Having not enough "friendly" vaginal bacteria could increase a woman's chance of ovarian cancer, new research suggests.
Researchers from the study team now hope the discovery could help identify women at a high risk of the cancer, for which there is currently no screening test.
The study, by University College London, published in the Lancet Oncology, involved 176 women with ovarian cancer, 109 with inherited high-risk genes for ovarian cancer (BRCA1 genes) and 295 women with no known genetic risk.
The women were examined and samples taken using the same collection method used in smear tests or cervical screening.
Findings revealed that lactobacilli bacteria levels were three times lower in the women under 50 with ovarian cancer, while those who had a familial history of ovarian cancer were also more likely to have lower quantities of the bacteria in their vagina.
Lactobacilli normally help prevent the overgrowth of "unfriendly" types of bacteria and is thought to protect against infection.
Commenting on the findings Prof Martin Widschwendter, from UCL, said: “This is a novel approach and could revolutionise the way that we can intervene and change the implications of being at high risk of ovarian cancer development.
“It’s the first time that we have been able to demonstrate that women with gene mutations have a change in their vaginal microbiome.”
What is vaginal bacteria and why is it so important?
Bacteria is naturally found in the vagina and is vital to gynaecological health.
A healthy vagina normally contains a balance of "good" and "bad" bacteria.
“The microbiome refers to thousands of microscopic bacteria that live inside our body and in recent years have been found to be essential to our health and wellbeing,” explains Dr Sonal Shah, NHS GP and lifestyle medicine expert.
“The bacteria in the vagina are in natural balance with one another, there are both 'good' and 'bad' bacteria.”
But sometimes an imbalance between the two can result in infections.
“When this balance is altered it can lead to infections and inflammation such as bacterial vaginosis, this is a non-sexually transmitted infection that leads to smelly, grey thin vaginal discharge or even candida (thrush),” Dr Shah adds.
The link between vaginal bacteria and ovarian cancer
This particular study is the first to examine the link between vaginal bacteria and the development of ovarian cancer.
Ovarian cancer, which kills more than 4,000 women in the UK each year, can be difficult to detect due to symptoms being vague and hard to notice.
“Research findings published in the Lancet have found the microbiome in the vagina may have been linked with developing ovarian cancer,” Dr Shah says.
“The team have shown that women who lack some of the healthy bacteria that naturally exist in the gut, may be at increased risk of developing ovarian cancer.
“This is really exciting research as it may help us identify patients with ovarian cancer earlier possibly even through a screening programme in the future,” Dr Shah continues.
“The symptoms of ovarian cancer are often vague and non-specific, including changes in bowel habit, bloating, abdominal pain, vaginal bleeding, and feeling tired all the time, this makes making a diagnosis difficult, but if women were screened similarly to cervical screening, then those who may be at risk could be identified earlier.”
Though is not clear whether the link suggested in the study is causal or if other factors might explain it, the new research seems to support the theory that lactobacilli bacteria are crucial to reducing the risk of developing ovarian cancer.
However, researchers say that further study is needed and until then it is too soon to recommend women should be given protective doses of the good bacteria to reduce their risk.
How can women balance the bacteria in their vaginas?
“Like our gut microbiome, the vaginal microbiome is also believed to be important in a woman’s overall health,” explains Claire Barnes, Nutritional Therapist at Bio-Kult.
“Whilst a healthy gut microbiome should have a diverse community of different species throughout the digestive tract, a healthy vagina microbiome is dominated by Lactobacillus species.”
According to the NHS there are many factors that may affect the balance of bacteria in the vagina, including a woman’s sexual history and whether she smokes or uses vaginal deodorants.
So how do women maintain good vaginal health?
Don’t over-clean it
Believe it or not the vagina is actually self-cleaning which means it doesn’t need any additional cleansing and anything you use to try and clean it could disrupt the good bacteria and pH balance, which could lead to discomfort at best, infection at worse.
“Practices such as vaginal douching, overusing soap, using feminine hygiene wipes or products, or even hoovering the vagina can disrupt that natural fine balance,” explains Dr Shah.
Try a pro-biotic
We know we should look after our gut but did you realise our vagina has a similar microbiome to the gut.
It follows therefore that what’s good for your gut is good for down there too.
“Improving the vaginal microbiome begins with improving the gut microbiome, as many of the harmful bacteria within the vagina are likely to have migrated from the rectum to the vagina in the first place,” explains Barnes.
“Increasing the beneficial bacteria in the gut, through eating fermented foods or taking a live bacteria supplement can help to inhibit harmful bacteria, therefore reducing the numbers that could then migrate from the rectum to the vagina.”
“Likewise, by ingesting more of the beneficial bacteria through foods or supplements, such as Bio-Kult Advanced multi-strain, RRP £9.48, could also potentially have beneficial effects whilst in the intestines and then also migrate from the rectum to the vagina to continue to have positive effects in this area.”
Choose contraception and lube wisely
According to Dr Shah using appropriate contraception, like condoms, can help to avoid getting sexually transmitted infections.
“During sex if lubrication is required, used products designed for this purpose instead of using vaseline, cream or baby oil,” she adds.
Some lubes also contain something called glycerine, which should also be avoided because it can encourage growth of bacteria.
Keep an eye on discharge
“Vaginal discharge changes (going from thick to thin and watery) over the menstrual cycle,” explains Dr Shah. “It is important to recognise what is normal for you and visit your GP if you notice anything out of the ordinary.”
Let it breathe
Dr Shah advises avoiding wearing tight fighting clothing, or frequent use of synthetic underwear or g-strings as these can also make women prone to infection.