An effective treatment for bacterial vaginosis

Common evil - bacterial vaginosis

Many women suffer from recurring bacterial vaginosis – an imbalance in the bacterial composition in favour of pathogenic bacteria in the vagina. By nature, the vagina of an adult woman of child-bearing age is mainly populated with different types of lactobacilli (for example Lactobacillus crispatus). Under unfavourable influences, the healthy vaginal flora can change and an increase in bacteria can occur, which can lead to undesirable symptoms (especially discharge, fishy smell, possibly inflammation) and can have serious consequences. For example, premature births and miscarriages or an increased risk of infection with the HI virus have been associated with this. The quantity of lactobacilli, which have a protective effect due to their pH-lowering property, decreases rapidly in bacterial vaginosis; on the other hand, germs such as Gardnerella vaginalis or other anaerobes multiply strongly.

The causes of dysbiosis in the vagina are manifold, including predisposition, excessive genital hygiene, treatment with antibiotics, use of a copper coil or stress. If the vaginal flora is already ailing, sexual intercourse can also increase the risk of this disease.

Diagnostics should be the first step

Before treatment, a precise diagnosis should always be made in order to exclude other diseases such as candidosis (colonisation with yeast fungi) or an infestation with trichomonads. The classical approach to conventional medicine treatment is the use of antibiotics, such as metronidazole or clindamycin. Apart from the long list of possible side effects, it must be emphasized that the supposed healing success of about 70 to 80 % is quite disappointing – if we look at the high recurrence rate of 50 % within 12 months. Despite this high probability of recurrence of bacterial vaginosis, treatment with antibiotics is still standard.

Using biotherapeutics to combat recurrence

To counteract this, researchers have been investigating for many years whether the high relapse rate can be reduced by prophylactic administration of lactobacilli (after treatment with antibiotics).

A very promising, randomized, placebo-controlled double-blind Phase II study was conducted from 2016 to 2019 and published in the New England Journal of Medicine in May 2020. The study, under the leadership of Craig R. Cohen et al., investigated a product of the American company Osel Inc.– the biotherapeutic agent Lactin-V (Lactobacillus crispatus CTV-05), which is introduced in powder form directly into the vagina using a vaginal applicator. L. crispatus is one of the most frequently found lactobacilli in the healthy vaginal flora. Among other things, they produce lactic acid and hydrogen peroxide, which suppress the growth of bacteria that promote bacterial vaginosis.

This is how it was tested

The study group consisted of a total of 228 women aged 18 to 45 years who had been diagnosed with bacterial vaginosis and had received treatment with metronidazole gel. Two thirds of them were in the Lactin-V group, one third in the placebo group. Treatment was started within 48 h after the last dose of metronidazole and over a period of 11 weeks (in the first week on 5 consecutive days, the first administration being under supervision in the clinic, then twice a week for 10 weeks). Clinical tests were performed after 4, 8, 12 and 24 weeks, and the colonization rate of L. crispatus CTV-05 was also measured. The participants kept records of influencing factors such as menstruation, sexual activity or other factors.

Promising results – in brief

• By week 12, only 30 % of the women in the Lactin-V group had a recurrence, compared to 45 % in the placebo group. This effect is considered significant by both the authors of the study and the National Institute of Health.
• Of the women who did not experience a recurrence of bacterial vaginosis within the first 12 weeks, only 12 % of the women in the Lactin-V group (13 of 106 women) experienced a recurrence by week 24, while in the placebo group it was 17 % (7 of 42 women). A positive effect is therefore also clearly visible after the treatment period with Lactin-V.
• Colonisation of the vagina with L. crispatus CTV-05 in the Lactin-V group was detected in almost 80 % of the participants after 12 weeks and in almost 50 % after 24 weeks.

No safety risks for the application of lactin-V were found.

Now what?

Further phase III studies are necessary before Lactin-V is ready for the market. However, the positive results give rise to the hope that the product will not only be used as a follow-up treatment for recurrence prophylaxis, but could also serve to strengthen the vaginal microbiome in general. This would be another milestone on the way to abandoning antibiotics!