Free tool
Vaginal Microbiome Explorer
The vaginal microbiome is the community of bacteria living in the vagina. In about 70% of women it is dominated by Lactobacillus species, which make lactic acid that keeps the vagina acidic. Researchers group these communities into five types. A type is a research label, not a diagnosis, so discuss any symptoms with a clinician.
How to use it
- Read across a row to see which bacteria dominate each community type and what research describes about it.
- Use the cards to see how communities shift with the menstrual cycle, sex and menopause.
- If you have unusual discharge, odor, itching, pain, fever or symptoms during pregnancy, see a clinician rather than relying on any microbiome label.
Reference
| Community type | Dominant bacteria | What research describes |
|---|---|---|
| Type I | L. crispatus | One of four types dominated by a single Lactobacillus species; Lactobacillus-dominated communities tend to be the most acidic. |
| Type II | L. gasseri | Dominated by a single Lactobacillus species; less common than types I and III in the 396-woman study. |
| Type III | L. iners | Dominated by a single Lactobacillus species; one of the most common types in the 396-woman study. |
| Type IV | No single dominant species; fewer lactobacilli and a wider mix of other bacteria | Found in some women without symptoms in research. A low-Lactobacillus mix is also the pattern CDC describes in BV, which only a clinician can diagnose. |
| Type V | L. jensenii | Dominated by a single Lactobacillus species; the least common type in the 396-woman study. |
Why lactobacilli matter
Vaginal lactobacilli produce lactic acid, which keeps the vagina acidic and has antimicrobial properties. That is why researchers pay close attention to whether a community is Lactobacillus-dominated.
Communities can shift
Tracking 32 women for 16 weeks showed vaginal communities can shift quickly with the menstrual cycle and sex, even in healthy women. One sample is a snapshot, not a fixed identity.
Life stage matters
As estrogen falls after menopause, Lactobacillus dominance tends to decline; reviewers say more trials are needed before probiotics can be recommended for this.
What Balance Complex does not contain
Balance Complex does not contain L. crispatus. It is not shown to change a person's community type, and probiotic effects are strain specific, so research on one strain does not carry over to another.
How this tool works
This is a fixed reference chart based on a study of 396 women that described five vaginal community types, reviews of vaginal Lactobacillus biology, a 16-week study of how communities change, and CDC clinical guidance on BV. It has no inputs and gives no result.
Frequently asked questions
What is a vaginal community state type?
It is a research label for the mix of bacteria found in a vaginal sample. A study of 396 women described five vaginal community types, four of them dominated by a single Lactobacillus species. The fifth has fewer lactobacilli and a wider mix of bacteria.
Which bacteria are most common in a healthy vagina?
About 70% of women have vaginal flora dominated by Lactobacillus, most often L. crispatus, L. gasseri, L. jensenii or L. iners. Many women without symptoms have other patterns, so a single sample does not define health.
Is a low-Lactobacillus community the same as BV?
Not on its own. Low-Lactobacillus communities were found in women without symptoms in research, while BV is a clinical diagnosis that CDC describes as normal Lactobacillus species being replaced by high levels of anaerobic bacteria. A clinician diagnoses BV with an exam and tests.
Can my vaginal community type change?
Yes. Tracking 32 women for 16 weeks showed vaginal communities can shift quickly with the menstrual cycle and sex, even in healthy women. After menopause, as estrogen falls, Lactobacillus dominance tends to decline.
Does Balance Complex contain L. crispatus?
No. Balance Complex does not contain L. crispatus, and it is not shown to change a person's community type. Probiotic effects are strain specific, so research on one strain does not carry over to another product's strains.
Should I get a vaginal microbiome test?
Consumer tests report which bacteria are present, but a result is not a diagnosis and communities change over time. If you have unusual discharge, odor, itching or pain, see a clinician, who can test for specific causes.
Why does vaginal acidity matter?
Vaginal lactobacilli produce lactic acid, which keeps the vagina acidic and has antimicrobial properties. CDC guidance uses a vaginal pH above 4.5 as one of several signs clinicians check for BV, alongside an exam and other tests.
Sources
- Ravel et al., 2011, Vaginal microbiome of reproductive-age women (PubMed 20534435)
- Petrova et al., 2015, Lactobacillus species as biomarkers and agents that can promote various aspects of vaginal health (PubMed 25859220)
- Gajer et al., 2012, Temporal dynamics of the human vaginal microbiota (PubMed 22553250)
- Tachedjian et al., 2017, The role of lactic acid production by probiotic Lactobacillus species in vaginal health (PubMed 28435139)
- Muhleisen and Herbst-Kralovetz, 2016, Menopause and the vaginal microbiome (PubMed 27451320)
- CDC: Bacterial Vaginosis, STI Treatment Guidelines
- NCCIH (NIH): Probiotics, usefulness and safety (effects are strain specific)
This tool gives general information for adults and does not diagnose or treat any condition. It is not a substitute for advice from a clinician. If you have severe symptoms, fever, or are pregnant, contact a healthcare professional.