Too much Lactobacillus can be bad.
Yes, you read it right. Even though Lactobacillus are considered the most beneficial bacteria when it comes to vaginal health, too much can cause a condition known as cytolytic vaginosis (CV).
It is not clear what triggers this Lactobacillus overgrowth. Antibiotics, antifungals, or overuse of high-strength probiotics might have to do something with it .
CV is often misdiagnosed
Chances are you have never heard of CV before. A study reported that it affects only about 1.7% of women. But we believe this percentage might be higher, as CV is often misdiagnosed as yeast infection. Not surprising, because the symptoms can be similar:
- White or yellowish vaginal discharge
- Red and inflamed vulvar skin
- A burning sensation
- Pain during sex and while peeing 
Strikingly, 85% of women with CV and treated with antifungals do not see their symptoms improve. This reflects how frequently CV can be mistakenly diagnosed as a yeast infection.
The clue to distinguish CV from other vaginal infections
A unique feature of CV is its cyclical nature. Symptoms tend to be worse during ovulation and in the days before your period .
During these days, your estrogen production increases, which promotes the accumulation of a molecule called glycogen in your vagina. Glycogen is eaten by Lactobacillus bacteria which then produce lactic acid. A lot of lactic acid will irritate and damage your vaginal cells .
We know, it’s super unfair that while these guys are feasting, you feel the worst.
A correct diagnosis of CV should be based on more than just symptoms
CV can be easily mistaken for a yeast infection when only symptoms are considered. A history of antifungal treatments that did not work supports it could be CV. When in doubt, ask your provider for additional tests, as these will help establish a correct diagnosis.
- Tests that check for yeast, trichomoniasis, chlamydia, and bacterial vaginosis (BV)-associated bacteria will help rule out other infections.
- A pH measurement can also provide helpful information. Vaginal pH tends to be lower in women with CV (from 3.5 to 4.4) [3, 4].
- Looking at your vaginal sample under a microscope can also be helpful to confirm CV and rule out other infections [1, 4].
In CV, the vaginal microbiome looks “normal”
All we know here is that in CV Lactobacillus are highly abundant. But this is also true for healthy women. A small study found an association between high levels of Lactobacillus crispatus with CV. The same association was not found for a different Lactobacillus species .
There are no known complications from CV
Unfortunately, there are no good quality studies that address CV complications in women. We hope this will change in the future as more women are correctly diagnosed and research moves forward.
Things you can do to avoid CV
There are some general rules that will help you maintain a healthy vaginal microbiome. You can check our guide on vaginal health tips.
Stay alert on any changes in the color, smell, and quantity of your vaginal discharge. It is normal for it to vary during the menstrual cycle (if you are not pregnant) but any major change or unpleasant smell should be taken care of.
Vaginal probiotics containing Lactobacillus species are sometimes recommended to promote a healthy vaginal community.
- If your vaginal community is already dominated by Lactobacillus, there is no need to take any extra vaginal probiotics.
- If you are taking a gut probiotic with Lactobacillus in it, follow the recommended dosage. It is super unlikely to overdose on probiotics, but it’s best to avoid any unwanted effects.
- If your vaginal community is not dominated by Lactobacillus, you could definitely benefit from vaginal probiotics. Depending on your particular case, the recommendation might be to take more than the recommended dosage, and that’s fine.
CV can be treated
The sooner you take action, the better.
CV treatment involves raising the vaginal pH for a short period of time to clear the excess of Lactobacillus. This can be done by using something called Sitz baths.
A Sitz bath is made by mixing one tablespoon of baking soda with 4 liters of lukewarm tap water. Then all you have to do is sit in there and wait for those Lactobacillus to stop partying. Ask your provider for detailed instructions on how to do this and for how long, especially if you are pregnant as it might not be recommended for you.
A study reported that doing Sitz baths every two days for ten days was enough to see an improvement in symptoms .