I grew up in a rural community just outside of Canberra. Whilst we had a large plot of land out there we didn’t have a farm, but many people around us did including a friend of mine up the road. We’d often get put to work by their parents when we wandered up there, tending to the chickens or help wrangle the cows when they got unruly. Thinking back to those times it was interesting to note that barely anyone I knew who lived out there didn’t suffer from asthma. Indeed the only people I knew who did were a couple kids at school who had grown up elsewhere. As it turns out there’s a reason for this: “farm dust” has shown to have a protective effect when it comes to allergies, meaning farm kids simply won’t develop conditions like asthma.
There’s been research in the past that identified a correlative relationship between living on a farm and a resistance to developing allergies and asthma. Researchers at the Vlaams Instituut voor Biotechnologie (VIB) in Belgium took this idea one step further and looked for what the cause might be. They did this by exposing young mice to farm dust (a low dose endotoxin called bacterial lipopolysaccharide) and then later checked their rates of allergy and asthma development against a control group. The research showed that mice exposed to the farm dust did not develop the severe allergic reactions at all whilst the control group did at the expected rate.
The researchers also discovered the mechanism by which farm dust provides its benefits. When developing lungs are exposed to farm dust the mucus membranes in the respiratory tract react much less severely to common allergens than those without exposure do. This is because when the dust reacts with the mucus membranes the body produces more of a protein called A20 which is responsible for the protective effects. Indeed when the researches deactivated the protein the protective effects were lost, proving that it was responsible for the reduction in allergen reactivity.
What was really interesting however was the genetic profiling that the VIB researchers did of 2000 farm kids after their initial research with mice. They found that, for the vast majority of children who grew up on farms, that they had the protection granted to them by their increased A20 production. However not all the children had it but for them it was found that they had a genetic variant which caused the A20 protein to malfunction. This is great news because it means that the mouse model is an accurate one and can be used in the development of treatments for asthma and other A20 related conditions.
Whilst this doesn’t mean a month long holiday at the farm will cure you of your asthma (this only works for developing lungs, unfortunately) it does provide a fertile area for further research. This should hopefully lead to the swift development of a vaccine for asthma, a condition that has increased in prevalence over the past couple decades. Hopefully this will also provide insight into other allergies as whilst they might not have the exact same mechanism for action there’s potential for other treatment avenues to be uncovered by this research.