Menopausal Changes in the Microbiome—A Review Focused on the Genitourinary Microbiome Original paper

What was reviewed?

This article presents a comprehensive review of the effects of menopause on the female microbiome, with a specific focus on the genitourinary microbiome, encompassing the gut, vaginal, and urinary microbial communities. The review synthesizes evidence from recent clinical studies, observational data, and randomized controlled trials to elucidate the interplay between hormonal changes during menopause and alterations in these microbiomes. It particularly emphasizes the urinary microbiome, a relatively underexplored area, and its potential associations with common postmenopausal conditions such as genitourinary syndrome of menopause (GSM), recurrent urinary tract infections (rUTI), and lower urinary tract symptoms.

Who was reviewed?

The review includes data and findings from studies involving premenopausal and postmenopausal women of varying ages and ethnic backgrounds. The populations studied encompass healthy women, women with menopause-related symptoms, and those with urinary tract disorders, including rUTI, overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), and GSM. Subjects in the included studies range from healthy controls to those receiving hormone therapy, probiotics, or other microbiome-targeted interventions. The review draws on both cross-sectional and longitudinal analyses, as well as clinical trials from diverse geographic locations.

Most important findings

Menopause induces significant shifts in the gut, vaginal, and urinary microbiomes, largely driven by estrogen decline. In the gut, although phylum-level changes are inconsistent, postmenopausal women show increased Firmicutes/Bacteroidetes ratios, higher abundance of genera like Lachnospira, Roseburia, and Bilophila, and changes in short-chain fatty acid (SCFA) profiles. The vaginal microbiome becomes less dominated by Lactobacillus species post-menopause, with increased prevalence of anaerobes such as Gardnerella, Prevotella, Atopobium, and Finegoldia. Notably, hormone therapy and probiotic interventions can partially restore Lactobacillus dominance and lower vaginal pH—benefits linked to symptom improvement.

The urinary microbiome also undergoes notable changes: postmenopausal women exhibit increased alpha diversity and reduced Lactobacillus abundance, with more Gardnerella, Prevotella, and Mobiluncus. The review highlights a substantial overlap between vaginal and urinary microbiomes, underscoring the interconnectedness of these sites. Both local estrogen therapy and specific probiotic administration have shown promise in restoring a healthier microbiome and reducing infection risk.

Key implications

Understanding menopause-related microbiome alterations is critical for developing targeted strategies to manage genitourinary health in postmenopausal women. The decline in Lactobacillus and increased diversity in the urinary and vaginal niches underpin higher rates of GSM, rUTI, and urinary symptoms. Interventions such as hormone therapy and probiotics can beneficially modulate the microbiome, alleviate symptoms, and lower infection risk. Clinicians should recognize the interdependence of the gut, vaginal, and urinary microbiomes in postmenopausal women and consider microbiome-focused therapies as adjuncts to conventional management. Further research into the urinary microbiome’s role in disease and its manipulation remains an urgent clinical need.