Thesis Format
Integrated Article
Degree
Master of Science
Program
Microbiology and Immunology
Supervisor
Prodger, Jessica L.
Abstract
Transfeminine individuals (tF) often elect to undergo vaginoplasty — surgically creating a neovagina, often using penile and scrotal tissue. While cisgender genital mucosae and their impact on genital health are well characterized, the neovaginal microenvironment remains poorly understood. Through quantitative microscopy, this study demonstrated that unlike natal vaginal epithelia, neovaginal epithelium lacks glycogen and retains many penile-like characteristics, including a thinner epithelium, a cornified outer layer, and low expression of mucosal markers. However, it also exhibits reduced cornification structural protein expression compared to natal foreskin. These differences likely drive the uniqueness of the neovaginal microbiome, impacting the utility of current diagnostics. We demonstrated the Nugent score, a gold-standard tool for assessing natal vaginal bacterial dysbiosis, is ineffective in the neovagina, as targeted bacterial morphotypes do not correlate with inflammation or symptoms. These findings highlight the need for trans-specific diagnostics and treatments to address the unique neovaginal microenvironment.
Summary for Lay Audience
Transfeminine individuals (tF) were assigned male at birth but have a female or feminine gender identity. This research examines the unique characteristics of genital tissue in tF after feminizing hormone therapy (e.g. estrogen) and vaginoplasty — a procedure to construct a vaginal canal, or neovagina, often using penile and scrotal tissue.
In cisgender individuals, the genital microenvironment plays a significant role in genital health, influencing factors such as inflammation, which has been linked to an increased risk of sexually transmitted infections (STIs) and HIV. However, the neovaginal microenvironment and its impact on genital health remain poorly understood.
Using quantitative microscopy, our findings revealed hat neovaginal tissue retains many features of natal penile tissue, from which it is derived, rather than resembling natal vaginal tissue. For example, the neovaginal epithelium does not produce glycogen, a substance important for supporting Lactobacillus bacteria, which are typically dominant in the natal vagina. Additionally, cytokeratin and proliferation markers, which influence tissue structure and thickness, were more aligned with natal penile tissue. However, our findings did observe a reduction in structural proteins associated with the barrier functions of penile epithelium.
These differences in tissue microstructure likely influence the bacterial communities in the neovaginal environment, which have been observed to be distinct from those of both natal penile and vaginal tissue. Current diagnostic tools like the Nugent score are designed to assess bacterial imbalances in the natal vagina, including reduction in the abundance of Lactobacillus bacteria. However, our study determined that the Nugent score is not effective at evaluating bacterial imbalances in the neovagina. The bacterial types it targets do not predict inflammation or symptoms in the neovaginal environment as they would in the natal vagina, making it an unreliable diagnostic tool for tF.
In conclusion, these studies highlight the urgent need for trans-specific healthcare approaches. The unique microenvironment of the neovagina requires tailored diagnostics and treatments to improve sexual and gynecological health for tF, moving beyond relying on adaptations from cisgender healthcare standards.
Recommended Citation
Parmar, Reeya, "Characterization of Neovaginal Epithelial Microstructures and Evaluation of the Nugent Score as a Dysbiosis Diagnostic Tool for Transfeminine Individuals Post-Vaginoplasty" (2025). Electronic Thesis and Dissertation Repository. 10703.
https://ir.lib.uwo.ca/etd/10703
Included in
Medical Immunology Commons, Medical Microbiology Commons, Urogenital System Commons, Women's Health Commons
