Phase 1 trial shows vaginal L. crispatus biotherapeutics colonize in bacterial vaginosis patients

This phase 1 randomized trial evaluated the safety and colonization of vaginally delivered live biotherapeutic products (LBPs) containing multiple Lactobacillus crispatus strains in 71 participants with bacterial vaginosis across the United States and South Africa. Participants received the LBPs for either 3 or 7 days, compared against a placebo, with follow-up for 12 weeks. The primary outcome was not reported; secondary outcomes focused on strain detection, colonization duration, and safety.

Regarding colonization, LBP strains were detected by metagenomics in 66.1% (47/71) of participants in the active arms. Among those initially colonized, persistence of colonization at the 12-week follow-up was observed in nearly half (49%, 23/47). Participants were most often colonized by one of three component strains, and no geographic differences in strain colonization patterns were observed. No serious adverse events were reported, and the LBPs were described as safe, acceptable, and well tolerated.

Key limitations include the early-phase design, small sample size, and lack of reported primary efficacy outcomes, p-values, or confidence intervals. The study did not report on discontinuations, funding, or conflicts of interest. The practice relevance is restrained to providing a foundation for future development of interventions aimed at optimizing the vaginal microbiome; clinical application for treating bacterial vaginosis is not yet supported.