Life on the land in Australia

Farm life nothing to sneeze at as children escape allergy sniffle

Scientists have uncovered why children who live on farms are protected from allergies image www.ozrural.com.au

Scientists have uncovered why children who live on farms are protected from allergies. Photo: James Alcock

Children who grow up on farms have fewer allergies than city youngsters and scientists think they know why.

Researchers have shown that mice exposed to dust-laden farm air are protected against allergic reactions to dust mites, the most common cause of allergies in people.

Scientists from the Flanders Institute for Biotechnology and Ghent University in Belgium hope their findings will pave the way for a vaccine against asthma, a disease that has increased dramatically in the past 30 years.

There is a close link between allergies and asthma. More than 80 per cent of people with asthma also have an allergy.

“At this point, we have revealed an actual link between farm dust and protection against asthma and allergies,” lead researcher Bart Lambrecht said.

His findings were published in the journal Science.

Lambrecht and his colleagues exposed mice to a farm dust extract from Germany and Switzerland.

When the same mice were exposed to dust mites, they did not experience an allergic reaction; unlike the mice guarded from farm dust.

Protective protein

They found when mice came in contact with farm dust, their bodies produced a protein called A20.

The effect of the protein was that it “makes the mucous membrane inside the respiratory tracts react less severely to allergens such as house dust mite”, they said.

When the group examined people who suffered allergies and asthma, they found many had a deficiency in the protein A20.

“We also assessed a test group of 2000 children growing up on farms and found that most of them are protected,” Professor Lambrecht said.

“Those who are not protected and still develop allergies have a genetic variant of the A20 gene which causes the A20 protein to malfunction,” he said.

The findings offer support to the popular “hygiene hypothesis”, which suggests the soaring rates of people with allergies and asthma are linked to Western society’s obsession with cleanliness and the widespread use of antibacterial agents to rid our environment of germs.

The team is trying to pinpoint the active substance in farm dust that triggers the protective protein, hoping it will lead to the development of a preventive medicine or vaccine for asthma.

Another researcher involved in the research, Hamida Hammad, said they suspected the active substance might be linked to endotoxins that formed part of the cell wall of certain bacteria found in farm dust.

“Discovering how farm dust provides this type of protection has certainly put us on the right track towards developing an asthma vaccine and new allergy therapies,” Professor Hammad said.

However, she said several years of research were required before they would be available to patients.

Other researchers have cautioned that this new mechanism may not totally explain why farm life protects against allergies.


Henry Sapiecha

September 6th, 2015

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