP19A1 and breast carcinoma.