Bacterial vaginosis: could there soon be a vaginal microbiota transplant ?

Could the success of fecal microbiota transplant to treat recurrent Clostridium difficile infections be extended to vaginal microbiota transplant for the treatment of bacterial vaginosis? This is what a team of American researchers hope to accomplish.

 

A healthy vaginal microbiota is characterized by very low bacterial diversity and predominance of one or few lactobacilli species. On the contrary, high diversity and reduced levels of lactobacilli unbalance the flora, as is the case in bacterial vaginosis. It is a benign infection but it predisposes to sexually transmitted infections, urinary tract infections, and increases the risk of premature delivery. Although effective in the short term, antibiotics do not prevent relapses, which reach a 70% rate within 3 months. Could vaginal microbiota transplant be the solution?

Carefully screened donors

An American team had 20 female volunteers fill out a standard questionnaire with additional health and sex related questions (vaginal infections, number of partners, use of condoms, method of contraception...). After completing clinical and biological exams to determine their infectious status, the investigators analyzed the composition of their vaginal microbiota. This very careful donor selection protocol allowed them to determine the ideal graft: vaginal secretions with high content of lactobacilli leading to acidic pH and ensuring a better protection against infectious germs.

Strict inclusion criteria

The authors suggested to extend the screening process to many other infections in addition to those usually planned in standard transplants and also recommended several exclusion criteria: previous exposure to herpes virus, history of recurrent urinary tract infections, presence of “foreign” bacteria in the vaginal microbiota... Donors must also abstain from sexual intercourse within at least 30 days before sampling and they cannot receive any hormonal treatment. The proportion of eligible women was thus reduced to 35%–a number that should be even lower under real conditions. Moreover, potential recipients should not be exempted from STI screening, not as an exclusion criterium, but to make sure they receive the safest possible post-transplant follow-up.

 

Sources:

DeLong K, Bensouda S, Zulfiqar F et al. Conceptual Design of a Universal Donor Screening Approach for Vaginal Microbiota Transplant. Front. Cell. Infect. Microbiol. 9:306.2019. https://doi.org/10.3389/fcimb.2019.00306