Vaginal Lactobacillus Alteration and Vaginal Symptom Relief After Carbon Dioxide Vaginal Laser Therapy in Postmenopausal Women

Abstract

Objective: To assess changes in the prevalence and abundance of vaginal Lactobacillus after fractional micro-ablative carbon dioxide (CO<inf>2</inf>) therapy in postmenopausal women with vulvovaginal atrophy (VVA). Methods: This prospective, single-arm clinical study was conducted in postmenopausal women who underwent treatment with CO<inf>2</inf> laser therapy. Eligible participants were enrolled before the first session of therapy and evaluated at weeks 0, 8, 20, and 32. Vaginal fluid samples were collected using a standardized protocol and processed for Gram staining and expanded quantitative urine culture (EQUC). The level of Lactobacillus was assessed using the Nugent scoring system. The secondary outcomes included the prevalence of Lactobacillus, VVA symptoms, and vaginal pH. The results were analyzed using multilevel mixed-effects linear regression and paired t-tests. Results: Forty-three postmenopausal women with at least one symptom of VVA, with a mean age of 67.3 ± 8.7 years, were recruited. The mean Nugent scores for Lactobacillus morphotypes gradually decreased from 2.84 (95% CI: 2.38–3.29) at baseline to 2.28 (95% CI: 1.79–2.77) at week 8, 2.09 (95% CI: 1.60–2.58) at week 20, and further to 1.84 (95% CI: 1.31–2.35) at week 32 (p < 0.05). The prevalence of Lactobacillus increased from 27.9% (12/43) at baseline to 48.8% (21/43) at week 8, 55.8% (24/43) at week 20, and 58.1% (25/43) at week 32 (p < 0.05). VVA symptom severity and vaginal pH consistently declined from baseline to week 32 (p < 0.05). Conclusion: Fractional CO<inf>2</inf> laser treatment improved the prevalence and level of Lactobacillus after treatment and sustained improvements were observed at 3- and 6-month follow-ups. These positive effects were correlated with improvements in VVA symptoms.