Assessing the Efficacy of Ligilactobacillus salivarius CLS0420 and Lacticaseibacillus paracasei CLPC0603 on Vaginal Well-Being in Healthy Women: A Pilot, Randomized, Double-Blind, Placebo-Controlled Trial.

Despite the growing development of probiotics for preventing bacterial vaginosis (BV), their effectiveness in women without BV has not been thoroughly investigated. This pilot, randomized, double-blind, placebo-controlled study aims to assess the impact of orally administered probiotic strains, exhibiting in vitro antimicrobial activity against Gardnerella vaginalis and Candida albicans, on vaginal well-being in women without preexisting health conditions. Healthy women (n = 30, aged 19-50) were enrolled and randomly assigned using simple randomization to receive either probiotic or placebo capsules. After excluding dropouts, 26 participants (15 in the probiotic group, 11 in the placebo group) completed the study, undergoing a 3-week intervention. Vaginal well-being was assessed before and after the intervention using self-assessed health on a 5-point Likert scale, along with analysis of the vaginal microbiome by targeting the 16S-ITS-23S rRNA operon region with the Nanopore sequencing platform and MIrROR database. Notably, only the probiotic group exhibited a significant improvement in self-assessed overall gut and vaginal health following the intervention (p = 0.009 and p = 0.003, respectively). Nevertheless, no significant changes were observed in the vaginal bacterial community following the intervention and confirming the vaginal colonization of orally ingested probiotic strains through metagenome sequencing proved challenging. In summary, these findings suggest that while oral probiotics may improve perceived vaginal well-being, their role in modulating the vaginal microbiome in healthy women remains inconclusive. Additional research with a larger sample size is necessary to substantiate the endorsement of oral probiotic consumption for preventing BV or maintaining vaginal health in healthy women. This study was retrospectively registered at Clinical Research Information Service (CRIS) (KCT0008957, November 15, 2023).