Doggy dust protects against respiratory infection: Study

Dust found in a house with dogs may help protect children against a common respiratory virus linked to the development of asthma, says a new study.

“We found that exposing mice to dust from homes that have dogs protected them against a childhood airway infectious agent, respiratory syncytial virus (RSV),” said study co-author Kei Fujimura from the University of California, San Francisco, US.

“RSV infection is common in infants and can manifest as mild to severe respiratory symptoms. Severe infection in infancy is associated with a higher risk of developing childhood asthma,” added Fujimura, according to a California statement.

Fujimura and colleagues compared three groups of animals: Mice exposed to dust from homes with dogs before being infected with RSV, mice infected with RSV without exposure to dust and a group of mice not infected with RSV.

“Mice exposed to dust did not exhibit symptoms associated with RSV-mediated airway infection, such as inflammation and mucus production. They also possessed a distinct gastrointestinal bacterial composition compared to animals with no exposure to dust,” says Fujimura.

Pet ownership, in particular dogs, has previously been associated with protection against childhood asthma development, says Fujimura.

Recently, she and her colleagues demonstrated that the collection of bacterial communities (the microbiome) in dust from homes that possess a cat or dog is compositionally distinct from the dust in homes with no pets.

“This led us to speculate that microbes within dog-associated dust may colonise the gastrointestinal tract, modulate immune responses and protect the host against the asthmagenic pathogen RSV,” said Fujimura.

“This study represents the first step towards determining the identity of the microbial species which confer protection against this respiratory pathogen,” added Fujimura.

These findings were presented at the 2012 General Meeting of the American Society for Microbiology.