Probiotics and Bacterial Vaginosis: The facts.
Bacterial Vaginosis (BV) is the most common infection in women of childbearing age, affecting approximately 1 in 3 women, and yet surprisingly many women have never even heard of it.
BV is characterised by an overgrowth of predominantly anaerobic, and pathogenic, organisms (such as Gardnerella vaginalis, the Prevotella species, Mycoplasma hominis and the Mobiluncus species) in the vagina, leading to a reduction in healthy lactobacilli populations. Reduced numbers of lactobacilli can lead to an increase in vaginal pH from a healthy acidic pH of less than 4.5, to a less healthy pH that can be as high as 7.0.
In effect, BV is dysbiosis in the vagina and uro-genital tract. In the same way that the flora of the GI tract can lose its healthy balance, so too can the flora in this ‘intimate’ area.
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, and reduced birth-weights (when pregnancy does occur). If symptoms are present these usually include: a thin, white discharge and an unpleasant, ’fishy’ odour.
So, what causes the condition?
Doctors are not always sure what causes BV, but certain lifestyle factors increase its likelihood. Women that have more than one sexual partner expose themselves to greater numbers of potential pathogens, and increase their chances of developing BV in that way. Also, women that douche frequently or use soaps or shower gels in the intimate area, run the risk of alkalising the area too much, which allows pathogenic strains of bacteria to flourish.
However for the large majority of sufferers there is no obvious, external ‘cause’ for the dysbiosis, and in these cases we need to consider the link between the gut flora and the vaginal flora.
Due to the close anatomical proximity of the vagina to the anus, it is easy for bacteria from the GI tract to ‘trans-locate’ (i.e. migrate) from one area to the other. Any pathogenic strains of bacteria that are present in the gut, can therefore infect the vaginal tract and imbalance the delicate balance of flora there.
In order to reintroduce beneficial strains of bacteria into the vagina, it is not so simple as to just use any strain of probiotic however. The strains need to be able to survive transit through the entire length of the digestive tract, and they also need to be able to successfully migrate to, and then colonise, the vagina. Strains of probiotic bacteria that colonise well in the digestive tract, do not necessarily show good adherence to the lining of the vaginal wall.
Which probiotic strains can help support health in those with BV?
There have been many different clinical trials over the years, looking at the efficacy of probiotics in the treatment of BV. It is understood that the Lactobacillus genus is the predominant genus of bacteria found in a healthy vagina, so most trials have centred around one or other Lactobacillus species.
Incidentally, Joanna has just written a piece about a new 'probiotic' to make women's intimate areas smell like peach! We are not convinced, and are not sure there is yet any research into it - but the blog post might be an interesting read.
In a rather small but well-designed double-blinded randomised, controlled trial1 34 women with BV received either a vaginal probiotic tablet (containing at least 109 viable lactobacilli, in particular Lactobacillus brevis CD2, Lactobacillus salivarius FV2, and Lactobacillus plantarum FV9) or a placebo for 7 days. The 2-week relief rates were 61% (11 out of 18) in the active treatment group as compared with 19% (three out of 16) in the placebo group (p = 0.017).
In another randomised, double-blind, placebo controlled study2 125 women were divided in to 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 strains Lactobacillus rhamnosus GR-1® and Lactobacillus reuteri RC-14®. The probiotic supplementation was continued for a further 3 weeks after the end of the antibiotic therapy. Treatment success rates increased from just 40% (as seen with antibiotic therapy alone) to 88% (on the combination therapy)!
These two strains, were originally isolated from a healthy vaginal tract; demonstrating that they are an integral part of the vaginal microbiota.
Not only do L. rhamnosus GR-1® and L. reuteri RC-14® reach the ‘intimate’ area and adhere to the wall lining, they have also been shown to effectively colonise the area, as demonstrated by their presence in vaginal swabs taken up to 3 weeks after probiotic supplementation ceased.
Update May 2017: Another great new clinical trial also shows promise for these strains in those with BV. Healthcare practitioners can follow this link to read more about the clinical trial.
I often see women in my clinic, complaining of unusual vaginal discharge and irritation. The symptoms are both uncomfortable and slightly embarrassing for them, and often they have suffered in silence for quite some time. If they have been to their GP, most likely they will have been prescribed a course of antibiotics. This may have brought temporary relief, however this is often short-lived as over time the antibiotics actually make the situation of dysbiosis worse.
Following a low sugar diet can be helpful, to reduce the likelihood of glucose being excreted in the urine (which can promote the overgrowth of pathogenic species of bacteria in the genito-urinary tract). However, probiotic supplementation alongside these dietary changes, is always the corner stone of any natural protocol to restore the health of the vaginal flora.
If you would like to read more about probiotics for female health, check our FAQ: Which probiotics are best for women?
1 Mastromarino et al, (2009) 'Effectiveness of Lactobacillus-containing vaginal tablets in the treatment of symptomatic bacterial vaginosis'. Clin Microbiol Infect, 15(1): 67-74