The Vaginal Microbiome of Transgender Men

Recruiting transgender men in the Southeastern United States for genital microbiome research: Lessons learned

BACKGROUND

Transgender men (TGM) are underrepresented in genital microbiome research. Our prospective study in Birmingham, AL investigated genital microbiota changes over time in TGM initiating testosterone, including the development of incident bacterial vaginosis (iBV). Here, we present lessons learned from recruitment challenges encountered during the conduct of this study.

METHODS

Inclusion criteria were assigned female sex at birth, TGM or non-binary identity, age ≥18 years, interested in injectable testosterone but willing to wait 7 days after enrollment before starting, and engaged with a testosterone-prescribing provider. Exclusion criteria were recent antibiotic use, HIV/STI infection, current vaginal infection, pregnancy, or past 6 months testosterone use. Recruitment initiatives included community advertisements via flyers, social media posts, and referrals from local gender health clinics.

RESULTS

Between February 2022 and October 2023, 61 individuals contacted the study, 17 (27.9%) completed an in-person screening visit, and 10 (58.8%) of those screened were enrolled. The primary reasons for individuals failing study screening were having limited access to testosterone-prescribing providers, already being on testosterone, being unwilling to wait 7 days to initiate testosterone therapy, or desiring the use of topical testosterone. Engagement of non-White TGM was also minimal.

CONCLUSION

Despite robust study inquiry by TGM, screening and enrollment challenges were faced including engagement by TGM not yet in care and specific study eligibility criteria. Excitement among TGM for research representation should be leveraged in future work by engaging transgender community stakeholders at the inception of study development, particularly regarding feasibility of study inclusion and exclusion criteria, as well as recruitment of TGM of color. These results also highlight the need for more clinical resources for prescribing gender-affirming hormone therapy, especially in the Southeastern US.

[Transmasculine people: Gender affirming hormonal therapy, sexual and reproductive health prevention and care, a medical review and follow-up suggestions]

Transmasculine individuals have a poor access to health care, mostly regarding the sexual and reproductive health. Despite a lack of official guidelines, they need a gynecological follow-up, the aim of this review was to describe it. The present study involved an exhaustive search of MEDLINE, 68 articles were included to analyze the impact of hormonal therapy, prevention, and care regarding sexual and reproductive health of transmasculine individuals. Despite a lack of solid data, the global literature agrees that transmasculine individuals require sexual and reproductive health care. Care must be adapted to each pathway and may be impacted by gender-affirming care. The cancer risk does not seem to be increased in this population, particularly in relation to hormonal therapy. Prevention programs do not differ from those offered to cis women in the absence of gender-affirming surgeries. Transmasculine individuals require follow-up and care adapted to their needs and their pathways. Healthcare professionals must be trained to provide such care.

Chronic pelvic pain among transgender men and gender diverse adults assigned female at birth

BACKGROUND

There are limited data on pelvic pain among transgender men and gender diverse people, and the impact of testosterone on pelvic pain is poorly understood.

OBJECTIVE

Characterize the prevalence and correlates of chronic pelvic pain (CPP) among transgender men and gender diverse people and examine the association between testosterone use and CPP.

MATERIALS AND METHODS

We used 2020-2022 data from The Population Research in Identity and Disparities for Equality (PRIDE) Study, an online prospective cohort study of sexual and gender minority adults in the United States, to conduct complementary cross-sectional and longitudinal analyses. Our primary outcome was self-reported CPP lasting 3 months or longer measured using the Michigan Body Map.

RESULTS

Among 2579 transgender men and gender diverse people assigned female at birth included in our sample, 457 (18%) reported CPP. CPP correlates included: inflammatory bowel disease, irritable bowel syndrome (IBS), kidney stones, pelvic inflammatory disease, polycystic ovary syndrome (PCOS), uterine fibroids, current hormonal intrauterine device use, prior pregnancy, vaginal delivery, hysterectomy, and oophorectomy. Individuals with CPP reported a high prevalence of IBS (37%), PCOS (20%), uterine fibroids (9%), post-traumatic stress disorder (51%), and severe depression and anxiety symptoms (42% and 25%, respectively). Current testosterone use was associated with a 21% lower prevalence of CPP (adjusted prevalence ratio (aPR) 0.79, 95% confidence interval [CI]: 0.65-0.96). In longitudinal analyses (N = 79), 15 (19%) participants reported any CPP after initiating testosterone: eight (56%) of whom reported CPP prior to testosterone initiation, and seven (47%) who reported new-onset CPP.

DISCUSSION AND CONCLUSIONS

The relationship between CPP and testosterone is complex. Although testosterone use was associated with a lower prevalence of CPP, some transgender and gender diverse individuals experienced new-onset pelvic pain after testosterone initiation. Given the significant impact that CPP can have on mental health and quality of life, future research must examine the role of testosterone in specific underlying etiologies of CPP and identify potential therapies.

Vaginal community state types (CSTs) alter environmental cues and production of the Staphylococcus aureus toxic shock syndrome toxin-1 (TSST-1)

Menstrual toxic shock syndrome (mTSS) is a rare but life-threatening disease associated with the use of high-absorbency tampons. The production of the Staphylococcus aureus toxic shock syndrome toxin-1 (TSST-1) superantigen is involved in nearly all cases of mTSS and is tightly controlled by regulators responding to the environment. In the prototypic mTSS strain S. aureus MN8, the major repressor of TSST-1 is the carbon catabolite protein A (CcpA), which responds to glucose concentrations in the vaginal tract. Healthy vaginal Lactobacillus species also depend on glucose for both growth and acidification of the vaginal environment through lactic acid production. We hypothesized that interactions between the vaginal microbiota [herein referred to as community state types (CSTs)] and S. aureus MN8 depend on environmental cues and that these interactions subsequently affect TSST-1 production. Using S. aureus MN8 ΔccpA growing in various glucose concentrations, we demonstrate that the supernatants from different CSTs grown in vaginally defined medium (VDM) could significantly decrease tst expression. When co-culturing CST species with MN8 ∆ccpA, we show that Lactobacillus jensenii completely inhibits TSST-1 production in conditions mimicking healthy menstruation or mTSS. Finally, we show that growing S. aureus in "unhealthy" or "transitional" CST supernatants results in higher interleukin 2 (IL-2) production from T cells. These findings suggest that dysbiotic CSTs may encourage TSST-1 production in the vaginal tract and further indicate that the CSTs are likely important for the protection from mTSS.IMPORTANCEIn this study, we investigate the impact of the vaginal microbiota against Staphylococcus aureus in conditions mimicking the vaginal environment at various stages of the menstrual cycle. We demonstrate that Lactobacillus jensenii can inhibit toxic shock syndrome toxin-1 (TSST-1) production, suggesting the potential for probiotic activity in treating and preventing menstrual toxic shock syndrome (mTSS). On the other side of the spectrum, "unhealthy" or "transient" bacteria such as Gardnerella vaginalis and Lactobacillus iners support more TSST-1 production by S. aureus, suggesting that community state types are important in the development of mTSS. This study sets forward a model for examining contact-independent interactions between pathogenic bacteria and the vaginal microbiota. It also demonstrates the necessity of replicating the environment when studying one as dynamic as the vagina.

Bacterial vaginosis testing gaps for transmasculine patients may exacerbate health disparities

Introduction

Bacterial vaginosis (BV) is associated with non-optimal changes in the vaginal microbiome and increased susceptibility to STIs and HIV in cisgender women. Much less is known about the sexual health of transmasculine people and susceptibility to BV, STIs, and HIV. This study's objective was to assess BV testing and outcomes of transmasculine and cisgender women patient populations at a large, LGBTQ + federally qualified health center.

Methods

Retrospective electronic health record data were extracted for eligible patients having at least one primary care visit between January 1, 2021, and December 31, 2021. Transmasculine patients were limited to those with a testosterone prescription in 2021. We conducted log binomial regression analysis to determine the probability of receiving a BV test based on gender identity, adjusting for sociodemographic characteristics.

Results

During 2021, 4,903 cisgender women patients and 1,867 transmasculine patients had at least one primary care visit. Compared to cisgender women, transmasculine patients were disproportionately young, White, queer, privately insured, living outside Chicago, and had a lower rate of BV testing (1.9% v. 17.3%, p < 0.001). Controlling for sociodemographics, transmasculine patients were less likely to receive a BV test [Prevalence Ratio = 0.19 (95% CI 0.13-0.27)].

Discussion

The low rate of BV testing among transmasculine patients may contribute to disparities in reproductive health outcomes. Prospective community- and provider-engaged research is needed to better understand the multifactorial determinants for sexual healthcare and gender-affirming care for transmasculine patients. In particular, the impact of exogenous testosterone on the vaginal microbiome should also be determined.

Vaginal Cuff Dehiscence in Transgender Patients After Minimally Invasive Hysterectomy

STUDY OBJECTIVE

To compare rates of vaginal cuff dehiscence (VCD) in transgender patients with cisgender patients after minimally invasive hysterectomy (MIH).

DESIGN

We performed a single-surgeon, retrospective cohort analysis comparing the rates of VCD in patients undergoing MIH for gender affirmation with other indications (benign, malignant, prophylactic) with our study surgeon between January, 2015, and December, 2021.

SETTING

Major, urban, academic tertiary care hospital in the United States.

PATIENTS

166 patients met inclusion criteria with 49 of those patients undergoing MIH (29.5%) for gender affirmation. Of the remaining 117 patients, 92 (78.6%) underwent MIH for cancer, 15 (12.8%) for prophylaxis, and 10 (8.5%) for benign indications.

INTERVENTIONS

Not applicable.

MEASUREMENTS

We assessed included patients for baseline demographics, presence of risk factors for VCD, details of index hysterectomy, and details of cuff dehiscence events.

MAIN RESULTS

Transgender patients tended to be younger at the time of surgery, but demographics were otherwise similar between both groups. Most transgender patients (n = 36, 73.5%) had both ovaries removed at the time of hysterectomy, 100% were on testosterone therapy pre- and postoperatively, and none used supplementary estrogen. Three of the 49 transgender patients (6.1%) experienced postoperative dehiscence of the vaginal cuff compared with 2 of the 117 cisgender patients (1.7%). This failed to reach statistical significance; however, our descriptive analysis showed that all cases of dehiscence in the cisgender group had identifiable precipitating factors (i.e., trauma). By comparison, all cases of dehiscence in the transgender group were spontaneous with few identifiable risk factors.

CONCLUSION

Transgender patients undergoing MIH may be at increased risk of VCD, although the rarity of this surgical complication precluded determination of statistical significance in our data set. We propose testosterone exposure as a possible risk factor for VCD, although we cannot exclude other factors, such as young age, as drivers of VCD in this population. Future studies of biospecimens are needed to evaluate for cellular differences in these patients.

Cervicovaginal Papanicolaou tests in transgender men: Cytomorphologic alterations, interpretation considerations, and clinical implications

BACKGROUND

The transgender population faces unique psychosocial and physical obstacles to cervical cancer screening. Additionally, most individuals undergo masculinizing testosterone hormone therapy, and the physiologic changes can cause cytomorphologic alterations that may mimic lesions. Although the literature on cervicovaginal cytology is growing in this patient population, it is still limited.

METHODS

The pathology information system was queried for all Papanicolaou (Pap) tests from transgender men from January 2013 to February 2023. The original diagnostic categories were catalogued. Cases were reviewed to evaluate the cytomorphologic alterations. Clinical data were also sought, including whether the sample was self-collected. Two comparison groups were established: one was a postpartum atrophic group and the other was an all-comer group.

RESULTS

A total of 51 cases from 43 individuals were identified, with a mean age of 31 years. Approximately a third of cases (18 of 51; 35%) were self-collected. The abnormal rate was low, with 5.9% of cases rendered atypical squamous cells of undetermined significance on original review and no lesions identified. The Pap unsatisfactory rate according to original reports was 3.9%. This increased to 13.7% when the cases were rereviewed, which was significantly higher than the all-comer comparison group. The unsatisfactory rate did not correlate with self-collection. Atrophy was a prevalent cytomorphologic alteration, with the vast majority of cases (92%) showing at least mild atrophy. Small blue cells and transitional cell metaplasia were seen in many cases (53% and 43%, respectively).

CONCLUSIONS

There are clinical and morphologic considerations that are distinct to the transgender patient population. Laboratory personnel and diagnosticians need to be aware of these in order to optimize patient care.

Impact of testosterone use on the vaginal microbiota of transgender men, including susceptibility to bacterial vaginosis: study protocol for a prospective, observational study

INTRODUCTION

The effect of testosterone (T) therapy on the vaginal microbiota of transgender men (TGM) is not well characterised, although one cross-sectional study comparing the vaginal microbiota of cisgender women to TGM on T≥1 year found that, in 71% of the TGM, the vaginal microbiota was less likely to be Lactobacillus-dominated and more likely to be enriched with >30 other bacterial species, many associated with bacterial vaginosis (BV). This prospective study aims to investigate changes in the composition of the vaginal microbiota over time in TGM who retain their natal genitalia (ie, vagina) and initiate T. In addition, we will identify changes in the vaginal microbiota preceding incident BV (iBV) in this cohort while investigating behavioural factors, along with hormonal shifts, which may be associated with iBV.

METHODS AND ANALYSIS

T-naïve TGM who have not undergone gender-affirming genital surgery with normal baseline vaginal microbiota (ie, no Amsel criteria, normal Nugent Score with no Gardnerella vaginalis morphotypes) will self-collect daily vaginal specimens for 7 days prior to initiating T and for 90 days thereafter. These specimens will be used for vaginal Gram stain, 16S rRNA gene sequencing and shotgun metagenomic sequencing to characterise shifts in the vaginal microbiota over time, including development of iBV. Participants will complete daily diaries on douching, menses and behavioural factors including sexual activity during the study.

ETHICS AND DISSEMINATION

This protocol is approved through the single Institutional Review Board mechanism by the University of Alabama at Birmingham. External relying sites are the Louisiana State University Health Sciences Center, New Orleans Human Research Protection Program and the Indiana University Human Research Protection Program. Study findings will be presented at scientific conferences and peer-reviewed journals as well as shared with community advisory boards at participating gender health clinics and community-based organisations servicing transgender people.

REGISTRATION DETAILS

Protocol # IRB-300008073.

Postoperative Vaginal Bleeding Concerns after Gender-Affirming Hysterectomy in Transgender Adolescents and Young Adults on Testosterone

STUDY OBJECTIVE

This study aimed to characterize the incidence and management of postoperative vaginal bleeding concerns experienced by transgender adolescents and young adults (AYA) on testosterone hormone therapy after gender-affirming hysterectomy (GAH).

METHODS

This was a retrospective cohort of transgender AYA, 18 years and older, using testosterone therapy who underwent a GAH between July 2020 and September 2021 at a tertiary care children's hospital. The incidence of patient-reported postoperative vaginal bleeding concerns and management of bleeding are described.

RESULTS

Patient ages ranged between 18 and 33 years. Among 25 patients who met the inclusion criteria, 13 (52.0%) reported vaginal bleeding concerns. No modifiable patient or operative characteristics reached statistical significance in association with postoperative bleeding concerns. Among patients with bleeding concerns, 10 (76.9%) experienced such concerns during the first 2 weeks after surgery, and 6 (46.2%) had resolution of bleeding without intervention. Among 11 patients who underwent an exam for evaluation of bleeding, findings included granulation tissue (n = 5, 45.5%), vaginal atrophy (n = 4, 36.4%), bleeding vessel (n = 1, 9.1%), mucosal separation (n = 1, 9.1%), or no cause of bleeding identified (n = 4, 36.4%).

CONCLUSIONS

Over half of transgender AYA on testosterone therapy in this cohort reported postoperative vaginal bleeding concerns that were most often secondary to atrophy and granulation tissue, suggesting possible susceptibility to vaginal tissue trauma at the time of GAH and granulation-susceptible healing in patients on testosterone. As vaginal bleeding could worsen gender dysphoria, these findings support the need for patient counseling on postoperative bleeding expectations and identification of interventions to reduce vaginal bleeding after GAH.

Urinary Tract Infections Among Gender Diverse People Assigned Female at Birth on Testosterone

IMPORTANCE

The current literature lacks evidence to support the relationship between gender-affirming testosterone use and urinary tract infections (UTIs).

OBJECTIVES

The aims of the study are to compare UTI rates among gender diverse people assigned female at birth on testosterone (GDT) to cisgender women (CW) and to identify factors associated with UTI.

STUDY DESIGN

This is a retrospective cohort study of GDT and age-matched CW over a 5-year period. The primary outcome was based on the International Classification of Diseases, Ninth/Tenth Revisions, Clinical Modification, UTI diagnosis codes with a filled pharmacy order for antibiotics within 7 days of the diagnosis.

RESULTS

The study included 2,401 GDT who were then age matched to 2,401 CW. The mean rates of UTI among GDT and CW were not significantly different at 0.09 and 0.10 UTIs per year, respectively. During the study period, 6.9% of GDT and 7.5% of CW had at least 1 UTI. Diabetes mellitus type 1 or 2 was significantly associated with UTI frequency among CW (P = 0.04) but not GDT (P = 0.96).

CONCLUSIONS

The rate of UTIs among our young cohort of GDT and CW was similarly low. Diabetes mellitus type 1 or 2 was significantly associated with UTIs among CW but not GDT. These findings suggest that testosterone-induced vaginal atrophy may not be associated with a higher a UTI risk. A deeper understanding of the pathogenesis of UTI in people assigned female at birth and more data on the relationship between testosterone and UTIs are needed before recommending vaginal estrogen to all GDT with recurrent UTI.

Female reproductive tract-organ axes

The female reproductive tract (FRT) and remote/versatile organs in the body share bidirectional communication. In this review, we discuss the framework of the "FRT-organ axes." Each axis, namely, the vagina-gut axis, uterus-gut axis, ovary-gut axis, vagina-bladder axis, vagina-oral axis, uterus-oral axis, vagina-brain axis, uterus-brain axis, and vagina-joint axis, is comprehensively discussed separately. Each axis could be involved in the pathogenesis of not only gynecological diseases but also diseases occurring apart from the FRT. Although the microbiota is clearly a key player in the FRT-organ axes, more quantitative insight into the homeostasis of the microbiota could be provided by host function measurements rather than current microbe-centric approaches. Therefore, investigation of the FRT-organ axes would provide us with a multicentric approach, including immune, neural, endocrine, and metabolic aspects, for understanding the homeostatic mechanism of women's bodies. The framework of the FRT-organ axes could also provide insights into finding new therapeutic approaches to maintain women's health.

Cervicovaginal cytology, HPV testing and vaginal flora in transmasculine persons receiving testosterone

BACKGROUND

Testosterone is one of the strategies that transmasculine persons can elect in order to align physical traits to their gender identity. Previous studies have shown morphologic changes in the genital tract associated with testosterone. Here, we aim to evaluate cervicovaginal cytology specimens (Pap tests) and high-risk HPV (HR-HPV) testing from transmasculine individuals receiving testosterone.

METHODS

This is a retrospective cohort of 61 transmasculine individuals receiving testosterone from 2013 to 2021. Cytologic diagnoses from 65 Pap tests were correlated with HPV status and histologic follow-up and compared with the institutional data and a cohort of cisgender women with atrophic changes.

RESULTS

The median age was 28 years and median time of testosterone use was 3 years. Transmasculine persons showed significantly higher rates of HSIL (2%) and unsatisfactory (16%) when compared with the institutional data and atrophic cohort of cisgender women. After reviewing slides of 46 cases, additional findings were noted: atrophy was present in 87%, glycogenated cells were seen in 30%, and Lactobacilli were substantially decreased in 89%. Among 32 available HPV tests, 19% were positive for HR-HPV and 81% were negative. On histologic follow-up, all HR-HPV-positive cases with abnormal cytology showed HSIL, while none of the HPV-negative cases revealed HSIL.

CONCLUSION

Our study cohort demonstrated a high percentage of abnormal Pap tests in transmasculine persons receiving testosterone. Testosterone seems to induce changes in squamous cells and shifts in vaginal flora. HR-HPV testing can be a useful adjunct in the workup of abnormal Pap tests from transmasculine individuals.

The vaginal microbiome: A complex milieu affecting risk of human papillomavirus persistence and cervical cancer

The purpose of this review is to describe the existing literature regarding the relationship between the vaginal microbiome, human papillomavirus persistence, and cervical cancer risk, as well as to discuss factors that mediate these relationships. Data suggest that alterations in the vaginal microbiome affect the risk of human papillomavirus infection and persistence, which has downstream effects on cervical dysplasia and cancer risk. The homeostatic Lactobillus species L. crispatus, L. gasseri, L. jensenii act to promote a healthy vaginal environment, while L. iners and pathogens causing bacterial vaginosis are associated with increased inflammation, human papillomavirus infection, cervical dysplasia, and potentially cancer. There are, however, still several large gaps in the literature, particularly related to the modifiable and non-modifiable factors that affect the vaginal microbiome and ensuing risk of pre-cancerous and cancerous lesions. Evidence currently suggests that endogenous and exogenous hormones, tobacco products, and sexual practices influence vaginal microbiome composition, but the nuances of these relationships and how changes in these factors affect dysplasia risk are yet to be delineated. Other studies examining how diet, exercise, race, socioeconomic status, and genetic factors influence the vaginal microbiome are difficult to interpret in the setting of multiple confounders. Future studies should focus on how changes in these modulatory factors might promote a healthy vaginal microbiome to prevent or treat dysplasia in the lower female genital tract.

Prevalence of Vulvar Pain and Dyspareunia in Trans Masculine Individuals

Purpose: The prevalence of vulvar pain and dyspareunia has not been studied in trans masculine individuals. The aim of this study was to determine the prevalence of self-reported vulvar pain symptoms and dyspareunia in this population and investigate its relationship to gender-affirming hormone therapy with testosterone. Methods: Trans masculine individuals of ages 18-64 years participated in a voluntary online survey including questions about demographics, hormone therapy, and whether they experienced vulvar pain symptoms. The study was conducted between May 2017 and October 2018. Descriptive statistics were used to analyze the data. Results: A total of 782 trans masculine individuals completed the survey. The mean age was 27 years (standard deviation 8.6). The majority was White (661/778, 85.0%) and had private health insurance (517/781, 66.2%). Testosterone use was reported by 468 of 782 (59.8%) individuals, and 566 of 672 (84.2%) individuals had been sexually active in their lifetime. Unintentional pain with sexual intercourse was experienced by 372 of 605 (61.5%) participants. A total of 236 of 399 (59.1%) individuals utilized testosterone compared with 136 of 206 (66.0%) individuals who did not (p = 0.11). Of survey respondents, 68 of 710 (9.6%) individuals reported vulvar pain symptoms, and 42 of 452 (9.3%) individuals were on testosterone compared with 26 of 258 (10.1%) individuals not on testosterone (p = 0.79). Of all participants experiencing vulvar pain symptoms, 42 of 68 (61.8%) individuals were on testosterone. Conclusion: In this study, trans masculine individuals had a higher prevalence of dyspareunia than the general population, whereas the prevalence of vulvar pain was similar to that reported in cisgender women. The use of testosterone did not appear to increase the risk of developing unintentional pain with intercourse or vulvar pain symptoms.

The Effect of Gender-Affirming Medical Care on the Vaginal and Neovaginal Microbiomes of Transgender and Gender-Diverse People

Transgender and gender diverse individuals may seek gender-affirming medical care, such as hormone therapy or surgery, to produce primary and/or secondary sex characteristics that are more congruent with their gender. Gender-affirming medical care for transmasculine individuals can include testosterone therapy, which suppresses circulating estrogen and can lead to changes in the vaginal epithelium that are reminiscent of the post-menopausal period in cisgender females. Among transfeminine individuals, gender-affirming medical care can include vaginoplasty, which is the surgical creation of a vulva and neovaginal canal, commonly using penile and scrotal skin. The effect of gender-affirming medical care on the vagina of transmasculine individuals and on the neovagina of transfeminine individuals is poorly characterized. This review summarizes what is known of the epithelium and local microbiota of the testosterone-exposed vagina and the neovagina. We focus on potential pathogens and determinants of gynecological health and identify key knowledge gaps for future research.

Gut and vaginal microbiomes on steroids: implications for women's health

This review discusses the interactions of steroids with the gut and vaginal microbiomes within each life phase of adult women and the implications for women's health. Each phase of a woman's life is characterized by distinct hormonal states which drive overall physiology of both host and commensal microbes. These host-microbiome interactions underlie disease pathology in disorders that affect women across their lifetime, including bacterial vaginosis, gestational diabetes, polycystic ovary syndrome (PCOS), anxiety, depression, and obesity. Although many associations between host health and microbiome composition are well defined, the mechanistic role of the microbiome in women's health outcomes is largely unknown. This review addresses potential mechanisms by which the microbiota influences women's health and highlights gaps in current knowledge.

HIV Pathogenesis in the Human Female Reproductive Tract

PURPOSE OF REVIEW

Women remain disproportionately affected by the HIV/AIDS pandemic. The primary mechanism for HIV acquisition in women is sexual transmission, yet the immunobiological factors that contribute to HIV susceptibility remain poorly characterized. Here, we review current knowledge on HIV pathogenesis in women, focusing on infection and immune responses in the female reproductive tract (FRT).

RECENT FINDINGS

We describe recent findings on innate immune protection and HIV target cell distribution in the FRT. We also review multiple factors that modify susceptibility to infection, including sex hormones, microbiome, trauma, and how HIV risk changes during women's life cycle. Finally, we review current strategies for HIV prevention and identify barriers for research in HIV infection and pathogenesis in women. A complex network of interrelated biological and sociocultural factors contributes to HIV risk in women and impairs prevention and cure strategies. Understanding how HIV establishes infection in the FRT can provide clues to develop novel interventions to prevent HIV acquisition in women.

Biocultural approaches to transgender and gender diverse experience and health: Integrating biomarkers and advancing gender/sex research

Transgender and gender diverse (TGD) people are increasingly visible in U.S. communities and in national media. With this increased visibility, access to gender affirming healthcare is also on the rise, particularly for urban youth. Political backlash and entrenchment in a gender binary, however, continue to marginalize TGD people, increasing risk for health disparities. The 2016 National Institute of Health recognition of sexual and gender minority people as a health disparities population increases available funding for much-needed research. In this article, we speak to the need for a biocultural human biology of gender/sex diversity by delineating factors that influence physiological functioning, mental health, and physical health of TGD people. We propose that many of these factors can best be investigated with minimally invasively collected biomarker samples (MICBS) and discuss how to integrate MICBS into research inclusive of TGD people. Research use of MICBS among TGD people remains limited, and wider use could enable essential biological and health data to be collected from a population often excluded from research. We provide a broad overview of terminology and current literature, point to key research questions, and address potential challenges researchers might face when aiming to integrate MCIBS in research inclusive of transgender and gender diverse people. We argue that, when used effectively, MICBS can enhance human biologists' ability to empirically measure physiology and health-related outcomes and enable more accurate identification of pathways linking human experience, embodiment, and health.

Daily Vaginal Microbiota Fluctuations Associated with Natural Hormonal Cycle, Contraceptives, Diet, and Exercise

The vaginal microbiome is a critical component of women’s sexual and reproductive health, with variations in microbial composition, particularly the loss of Lactobacillus species, being implicated in gynecologic and obstetric diseases. Given that the vaginal microbiome is so crucial, why do vaginal microbial profiles vary strikingly from person to person and even change over time within the same person? In the present study, which tracked the daily vaginal microbiomes of young healthy women through different lifestyles, we found that use of a locally released progestin contraceptive, a vegetarian diet, and intense exercise appear to lead to vaginal microbiome alterations and loss of Lactobacillus species. The impact of these vaginal microbiome changes on immediate and long-term health remain to be investigated.

The microorganisms of the vaginal tract are critical for vaginal and reproductive health. However, the regulation of these microorganisms is not well understood. Therefore, we investigated whether different factors regulate the vaginal microbiota of healthy college-aged women (n = 26) with high temporal resolution by collecting daily self-administered vaginal swabs and using 16S rRNA sequencing for bacterial identification. As expected, vaginal microbiota clustered into five predefined community state types. Vaginal microbial diversity, stability, and Lactobacillus abundances were associated with the menstrual cycle and hormonal contraceptive use. Vaginal microbial diversity, as measured using the Shannon index, increased during menses (P < 0.001), while Lactobacillus abundances decreased (P = 0.01). The covariance of these microbial measures with previously established estradiol levels suggests that estrogens can regulate vaginal microbiota. Moreover, the use of hormonal contraceptives may alter the temporal dynamics of the vaginal microbiota and decrease Lactobacillus abundances, depending on hormonal content and release method. Interestingly, intrasample diversity was greater in participants on a vegetarian diet (P = 0.004) and among participants who exercised more (P = 0.04). These findings indicate that ovarian hormones, diet, and exercise can regulate vaginal microbial composition and stability and may impact vaginal and reproductive health.

IMPORTANCE The vaginal microbiome is a critical component of women’s sexual and reproductive health, with variations in microbial composition, particularly the loss of Lactobacillus species, being implicated in gynecologic and obstetric diseases. Given that the vaginal microbiome is so crucial, why do vaginal microbial profiles vary strikingly from person to person and even change over time within the same person? In the present study, which tracked the daily vaginal microbiomes of young healthy women through different lifestyles, we found that use of a locally released progestin contraceptive, a vegetarian diet, and intense exercise appear to lead to vaginal microbiome alterations and loss of Lactobacillus species. The impact of these vaginal microbiome changes on immediate and long-term health remain to be investigated.