While the benefit of Lactobacillus supplements has been shown in many cases, such as bacterial vaginosis, more information is needed about routine use in infertility treatment.

The use of probiotics has long been shown to be an important health promoting factor, by maintaining a healthy balance among of the body’s microorganisms. 

Probiotics are live microorganisms that when given in adequate amounts have certain beneficial effects by boosting immunity system, helping in elimination of harmful bacteria and by preventing infection.

Although probiotics were initially studied with regards to the digestive system, it gradually appeared that their role may be equally important in the reproductive system, as well. Probiotic use has been associated with a healthy and balanced bacterial population inside the vagina, known as vaginal flora.

Lactobacillus is the main probiotic organism found in vaginal flora. Its presence is considered a crucial marker of a healthy vaginal flora. It protects the reproductive system from pathological bacteria by producing lactic acid, a substance that helps getting rid of harmful bacteria, also by stimulating the local immune system to produce anti-inflammatory substances to keep a healthy state in the vaginal microenvironment. 

This vaginal ecosystem is apparently dependent on many factors such as the stage of menstrual cycle, sexual behaviour and hygienic habits, pregnancy, menopause. It has been shown that when there is an imbalance in the vaginal microorganisms with reductions in the population of lactobacillus, bacterial vaginosis develops, a pathologic condition where harmful bacteria outgrow the population of Lactobacillus in the vagina. 

Several pathologic conditions have been described in association with bacterial vaginosis, such as sexually transmitted infections, tubal damage and infertility, pregnancy complications, as well as cancers of the reproductive tract, in the long term.

Many studies have shown that the use of Lactobacillus probiotics have the capability to restore the normal vaginal flora, this way improving sexual health, fertility and pregnancy outcomes. Lactobacillus has a clear anti-inflammatory effect on pathologic bacteria and its use has been shown to help in infertility management associated with genital tract inflammation. Even in the management of bacterial vaginosis, the use of Lactobacillus probiotics appears to be more effective in the long-term compared to antibiotic treatment alone. This is highly important for women that tend to have repeated episodes of bacterial vaginosis. 

Research in the field of assisted reproduction has also suggested that success in in vitro fertilization (IVF) treatments depends a lot on the composition of the vaginal flora at the time of embryo transfer. Patients with Lactobacillus dominant vaginal flora had the highest chances of getting pregnant. 

A beneficial effect with the use of Lactobacillus probiotics has been shown in women with polycystic ovarian syndrome (PCOS), where supplements of Lactobacillus have improved fertility by managing effectively the inflammation which often accompanies PCOS. 

While the benefit of using probiotics to treat bacterial vaginosis and PCOS related inflammation is documented, less is known about the impact probiotics may have when given as a routine to all women about to start IVF treatment. A recent study has tried to summarise the findings of research so far without reaching a conclusion of clear benefit in routine use of probiotics in IVF patients.

In addition, some caution is needed over the liberal use of probiotics, until more is known about some of the properties of Lactobacillus, such as the effect of its attachment on the ejaculated sperm. Recent research data suggest that high doses of Lactobacillus may have a negative impact on unexplained infertility, where relatively weakly moving sperm may be prevented by reaching the egg after ovulation, due to an “immobilising effect” of Lactobacillus.

As our understanding of the microbiology of the genital tract continues to increase, more information will soon be available on issues such as the correct dose, frequency and way of receiving probiotic supplements.

©2021, Nicholas Christoforidis, Fertility Matters
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