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Rural microbe exposure may ease asthma, allergy disorders for some

Patients of lower socioeconomic status may have a greater prevalence of asthma, allergies or other chronic inflammatory disorders due to reduced exposure to rural microbes, according to a new study published in the journal Clinical and Experimental Immunology.

“Chronic inflammation can lead to all kinds of problems from irritable bowel syndrome to asthma to allergies and even depression,” Christopher A. Lowry, PhD, associate professor department of integrative physiology and Center for Neuroscience University of Colorado Boulder, said in a press release. “The rise of chronic inflammation and these associated disorders, especially among people living in the cities of developed countries, is troubling.”

Christopher A. Lowry

Lowry and Graham A.W. Rook, MD, of the Centre for Clinical Microbiology and the department of infection at the University College London, UK, and colleagues wrote that microbiological encounters should be considered in terms of evolutionary history.

They refer to commensal microbiotas transmitted by mothers and other family members as ‘old friends,’ and childhood virus infections as ‘crowd infections.’

Graham A.W. Rook

“You don’t want the crowd infections,” Lowry said. “But you do want to find ways to increase your exposure to ‘old friends.’”

Increased hygiene in areas of low socioeconomic status may help to protect from infections, but also protect against “new enemies,” they wrote.

“The idea that we’re too clean—that gives the wrong impression,” Lowry said in the release. “You want people to wash their hands because hygiene is important to avoid infections that are harmful.”

Furthermore, the researchers reported that urbanization may reduce the exposures to the immunoregulatory role of the natural environment.

“Helminthic parasites need to be tolerated by the immune system because, although not always harmless, once they are established in the host efforts by the immune system to eliminate them are futile, and merely cause tissue damage,” Rook said in the release.

The researchers conclude there is a need for greater understanding of the relationship between organisms in the natural environment.

Disclosure: Lowry and Rook report no relevant financial disclosures.