Five Lactobacillus probiotic strains have been shown to reduce vaginal pathogens in new in vitro data, with a clinical trial ongoing.
Lactobacillus rhamnosus IMC 501, L. paracasei IMC 502, and their combination in the form of a proprietary blend called SYNBIO, patented by Italian firm Synbiotec, were found to be the most effective in battling pathogenic Candida strains that can cause problems like vaginosis.
One of the most common causes of genital discomfort in women of reproductive age, bacterial vaginosis or thrush occurs when the population of normal vaginal micro-organisms, dominated by Lactobacilli, is overgrown by other types of bacteria, like Candida.
Since treating this condition with antibiotics can be ineffective and is associated with high rates of recurrence, the depleted lactobacilli population is sometimes augmented by the oral or vaginal introduction of probiotic strains.
The present study, published in the Journal of Applied Microbiology and led by Dr M. Cristina Verdenelli at the Univerity of Camerino in Italy, tested the strains for their ability to produce hydrogen peroxide (H2O2) and co-aggregate with pathogens.
“The in vitro experiments demonstrated that all the five Lactobacillus strains tested possessed inhibitory action against the Candida strains using the radial streak method, but the effect is strain dependent,” they observed.
“The same situation arises with regard to the ability of coaggregation that is present in all the strains into different degrees. Only Lactobacillus rhamnosus IMC 501 and Lactobacillus paracasei IMC 502 were able to produce H2O2…”
Dr Verdenelli added: "We've all heard of using natural yoghurt to manage vaginal thrush as an alternative to antimicrobial medicines, but we wanted to test whether the type of probiotic bacteria found in yoghurt could actually kill or restrict the growth of candida.”
“The results in the lab have been very good and we have moved on to test our formulation in patients."
The human study is being conducted at the Department of Obstetrics/Gynecology and Centre for Perinatal and Reproductive Medicine, Santa Maria della Misericorida, University Hospital of Perugia.
The other strains tested were Lactobacillus paracasei subsp. paracasei 303, Lactobacillus plantarum 319 and Lactobacillus fermentum 404.
Journal of Applied Microbiology
Article first published online: 19 FEB 2014 DOI: 10.1111/jam.12459
‘Evaluation of antipathogenic activity and adherence properties of human Lactobacillus strains for vaginal formulations’
Authors: M.C. Verdenelli, M.M. Coman, C. Cecchini, S. Silvi, C. Orpianesi, A. Cresci