Researchers at the National Institute of Health (NIH) revealed why dust exacerbates asthma so severely: bacterial protein. Doctors and asthma sufferers have long recognized the effect dust has on asthma symptoms, but it has never been scientifically clear as to why the effect is so acute. The study by the NIH and Duke University identified a bacterial protein as the culprit worsening the allergic reaction. Such a component had long been suspected, but the presence of a protein flagellin in house dust has since been documented.
The research, which studied both humans and mice, was published by Duke University Medical Center and the National Institute of Environmental Health Sciences (NIEHS). The article discusses how protein flagellin is not itself an allergen but is able to boost allergic responses in scenarios where allergens are present. The study also showed that there is a gene in people and mice that allows for the detection of the flagellin. After inhaling common house dust, the mice who had the appropriate gene responded to the presence of the flagellin with mucus production and obstruction and inflammation of the airways. The mice that did not have the gene did not respond to the flagellin and responded to the dust in a much milder manner.