The Vaginal Microbiome of Transgender and Gender Nonbinary Individuals.

Purpose: The goal of this preliminary study is to describe the vaginal microbiome of transgender and gender nonbinary (TGNB) individuals using nonculture-based techniques. TGNB individuals may undergo gender-affirming surgical procedures, which can include the creation of a neovagina. Little is known about microbial species that comprise this environment in states of health or disease.

Methods: In this pilot study, vaginal swabs were self-collected from 15 healthy self-identified TGNB participants (age 26-69 years) and 8 cisgender comparator participants (age 27-50 years) between 2017 and 2018. Next-generation 16S ribosomal RNA sequencing was used to profile individual bacterial communities from all study samples.

Results: The TGNB cohort demonstrated significantly higher intraindividual (alpha) diversity than the cisgender group (p=0.0003). Microbial species commensal to the gut and skin were identified only in specimens from TGNB participants. Although Lactobacillus species were dominant in all cisgender comparator samples, they were found at low relative abundance (≤3%) in TGNB samples.

Conclusion: In this study, specimens collected from neovaginas showed increased alpha diversity and substantially different composition compared with natal vaginas. In contrast to natal vaginas, neovaginas were not dominated by Lactobacillus, but were hosts to many microbial species. Studies that help to improve our understanding of the neovaginal microbiome may enable clinicians to differentiate between healthy and diseased neovaginal states.