New Research Uncovers Complexity of Vaginal Microbiome, Challenging Old Assumptions

Scientists at the University of Maryland School of Medicine (UMSOM) have published new research challenging long-held assumptions about the vaginal microbiome. Historically, gynecological tests have categorized bacteria as either "good" (Lactobacillus) or "bad" (Gardnerella).

Challenging Traditional Views

The new study, published on February 5, 2026, in the journal mBio, reveals that bacteria of the same species can exhibit fundamentally different behaviors. This marks a significant shift from the previous classification of "optimal" or "non-optimal" based on a limited number of bacterial species.

Unveiling New Microbiome Types

Researchers identified 25 distinct vaginal microbiome types. Among these, six were found to be dominated by Gardnerella.

One Gardnerella-dominated type displayed functional and inflammatory characteristics similar to those dominated by Lactobacillus, indicating significant biological diversity within what was previously considered a single category.

Innovative Computational Tools Drive Discovery

To facilitate this detailed analysis, the UMSOM team developed two open-source computational tools: VIRGO2 and VISTA.

VIRGO2 is an expanded gene catalog containing approximately 1.7 million genes from various microorganisms in the vaginal microbiome.

VISTA (Vaginal Interference of Subspecies and Typing Algorithm) allows for the examination of vaginal microbiomes at the strain-community level, rather than solely by species identification.

Expert Perspectives

Lead author Amanda Williams, PhD, emphasized a crucial aspect of the study's findings:

Understanding the functional capabilities of bacterial species is crucial, not just their presence.

Johanna Holm, PhD, senior author, stated that while the work does not immediately alter clinical practice, it establishes a framework for future studies. These studies will aim at improving diagnostics, risk stratification, and treatment strategies in women's health.

Further research is necessary to determine the relationship between these identified microbiome types and clinical outcomes, and how this information can inform more personalized diagnostic and treatment approaches.