Series, resources, tools

DefinitionsFor ParentsSeed 101SeedLabs

Coming Soon

Skin Microbiome

Oral Microbiome


Vaginal Health Research Has Lagged For Years: That's Starting to Change

The history of vaginal health research is marred by gender biases and sexist science. Finally, that’s starting to change—thanks in part to cutting-edge vaginal microbiome research.

10 minutes

42 Citations

The term “hysteria” is derived from the Greek word hystera, which means uterus.1 This is just one example of how the (predominantly male) physicians of centuries past treated female reproductive organs. A site of disgust and disease, the uterus has been referred to as a “sewer”, while the clitoris has been deemed a “shameful member” and “the devil’s teat.”2,3,4 In the 1800s, neurologist Jean-Martin Charcot attempted to free women of hysteria by creating a device called the “ovary compressor,” which did exactly what you’d think it did.5 (Spoiler: It didn’t work.) 

Clearly, the study of vaginal health is seeped in an infuriating history full of gender biases and systemic inequalities. This has caused generations of women in the U.S., especially Black and Latina women, to face mistreatment and neglect from the medical community—and unfortunately, these issues persist today.6,7 Today, we’re taking a tour of how the gender health gap has affected vaginal health research, the milestones we’ve reached, and what we have yet to uncover.

A Brief History of the Gender Health Gap

The deep roots of patriarchal medicine meant that women actually weren’t included in clinical research until relatively recently.

“Women—whose hormonal cycles were thought to introduce too many complicating variables—were actively excluded from participating in most clinical trials until the early 1990s, when Congress passed a mandate requiring that clinical research include members of the other half of the population” explains Ava Mainieri, Ph.D., a geneticist and evolutionary biologist specializing in female reproductive health.

The lack of research on women was partly a response to the thalidomide tragedy.8 In the late 1950s and early 1960s, pregnant women across 46 countries were prescribed the medication thalidomide, which was intended to treat morning sickness but unknowingly resulted in severe birth defects in thousands of children.8,9 After that, researchers thought it was best not to include women of childbearing age in studies as a safety measure. 

It wasn’t until the establishment of the National Institute of Health (NIH) Revitalization Act in 1993 that the NIH established guidelines for women to be more prominently included in clinical research trials.10 Though even then, says Dr. Mainieri, studies of female health were largely limited to fertility.

Many years later, in 2015, the NIH introduced another policy that required anyone who applied for grant funding from the NIH to take into account both males and females in developing research questions, designing studies, collecting data, analyzing results, and reporting findings. If there’s a valid reason for examining only one sex, researchers had to explain why.11 

And Dr. Mainieri notes that it was only in 2014 that the NIH established a branch of gynecological research to study female sexual organs—such as the vagina, uterus, and ovaries—in their own right, beyond their role in reproduction.12 “In other words: it was less than 10 years ago that a federal research institution first acknowledged the importance of these organs to the health of a woman, whether or not she intends to get pregnant,” she says. It really shows you where their priorities were, huh?

This shouldn’t come as much of a surprise when you consider that the medical industry has long treated female reproductive organs as mysterious at best; shameful and dirty at worst. Back in 1955, bacteriologist Herman L. Gardner, M.D. wrote of bacterial vaginosis (BV): “While the disease is not a serious one, it is physically and esthetically objectionable, and has undoubtedly contributed to the popular believe that all vaginas are tainted and in need of frequency douching.” As Rachel E. Gross reports in her book, Vagina Obscura: An Anatomical Voyage, Gardner then went on to conduct in which he transferred the bacteria he suspected caused BV into women who had never had the condition—some of whom were pregnant. These questionable trials didn’t land him in jail or get him disbarred from medicine. In fact, it just got the bacteria in question named after him: Gardnerella.13

Gross goes on to write that this study was happening around the same time that women were encouraged to inject dubious ingredients—from mercury to nitrate of silver—to treat any odor and unusual discharge that society deemed unladylike. 

The Lingering Effects of Sexist Research

We’ve come a long way from a time when women were told to douche with Lysol, but the exclusion of female participation has created a vacuum of data that still lingers.14 

Today, only 4% of medical technology research and development spending in the United States is focused on female-specific conditions.15 According to a 2021 study, far more resources are allocated towards diseases that primarily affect men, and those that affect women receive half as much funding on average.16 

As a result of this underfunding, we’re still lacking solutions for some of the most pervasive vaginal health complaints. Just consider the fact that so many women who experience dyspareunia (painful sex) never report it to their doctor. “Among those who do seek treatment, negative experiences are common, including invalidated concerns, not receiving a formal diagnosis, and being given treatment perceived as ineffective,” reads a report in BJOG: An International Journal of Obstetrics & Gynaecology.17 

It also takes around 10 years on average for a woman to receive a diagnosis for endometriosis, a condition that affects 1 in 10 reproductive-age women globally.18,19 This, too, is partially due to a lack of research. As Abby Norman writes in Ask Me About My Uterus, if you put endometriosis into PubMed, you get about 1,800 pages of results. Liver disease—which affects significantly fewer people—yields over 30,000.20 

Researchers also have yet to determine the exact cause of polycystic ovary syndrome (PCOS), a disorder that impacts 5-10% of women ages 18 to 44.21

And despite over 20 million women in the U.S. currently harboring BV, there are still many unknowns about the disorder, and effective long-term treatments are scarce.22 Thanks to underfunding, Dr. Mainieri explains, the antibiotics currently used for BV treatment have remained unchanged since 1982, and over half of women who are treated experience a recurring infection within 6-12 months.23,24

But amidst this bleak landscape, there shines a beacon of hope: the study of the vaginal microbiome.

The Vaginal Microbiome: An Exciting New Frontier

Although research on the vaginal microbiome (VMB) has lagged in comparison to research on the gut microbiome, scientists are learning that it’s a key player in women’s health—one that may hold the key to progress in an area that hasn’t advanced nearly enough.

Many vaginal infections are linked to “dysbiosis,” or an imbalance in the vaginal microbiome.25 Vaginal microbiome dysbiosis is associated with conditions like urinary tract infections (UTIs) and BV, as well as infertility, pregnancy loss, and possibly even cancer.25-30

A handful of milestone discoveries have provided valuable insights into the dynamics of microbial communities in the vagina, laying the groundwork for understanding their role in women’s health. 

In 2011, Jacques Ravel, Ph.D. a leading expert in vaginal microbiome science, published a fascinating study on the vaginal microbiome.31 “Dr. Ravel’s work is crucial to understanding the vaginal microbiome’s role in preventing or treating common issues in gynecology, urology, infectious disease, and reproductive medicine, highlighting the critical need for innovation in women’s health,” says Dr. Mainieri. 

The research found that most women have one of five “types” of vaginal microbiomes. These Community State Types (CSTs) are determined by which species of Lactobacillus bacteria is (or isn’t) currently dominating the vaginal environment: 

  • CST I: Lactobacillus crispatus dominant
  • CST II: Lactobacillus gasseri dominant
  • CST V: Lactobacillus jensenii dominant
  • CST III: Lactobacillus iners dominant
  • CST IV: Non Lactobacillus dominated

Though we still have a lot to learn about variations within these types, some seem to be more protective, while others are at a higher risk for a range of adverse outcomes such as recurring BV, STI acquisition, and preterm birth.32

CST I is largely considered the most stable and protective type of vaginal microbiota. Research shows that its dominant bacterium, L. crispatus, is associated with anti-inflammatory effects that help protect its host against BV and HIV.32,33

This could mean that the vaginal microbiome affects not only your overall well-being and future health outcomes, but the specific species of Lactobacillus that inhabit it can help predict disease risk and acquisition.

The Next Wave of Vaginal Health Research

There’s still plenty we don’t know about the vaginal microbiome, but scientists are hard at work learning more about this invaluable element of women’s health. Here’s a peek into the future of VMB research:

Microbiome transplants: Researchers are exploring the potential of vaginal microbiome transplants (VMTs) to treat chronic dysbiosis. VMTs involve transferring vaginal fluid from someone with a steady-state vaginal microbiome to someone with an unbalanced vaginal environment. Though it’s a new treatment approach, early results are promising. After successfully helping one patient with vaginal dysbiosis get pregnant, it is now being tested on a larger group of women in the U.S. with recurrent BV.34,35

3D tissue models: “The study of the vaginal microbiome is further complicated by the absence of suitable animal models,” explains Dr. Mianieri. Humans appear to be the only species with Lactobacillus-dominant VMBs starting at puberty (rats, mice, and nonhuman primates have communities dominated by different bacteria).36 “This difference hampers the ability to effectively test scientific hypotheses,” she adds. Now, some researchers are developing alternatives to animal models for clinical research, such as 3D cell tissue models.37 Compared to traditional 2D cultures, 3D models are more accurate representations of the female reproductive system. Researchers are also using these 3D models to develop and test treatments for cervical cancer.38

Live biotherapeutics: Dr. Ravel’s ongoing CST research continues to open doors for novel vaginal care therapies, including live biotherapeutics—vaginal probiotics that utilize beneficial Lactobacillus strains along with the nutrients they need to grow. Utilizing data collected over 15 years, Dr. Ravel’s team has assembled the VIRGO database, the most detailed map of the vaginal microbiome landscape to date.39 This database combs through a bank of over 1,000 microbial strains to find the L. crispatus strains most associated with VMB stability and resilience. Now that these have been identified, they can be used in clinically validated probiotics that help restore a strong, thriving vaginal microbiome.

New approaches to cancer care: “An area of keen interest is the interaction between vaginal microbes and the development of cancer, particularly in how the microbiome influences vaginal and cervical cell health,” explains Dr. Mainieri. She explains that microbiomes dominated by non-Lactobacillus species seem to correlate with a higher infection rate of human papillomavirus (HPV) and an increased risk of cervical cancer.32,40 “This raises critical questions about whether these bacteria potentially contribute to cancer development or thrive in the environment created by cancer,” she adds. The next step will be determining whether treatments aimed at the VMB can be used to prevent or alleviate these all-too-common diseases.

Solutions to fertility challenges: Another area of research with exciting potential is the vaginal microbiome’s impact on fertility. “Research on in vitro fertilization (IVF) has indicated that the types of microorganisms present in the uterus during embryo transfer can affect pregnancy outcomes,” Dr. Mainieri says.41 “This suggests that understanding the microbiome’s role in the upper reproductive tract could be a significant next step in microbiome research, potentially revealing how it influences pregnancy and fertility.”

An Infuriating Past Gives Rise to a Promising Future 

We’ve made significant progress since the days when physicians believed that the uterus could wander around the body, but there’s still a long way to go in achieving gender equality.42 

Women have been ignored, gaslit, and left behind in the medical field for too long. By bridging the gender health gap and prioritizing research on the vaginal microbiome, we can pave the way for a future where all women receive the attention and care they deserve.


  1. Bailey, P. (1966). Hysteria: The history of a Disease. Archives of General Psychiatry, 14(3), 332.
  2. The history of the female reproductive system. (n.d.).
  3. Gross, R. E. (2020, March 4). The clitoris, uncovered: An intimate history. Scientific American.
  4. Russo, N. (2023, May 15). The still-misunderstood shape of the clitoris. The Atlantic.
  5. Shorvon, S. (2007). Fashion and cult in neuroscience the case of hysteria. Brain, 130(12), 3342–3348.
  6. Swanson, M. L., Whetstone, S., Illangasekare, T., & Autry, A. M. (2021). Obstetrics and gynecology and reparations: The debt we owe (and continue to accumulate). Health Equity, 5(1), 353–355.
  7. Fortuna, L. R., Noroña, C. R., Porche, M. V., Tillman, C., Patil, P. A., Wang, Y., Markle, S. L., & Alegría, M. (2019). Trauma, immigration, and sexual health among Latina women: Implications for maternal-child well-being and reproductive justice. Infant Mental Health Journal, 40(5), 640–658.
  8. Kim, J. H., & Scialli, A. R. (2011). Thalidomide: The tragedy of birth defects and the effective treatment of disease. Toxicological Sciences: An Official Journal of the Society of Toxicology, 122(1), 1–6.
  9. Vargesson N. (2015). Thalidomide-induced teratogenesis:History and mechanisms. Birth Defects Research. Part C, Embryo Today: Reviews, 105(2), 140–156.
  10. Mastroianni, A. C., Faden, R., & Federman, D. (1994a). NIH Revitalization Act of 1993 Public Law 103-43. Women and Health Research – NCBI Bookshelf.
  11. NIH policy on sex as a biological variable. (2024, April 30).
  12. Gynecologic Health and Disease Branch (GHDB). (2024, May 2).
  13. Gross, R. E. (2022). Vagina obscura: An anatomical voyage. W. W. Norton & Company.
  14. Eveleth, R. (2013, November 15). Lysol’s vintage ads subtly pushed women to use its disinfectant as birth control. Smithsonian Magazine.
  15. Unlocking opportunities in women’s healthcare. (2022, February 14). McKinsey & Company.
  16. Mirin, A. (2021). Gender disparity in the funding of diseases by the U.S. National Institutes of Health. Journal of Women’s Health, 30(7), 956–963.
  17. Mitchell, K. R., Geary, R., Graham, C. A., Datta, J., Wellings, K., Sonnenberg, P., Field, N., Nunns, D., Bancroft, J., Jones, K. G., Johnson, A. M., & Mercer, C. H. (2017). Painful sex (dyspareunia) in women: Prevalence and associated factors in a British population probability survey. BJOG : An International Journal of Obstetrics and Gynaecology, 124(11), 1689–1697.
  18. Pugsley, Z., & Ballard, K. (2007). Management of endometriosis in general practice: The pathway to diagnosis. The British Journal of General Practice: The Journal of the Royal College of General Practitioners, 57(539), 470–476.
  19. World Health Organization: WHO & World Health Organization: WHO. (2023, March 24). Endometriosis.
  20. Norman, A. (2018). Ask me about my uterus: A quest to make doctors believe in women’s pain. Bold Type Books.
  21. Ndefo, U. A., Eaton, A., & Green, M. R. (2013). Polycystic ovary syndrome: A review of treatment options with a focus on pharmacological approaches. P & T: A Peer-Reviewed Journal for Formulary Management, 38(6), 336–355.
  22. CDC – Bacterial Vaginosis Statistics. (n.d.).
  23. An uncomfortable truth: How stigma and a lack of funding has set back research and treatments for vulvovaginal disorders. (n.d.). EurekAlert!
  24. Chow, K., Wooten, D., Annepally, S., Burke, L., Edi, R., & Morris, S. R. (2023). Impact of (recurrent) bacterial vaginosis on quality of life and the need for accessible alternative treatments. BMC Women’s Health, 23(1), 112.
  25. Yuan, D., Chen, W., Qin, J., Shen, D., Qiao, Y., & Kong, B. (2021). Associations between bacterial vaginosis, candida vaginitis, trichomonas vaginalis, and vaginal pathogenic community in Chinese women. American Journal of Translational Research, 13(6), 7148–7155.
  26. Stapleton, A. E. (2016b). The vaginal microbiota and urinary tract infection. Microbiology Spectrum, 4(6).
  27. Amabebe, E., & Anumba, D. (2018). The vaginal microenvironment: The physiologic role of Lactobacilli. Frontiers in Medicine, 5.
  28. Ravel, J., Moreno, I., & Simón, C. (2021b). Bacterial vaginosis and its association with infertility, endometritis, and pelvic inflammatory disease. American Journal of Obstetrics and Gynecology, 224(3), 251–257.
  29. Saadaoui, M., Singh, P., Ortashi, O., & Al Khodor, S. (2023). Role of the vaginal microbiome in miscarriage: Exploring the relationship. Frontiers in Cellular and Infection Microbiology, 13, 1232825.
  30. Champer, M., Wong, A. M., Champer, J., Brito, I., Messer, P. W., Hou, J. Y., & Wright, J. D. (2017). The role of the vaginal microbiome in gynaecological cancer. BJOG, 125(3), 309–315.
  31. Ravel, J., Gajer, P., Abdo, Z., Schneider, G., Koenig, S., McCulle, S. L., Karlebach, S., Gorle, R., St Clair Russell, J., Tacket, C. O., Brotman, R. M., Davis, C., Ault, K. A., Peralta, L., & Forney, L. J. (2010). Vaginal microbiome of reproductive-age women. Proceedings of the National Academy of Sciences of the United States of America, 108(supplement_1), 4680–4687.
  32. France, M., Alizadeh, M., Brown, S. E., Ma, B., & Ravel, J. (2022). Towards a deeper understanding of the vaginal microbiota. Nature Microbiology, 7(3), 367–378.
  33. Armstrong, E., & Kaul, R. (2021). Beyond bacterial vaginosis: Vaginal Lactobacilli and HIV risk. Microbiome, 9(1), 239.
  34. Wrønding, T., Vomstein, K., Bosma, E. F., Mortensen, B. O. G., Westh, H., Heintz, J., Mollerup, S., Petersen, A. M., Ensign, L. M., DeLong, K., Van Hylckama Vlieg, J. E. T., Thomsen, A. B., & Nielsen, H. S. (2023b). Antibiotic-free vaginal microbiota transplant with donor engraftment, dysbiosis resolution and live birth after recurrent pregnancy loss: A proof of concept case study. EClinicalMedicine, 61, 102070.
  35. Kwon, D. (2021, April 22 – 2025, June). Vaginal microbiota transplant to promote Lactobacillus-dominant cervicovaginal communities. Identifier NCT04046900.
  36. Miller, E. A., Beasley, D. E., Dunn, R. R., & Archie, E. A. (2016). Lactobacilli dominance and vaginal Ph: Why is the human vaginal microbiome unique?. Frontiers in Microbiology, 7, 1936.
  37. Łaniewski, P., & Herbst‐Kralovetz, M. M. (2021). Bacterial vaginosis and health-associated bacteria modulate the immunometabolic landscape in 3D model of human cervix. Npj Biofilms and Microbiomes, 7(1).
  38. Karolina Zuk, A., Wen, X., Dilworth, S., Li, D., & Ghali, L. (2017). Modeling and validating three dimensional human normal cervix and cervical cancer tissues in vitro. Journal of Biomedical Research, 31(3), 240–247.
  39. Ma, B., France, M., Crabtree, J., Holm, J. B., Humphrys, M. S., Brotman, R. M., & Ravel, J. (2020). A comprehensive non-redundant gene catalog reveals extensive within-community intraspecies diversity in the human vagina. Nature Communications, 11(1).
  40. Kyrgiou, M., & Moscicki, A. B. (2022). Vaginal microbiome and cervical cancer. Seminars in Cancer Biology, 86(Pt 3), 189–198.
  41. Haahr, T., Jensen, J. S., Thomsen, L., Duus, L., Rygaard, K., & Humaıdan, P. (2016). Abnormal vaginal microbiota may be associated with poor reproductive outcomes: A prospective study in IVF patients. Human Reproduction, 31(4), 795–803.
  42. Guidone, H. C. (2020). The womb wanders not: Enhancing endometriosis education in a culture of menstrual misinformation. In C. Bobel, I. T. Winkler, B. Fahs, et al. (Eds.), The Palgrave Handbook of Critical Menstruation Studies (Chap. 22). Palgrave Macmillan.