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What is the vaginal microbiome?

Your vaginal microbiome is associated with everything from recurrent infections to fertility challenges to STI acquisition. Don't worry if you've never heard of it — we'll introduce you!
Read Time — 5 minutes
By the Evvy team; Medically reviewed by Dr. Sabrina Sahini, MD

Despite centuries of stigmatization, the vagina is truly incredible. Among many other things, it’s the structural connection between the outside world and the female body’s most powerful reproductive organs. 

So it makes sense that the vaginal microbiome — defined as the complex ecosystem of microorganisms, including bacteria and fungi, that lives inside the vagina — has biologically evolved to help protect that reproductive system. 

Every day, the vaginal microbiome performs the equivalent of modern health miracles. It can fight off yeast infections and bacterial vaginosis (BV), protect a pregnancy, and possibly even defend against cancer, as well as play a crucial role in your overall health. 

Fig 1 -> Lactobacillus acidophilus, a protective vaginal bacteria

Microbiome research is a relatively new field, and lots of resources have been invested in understanding other human microbiomes like the one in your gut. But when it comes to your vagina, the microbiome has been overlooked.

We wish the reason why wasn’t yet another gender gap…but that’s why we’re here!

We created the Evvy Vaginal Health Test to provide you with groundbreaking insights into your own microbiome, while also elevating the vaginal microbiome to its rightful place in research and clinical care. 

‍How does the vaginal microbiome work?

While a variety of bacteria and fungi can exist in the vagina, a type of bacteria called lactobacilli are the local heroes. Lactobacilli ensure that the vaginal environment is inhospitable for potential pathogens. These bacteria work their magic in a variety of ways:

  1. Creating lactic acid that helps keep the pH low, ideally between 3.8 and 4.5. (Ever taken a vaginal pH test? Measuring the acidity of your vagina is a rough metric for the presence of protective bacteria in your vaginal microbiome!)
  2. Taking up space on the vaginal wall and preventing other pathogens from hanging around 
  3. Producing bacteriocins (your body’s natural antibiotic) to further inhibit the growth of disruptive bacteria 
  4. Keeping inflammation down in the genital tract

 A lack of lactobacilli in your vaginal microbiome can allow pathogens to colonize. If and when they do, that's referred to as vaginal dysbiosis

In a state of dysbiosis, there is a high diversity of various types of bacteria, in which disruptive microbes such as Gardnerella, E.coli, or Mycoplasma can flourish. 

These bacteria can then cause unwanted symptoms like itching, burning, irritation, or pain, as well as catalyze vaginal infections like BV, yeast infections, and urinary tract infections (UTIs).

An Evvy kit laid out on a table

Recurrent symptoms? Meet Evvy's at-home vaginal microbiome test, approved by leading OB-GYNs.

Learn more

Vaginal infections and the microbiome

Unfortunately, your vaginal microbiome isn’t just home to protective microbes. The bacteria and fungi that cause vaginal infections are also part of your microbiome. When the vaginal microbiome is disrupted, it creates an opportunity for these bad microbes to thrive.

The most common vaginal infection is bacterial vaginosis (BV), an umbrella term for bacterial infections. BV is defined by high bacterial diversity and an abundance of disruptive bacteria.

One in three women will get BV each year, and up to 84% of these cases are asymptomatic. BV disproportionately affects Black and Hispanic women, with disappointingly lacking research as to why (that's one of the many things Evvy's here to change!). 

Dysbiosis of the vaginal microbiome can also catalyze other types of infections, such as yeast infections,  aerobic vaginitis (AV) and cytolytic vaginosis (CV), many of which can have frustrating — and confusingly similar — symptoms, such as itchiness, abnormal discharge, and burning.

 If you’ve come to Evvy because you experience infections again and again - you’re not alone. Evvy was built by women who have been there! Moreover, vaginal infections are one of the largest categories of health issues that female-bodied people face. Aside from BV, 1 in 3 women will have a UTI by age 24, and 1 in 2 will experience one in their lifetime. Meanwhile, 75% of women will experience a yeast infection at least once in their lifetime. 

Through testing the vaginal microbiome, we can both provide better care for those who are suffering and move the needle in furthering research to better understand and treat these conditions. 

Fig 2 -> Microbes on the vaginal wall

The impact of the vaginal microbiome on overall health 

To add to the many reasons the vaginal microbiome deserves more attention: recent research has uncovered groundbreaking insights on the vaginal microbiome’s role in female health beyond the vagina.

 It turns out that having beneficial bacteria like lactobacilli in your vaginal microbiome can protect you from a variety of other potential health outcomes. Meanwhile, disruptive microbes can create a favorable environment for other infectious microorganisms to enter, increase inflammation, and inhibit your immune response.

Research has shown that the composition of your vaginal microbiome is associated with the risk of:

By knowing your individual microbial composition, you can take a proactive approach to your long-term health, as well as potentially prevent future health complications.

Not all microbiomes are the same 

Just as there are different blood types, research has shown that most vaginal microbiomes fall into one of five general categories, known as "Community State Types” (CSTs)

The level of protection and propensity for certain symptoms or health risks varies based on which Community State Type you are in. Unlike blood types, you can shift from one CST to another. 

Four of the types are dominated by a specific species of lactobacilli: 

  • Type 1: ‍Lactobacillus crispatus 
  • Type 2: ‍Lactobacillus gasseri 
  • Type 3: ‍Lactobacillus iners 
  • ‍Type 5: Lactobacillus jensenii 

Those who don't have a dominant species of lactobacilli are labeled as Type 4. Individuals who are experiencing vaginal dysbiosis (i.e. infections)  fall into this group. However, so do some rare healthy vaginal microbiome compositions, too. For this reason, Type 4 is broken into five more subgroups that get into further specifics. 

Want to know your CST?

Our Vaginal Health Test not only shows you all bacteria and fungi in your microbiome but what CST your microbiome falls into at that point in time.  

While research on the types is ever-evolving, testing for your type with Evvy can provide insight into your individual bacterial composition — both now and as it changes over time. Armed with the most comprehensive data and advanced testing methods, our team can help you understand what your type means for your health! 

Fig 3 -> We're looking to close the gender health gap (in addition to empowering women with information on their vaginal microbiome.)

An ecosystem in flux

Your vaginal microbiome is ever-evolving and fluctuates as other aspects of your life shift. There are multiple reasons that the vaginal microbiome changes over time, but some major contributors to this include:

Day-to-day behaviors also influence the health of the vaginal microbiome, including: 

Testing over time with Evvy can help correlate your habits and treatments with what’s going on in your microbiome, so you can isolate your specific triggers and take control of your vaginal health! 

Testing your vaginal microbiome

Evvy’s Vaginal Health Test is the first-ever metagenomic vaginal microbiome test to help you understand and improve your vaginal health. It’s a simple, at-home swab that uncovers all bacteria and fungi present in your vaginal microbiome. 

Unlike genetic results, which are static, microbiomes are dynamic and can reflect progression towards or away from disease. By testing over time, you can catch potential imbalances early, giving you the chance to proactively promote the protective bacteria and prevent the disruptive bacteria from taking hold.

Fig 4 -> Different treatments, medications, and supplements can affect your vaginal microbiome

And when you do change up your routine — try a new probiotic, change your birth control, etc. — we'll take the guesswork out of figuring out how it’s affecting your microbiome. By testing over time, you can see how your life and supplements are impacting your vaginal microbiome’s defense.

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