In the ProVag study with Maastricht University Medical Centre we investigate if oral probiotics contribute to vagina microbiome and thus to overall women’s health.
Women’s health outcomes are closely tied to the vaginal microbiome. Yet one key question remains unanswered: can oral probiotics meaningfully support it? While the vagina is naturally dominated by protective Lactobacillus species, composition differs between women and can shift over time. This influences overall women’s health, including reproductive health. Together with the Maastricht University Medical Centre+ (MUMC+), we initiated the ProVag study to generate evidence on whether oral probiotics can influence the vaginal microbiota.
Why is the ProVag study relevant?
The main aim of the ProVag study is to address an important and unanswered question in women’s health probiotics: can an oral probiotic meaningfully influence the vaginal microbiome? There is not yet clear evidence showing whether this is possible. If the study demonstrates even partial influence, it opens a big window of opportunity for the entire women’s health field. Oral intake is a simple, accessible, low‑barrier approach for all women.
Composition of the vaginal microbiome
The vaginal microbiota is predominantly composed of Lactobacillus species and influences overall women’s health, and specifically reproductive health. Lactobacilli abundance has been associated with higher pregnancy rates. Abundance of Lactobacilli can be determined with the ReceptIVFity test, a diagnostic tool that analyses a woman’s vaginal microbiota. Using this test, researchers did not only discover the impact of Lactobacilli on women’s reproductive health but also found that the vaginal microbial composition naturally shifts over time. This implies that we can steer the vaginal microbiota into a more favourable composition. Interestingly, one possible approach to steer the vaginal microbiota could be through oral probiotics.
Study design
The ProVag study is a randomized, placebo-controlled, double-blind intervention study in which we aim to include at least 110 women who are undergoing IVF treatment. For a duration of 8 weeks, these participants will receive either 3 grams of oral probiotics or a placebo daily. At the 4-, 6-, and 8-week time points of the trial, rectal and vaginal swabs will be taken to track whether probiotic strains reach the vagina and how quickly the microbiota responds.
ProVag study design overview
After 12 months, all participating women will have a follow-up in which pregnancy results will be monitored. Collectively, the results of this study can show whether oral probiotics can indeed improve the vaginal microbial composition and the chances of successful pregnancy after IVF/ICSI-treatment. Moreover, the results can help point out if the bacteria from the oral probiotics do so by traveling from the gut to the vagina or by supporting the vaginal microbiota from a distance. This might even have much greater impact on women’s health than on pregnancy success alone.
Beyond fertility: women’s health deserves scientific attention
A healthy vaginal microbiota is a cornerstone of women’s health, influencing not only reproductive outcomes but also broader physical well‑being throughout life. Yet despite its enormous societal relevance, women’s health remains significantly underrepresented in scientific research and in the development of targeted interventions. At Winclove, we are committed to changing this. By prioritising women’s health as one of our key focus areas, we aim to help close this persistent knowledge gap and contribute to solutions that genuinely support women. Through collaborative efforts such as the ProVag study, we hope to advance science in an area where progress is urgently needed and long overdue. The insights we gain will strengthen the evidence base for future development and guide the entire field forward. Want to explore how this research connects to your work? Reach out to our team.
