Low gut bacteria diversity puts kids at asthma risk

Low diversity of gut microbes in the intestines of infants can increase the risk for developing asthma, says a study.

"A high diversity of gut microbiota (a huge microbe population living in our intestine) during the first months of life seems to be important for the maturation of the immune system," said Thomas Abrahamsson, paediatrician and researcher at Linköping University in Sweden.

Researchers first looked at a comprehensive survey of the intestinal microbiota of allergic and healthy infants.

In the samples from the infancy period, the diversity of the bacteria strains was significantly lower among those who had developed allergic eczema when they were two years' old.

A follow-up study was conducted when the 47 participating infants reached their seventh birthday.

By then, 17 percent were suffering from chronic asthma, 28 percent had hay fever, 26 percent still had eczema and 34 percent reacted to the allergens in a skin prick test, said the study published in the journal Clinical and Experimental Allergy.

"It was only the asthma cases that could be connected to low intestinal microbial diversity at the age of one week and one month," said the results.

A high gut microbial diversity has also been shown to strengthen the barrier function of the mucous membrane.

"We are speculating that a deficient maturity of the immune system at an earlier age and a less efficient mucosa barrier function can open the way to certain types of viral infection that can be linked to the development of asthma," added senior author Maria Jenmalm, professor of experimental allergology.