Effects of pelvic organ prolapse ring pessary therapy on intravaginal microbial flora

Introduction and hypothesis: The purpose of this paper is to report our evaluation of changes in intravaginal microbial flora after ring pessary therapy for pelvic organ prolapse (POP) using conventional and our clone library method. Methods: Thirteen patients with POP who were fitted with a ring pessary participated in this longitudinal study that incorporates data from before and 1 month after beginning ring pessary therapy. Changes in intravaginal microbial flora were evaluated by conventional methods, i.e., vaginal pH, lactobacillary grade (LAC grade), Nugent score, and culture-based bacterial detection methods. In addition, we performed our clone library method using 16S ribosomal RNA (rRNA) sequencing of vaginal fluid. Results: Conventional methods revealed that most patients had abnormal intravaginal microbial flora. Mean numbers of detected bacterial species by the culture-based and our clone library method were 3.1 (1–6) and 11.8 (1–25), respectively. Our clone library method showed that Lactobacillus spp. increased in four and decreased in two cases after ring pessary therapy but reappeared after therapy in two cases; no Lactobacillus spp. were detected in five cases. Conclusions: Our study showed that ring pessary therapy did not always disturb intravaginal microbial flora, especially for patients with Lactobacillus spp. prior to ring pessary insertion. Anaerobic circumstances in the vagina after therapy seem to have induced the growth of anaerobic bacteria.