CHICAGO, March 9 (Xinhua) -- U.S. researchers recently found that the kinds of microbes living in the gut influence the severity and recurrence of parasitic worm infections in developing countries, and suggest that manipulating the gut's microbial communities may protect against intestinal parasites, which affect more than 1 billion people worldwide.
Studying communities in Liberia and Indonesia, the researchers found that the gut microbiomes of people who are able to clear the infections without drugs were more alike and differed markedly from the microbiomes of those who could not clear the infections without treatment.
"People who have sustained infections or who experience multiple infections have a different microbiome to start with compared with those who do not have as much trouble with infection," said senior author Makedonka Mitreva, an associate professor of medicine at Washington University School of Medicine in St. Louis.
"Our work included samples from a placebo-controlled trial of drugs against these parasitic worms. It suggests that the microbiomes of people who retained infection are somehow compromised to begin with. Something about their microbiomes makes them more prone to getting infected and to maintaining a chronic infection."
The researchers have identified 12 microbes associated with worm-infected individuals and one type of bacteria associated with uninfected individuals.
In particular, gut bacteria associated with increased inflammation were linked to healthy uninfected individuals, perhaps because this type of inflammatory environment makes it harder for the worms to establish themselves in the gut.
According to the World Health Organization, about one quarter of the world's population, over 1.5 billion people, is infected with parasitic worms called helminths. These worm infections are most common in tropical and subtropical areas with poor sanitation.
Currently, antihelminthic drugs are used to deworm people who are infected, especially school-age children and women of reproductive age.
As the study found characteristics of the microbiome that are discriminative of infection, this information could be used to predict who is most likely to develop severe and chronic infections and direct more preventive efforts to those individuals, said Mitreva.
The study has been published online in the journal Microbiome.