Jiyeon Si,¹ Hyun Ju You,^1,3 Junsun Yu,¹ Joohon Sung,² and GwangPyo Ko<sup>1,3,4,5,6,*

1</sup>Department of Environmental Health Sciences, School of Public Health
²Department of Public Health Science, School of Public Health
³Center for Human and Environmental Microbiome, Institute of Health and Environment
⁴N-Bio
Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea
⁵KoBioLabs, Inc., 1 Gwanak-ro, Gwanak-gu, Bldg 220, Rm 630, Seoul 151-742, Korea
⁶Lead Contact

^*Correspondence : GwangPyo Ko

Summary
While the vaginal ecosystem is maintained through mutualistic relationships between the host and the vaginal bacteria, the effect of host genetics on the vaginal microbiota has not been well characterized. We examined the heritability of vaginal microbiota and its association with obesity in 542 Korean females, including 222 monozygotic and 56 dizygotic twins. The vaginal microbiota significantly varied depending on host menopausal status and bacterial vaginosis. Lactobacillus and Prevotella, whose relative abundances are strongly associated with bacterial vaginosis, were the most heritable bacteria among the beneficial and potentially pathogenic vaginal microbiota, respectively. Candidate gene analysis revealed an association between genetic variants of interleukin-5 and the abundance of Prevotella sp. Furthermore, host obesity significantly increased the diversity of the vaginal microbiota in association with Prevotella. Our results provide insight into the effect of host genetics on the vaginal microbiota and their association with both vaginal and non-vaginal health.

Keywords : heritability, vaginal microbiome, Prevotella, Lactobacillus, twins, host genetics, obesity