London: A new study has confirmed that children living on farms are significantly less likely to develop asthma than others.
The study conducted by an international team of researchers including Dr. Markus Ege and Professor Erika von Mutius of Children``s Surgical Clinic in the Dr. von Hauner Children``s Hospital (Medical Center of the University of Munich), shows that exposure to a greater variety of microorganisms on the farm makes children less susceptible to asthma.
The results have broad implications for the prevention of asthma in other sectors of the population.
"We have a long way to go before we can present new preventive measures, but at least we now have candidates for the development of a vaccine,” said Ege.
Asthma results from a combination of genetic and environmental factors.
To confirm the difference of the risk in children living on farms and cities, the LMU researchers selected a group of Bavarian schoolchildren for detailed study. In the context of two large-scale, pan-European, epidemiological projects and compared children living on farms with others from the same rural districts who had little direct contact with farms.
The results showed that farm children must cope with a much greater range of microorganisms than are children who live in other types of environment.
The bacteria and fungi seem to act as guardians of health, for it turned out that the more diverse the microbial population, the lower the risk of asthma.
The researchers said they were yet to find out exactly why this happened.
"Within the large spectrum of organisms that we examined, there are some that may be of special interest," reports Ege.
"Among these are certain species of bacilli and staphylococci - Staphylococcus sciuri, for instance – as well as fungi of the genus Eurotium."
The next challenge facing the team is to elucidate, at the level of single species, the nature of the link between the microorganisms in household dust and the protective effect, with the long-term goal of identifying candidates that might serve as the basis of a live vaccine against asthma.
The study appears in New England Journal of Medicine online on 24 February 2011.