Menstrual cups and the vaginal environment: from within-host interactions to women’s heath – CUPS2

Girls and women need available, efficient, and safe menstrual products. Vaginal cups used specifically for menstrual collection have been commercially available since 1937 but only gained widespread attention in recent years. To our knowledge, a complete picture of the vaginal microbiota and immunological landscape induced by the use of different menstrual protections, in particular silicone cups, is still lacking. As the demand for "green" alternatives to disposable menstrual protection grows, there is an urgent need to improve our understanding of the effect of these products on women's health. We will establish two cohorts to characterize the impact of the use of silicone menstrual cups on the vaginal environment, compared to the use of other types of protection such as tampons or pads. The first large cohort will be cross-sectional and will mainly involve a questionnaire. The second cohort will be smaller (150 women) and will involve a gynaecological consultation with biological sample collection. At the microbiological level, the analyses will rely on high-throughput sequencing technology. These will be completed by gas chromatography-mass spectrometry (GC-MS) analyses of key components, e.g. phthalates. At the immune level, mass cytometry technology (CyTOF) will provide a unique description of the local cellular response. This will be complemented by cytokine analyses. These biological and chemical data will be analyzed in the light of behavioural meta-data but also health data (urinary tract infections and sexually transmitted infections in particular). In addition to this integrative approach to health, the project will involve mathematical and statistical models to optimise the exploitation of the data collected. The results will provide groundbreaking scientific information and help shape public health recommendations.