Circunaro SL is a Spanish company with a two-person founding team. We are developing a non-antibiotic approach, applied by the male partner, to reduce recurrence of bacterial vaginosis (BV) in women. We are at an early stage: we have no product on the market and no clinical data of our own yet.
In the StepUp trial, treating the male partner with oral metronidazole plus topical 2% clindamycin cream for 7 days reduced BV recurrence in women within 12 weeks from 63% (43/68) to 35% (24/69); hazard ratio 0.37 (95% CI 0.22–0.61). The trial was stopped early for benefit.
Female partners of circumcised men had a lower prevalence of BV one year later (adjusted prevalence ratio 0.60 for any BV; 0.39 for severe BV). A secondary finding of an HIV prevention trial.
A cross-validated model using taxa at the male partner's penile meatus discriminated which women developed BV, with an AUC of about 0.89. A prediction, not proof of transfer or cause.
What these studies do not show: that a non-antibiotic approach works, effects beyond 12 weeks, or any effect on pregnancy outcomes.
Changing the male genital environment without antibiotics may reduce BV recurrence in the female partner. None of the studies above tested this. Our development program exists to test it.
Women's health and microbiome investors interested in an early-stage company built on a new clinical result.
Microbiome and women's health companies, and formulation or manufacturing partners.
Groups able to run studies in couples: BV, urinary tract infection, genital microbiome.
Global health and maternal health funders.
PhD in microbiology, microbiome, infectious diseases or pharmacy. Experience with mucosal microbial communities, not only cultured strains. Has taken at least one study from design to publication. Equity-based until funding; no salary yet.
Experience taking regulated health products through manufacturing and EU or US regulatory pathways, and working with contract manufacturers. Co-founder, consultant or advisor.
We will be at the South San Francisco Conference Center. Request a meeting with Manuel Becerril (CEO) through the partnering platform or write to research@circunaro.com.
Circunaro has a commercial interest in this area. Our research collaborations are governed by independence agreements: research partners keep full rights over data and publication. Nothing on this page describes a product available for sale or makes claims about preventing or treating any condition. Last updated: October 2026.