In postmenopausal women, estrogen may help protect their urinary tract from infection, according to a new study. The findings help explain why estrogen supplements may ward off recurring infections in postmenopausal women. Up to 60 percent of women develop at least one urinary tract infection, and 25 percent have recurrent urinary tract infections. PetraLthje and colleagues found that estrogen increases the body’s own production of antibiotics called antimicrobial peptides. The researchers gave a group of postmenopausal women a 2-week period of estrogen supplements and analyzed them. They found that estrogen acts on gene expression to help activate the production of certain antimicrobial peptides in the bladder. The hormone also structurally strengthens the urinary tract tissue by binding the gaps between the bladder lining cells together, making it more difficult for bacteria to pass through the bladder lining cells and into the deeper tissue of the bladder wall.