Logo Image
News|Videos|July 6, 2026

Kate McLean, MD, MPH, explains microbial subtypes within bacterial vaginosis

Key Takeaways

  • Statistical clustering of Evvy's vaginal microbiome dataset surfaced distinct microbial subtypes among patients diagnosed with bacterial vaginosis.
  • The identified subtypes are an initial framework, with symptom correlation and treatment response studies still to come.
SHOW MORE

Kate McLean, MD, MPH, FACOG, describes how statistical clustering of more than 15,000 BV-diagnosed patients surfaced distinct microbial subtypes without predefined assumptions.

Statistical analysis of large vaginal microbiome datasets has surfaced distinct microbial patterns among patients diagnosed with bacterial vaginosis (BV), a step toward understanding why patients with the same clinical diagnosis can have fundamentally different underlying biology, according to Kate McLean, MD, MPH, FACOG, OB-GYN, Chief Medical Officer, Evvy. This Contemporary OB/GYN continues a prior conversation with McLean, who explained the background on this potential better and deeper understanding of BV.1

Click here to watch.2

How does data define BV categories?

McLean described an analysis that drew on a subset of Evvy's dataset of more than 100,000 tested patients, without imposing predefined expectations on the results.1

“We took a subset of that data, it was over 15,000 patients who had been diagnosed with BV through their testing with us, and then we used some sophisticated statistical methodologies to allow clusters of microbiome data to surface from a statistical perspective,” she said. “We did not put preconceived bounds on that, meaning we asked the models to surface these clusters and how they naturally seem to group together, instead of saying, ‘we think a group is going to look like this, or we think there are going to be 6 different types of BV from the beginning,’” she explained.

Per Evvy's February announcement, the clustering identified 6 distinct microbial subtypes among clinically diagnosed BV patients, intended to complement, not replace, established diagnostic criteria.1

The 6 distinct microbial patterns include:

  • Typical BV
  • Transitional BV
  • Lacto-dominant BV
  • Biofilm BV
  • Mixed BV
  • Atypical BV

“The first is a very standard cluster, we call that typical BV, so it was a classic presentation of BV driven by overgrowth of classic BV bacteria like Gardnerella and Prevotella, and low levels of healthy bacteria, so low levels of lactobacilli,” she said.

Other clusters included transitional BV, biofilm-driven BV, and mixed BV, which McLean noted the last of these underscores the condition's complexity.

“We noticed classic BV-related microbes mixed with more aerobic-related bacteria, and so this is very interesting because it just highlights the fact that vaginal symptoms and the bacteria that then cause vaginal symptoms do not always fit into one clean category,” she said.

McLean framed the findings as an initial framework rather than a clinical endpoint, emphasizing that symptom correlation and treatment response remain to be studied.

“This was that first kind of step for scientific interest to classify these, and the next sort of steps will be, so what do we do with this?” she said.

References:

  1. Evvy Unveils Data-Driven Subtypes of Bacterial Vaginosis. Evvy. Press release. Published February 26, 2026. Accessed July 1, 2026. https://www.businesswire.com/news/home/20260226236249/en/Evvy-Unveils-Data-Driven-Subtypes-of-Bacterial-Vaginosis
  2. Fitch J. Kate McLean, MD, MPH, FACOG: Better understanding bacterial vaginosis. Contemporary OB/GYN. Published July 1, 2026. Accessed July 1, 2026. https://www.contemporaryobgyn.net/view/kate-mclean-md-mph-facog-better-understanding-bacterial-vaginosis

Related Content