Breakthrough Trial Uses Beneficial Bacteria To Tackle Bacterial Vaginosis Beyond Antibiotics

Published in the scientific journal Cell Host & Microbe, the aim of the Vibrant (Vaginal Live Biotherapeutic Randomised Trial) study was to test a new approach to BV treatment using beneficial vaginal bacteria as a live biotherapeutic product. These products contain multiple strains of Lactobacillus crispatus, a bacterium commonly found in healthy vaginal microbiomes.

BV is one of the most common conditions affecting women. It occurs when the healthy bacteria that normally protect the vagina are replaced by other microbes. BV is associated with significant genital inflammation, which can increase a woman’s risk of acquiring sexually transmitted infections, including HIV. It is also linked to adverse pregnancy outcomes.

Although antibiotics can treat BV in the short term, the condition frequently returns because the protective bacteria that maintain a healthy vaginal environment often fail to recover after treatment.

Beyond antibiotics

“This study shows how microbiome science can move beyond antibiotics to harness beneficial bacteria themselves as medicine – opening the door to a new generation of treatments that restore women’s reproductive health by rebuilding the natural microbial ecosystems that protect it,” said Professor Jo-Ann Passmore from the Division of Medical Virology at UCT’s Department of Pathology.

In this early clinical trial, the live bacterial products were safe, well-tolerated and successfully colonised the vagina in many participants.

In some women, the beneficial bacteria remained detectable several months later, suggesting that this approach could help restore a healthy vaginal microbiome and reduce BV recurrence.

Passmore said for many years their research has focused on the vaginal microbiome and genital inflammation in women, particularly in African populations where BV is extremely common and is linked to increased risk of HIV and other reproductive health complications. BV affects around one in three women globally.

Restoring natural balance with microbiome-based therapies

“One of the challenges with BV is that current treatments rely almost entirely on antibiotics, which do not address the underlying problem – the loss of protective bacteria. That is why microbiome-based therapies are so exciting. They aim to restore the natural microbial balance of the vagina, rather than simply eliminating bacteria,” she said.

“We were particularly interested in contributing bacterial isolates from women in Cape Town, because microbiome therapies should be developed using strains that reflect the diversity of women globally, not only those from Europe or North America,” said Passmore.

Passmore said by contributing bacterial isolates from African women whose vaginal microbiomes were naturally dominated by L. crispatus, the researchers hoped to help identify strains that could be used to develop live biotherapeutic products capable of establishing stable colonisation in the vagina.

“Ultimately, the aim is to develop treatments that help women rebuild a protective vaginal microbiome, reducing recurrence of BV and improving reproductive health,” she said.

This research helps in identifying new treatment strategies that work with the body’s natural microbial ecosystem rather than relying solely on antibiotics.

“An important aspect of this project is that it reflects true international collaboration in microbiome science. The live biotherapeutic products tested in the study were developed using L. crispatus strains isolated from women in both the United States and South Africa, thereby reflecting the diversity of vaginal microbiomes across populations.

“Ensuring that African populations are represented in microbiome research is essential if we want to develop effective therapies that benefit women everywhere,” said Passmore.

This research was supported by funding from the Gates Foundation. The findings and conclusions described are those of the authors and do not necessarily reflect the positions or policies of the foundation.