Effect of Reproductive Tract Microbiota on Vaginal Fibroblasts in Pelvic Organ Prolapse.

Importance: The effect of vaginal bacteria on wound healing is an evolving area of study. Bacterial vaginosis (BV), characterized by an overgrowth of anaerobic bacteria, is linked to increased surgical site infections after pelvic surgery. While BV-associated microbes are known to impair epithelial repair, their effects on fibroblasts, which are crucial for wound healing and prolapse recurrence after pelvic organ prolapsesurgery, are unclear. Understanding these interactions can deepen knowledge of vaginal tissue remodeling.

Objective: This study aimed to compare the effects of BV-associated bacteria and commensal lactobacilli on fibroblast cell number and function, using estradiol as a positive control.

Study design: Fibroblasts were isolated from vaginal wall biopsies of 9 participants undergoing pelvic organ prolapse surgery. Cells were co-cultured in media alone, media containing estradiol, and media with cell-free supernatants (CFS) from Lactobacillus crispatus, Lactobacillus iners, and Gardnerella vaginalis. Intact cell number was assessed using an lactate dehydrogenase assay at 0, 24, and 48 hours, and ELISA measured IL-6, type I collagen, and fibronectin levels.

Results: Fibroblasts exposed to G vaginalis CFS showed significantly reduced cell number and type I collagen production, with increased fibronectin levels. Cell-free supernatants from L crispatus and L iners did not affect fibroblast proliferation. While some donor cells showed an increase in cell number with estradiol, the change was inconsistent and not statistically significant. IL-6 levels showed a nonsignificant increase with any bacterial CFS.

Conclusions: G vaginalis significantly impairs fibroblast cell number and type I collagen production, suggesting BV-associated microbes may alter fibroblast function, emphasizing the vaginal microbiome's role in outcomes.