Beneficial Vaginal Bacteria: Why They Matter for Your Health and Fertility
Learn how beneficial vaginal bacteria protect your health and fertility, and when to seek expert care.
In short: The beneficial bacteria of the vagina, best known as lactobacilli, are an essential part of the body’s natural defence: they keep vaginal acidity between 3.8 and 4.5 and stop harmful bacteria multiplying. Their balance is upset by repeated antibiotics, hormonal changes and vaginal douching, and imbalance may be linked to preterm birth, miscarriage, delay in conceiving and IVF failure. It is treated with probiotics and local treatments.
The vagina naturally hosts beneficial bacteria that live in balance with your body, helping to maintain a healthy vaginal environment every day.
What is the importance of beneficial vaginal bacteria?
- Maintaining the natural vaginal pH between 3.8-4.5
- Preventing the proliferation of harmful bacteria and germs
Does the presence of beneficial bacteria prevent vaginal infections?
Yes, a healthy balance of these bacteria plays an important protective role against infections.
What is the most common type of beneficial bacteria found in the vagina?
Lactobacillus
What substances do Lactobacillus bacteria secrete to maintain a healthy vaginal environment?
- Lactic acid
- Hydrogen peroxide
- Bacteriocins (substances that help kill harmful bacteria)
What is meant by bacterial imbalance in the vagina?
This occurs when the concentration of Lactobacillus bacteria decreases and the concentration of anaerobic bacteria increases, disrupting the natural vaginal balance.
What are the common causes of bacterial imbalance in the vagina?
- Frequent use of antibiotics
- Hormonal changes in the blood due to menstruation or menopause
- Sexual intercourse
- Use of certain non-medical vaginal douches
- Some types of contraception, such as IUDs or spermicides
Does an imbalance of vaginal bacteria affect fertility or pregnancy?
It may, and this is why maintaining vaginal health matters for women trying to conceive or undergoing fertility treatment. Possible effects include:
- Premature birth
- Miscarriages
- Infertility
- Repeated IVF failures
- Severe pelvic inflammatory disease
- Increased risk of sexually transmitted infections such as HPV and HIV
What is the effect of pregnancy on the concentration of lactobacillus bacteria?
It increases their concentration.
What treatments are used to modify the concentration of beneficial bacteria in the vagina?
- Antibiotics such as metronidazole or clindamycin, when bacterial vaginosis is diagnosed — this is the main proven treatment - Probiotics (lactobacillus), which may help some women after treatment, although the evidence for them is still limited
- Treating the sexual partner in some cases
- Some hormonal treatments, such as topical estrogen
If you have concerns about vaginal health, recurrent infections, or how it may relate to your fertility journey, Dr. Najeeb Layyous and his team are available to discuss personalized care options and guide you toward the right evaluation and treatment plan.
Dr Najeeb Layyous F.R.C.O.G
Consultant Obstetrician, Gynecologist and Infertility Specialist
We’re grateful for dealing with such a physician — he’s very caring and deals with each case separately. We would’ve loved to spend more time with him, however he was never in a hurry during our given time.