Two men want to change the way we smell and by we I mean women and by smell I mean specifically our vaginas. They apparently also want to change the way dog feces smells, but I’m only going to talk about vaginas because that is my area of expertise.

Austen Heinz and Gilad Gome, founders of biotech startups Cambrian Genomics and Personalized Probiotics respectively, pitched the idea of customizable vaginal odors at a tech conference for start ups in California last week. Specifically a probiotic supplement that will enable women to change their vaginal odor. Called Sweet Peach, of course.

Probiotics are good bacteria that function as gatekeepers keeping bad bacteria in check. Until recently we thought this was all about lactobacillus acidophilus, however wIth the advent of DNA sequencing we can now study what is growing in the vagina without having to grow it in the lab (it turns out a lot of bacteria grows well in the vagina but poorly in a petri dish). We now know there are far more important strains of lactobacilli for vaginal health than acidophilus.

What makes a healthy vaginal ecosystem varies. While we know some types of bacteria are definitely good the specific combination that keep me healthy might not keep you healthy. In addition, while women who have low counts of good bacteria are more likely to develop a condition called bacterial vaginosis or catch gonorrhea or chlamydia if exposed other women can have low counts of good bacteria and never develop a healthy problem. Basically there are many co-factors we have yet to understand. It’s a complex ecosystem.

While probiotic supplements sound like a good idea (especially for a vagina lacking in good bacteria), there are no convincing studies that what is currently commercially available works. Some probiotics are just so hard to grow that supplements don’t exist, but again there are so many things we just don’t know yet.

Back to vulvovaginal odor. The genital scent of a woman is not just due to the mix of bacteria in the vagina, but also due to secretions from the multitude of sweat glands on the vulva and around the anus as well as the bacteria on the skin. Vulvovaginal odor can change in a way that we consider pathologic (i.e. a sign of a medical condition) with infections or when estrogen levels drop in the menopause. Vulvovaginal odor can also change when women remove their pubic hair as this alters skin bacteria and increases daily friction on the skin increasing gland secretions. Also, over cleaning the area paradoxically increases odor as the more you clean the more your glands produce. Douching is an especially bad habit for the vaginal ecosystem as it damages the good bacteria. Antibiotics, by killing good bacteria, and sexual activity can also change vaginal odor. Smoking can as well. 

It is a laudable goal to have a better understanding of the vaginal microbiome and design a probiotic that could help replace good bacteria. Bacterial vaginosis is a notoriously vexing health condition with a high recurrence rate and if everyone had very healthy vaginal bacteria that might help prevent bacterial vaginosis from recurring and reduce the transmission of HIV. However, there are lots of issues with the product (and message) Heinz and Gome are selling.

Personalized Probiotics tells you to send a sample and they will customize a strain of probiotics for you. But how do they you know if your sample reflects a heathy microbiome? Some women have what we think in the lab might not be an idea bacterial mix and yet never, ever lead to any health issues. And what time of day and month should you send in a sample? How long after having sex? Also, the vaginal microbiome is in flux so a single specimen in no way reflective.

Heinz and Gome implied they are going after the vaginal biome because it’s easier to “hack” than the bowel, but there are entire labs devoted to understanding the make-up of the vaginal microbiome and how it interacts with a woman’s environment and we are still a long way from understanding how to “hack.” I disagree that the vaginal microbiome is less complex that the bowel microbiome.

This lack of understanding of the microbiome is summarized in a quote from Heinz, “All your smells are not human. They’re produced by the creatures that live on you.” This is wrong. The “creatures” that live on us and in us, our bacteria, are us. The fact that they make us smell they way we do is not because they are bad or not human but rather this is how we evolved. We need good bacteria and they need us.

What about changing the way we smell like changing hair color? According to the Sweat Peach guys this new not-vagina but pleasant scent will help “connect you to yourself in a better way,” and let you know the “product is working.” (I assume he means the probiotics are growing). So a vagina not smelling like a vagina will be healthy and better! So the normal vulvovaginal scent is somehow disconnecting? Wow.

Vaginas do not need a different smell. They need to smell like vaginas. Telling women they can (and actually might want to) change that is the opposite of empowerment, never mind the potential health ramifications of using untested probiotics that will release an untested protein to change the odor of vaginal secretions. Women are already removing pubic hair and some are getting labia reductions to achieve a non-anatomical ideal that is being pushed as normal (and I see health ramifications of that almost every day). Now the way we smell is wrong too?

Building a better probiotic for vaginal health is a great goal, but there are no studies suggesting any commercially available probiotics can do that, so how the product from Personalized Probiotics will be any different remains to be seen.

How well an untested probiotic combination mixed up based on a single vaginal sample analyzed by Sweet Peach will help anything is unknown.

The ramifications of introducing a new variable to the vagina, a protein that changes odor is also completely unknown. It is a delicate ecosystem. I see women whose report long-term changes in vaginal odor after a single course of antibiotics for a sinus infection. There are often unforeseen consequences of messing with science before you have truly worked out the potential consequences.

You want to a build a better probiotic for vaginal health? Great. Study it. Prove it works and you’ll get a lot of people on board. But that message that a vagina should smell like anything but a healthy vagina is so painful it’s offensive and is the exact opposite of being connected with your body.

***Update, 5 pm PST

The owner of Sweet Peach Probiotics is not the two guys noted above, but a 20 year old woman named Audrey Hutchinson. She is apparently horrified at what was said and that her product was misrepresented and is not designed to change vaginal odor to something different than vagina. I am sad her product was misrepresented.

However, the goal of her company is to still design a customized probiotic supplement based on a a vaginal swab. This sounds like medical diagnostics to me and Hutchinson appears to make health claims (such as balancing the pH of the vagina), so this is something that will likely need FDA approval/oversight in someway or risk an FDA slap down like 23andme.

It’s a cool idea, but the science isn’t really there yet (as I detailed above). No study has convincingly shown probiotic supplements help vaginal health. Also, knowing the bacterial make-up at a given point in time does not tell you if this is unhealthy for a women or healthy and it’s the equivalent of seeing one or two frames from a movie.


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  1. TL;DR but I’ve never had a problem with the smell of a vagina. If it ain’t broke don’t fix it? (I did read the whole thing, because I read everything Jen writes. She’s the best!)

  2. Remember vaginal deodorants? I don’t know if they still exist, but my Mother introduced them to me in the mid-70’s when I got my first period. This mentality goes along with calling periods “the curse”, (another one of her faves!). It is a negative idea that belongs in the rubbish bin of human history, if we don’t know how our bodies smell when they are well, how are we going to identify when all is not as it should be? Masking smells with other smells, or changing the bacterial balance of the vagina is absolutely unnecessary, in my (not so humble) opinion, it is another unwanted assault on nature, (like bottled water in the Western world, but that is a whole other topic).

    1. The idea of personalized probiotics based on a single sample is still unlikely to be helpful. One of the most important strains is very difficult to grow. And then there is the fact a single sample is not representative and how do you decide what is optimal for a women? Science has yet to answer that question…

  3. Hang on…are you sure you dont want this. We can get versions of bacteria mix for different occassions. One might smell nice to women and could repel men. This will prevent rapists or a over horny partner or local neighbourhood perv from sniffing knickers… and lesbians can make selves unavailable to men highly attractive to women. Others might leave men smelling awful so their wives find out they have been cheating or make him unappealing to women. Other mixes could attract a particular man or male type. We could see a spin off business or two for fanny fans that help circulate smell around you.

    Im warming to try a different fanny fragrance.

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