Farm dust protects children against allergies, asthma

The researchers got similar results when they exposed mice lacking the gene responsible for A20 to farm dust that contains fragments of different bacteria, extracellular polysaccharides from fungi, to name a few.

You may want to give your kids a taste of farm life as new study has suggested that doing so can protect them against asthma and allergies.

‘The hygiene hypothesis states that the rise in allergy and asthma that has been observed in affluent countries since the Second World War is caused by reduced “infectious pressure” from the Western lifestyle environment’. In the US, respiratory allergies are the most widespread type of allergy in kids. Children living in rural areas, especially in farms with cows, display significantly lower rates of respiratory allergies and asthma.

Researcher Bart Lambrecht (VIB/Ghent University/Ghent University Hospital) said that they revealed an actual link between farm dust and protection against asthma and allergies by exposing mice to farm dust extract from Germany and Switzerland.

They examined a number of 2,000 participants, all of which grew up on farms, and inquired about the aforementioned medical health issues.

One of the key protective elements found on farms – endotoxin – a protein found in bacterial cell walls is also found in smaller quantities in household dust. While the mice exposed to endotoxins did not develop allergic features, the mice in the control group did.

The one that played a role in reducing the inflammatory response in the endotoxin-exposed mice was a particular anti-inflammatory enzyme called A20, which is made by the epithelial cells. In order to test that theory, the team grew laboratory rodents that didn’t have the molecule in their lungs.

Preventing many allergies could be as simple as taking a breath – of farm dust.

To confirm the role of A20 had to be functional for the protective effect to work, the researchers turned to humans, using lung biopsy samples from healthy adults and asthmatics. Healthy human tissue had a normal reaction to dust bacteria, but in lung tissue from asthma patients the immune response to dust bacteria was exaggerated and the production of A20 molecules was much lower.

Martijn J. Schuijs, the first author of the paper from the VIB Inflammation Research Center, Ghent, Belgium, and others tried to establish whether exposure to environmental endotoxin offered the protective effect against asthma in mice and also study the mechanism of protection.

Further research found that endotoxin exposure appears to have protected the mice by squashing the ability of the animals’lung epithelial cells to generate pro-inflammatory molecules, but this protective effect only worked in the presence of the A20 protein.

The latest findings help to support “the hygiene hypothesis” – that our homes stop our immune systems functioning properly. Allergies are an overblown response to a “false alarm”.