First-void urine and cervicovaginal brushes for vaginal microbiome profiling: a proof-of-concept study

The human vaginal microbiome is a cornerstone of female reproductive health, influencing susceptibility to vaginal conditions, pregnancy complications, and urogenital infections. Understanding this microbiome is critical for advancing preventive, diagnostic, and therapeutic interventions, yet its intimate and dynamic nature poses challenges for accurate, representative, and more inclusive sampling methods. This proof-of-concept study evaluated the performance of first-void urine (FVU) samples and cervicovaginal brushes for vaginal microbiome profiling relative to vaginal swabs. FVU refers to the initial stream of urine that flushes away cervicovaginal secretions that accumulate between the small labia and around the urethral opening, capturing immune, cancer, disease, pathogen, and microbiome biomarkers. Next to FVU, we evaluated cervicovaginal brushes, which are commonly used as self-sampling devices for human papillomavirus (HPV) DNA screening and thus present an interesting opportunity for evaluating the cervicovaginal microbiome while also collecting human vaginal cells. Here, we performed microbiome profiling in 10 women based on a total of 40 samples. In six out of nine participants, high-quality microbial profiles were obtained for both fresh FVU and cervicovaginal brush samples, comparable to those derived from vaginal swabs. Storage at room temperature for 7 days influenced the microbial composition of four out of seven FVU samples. Overall, our findings demonstrate the potential of FVU as a practical and accessible self-sampling method for advancing women’s health research.

IMPORTANCE

Current approaches for mapping and assessing the vaginal microbiome predominantly rely on sampling through vaginal swabs. However, their use can be perceived as uncomfortable, and cultural norms, stigmas, and privacy concerns in certain communities can also limit their acceptability and accessibility, especially in minors. In this proof-of-concept study, we show that first-void urine (FVU) samples and cervicovaginal brushes can be used as non-invasive, user-friendly alternatives in vaginal microbiome research, enabling more accessible and scalable methods for microbiome composition analysis, paving the way for large-scale applications in future projects. This would also enable us to conduct a longitudinal study of the vaginal microbiome in children and to explore its evolution through to adulthood, capturing microbial community dynamics that remain largely uncharacterized. Such improvements could strengthen our understanding of the vaginal microbiota and their role in women’s health.