The Impact of Testosterone Therapy on the Vaginal Microbiota of Transgender Men and Non-Binary People: A Prospective Study

Authors

Olivia T. Van Gerwen, University of Alabama at Birmingham, Birmingham, AL
Kristal J. Aaron, University of Alabama at Birmingham, Birmingham, AL
Emma Sophia Kay, University of Alabama at Birmingham, Birmingham, AL
Krishmita Siwakoti, University of Alabama at Birmingham, Birmingham, AL
Angela Pontius, University of Alabama at Birmingham, Birmingham, AL
Saralyn Richter, University of Alabama at Birmingham, Birmingham, AL
Z Alex Sherman, University of Alabama at Birmingham, Birmingham, AL
Keonte J. Graves, University of Alabama at Birmingham, Birmingham, AL
Ashutosh Tamhane, University of Alabama at Birmingham, Birmingham, AL
Jacob H. Elnaggar, LSU Health Sciences Center - New OrleansFollow
Meng Luo, LSU Health Sciences Center - New OrleansFollow
Evelyn Toh, Indiana University School of Medicine, Indianapolis, IN
David E. Nelson, Indiana University School of Medicine, Indianapolis, IN
Nicholas J. Van Wagoner, University of Alabama at Birmingham, Birmingham, AL
Christopher M. Taylor, LSU Health Sciences Center - New OrleansFollow
Christina A. Muzny, University of Alabama at Birmingham, Birmingham, AL

Document Type

Article

Publication Date

3-3-2025

Publication Title

The Journal of Infectious Diseases

Abstract

BACKGROUND: Understanding the impact of testosterone on the vaginal microbiota of transgender men (TGM) and non-binary people assigned female sex at birth over time is imperative as vaginal dysbiosis and incident bacterial vaginosis (iBV) may cause bothersome genital symptoms and increase HIV/STI acquisition risk. We investigated shifts in the composition of the vaginal microbiota over time in TGM initiating testosterone for gender-affirming hormone therapy, including development of vaginal dysbiosis and iBV. METHODS: Participants ages ≥18 years, assigned female sex at birth and reporting TGM or non-binary identity, interested in starting injectable testosterone, demonstrating optimal vaginal microbiota, with no current STI(s) were enrolled. Participants self-collected daily vaginal specimens for 7 days prior to testosterone initiation and 90 days thereafter for vaginal Gram staining and 16S rRNA gene sequencing. Episodes of vaginal dysbiosis and iBV were defined as Nugent scores ≥4 or ≥7, respectively, each for ≥2 consecutive days. RESULTS: Between February 2022-November 2023, 9 participants enrolled, 89% (8/9) developed ≥1 episode(s) of vaginal dysbiosis after testosterone initiation, and 56% (5/9) developed iBV. Among those who developed iBV, most did so between days 20-40 after testosterone initiation. Community state type (CST) I was found most often in participants who did not develop iBV and CST IV-B most often in participants who developed iBV. Sexual activity and menses also appeared to influence the development of iBV. CONCLUSION: The majority of participants developed vaginal dysbiosis including iBV.. Additional studies with larger sample sizes are needed to further elucidate how testosterone impacts the vaginal microbiota.

PubMed ID

40037329

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.

Recommended Citation

Van Gerwen, Olivia T.; Aaron, Kristal J.; Kay, Emma Sophia; Siwakoti, Krishmita; Pontius, Angela; Richter, Saralyn; Sherman, Z Alex; Graves, Keonte J.; Tamhane, Ashutosh; Elnaggar, Jacob H.; Luo, Meng; Toh, Evelyn; Nelson, David E.; Van Wagoner, Nicholas J.; Taylor, Christopher M.; and Muzny, Christina A., "The Impact of Testosterone Therapy on the Vaginal Microbiota of Transgender Men and Non-Binary People: A Prospective Study" (2025). School of Medicine Faculty Publications. 3674.
https://digitalscholar.lsuhsc.edu/som_facpubs/3674
10.1093/infdis/jiaf114