New treatments are possible using women’s’ natural probiotic defence against the world’s most common sexually transmitted disease
Women have a natural bacterium that fights against the most common sexually transmitted infection (STI) in the world, according to a study published online in the journal Sexually Transmitted Infections.
New therapeutic approaches could now be developed using the knowledge that a woman’s natural protective barrier made up mostly of a lactic acid bacterium called lactobacilli could help prevent them from being infected with a common STI.
One of the most common STIs in the world is Trichomonas vaginalis , a parasite that can cause a painful infection known as trichomoniasis manifested by itching and a discharge.
Trichomonas vaginalis infects an estimated 174 million people globally each year and flourishes because around half of people who have it do not show the trademark symptoms or irritation and discharge, and pass it on to others without knowing. It can bind to the inside of the vagina and cause damage to the cells in its surface.
Previous indirect evidence has suggested that T vaginalis and lactobacilli are competitors, but their microbial interaction has not been fully investigated so far.
Researchers from the University of Auckland in New Zealand set out to study the role of lactobacilli in preventing T vaginalis from binding to a woman’s cells and causing full infection.
Using vaginal cells, the team tested how easily the parasite bound itself on to the cells when they were incubated with three strains of T vaginalis and nine different types of lactobacilli, while also doing the same test without lactobacilli being present.
Overall with very few exceptions, the lactobacilli inhibited the parasite from binding to the cells to a variable degree.
Particular types of lactobacilli were better at preventing the parasite from binding to the cells, but this preventative effect was contact dependent.
The authors said:”The interaction between these micro-organisms is critical for understanding the initial steps of T vaginalis infection when parasites must overcome an unfavorable environment dominated by lactobacilli.
“This study reinforces the important role that our microbiomes play in health, infection and disease. Understanding the role that Lactabacillus plays in T vaginalis infection/disease might reveal new therapeutic approaches which include taking advantage of the natural probiotic activity of lactobacilli.”
“The adherence of Trichomonas vaginalis to hostectocervical cells is influenced by lactobacilli”,
Niha Phukan et al.
Sex Transm Infect. 2013;00:1–5. doi:10.1136/sextrans-2013-051039