A side effect of writing this blog is getting a LOT of targeted ads for various supplements, vitamins, and probiotics. It’s awesome because it gives me constant content, but also sends me on weird rabbit holes and makes me wonder whether these things are maybe actually worth their salt. Today we’re talking about so-called “probiotics for women”- more accurately, probiotics for vaginal health. Do they actually prevent urinary tract infections (UTIs), bacterial vaginosis (BV), and yeast infections?
Note: While I mention “probiotics for women”, this is primarily because these probiotics are often trendy and marketed towards a young, woman audience. However, what I’m talking about in regard to vaginal probiotics applies to anyone who has a vagina, regardless of gender identity.
Probiotics and how they impact the microbiome
In our bodies, there are between 10-100 trillion bacteria that exist symbiotically (aka in a mutually beneficial way ) with us. We use the term “microbiome” to refer to the whole catalog of these bacteria and their genes, the majority of which exist in the digestive tract.
Probiotic is a term for these live bacteria (or yeasts) that are beneficial to your body—”probiotics” as we usually refer to them is in reference to a probiotic supplement. Taken in sufficient quantities, probiotic supplements have the alleged ability to impact everything from obesity to eczema.
We are learning more and more about probiotics and their impact on the microbiome. 1.7 billion USD has been spent on research into the human microbiome in the past decade alone, and much of this is focused on understanding the role of probiotics in changing our health.
What is the difference between “probiotics for women” and vaginal probiotics?
Most of the probiotics on the market targeted to women seem to be focused on improving gut health. Women have irritable bowel syndrome (IBS) at nearly 2 to 2.5 times the rate of men, and are more likely to suffer from IBS-C (constipation). Given this disparity, it makes sense that constipation may be a target in “probiotics for women”, especially those containing B. lactis, a promising probiotic for treating constipation.
As far as treatment for stomach issues, there’s fairly good evidence to suggest that probiotics can make a difference. (We can get into this another time, because the gut microbiome absolutely fascinates me.)
When talking about vaginal probiotics, there’s two main kinds:
- oral probiotics- taken via the mouth
- suppositories- inserted directly into the vagina
What do probiotics for women claim they’re good for?
Yeast infections
Yeast infections, also known as vaginal candidiasis, are caused by a fungus (yeast) called Candida. Although around 20% of people with Candida in the vagina are asymptomatic, in the other 80%, they are likely to have burning, itching, pain, and abnormal discharge.
Bacterial vaginosis
Bacterial vaginosis, aka BV, occurs when the vaginal bacteria overgrows. It’s not caused by any one thing, but often comes along when something throws the pH of your vagina out of whack. This can be the result of douching (just say no!) or a new sexual partner, but it’s not considered an STI.
Urinary tract infections
UTIs occur when bacteria from the skin or the rectum make their way into the urinary tract. This means they can exist in the urethra, bladder, or kidneys. Again, while new sexual partners can increase the risk of getting a UTI, they aren’t necessarily caused by sex.
In people with vaginas, the urethra is closer to the vagina and rectum, which means there are more opportunities for bacteria to get into the urethra. It’s all a question of mechanics, and some people are simply more likely to get frequent UTIs. (A note: while peeing after sex is a good way to “flush” bacteria out of the urinary tract, it’s certainly not a cure-all, and some people who never pee will never get a UTI, whereas others can have a perfect pee-after-sex record, but are still prone to them).
Why do vaginal probiotics work (in theory)?
The general reasoning behind taking vaginal probiotics makes sense: insufficient amounts of certain bacteria (namely lactobacilli) are associated with UTIs and yeast infections. Probiotics seem like an easy fix since they can introduce live lactobacilli back into the body, and help restore the quantities of lactobacilli to a healthy level. This same method of ingesting probiotics orally has been shown to work fairly well in the gut, but it doesn’t really seem to be the case for the vagina.
What science says about vaginal probiotics
A meta-analysis (statistical analysis that combines the results from multiple studies), found that from 12 studies and over 1,300 patients, a beneficial effect from probiotics was seen for patients with bacterial vaginosis. However, the authors of the meta-analysis cautioned that the studies, due to their varied designs, didn’t give sufficient evidence for or against the use of probiotics for bacterial vaginosis.
Yet ANOTHER meta-analysis on bacterial vaginosis found that while probiotics helped either in conjunction with an antibiotic called metronidazole or the estrogen estriol, there wasn’t sufficient evidence to show that they helped on their own. Welp.
The literature on yeast infections is equally dismal—many of the studies on yeast infection prevention or treatment with probiotics have small sample sizes, no control group, or included those who didn’t even have confirmed instances of recurring yeast infection (!!!).
Some thoughts:
- If you’ve only had one yeast infection, you’re clearly a chosen one from a higher power, and I envy you.
- It makes it hard to determine if probiotics prevent yeast infections from occurring if there isn’t already a history of someone getting yeast infections.
One good sign- probiotics that are taken alongside the typical antifungal treatment help to decrease the rate of yeast infection returning within one month, but unfortunately this doesn’t extend to any long-term benefit in continuing to take probiotics.
Finally, UTIs. There is SO much talk about the ability of probiotics to prevent UTIs, but the science is…murky. Some probiotic companies (which will go unnamed) have cited this study about the potential of probiotics to resolve UTIs. The study is 10 years old, has only 10 subjects (6 of whom saw improvement), and has no controls. Using this study to justify probiotics for UTI treatment is what we here at Girls Love Evidence call “not evidence-based”.
Lactobacillus strains seem to be the best bacteria for keeping the vaginal flora in line and preventing UTIs. Many of these studies use intravaginal (yes, in-the-vagina) ovules that contain probiotics.
(P.S. Cranberry juice is also not a cure-all for UTIs, I’m sorry. But it is delicious.)
Final Verdict
Are probiotics for women/vaginal probiotics effective? Well… kinda. There is certainly anecdotal evidence that would suggest they do, but if you’re here, you probably care about whether or not they work from a clinically-validated perspective.
And like most things I tend to research, we just don’t know yet. This article has been requested by many and took me forever to write because I spent so much time digging through papers to see if anything had solid evidence.
After reading a whole lot and finding nothing promising, I finally thought to look to the Internet’s favorite gynecologist, Dr. Jen Gunter, and her book The Vagina Bible.
Seriously. If you have a vagina or have ever come in contact with anyone who does, you NEED this book. It is life-changing magic. I’m kind of a nerd when it comes to this stuff (shocking, I know) and I learned so much about topics I’ve never even really thought twice about.
In her book, she comes to essentially the same conclusion I did — that the science just isn’t all there, and that they can be pretty dang expensive. I sincerely hope that the science does get there because I would love to have an easy solution for irritating medical issues that leave me scrambling to get a doctor’s appointment.
I don’t take vaginal probiotics, and don’t see myself starting to unless more research shows their benefit. However, if you want to try them out, there isn’t a significant risk in doing so, just consult your doc beforehand as you should always do before adding a new supplement or OTC medication into your routine.
Thank you for reading, and I will see you soon for some more evidence-based health and wellness fun. I realize that this blog is slowly turning into “Al Ruins Everything”, and I really, really, DO want to write an article someday where I find awesome scientific evidence for the claims I’m investigating. I promise it will happen. Until then, I will be chugging cranberry juice regardless of whether or not it works because I genuinely enjoy it.
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