In Australia, bacterial vaginosis (BV) affects up to 12% of women, and up to 30% of women in some higher-risk groups, according to Jean Hailes for Women's Health. Jean Hailes links BV directly to the vaginal flora: the lactobacillus bacteria that dominate a healthy vagina make it acidic, and that acidity helps prevent BV.
This guide explains how that natural balance works, what can disrupt it and the simple habits Australian women's health services recommend to look after it.
Quick answer: Vaginal flora is the community of microorganisms living in the vagina, and a healthy one is dominated by lactobacillus bacteria. These produce lactic acid, which keeps the vagina acidic and helps hold bad bacteria and yeast in check. To keep it balanced, wash the vulva with warm water, skip douching and scented products, and use condoms.
What does lactobacillus do in the vagina?
Lactobacillus is the main "good" bacteria in a healthy vagina. Jean Hailes reports on a review of 142 studies which found that a healthy vagina needs certain types of lactobacillus that produce high levels of lactic acid. The researchers concluded that the vagina is most stable when its microbiome is dominated by favourable lactobacillus, most likely because lactic acid can kill harmful bacteria.
What happens when the vagina becomes less acidic?
When acidity drops, unwanted microbes get more room to grow. Jean Hailes explains in five things you didn't know about vaginas and vulvas that an acidic environment protects the vagina from infection and keeps bad bacteria and yeast in check. If the vagina becomes too alkaline, unhealthy levels of these organisms can grow, raising the risk of BV. The vagina also becomes more alkaline naturally after menopause, which makes bacterial infections more likely at that stage of life.
What knocks the balance of vaginal bacteria out of whack?
BV happens when the natural balance of bacteria in the vagina changes, says healthdirect. It lists these as linked to a higher risk:
- new or multiple sexual partners;
- not using condoms;
- douching;
- having a copper IUD;
- having a partner with a vagina;
- smoking.
Jean Hailes adds that soaps, perfumed products and douching can disrupt the vaginal flora.
How can you keep vaginal flora in balance?
The vagina is a self-cleaning organ, Jean Hailes says, so the inside needs no cleaning at all. For everyday care, the two services recommend:
- gentle daily washing of the vulva with warm water only;
- no douching, vaginal deodorants or scented products around the vagina;
- condoms or other barrier contraception during any type of sex;
- stopping smoking or vaping.
Probiotics come up often, but the evidence is mixed. Jean Hailes reports there has not been enough research to show a consistent benefit from lactobacillus-based probiotics, and healthdirect says probiotics and pH-changing products may ease symptoms but are not cures. For more on acidity, see our guide to vaginal pH balance.
When to see a doctor
Make an appointment with your doctor if you notice:
- a thin white or grey discharge;
- a "fishy" vaginal smell;
- mild discomfort around the vagina and vulva;
- any change in your normal vaginal discharge;
- BV symptoms during pregnancy (your midwife can help too).
Jean Hailes notes that BV has been linked with sexually transmitted infections, pelvic inflammatory disease and pregnancy complications such as premature delivery, so it is worth getting symptoms checked rather than waiting.
Frequently asked questions
Do probiotics cure BV?
No. Jean Hailes says the current recommended treatment for BV is antibiotics, and research has not yet shown a consistent benefit from lactobacillus-based probiotics. healthdirect agrees that probiotics and pH-changing products may ease symptoms but are not cures. Talk to your doctor before trying them alongside treatment.
Is BV a sexually transmitted infection?
No. healthdirect explains that BV is often linked to sexual activity but is not classed as a sexually transmitted infection. New or multiple partners and not using condoms raise the risk, which is why barrier contraception during any type of sex is one of its prevention tips.
Can BV come back after treatment?
Yes, and quite often. healthdirect says BV commonly returns within 6 to 12 months after treatment ends, usually treated with antibiotic tablets or a vaginal cream or gel. Avoiding douching matters here, because healthdirect notes that douching can make BV worse rather than better.
Can you have BV without any symptoms?
Yes. Jean Hailes reports that half of BV cases show no symptoms, and these can only be diagnosed with a vaginal examination by your doctor. When symptoms do appear, the main ones are a white discharge and a strong fishy odour, according to the same article.
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This page shares general information rather than medical advice. If you notice changes or discomfort, talk to your GP.
