UVMR detected a higher abundance of genus Sellimonas predicted a higher risk of estrogen receptor‐positive breast cancer (OR = 1.09, 95% CI 1.05–1.14, p = 2.01 × 10−5), and a higher abundance of class Alphaproteobacteria was associated with a lower risk of prostate cancer (OR = 0.84, 95% CI 0.75–0.93, p = 1.11 × 10−3). This evidence concerns the gene ESR1 and breast cancer.