Microbial subtypes of bacterial vaginosis (BV) are emerging as a way to validate patient symptoms and guide tailored treatment, according to Kate McLean, MD, MPH, FACOG, Chief Medical Officer at Evvy. In a discussion with Contemporary OB/GYN, McLean explained how refining the classification of BV could reshape clinical encounters and treatment strategies.
Refining the diagnosis
The work builds on Evvy’s February announcement, which identified six distinct microbial subtypes from the sequencing of over 100,000 vaginal microbiome samples. The subtypes include typical, transitional, lacto-dominant, biofilm, mixed, and atypical BV.
McLean said the primary benefit of subtyping is helping patients whose symptoms do not fit the classic presentation of BV feel understood. She noted that individuals with unusual symptoms have often been told they do not actually have the condition or that their symptoms are psychological.
“I think patients whose symptoms do not classically fit BV have been told, ‘Well, maybe you do not actually have BV. Are these symptoms just in your head?’” McLean said. “And so I think adding more nuance helps patients feel understood and included. And then I think on the flip side, it helps us understand the science even better.”
She added that matching symptoms to microbial signatures could be affirming for patients who have struggled to get answers.
“If we can say to somebody, it actually makes sense that you are experiencing burning because we see these particular microbial signatures, somebody is going to be like, ‘Wow, it just feels validating to know that there are other patients just like me, that this is a known pattern, and that this burning is not in my head because I went to five other doctors before this and they told me I was crazy,’” McLean said.
Hypotheses for future care
McLean offered several hypotheses about how the subtypes might inform treatment, though she emphasized these remain to be tested against the data. For the biofilm-producing subtype, she suggested that patients might fare better if they use boric acid to break up biofilm before starting a vaginal antibiotic course.
For typical BV, she hypothesized that patients using vaginal probiotics containing Lactobacillus crispatus after antibiotic treatment could achieve better outcomes by boosting healthy bacteria.
Despite the potential, McLean noted that the subtypes remain an early framework. Correlating the subtypes with symptoms and treatment outcomes is the next phase of research.
Some experts suggest that this subtle approach may eventually help address issues with access to care by clarifying who requires specific interventions.
