Effect of vaginal laser therapy for gynecologic patients on vaginal microbiota: a prospective cohort study

We aimed to evaluate vaginal microbiota distribution before and after laser therapy for gynecologic patients with stress urinary incontinence (SUI) and genitourinary syndrome of menopause (GSM).

Fifty patients undergoing CO₂ vaginal laser treatment were enrolled. The primary outcomes included UDI-6, IIQ-7, OABSS, and VSQ-21 scores before and at 1, 2, and 3 months after laser treatment, as well as vaginal microbiota diversity before and 1 month after laser treatment.

UDI-6, IIQ-7, OABSS, and VSQ-21 scores for patients who received CO₂ laser therapy all showed significant improvement at 1, 2, and 3 months post-treatment. Vaginal pH showed no significant change after laser treatment. Overall, 91 samples were successfully sequenced. Alpha diversity showed significant differences in the menopause (p = 0.034) and GSM (p = 0.004) groups, but not between pre- and post-laser treatment samples. PERMANOVA revealed differences in microbiota composition associated with menopause (p = 0.009) and SUI (p = 0.026). Beta diversity analysis showed no significant treatment effect due to high inter-individual variability. The six most abundant vaginal bacterial genera included Lactobacillus (40.4%), Gardnerella (8.4%), Prevotella (7.4%), Escherichia-Shigella (6.0%), Streptococcus (5.6%), and Bifidobacterium (3.2%), with changes in Lactobacillus dominance observed in some patients post-treatment. Network analysis revealed that Gardnerella disappeared post-laser treatment, as Lactobacillus increased in abundance.

CO₂ laser treatment may improve SUI and GSM, and be associated with shifts in microbiota.