Vaginal microbiota impacts of a Lactobacillus crispatus live biotherapeutic and predictors of colonization in randomized controlled trial

Clinical Snapshot

Key Findings

• P Value: p < 0.005

• Effect Size: Benefit ratio: 3.31

• Primary Outcome: L. crispatus-dominant microbiota achieved in 30% of LACTIN-V recipients vs 9% of placebo recipients by week 12

• Nnt Or Sensitivity: Number needed to treat: approximately 5 (based on 21% absolute risk reduction)

• Confidence Interval: Not reported in abstract

Clinical Application

Requires specialized live biotherapeutic manufacturing and cold-chain distribution; may need TGA approval as novel therapeutic Would require TGA evaluation as prescription medicine; potential PBS listing consideration given BV recurrence burden; aligns with RACGP guidelines emphasizing evidence-based BV management Women with recurrent bacterial vaginosis following standard antibiotic treatment, particularly those with specific microbiota and inflammatory profiles

Abstract

Bacterial vaginosis (BV) affects >25% of women worldwide and often recurs after standard-of-care metronidazole (MTZ) treatment. LACTIN-V, a live biotherapeutic product (LBP) containing Lactobacillus crispatus strain CTV-05, significantly reduced recurrent BV in a phase 2b clinical trial, but efficacy was incomplete. Here, we characterize microbiota and immune effects using multi-omics and define correlates of treatment success. By week 12, an L. crispatus-dominant microbiota was achieved in 30% of LBP recipients compared with 9% of placebo recipients (benefit ratio: 3.31; p < 0.005). This is primarily due to CTV-05, but native L. crispatus strains are also present and increase over time. Inflammatory cytokines decrease in both arms after MTZ but return to baseline in placebo recipients. Successful L. crispatus colonization is associated with pre-MTZ microbiota, baseline inflammatory profiles, post-MTZ bacterial load, and clinical and behavioral variables. These findings elucidate LBP microbiota effects and identify predictors of treatment success, informing improved intervention strategies to advance women's health.

References

1. 1.Bloom, S. M., Symul, L., Elsherbini, J., Xu, J., Hussain, S., Shih, J., Sango, A., Mitchell, C. M., Hemmerling, A., Parks, T. P., Kannan, A., Hussain, F. A., Cohen, C. R., Holmes, S. P., & Kwon, D. S. (2026). Vaginal microbiota impacts of a Lactobacillus crispatus live biotherapeutic and predictors of colonization in randomized controlled trial. Cell Host & Microbe. https://doi.org/10.1016/j.chom.2026.03.003