Vaginal microbiota transplantation for treatment of vaginal dysbiosis without the use of antibiotics: a double-blind, randomised controlled trial in women with vaginal dysbiosis

BACKGROUND: A vaginal microbiota dominated by Lactobacillus species is associated with reduced risk of infection and adverse reproductive outcomes. Effective interventions to restore healthy microbiota remain scarce. In this study, we aimed to assess the efficacy of vaginal microbiota transplants (VMTs) without antibiotic pretreatment in achieving conversion to a Lactobacillus-dominated vaginal microbiome. METHODS: This single-centre, double-blind, randomised controlled trial was done at Copenhagen University Hospital (Hvidovre, Denmark) between June 1, 2021, and March 1, 2023. We enrolled women aged 18-40 years with asymptomatic or symptomatic molecular vaginal dysbiosis (20% relative abundance of Gardnerella spp, Fannyhessea vaginae, and Prevotella spp) who were otherwise healthy premenopausal women and not pregnant as recipients; donors were healthy women aged 18-40 years with a Lactobacillus-dominated vaginal microbiota (>80%) and a low (