Background The Keystone Symposium on ‘Role of the Genital Tract Microbiome in Sexual and Reproductive Health’ was held in Cape Town in December 2018.

Methods The aims were to discuss the most current and cutting-edge research findings, consider future directions, stimulate collaborations, and provide a forum for trainees and new investigators to present, learn, and network.

Results/Conclusions All aims were met. The Symposium was particularly successful in bringing researchers in HIV/STI and maternal and child health together. Areas of scientific consensus included: 1) Optimal is a better term to use than normal in the context of vaginal microbiota. L. crispatus-domination is considered optimal. L. iners is sometimes a friend and sometimes a foe. 2) Vaginal microbiota diversity on its own misses important dysbiosis types (such as G. vaginalis-domination). 3) Taxonomic community state types are useful, but we may need to move towards community state types that incorporate pathogenicity (e.g. inflammatory potential), and are therefore more useful from the prevention, diagnosis, treatment and prognosis perspectives. For some key bacterial taxa (e.g. G. vaginalis), we should differentiate between clades. In the meantime, we should use precise definitions of predictors and outcomes. 4) Moving from correlation to causality, the field needs more mechanistic studies and sufficiently powered longitudinal human studies. The latter could include frequent sampling studies to determine community dynamics, observational studies with clinically relevant endpoints, and intervention studies. These studies should ideally include quantification of total bacterial load and bacterial species (not relative abundance only), and measurement of all relevant microorganisms, biofilms, and host responses in the genital tract. 5) The efficacy of existing interventions, and pipeline of new interventions, are limited. We should expand the pipeline, which requires industry involvement and more investment into the field in general. We now have the tools to assess the effects of those interventions.

Disclosure No significant relationships.