Vaginal Microbiota Transplantation (VMT) for treatment of vaginal dysbiosis without the use of antibiotics – A Double-Blinded Randomized Controlled Trial in healthy women with vaginal dysbiosis

Here we describe the first double-blinded, randomized, placebo-controlled trial (RCT) on vaginal microbiota transplantation (VMT) without antibiotics in women with both symptomatic and asymptomatic vaginal dysbiosis. Forty-nine women were randomly assigned to VMT or placebo. The trial did not show a significant conversion to our predefined Lactobacillus -dominated microbiome. However, in participants not initially converting, antiseptic pretreatment before a subsequent VMT led to a 50% conversion rate, associated with an anti-inflammatory shift in gene expression. Metagenomic sequencing and strain-level genetic analysis confirmed donor engraftment in five of 10 women who showed microbiome conversion. Extensive exploration of the microbiome, immune response and metadata revealed differences in baseline energy metabolism in participants who later experienced donor engraftment. Treatments for vaginal dysbiosis are urgently needed and given that VMT can lead to donor engraftment and change the vaginal immune profile, future studies should focus on optimizing this treatment for various women’s health diseases.