The Vaginal Microbiome, Explained

Your gut has a microbiome; your skin has a microbiome; and yes, your vagina does too. In fact, the vaginal microbiome is arguably one of the most fascinating (and misunderstood) ecosystems in the body. So let’s talk about it. 

Whether you’re somebody who’s struggled with recurrent yeast infections, BV, been frustrated by mysterious odors, or you’re just curious to know what’s going on down there, this one’s for you. 

What is the vaginal microbiome? 

The vaginal microbiome is the community of microorganisms — mainly bacteria — that live in and around the vagina. Just like your gut microbiome helps regulate digestion and immunity, your vaginal microbiome plays a major role in keeping you healthy, comfortable, and protected.

What makes the vaginal microbiome unique compared to other microbiomes in the body is that less diversity is actually better. In most ecosystems, biodiversity is a sign of health. But in the vagina, a healthy microbiome is typically dominated by just one genus of bacteria: Lactobacillus.¹ 

 

Lactobacillus: The unsung hero of vaginal health 

Lactobacillus bacteria are the good guys. They’re the reason your vagina is naturally acidic, and it’s that acidity that keeps harmful microorganisms from taking over. 

Here’s how it works: Lactobacillus produces lactic acid and hydrogen peroxide, which keeps vaginal pH within a healthy range between about 3.8 to 4.5.² At that pH level, most harmful bacteria and fungi simply can’t survive. This system is self-cleaning and self-protecting, which is why things like douching can be so harmful. (We’ll get to that in a second!) 

But in order for the system to work, Lactobacillus has to be thriving. 

There are a few common species of Lactobacillus in the vagina: L. crispatus, L. iners, L. jensenii, and L. gasseri. These three powerhouses contribute to that protective acidic environment.³

Basically, when Lactobacillus populations are robust, your vaginal environment stays balanced. When they drop because of stress, antibiotics, hormonal changes, diet, or sexual activity, other microorganisms can move in. And that’s a problem. 

 

The “bad” guys  (sort of)

While Lactobacillus may be the star of the show, the vaginal microbiome can also harbor a bunch of other bacteria, like Gardnerella vaginalis, Mycoplasmagenitalium, and Group B streptococcus, that cause trouble when they overgrow.⁴

We don’t want to say these are the “bad” bacteria, necessarily; but when they get out of control, they can cause things like Bacterial Vaginosis, or BV. 

BV is actually the most common vaginal condition in women ages 15 to 45.⁵  Lots of people with BV don’t have any symptoms at all, but if you do, you might notice: unusual vaginal discharge; pain, itching or burning in the vagina; a fishy-like odor; burning when peeing; or itching around the outside of the vagina.⁵ This imbalance in vaginal bacteria is, fortunately, easy to treat. You just need to get things back in balance. 

Yeast infections, on the other hand, are not directly caused by bacteria but by a common fungus, Candida albicans. Symptoms of a yeast infection include itching, burning, and thick white discharge.⁶ While yeast is normally present in the vagina in small amounts, a shift in vaginal pH or a dip in Lactobacillus can allow it to grow out of control. 

 

How do I know if my pH balance is off? 

Some common signals from your body that your pH is out of whack include²: 

• A noticeable change in odor (fishy, strong, or just "off")
• Unusual discharge — in color, consistency, or amount (learn more about What Your Vaginal Discharge Is Telling You About Your Health)
• Itching, burning, or general discomfort
• Recurring BV or yeast infections

What causes my pH to get thrown off? 

According to Cleveland Clinic, there are several things that can disrupt the somewhat delicate balance that is our vaginal ecosystem. Some of the most common are²:

• Infections: Untreated infections like yeast infections, bacterial vaginosis, and trichomoniasis. 
• Antibiotics: Just like taking antibiotics can wipe away your healthy gut bacteria, they can wipe away your healthy vaginal bacteria as well.
• Hormone levels: Fluctuating hormones during pregnancy, menopause, and your menstrual cycle can all impact vaginal pH. (Yay.) Hormonal birth control can also cause an imbalance. 
• Douching or using certain hygiene products: Experts discourage women from using douches to “clean” their vaginas. The vagina is a self-cleaning system, and using products that strip away the good bacteria in there should be avoided. 
• Some sexual activity: Sexual lubricants, condoms, and semen can all affect your pH. Using dirty sex toys can also introduce harmful bacteria to your vagina. (More on how to properly clean your sex toys here!) 
• Pretty much anything on this list: Throughout history, women have used some shocking methods to clean and “purify” their vaginas. We’ve made a whole list of torturous tools used from the Middle Ages to now. All of this would be considered a major no no.
• Food play: Strawberries and cream might seem like a sexy idea, but try to keep them far away from the vagina. Sugary foods (actually, most foods) can cause pH imbalance issues when put near or in the vagina. 
• Sugary foods: In fact, eating too much sugar can also throw the vagina’s pH out of whack. 

 

What to know about vaginal probiotics

Since the vaginal microbiome is essentially a Lactobacillus ecosystem, it makes sense that supporting those bacteria is a key part of maintaining vaginal health. That's where vaginal probiotics can come in. 

Unlike most probiotic supplements designed for gut health, vaginal probiotics are specifically formulated with strains of Lactobacillus that support the vaginal environment. Research shows that supplementing with Lactobacillus probiotics can help restore and maintain a healthy vaginal flora; especially after taking antibiotics or during periods of hormonal change.*⁷

That’s why URO Vaginal Probiotic is formulated with clinically-studied ingredients—Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus fermentum, and  Xylooligosaccharides (XOS) — specifically chosen for their role in vaginal flora support. Rather than a generic multi-strain formula, this supplement targets the exact bacteria your vaginal microbiome relies on most, to keep things comfortable, healthy, and balanced.