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Bacterial vaginosis (BV) is the most common infection in women of childbearing age, affecting approximately 1 in 3 women. Yet, surprisingly, many women have never even heard of it. In this article, we look at what BV is, how probiotics for BV might help those who are suffering with the condition, and discuss which are the best probiotic strains for vaginal health.
Bacterial vaginosis (BV) is a vaginal condition that creates a grey and watery discharge, which can smell unpleasant. It caused by an overgrowth of bad bacteria, known as pathogens.
In the same way that our gut microbiome is made up of a mixture of ‘friendly’ probiotic bacteria, and a small number of ‘harmful’ pathogenic bacteria, so too is the vaginal microbiome. When pathogens outnumber good bacteria in any microbiome, it is known as dysbiosis, which can lead to infection. You may like to read more about gut dysbiosis and how to address it in the article what is dysbiosis?
If you are diagnosed with BV, it is likely that your doctor will prescribe antibiotics to treat the infection. This may bring temporary relief; however, over time the antibiotics can actually make dysbiosis worse. Read our article about taking probiotics with antibiotics.
BV is usually caused by an overgrowth of Gardnerella vaginalis, though Prevotella, Mycoplasma hominis, and Mobiluncus can also be implicated in BV infections. A healthy vagina contains plenty of bacteria from the Lactobacillus genus. Read this article to find out more about Lactobacillus.
Lactobacilli help to keep the vaginal environment healthy by fermenting glycogen from the vaginal wall to produce lactic acid. Lactic acid decreases the vaginal pH, keeping it within healthy levels below 4.5, which is important for intimate health. If the vagina becomes too alkaline, pathogenic species of bacteria will flourish. This becomes a vicious cycle as pathogenic overgrowth raises the pH, which in turn encourages yet bad bacteria to thrive.
Women are often unaware that they have BV, as in 50% of cases it does not produce symptoms. However, if left untreated it can lead to other complications, such as reduced fertility, increased risk of miscarriage, and reduced birthweights when pregnancy does occur.
As already explained, BV is an imbalance of the delicate flora resident in the vagina. It is not regarded as a sexually transmitted infection.
The vaginal microbiome can become unbalanced for a variety of reasons:
However, for the large majority of sufferers there is no obvious, external cause for the dysbiosis. In these cases, we need to consider the link between the gut flora and the vaginal flora.
Due to the vagina being located close to the anus, it is easy for bacteria to travel from one area to the other. Any pathogenic strains of bacteria that are present in the gut can therefore travel to the vaginal tract via the anus and cause an imbalance of the delicate balance of flora there.
To find out more about how to keep the vaginal microbiome in balance, read All about your vaginal flora.
Given that BV is an imbalance of bacteria in the vagina, it would make sense that increasing levels of ‘friendly’ bacteria by using probiotic supplements could be beneficial. But which are the best BV probiotics?
Scientists are well aware that different probiotics do different things. The strains to help with BV need to be able to survive transit through the digestive tract, then migrate to, and colonise, the vagina.
There is extensive research looking into the efficacy of vaginal probiotics. It is understood that the Lactobacillus genus is the predominant genus of bacteria found in a healthy vagina. Read this article to find out more about Lactobacillus.
So, most studies on probiotics for vaginal health centre around the Lactobacillus species. In this section we look at the following Lactobacillus strains which have been researched for the support of BV:
In a randomised, double-blind, placebo-controlled study1, 125 women with BV were divided into two groups. One group received a 7-day course of antibiotics, and the second group received both the antibiotics coupled with a probiotic formulation, containing the probiotic strains L. rhamnosus GR-1® and L. reuteri RC-14®. These two strains of friendly bacteria were originally isolated from a healthy vaginal tract, demonstrating that they are an integral part of the vaginal microbiota.
The probiotic supplementation was continued for a further 3 weeks after the end of the antibiotic therapy. Success rates increased from just 40% (as seen with antibiotic therapy alone) to 88% (on the combination therapy)!
Not only do L. rhamnosus GR-1® and L. reuteri RC-14® reach the intimate area and adhere to the vaginal wall lining, they have also been shown to effectively colonise the area. Their presence in vaginal swabs, taken up to 3 weeks after probiotic supplementation ceased, is demonstration of this.
A 2006 clinical trial demonstrated that the probiotic strain Lactobacillus paracasei F-19® was able to improve vaginal pH and odour in those with vaginosis5. Women who were orally administered the probiotic Lactobacillus paracasei F-19®, in addition to vaginal suppositories containing Lactobacilllus acidofilus, maintained relief even 3 months after the end of treatment.
Graph to show efficacy of probiotic strains in supporting those with BV
Another great clinical trial shows further promise for the use of probiotic strains in sufferers of BV. Healthcare practitioners can find out more about this clinical trial on the Probiotic Professionals page.
In a rather small but well-designed double-blind, randomised, controlled trial2 34 women with BV received either a vaginal probiotic tablet or a placebo for 7 days. The probiotic contained at least 10 billion viable Lactobacilli; in particular L. brevis CD2®, L. salivarius FV2®, and L. plantarum FV9®. The 2-week symptom relief rates were 61% (11 out of 18) in the active treatment group. When compared to 19% (three out of 16) in the placebo group (p = 0.017) - these are astounding results!
A double-blind, placebo-controlled randomised trial3 investigated the probiotic strains L. acidophilus La-14® and L. rhamnosus HN001, alongside bovine lactoferrin. When added to antibiotic treatment, this combination was shown to significantly improve symptoms of BV. Furthermore, it also decreased the recurrence rate, as compared with antibiotic treatment alone.
48 adult women presenting with symptoms of BV received either antibiotics and an oral probiotic mixture, plus lactoferrin, for seven days; or antibiotics plus a placebo. Following this, the groups were instructed to take one capsule per day for ten days each month (starting on the first day of menstruation) of either the probiotics plus lactoferrin, or placebo for a duration of six months.
Symptoms such as vaginal discharge and itchiness were markedly improved with the probiotic combination therapy, in comparison to the placebo. Most importantly, recurrence rates were much lower too. Health professionals can visit the Probiotics Database to read more about research featuring L. rhamnosus HN001
Lactobacillus crispatus CTV-05 has recently been assessed in a double-blind randomised placebo-controlled trial for its effects in 228 premenopausal women with recurrent bacterial vaginosis. In the intervention group, women were administered 2 billion CFU of L. crispatus CTV-05 using a vaginal applicator daily for 24 weeks compared with a placebo. By week 12, 30% of the intervention group had a recurrence of bacterial vaginosis compared with 45% of the placebo group (p=0.01). These positive results persisted to week 244.
You might wonder how vaginal probiotics work and whether probiotics for the vagina are best taken orally or inserted intra-vaginally.
The answer is both methods show the same efficacy, so it depends on individual preference. Most women prefer the ease and convenience of an oral capsule. Research has shown that so long as the correct strains of bacteria are taken orally (i.e. ones that like to colonise in the vaginal tract) then the bacteria are easily able to survive transit through the intestines. They can then make the journey from rectum to vagina. This has been proven in clinical tests whereby the specific probiotics taken have been found in vaginal swabs shortly after they were ingested.
The question regular BV sufferers ask is “how do I prevent BV recurring?”.
We’ve learned so far that BV is an imbalance in the vaginal microbiome, and the following measures may help to keep your vaginal bacteria in balance and reduce your risk of recurring BV infections:
If you would like to find out more about female intimate health, you can read more here: