Vaginal estrogen links to premenopausal-like bladder microbes

In an observational study released as a preprint, researchers examined the urinary bladder microenvironments of premenopausal women, postmenopausal women, and postmenopausal women using vaginal estrogen. The team used sequencing and metabolomic data to assess shifts across menopause. While urinary microbiomes differed between premenopausal and postmenopausal women, at least six weeks of vaginal estrogen was associated with higher urinary lactobacilli and fewer opportunistic pathogens. This profile more closely approximated the premenopausal state. Changes in urinary Lactobacillus species correlated with vaginal pH, and matching species were typically identified across both vaginal and bladder microbiomes. Urinary metabolites also differed between the three groups, although most distinguishing metabolites remain unannotated. Among shared metabolites, Lactobacillus iners showed consistently inverse relationships compared to Lactobacillus crispatus, Lactobacillus gasseri, or Lactobacillus jensenii.