Postmenopausal women with a more diverse population of gut bacteria may be more efficient at breaking down estrogen, a new study suggests. Because estrogen plays a role in causing breast cancer, researchers speculate a healthy bacterial population may lower the risk for cancer.
“The composition and diversity of the intestinal microbiota were associated with patterns of estrogen metabolism that are predictive of the risk of breast cancer in postmenopausal women,”
Estrogen is metabolized in the liver and in other tissues such as the breast, yielding fragments that are excreted in urine or, through bile, into the gut. Gut microbes can degrade these metabolites, allowing them to be reabsorbed into the bloodstream and further recycled in the liver. Dr. Fuhrman and colleagues suggest that women whose gut bacteria more efficiently process estrogen may have a lowered risk for breast cancer.
