Probiotic benefits on vaginal health cannot be confirmed, study flags

05 Jul 2022 --- There is no relationship between improved vaginal flora and probiotics for fertility treatment preparations and overall vaginal bacterial imbalance, a study by The Fertility Clinic at Zealand University Hospital, Denmark, reveals. 

Women were given probiotics or placebos through daily capsules to vaginally administer ten days before in-vitro fertilization (IVF). No differences were shown between the participant groups. However, 34% of the women on probiotics or a placebo showed an improvement one to three months post the trial.

“The study indicates that administering vaginal lactobacilli probiotics may not improve a suboptimal vaginal microbiome. However, a spontaneous improvement rate over one to three months may provide the basis for an alternative therapeutic approach,” Ida Engberg Jepsen, principal investigator, The Fertility Clinic at Zealand University Hospital, tells NutritionInsight.

“The strategy would involve postponing fertility treatment until spontaneous improvement occurs, but further research is needed. The specific vaginal probiotic tested in this study did not affect the favorability of the vaginal microbiome before IVF. But probiotics, in general, should not yet be discounted.”

The improvement rate observed among patients may provide grounds for a change in approach toward IVF timing. “I think the cause for this spontaneous improvement we saw is multifactorial. We did not see anything in our dataset that gives a specific reason for the spontaneous changes,” Jepsen underscores.

Spontaneously improved qualityHigher vaginal microbiome health increases birth and pregnancy rates.
The probiotics contained two strains of lactobacillus, Rhamnosus – friendly bacteria in the gut beneficial for gut health and inflammation – and Gasseri – aiding digestion and immune function while reducing inflammation.

The vaginal microflora is a “rich and complex ecosystem,” consisting mainly of lactobacillus – a genus of lactic-acid-producing bacteria. It helps keep a balance in the vaginal environment, which is easily affected by internal and external factors, such as gut health, immunity, mood balance and intimate health.

When the vaginal microbiota is dominated by lactobacillus, previous research has demonstrated its link to higher birth and pregnancy rates. When having vaginal dysbiosis – an imbalance of lactobacillus concentration – there is a decreased chance of an embryo embedding in the uterus. 

“Our study suggests, as previous studies have also suggested, that the vaginal microbiome (flora) is a dynamic size and therefore varies over menstrual cycles. We know that many factors influence the vaginal microbiome (flora), for example, diet, exercise, intercourse, menstrual cycle etc., but there is a lot that we do not know,” Jepsen underscores.

Probiotics and fertility
To test the effect on the vaginal microbiome in terms of fertility improvement, the women were tested around the same days of their menstrual cycle – days 21-25. The vaginal microbiome health was characterized as “low,” “medium” or “high.” If moving up in categories, it was registered as an improvement.

In the study, 74 women with “low to medium quality” lactobacillus profiles participated, and were already referred for IVF treatment. The experiment’s time frame consisted of ten days of consuming probiotics. Approximately half of the women received probiotics and the other half a placebo.

However, the results were insignificant, as the vaginal microbiome improved by 40% for those in the placebo group and 29% for those receiving the probiotic, meaning that no relationship was found between probiotics and improvement.

Further studies neededAmong all women, 70% will experience yeast infection minimum once.
Vaginal imbalance affects most women, as previous studies have shown that 70% of all women are estimated to experience a yeast infection minimum once in their life, and 30% will suffer from recurring bacterial vaginosis.

Probiotic ingredients are seeing an increased interest in women’s health. Previous studies have claimed that they may contribute to more health benefits and tackle more areas than vaginal health, such as stress and immunity.

There has been an increased demand for “beauty-from-within” products where immunity, stress and vaginal probiotics are in the spotlight. 

“This study was not designed to cover the whole area of vaginal health. It could be that different types of probiotics or other treatment regimes could have an effect. The previous study shows that in combination with antibiotics, probiotics probably have a beneficial effect in restoring vaginal colonization in bacterial vaginosis,” says Jepsen.

“Research is the only way to move forward in improving treatment for patients, and a lot remains to be investigated when it comes to probiotics in vaginal health,” she concludes. 

By Beatrice Wihlander