TL;DR
The link between vaginal microbiome and fertility is one of the most active areas of reproductive health research, and it is something you can actively support with diet, testing, and clinician-guided flora care.
A 2017 review describes vaginal dysbiosis, meaning loss of Lactobacillus dominance and overgrowth of anaerobes, as associated with adverse urogenital and reproductive health outcomes in general terms 3. It does not report implantation, IVF or pregnancy-loss rates.
Dysbiosis, when Lactobacillus species drop and a mix of anaerobes takes over, is the pattern seen in bacterial vaginosis. The 2020 systematic review by van de Wijgert and Verwijs evaluated vaginal probiotics for BV and candidiasis and reported no fertility outcomes 4.
A vaginal microbiome test uses PCR or sequencing to identify your dominant flora. Whether testing changes IVF or recurrent-loss outcomes has not been shown in evidence we can cite here, so treat the result as information for a conversation with your clinician.
Fermented foods, prebiotic fiber, and avoiding douching are among the most studied lifestyle levers for a healthy vaginal microbiome.
L. acidophilus, L. rhamnosus, L. reuteri, and L. plantarum are among the species most studied for vaginal flora, though not for fertility outcomes.
Introduction: Why Your Vaginal Microbiome Matters When Trying to Conceive
The vaginal microbiome and fertility connection is one of the most active areas of reproductive research today. A 2017 narrative review by Tachedjian and colleagues describes the antimicrobial, antiviral and immunomodulatory properties of the lactic acid that lactobacilli produce, and notes that vaginal dysbiosis is associated with an increased risk of adverse urogenital and reproductive health outcomes 3.
What Is the Vaginal Microbiome, and Why Does It Affect Fertility?
The vaginal microbiome is a community of bacteria that supports reproductive-tract conditions through lactic acid production, low pH, and ecological balance. The review cited here characterises that state as vaginal eubiosis and contrasts it with dysbiosis, which it associates in general terms with adverse reproductive health outcomes 3. Four Lactobacillus species appear often in the vaginal-flora literature: L. acidophilus, L. rhamnosus, L. reuteri, and L. plantarum. A 2023 trial gave the first three orally to 36 asymptomatic women and measured Nugent scores, not fertility 1.
Not for use if pregnant, nursing, or trying to conceive: Balance Complex contains wormwood and black walnut hull. Understanding these baseline species matters because they anchor most clinical conversations about flora support during preconception.
How Does a Lactobacillus-Dominant Environment Shape Reproductive Outcomes?
A Lactobacillus-dominant vaginal community is the pattern described as vaginal eubiosis, with dysbiosis associated with adverse urogenital and reproductive outcomes in broad terms 3. The 2017 Tachedjian review describes vaginal dysbiosis as associated with adverse urogenital and reproductive health outcomes in general terms; it does not report implantation or pregnancy-loss rates 3. The proposed mechanism involves pH regulation and suppression of anaerobic overgrowth; the 2020 systematic review that is often cited here evaluated vaginal probiotics for bacterial and fungal dysbiosis, not fertility endpoints 4.
How Can Vaginal Flora Imbalance Affect Conception and Pregnancy?
The 2017 Tachedjian review associates dysbiosis with an increased risk of adverse urogenital and reproductive health outcomes, stated at that level of generality rather than as conception or complication rates 3. Recurrence matters too: bacterial vaginosis often comes back after treatment, which is one reason to involve a clinician rather than self-treat.
| Stage | Potential Impact of Dysbiosis | Evidence |
|---|---|---|
| Sperm transit | Plausible mechanism only | Not measured in the evidence cited here |
| Embryo implantation | Plausible mechanism only | Not measured in the evidence cited here |
| Early pregnancy | Dysbiosis associated with adverse reproductive outcomes in general terms | 3 |
| IVF success | Not measured in the evidence cited here | (no source) |
| Preterm birth risk | Not measured in the evidence cited here | (no source) |
To read more about the recurrence angle, see Probiotics For Bv.
What Does a Vaginal Microbiome Test Actually Measure?
A vaginal microbiome test sequences bacterial DNA from a self-collected swab to classify community state type and identify dominant species. The 2017 Tachedjian review describes Lactobacillus dominance as the eubiotic state and dysbiosis as associated with adverse reproductive health outcomes in general terms 3. Panels vary in what they report, and whether a test result should change your fertility plan is a question for your clinician.
Once you know what your flora looks like, the next practical question most women ask is whether food and lifestyle alone are enough, or whether a supplement makes sense.
How Can Diet and Lifestyle Support a Healthy Vaginal Microbiome?
Diet and lifestyle are the most accessible levers, though the evidence linking specific foods to vaginal flora is still limited. Avoiding douching and scented products, wearing breathable underwear, and eating a varied, fiber-rich diet are reasonable, low-risk habits. Many people exploring vaginal microbiome and fertility find that small, consistent routine shifts help most.
What Does Research on Probiotics and Vaginal Flora Actually Show?
Probiotic supplementation is one of the most studied adjunct strategies in this space, and the evidence base spans oral and vaginal formats. Ansari and colleagues (2023) gave an oral Lactobacillus combination to 36 asymptomatic women for six weeks; 6 of the 10 who started with a high Nugent score moved to a low score 1. It was a small trial with no fertility endpoint. Mechanistic work summarized by Tachedjian and colleagues describes how L. reuteri and L. rhamnosus produce lactic acid and bacteriocins that may discourage anaerobic overgrowth 3.
A 2024 trial by Bertarello and colleagues evaluated L. plantarum P17630 against vaginal candidiasis in a controlled trial of a vaginal capsule 2, and a 2020 systematic review by van de Wijgert and Verwijs found that lactobacilli-containing vaginal probiotics may help shift flora composition in women with dysbiosis; note that specific strain identity, dose, and delivery route in that review differ from oral multi-strain blends, so results are not directly transferable 4.
When Should You Talk to Your Doctor About Flora and Fertility?
Self-management has limits. Unusual discharge, odor, itching, pelvic pain, or a conception delay of 12 months (6 months if you are 35 or older) are reasons to see a clinician.
Women working through vaginal microbiome and fertility questions usually get the clearest answers by pairing steady daily habits with clinician input.
How Do Common Flora-Support Approaches Compare?
| Approach | What it addresses | Note for readers trying to conceive |
|---|---|---|
| Fermented foods and prebiotic fiber | General flora support through diet | Low risk; mention major diet changes to your clinician |
| Avoiding douching and scented products | Fewer disruptions to protective acidity | A simple habit change with no supplement involved |
| Vaginal microbiome testing | Identifies your dominant community type | Treat results as information for a clinician conversation |
| Probiotic supplements | Flora composition, not fertility outcomes | Clear any supplement with your OB/GYN or fertility specialist first |
| Clinician-guided care | Diagnosis and treatment of BV or other infections | The right starting point when symptoms or conception delays persist |
Conclusion and Next Steps for Your Vaginal Microbiome and Fertility Plan
The vaginal microbiome and fertility research base is still developing, and most of it measures flora rather than conception. Nutrition, stress management, testing where appropriate, and clinician-guided care all matter, and any supplement decision while trying to conceive belongs in a conversation with your OB/GYN or fertility specialist.
Reviewed by: Balance Complex Editorial
Frequently Asked Questions
What is the vaginal microbiome and fertility connection I should know about?
Your vaginal microbiome is the community of bacteria in the vaginal tract, dominated in healthy reproductive-age women by Lactobacillus species. Researchers are studying whether an imbalanced community affects conception and early pregnancy, but the evidence cited on this page does not measure those outcomes. The 2017 Tachedjian narrative review is often cited in fertility discussions, but it is a review of lactic acid biology and BV, and it reports neither IVF success nor miscarriage rates 3. What it does support is that a lactobacillus-dominant vagina is the eubiotic state and that dysbiosis carries increased reproductive risk in general terms.
What does a Lactobacillus-dominant vaginal microbiome mean for getting pregnant?
This flora profile helps maintain healthy acidity and limits overgrowth of bacteria associated with inflammation. Neither of the reviews cited on this page reports IVF success rates, sperm transit or embryo implantation. Tachedjian (2017) reviews lactic acid biology and BV 3, and van de Wijgert and Verwijs (2020) reviews vaginal probiotics for BV and candidiasis cure and prevention 4. The fertility link described in this section comes from the wider literature on vaginal dysbiosis and reproductive risk, not from these two papers.
Can vaginal flora imbalance cause infertility or miscarriage?
Imbalanced vaginal flora is discussed in the wider literature in connection with reproductive risk, but not by the review cited on this page. The 2020 van de Wijgert and Verwijs systematic review of vaginal probiotics evaluated bacterial vaginosis and candidiasis cure and recurrence, vaginal microbiota composition, and detection of the dosed strains; it reports no implantation, miscarriage or preterm birth outcome 4. Testing and targeted support are increasingly discussed by reproductive specialists, and that discussion rests on other evidence.
What foods support a healthy vaginal microbiome?
Fermented foods such as yogurt, kefir, and kimchi contain lactobacilli, and a varied diet rich in fiber is a reasonable baseline, although evidence that specific foods change vaginal flora is limited.
Do probiotics help improve vaginal flora for fertility?
A small 2023 trial found that six weeks of an oral Lactobacillus combination improved Nugent scores in some asymptomatic women 1, but no evidence cited here shows that probiotics improve fertility. If you are trying to conceive, clear any supplement with your clinician first.
Which probiotic strains are best studied for vaginal flora and fertility support?
L. rhamnosus, L. reuteri, L. acidophilus, and L. plantarum are among the most researched strains for vaginal health per the 2017 Tachedjian and 2020 van de Wijgert and Verwijs reviews. These species produce lactic acid and hydrogen peroxide, helping maintain protective acidity. Those reviews concern flora, not fertility.
Is it safe to take a vaginal probiotic supplement during IVF or fertility treatment?
Consult your fertility specialist before adding anything to an active protocol, and ask specifically about interactions with your medications and about any herbal ingredients in the product.
How long does it take to restore healthy vaginal flora?
It depends on the cause. Bacterial vaginosis is treated by a clinician, often with antibiotics. In a small oral probiotic trial, flora changes were measured after six weeks 1, and a 2020 review of vaginal probiotics found dosed strains were not detected for long after dosing stopped 4.
What is a vaginal microbiome test and should I get one before fertility treatment?
This test uses DNA sequencing on a self-collected swab to identify which community type dominates your flora and flag species linked to dysbiosis. Whether testing before fertility treatment improves outcomes has not been established, so ask your fertility specialist whether a result would change your plan. The 2017 Tachedjian review supports the underlying biology, that lactobacilli and the lactic acid they produce define the eubiotic state, rather than any testing protocol 3.
Can improving vaginal flora support IVF success rates?
We cannot point you to a trial linking a Lactobacillus-dominant vaginal community to embryo implantation in IVF cycles; the systematic review often cited here evaluated vaginal probiotics for bacterial and fungal dysbiosis, not fertility endpoints 4. A 2023 trial did find that six weeks of an oral Lactobacillus combination improved vaginal dysbiosis in asymptomatic women 1, which is a flora endpoint rather than a fertility one.
Not for use if pregnant, nursing, or trying to conceive: Balance Complex contains wormwood and black walnut hull.
References
- Ansari et al., 2023. PMID: 37111086
- Bertarello et al., 2024. PMID: 38235890
- Tachedjian et al., 2017. PMID: 28435139
- van de Wijgert J, 2020. PMID: 31299136