Synthetic Bacterial Consortia Transplantation Attenuates Vaginal Inflammation and Modulates the Immune Response in a Mouse Model of Gardnerella vaginalis-Induced Bacterial Vaginosis

Abstract

Bacterial vaginosis (BV) disrupts the vaginal microbiota, leading to health risks. Antibiotics often fail to prevent recurrence. This study examines synthetic bacterial consortia transplantation (SBCT) as a safer, more controlled treatment alternative to restore healthy vaginal flora and immune response, showing promise against BV. This study aimed to evaluate the efficacy of SBCT and compare it with VMT in a mouse model of Gardnerella vaginalis-induced BV. A murine model of G. vaginalis-induced BV was established, and mice were treated with SBCT, VMT, or saline. Histopathological changes, inflammatory cytokine levels, pro-inflammatory biomarker expression, helper T cell transcription factor expression, and vaginal microbiota composition were assessed. SBCT and VMT effectively suppressed G. vaginalis growth, reduced inflammation, and restored vaginal microbiota diversity. Both treatments attenuated epithelial damage, downregulated pro-inflammatory cytokines (IL-1β and IL-8), and upregulated the anti-inflammatory cytokine IL-10. SBCT and VMT also inhibited NF-κB activation, suppressed IL-17 expression, and enhanced Foxp3 expression in vaginal tissues. SBCT is a promising therapeutic approach for treating BV, as it effectively modulates the immune response and restores vaginal microbiota diversity in a mouse model of G. vaginalis-induced BV.