Short answer: The vaginal bacterial flora is normally dominated by lactic acid bacteria (lactobacilli), which keep the environment acidic and protective. Research suggests that a lactobacilli-dominated flora is associated with better chances in IVF and implantation, while imbalance (dysbiosis) has been linked to repeated failed attempts. However, the evidence for taking supplements with the aim of getting pregnant is still limited.
Vaginal bacterial flora
A healthy vagina is dominated by lactobacilli, which produce lactic acid and maintain a low pH. The acidic environment protects against harmful bacteria. When the balance is disturbed (dysbiosis), for example in bacterial vaginosis, other bacteria take over.
Connection to fertility
Studies have shown that a lactobacilli-dominated flora – particularly of the species Lactobacillus crispatus – is associated with a higher rate of pregnancies and live births after embryo transfer in IVF. Conversely, dysbiosis has been linked to repeated implantation failures. However, the connections are complex, and research is still in its early stages.
What can be done?
Supporting a healthy flora is largely about the overall picture: avoiding unnecessary intimate washes, treating any infections, and living a healthy lifestyle. Some choose lactic acid bacteria as supplements, but the scientific evidence that it improves fertility is still limited. In case of recurrent problems or failed IVF attempts – discuss it with your clinic.
Frequently asked questions
Can lactic acid bacteria help me get pregnant?
A healthy flora is associated with better outcomes, but it is not established that supplements themselves increase the chances. See it as part of the whole.
What is dysbiosis?
An imbalance where protective lactobacilli decrease and other bacteria take over.
This article is general information and does not constitute medical advice. Consult healthcare providers for problems.
Sources
- The Role of the Genital Tract Microbiome in Human Fertility: A Literature Review (2025). Journal of Clinical Medicine.