Gut, vaginal, and urinary microbiome alterations in women with genitourinary syndrome of menopause: A systematic review.

BACKGROUND AND

OBJECTIVE

Genitourinary syndrome of menopause (GSM) is a chronic condition caused by estrogen deficiency, encompassing vaginal dryness, dyspareunia, and urinary symptoms. Alterations in the vaginal, urinary, and gut microbiome may contribute to GSM pathophysiology. We synthesize the evidence on microbiome composition and diversity across these compartments in postmenopausal women with GSM.

METHODS

PubMed, Scopus, and Embase were searched from inception to April 2026 for studies assessing the microbiome in postmenopausal women with GSM using 16S rRNA gene sequencing, metagenomics, or culture-based methods.

RESULTS

Twenty-three studies (5027 participants) were included: 15 examined the vaginal microbiome, seven the urinary microbiome, and one the gut microbiome. Postmenopausal women consistently showed reduced Lactobacillus abundance and increased microbial diversity. Estrogen therapy partially restored Lactobacillus dominance but did not uniformly improve symptoms. In the SWAN cohort (n = 1320), sexual pain was the only GSM symptom independently associated with a specific community state type (CST IV-C1; OR 2.26, 95% CI 1.20-4.23). Specific species showed associations with distinct symptom domains: Prevotella with urinary symptoms, Finegoldia magna with recurrent urinary tract infection, and Streptococcus with sexual pain. Parallel Lactobacillus depletion and pathobiont enrichment across all three compartments pointed toward a vaginal-bladder-gut axis, potentially linked through estrobolome disruption and bacterial translocation.

CONCLUSION

The postmenopausal genitourinary microbiome is characterized by Lactobacillus depletion and increased diversity, but microbiome restoration alone does not predict symptom resolution. The shared microbial alterations across compartments suggest a vaginal-bladder-gut axis that may collectively drive GSM, but this requires multi-compartment longitudinal validation. PROSPERO registration: CRD420261335478.