Different effects of CO₂ laser and estrogen treatment on vaginal mucosa microbiota and function in genitourinary syndrome of menopause patients

Aim: To characterize the effects of CO₂ laser treatment and estrogen treatment on vaginal microbiota in patients with genitourinary syndrome of menopause (GSM).

Methods: Sixty-four patients with genitourinary syndrome were divided into the estrogen group, the CO₂ laser group, and the control group. The control group did not receive any treatment. Vaginal mucosa was collected after 3 and 12 months of treatment. The former was used for 16S rRNA sequencing, and the latter was used for pathological evaluation. Vaginal health and voiding function were assessed using the vaginal health index (VHI) scale and the UDI-6 scale at 3 and 12 months after treatment.

Results: The results showed that both treatments reduced alpha diversity in the vaginal flora. Additionally, the abundance of 65 genera differed significantly between the treatment and control groups, with an increase in potentially beneficial bacteria such as Lactobacillus, IheB3_7, Mycoplasma urealyticum, and Streptococcus. In addition, the VHI and UDI-6 scores improved in both treatment groups compared to the control group after 3 months. Whereas VHI and UDI-6 scores were close to baseline in the estrogen group, and remained significantly improved in the CO₂ laser group after 12 months. Pathological results showed that both methods improved the vaginal health status of patients with GSM after 12 months of treatment. However, the CO₂ group exhibited a more significant increase in type III collagen.

Conclusions: Both CO₂ laser and estrogen therapies can regulate the vaginal flora imbalance of GSM and improve the corresponding symptoms. However, the long-term efficacy of CO₂ laser therapy is superior compared to estrogen therapy.