Owning a dog or cat may have benefits for children, suggests a new Canadian study. The University of Alberta study found that babies from families with pets — 70 per cent of them were dogs — showed higher levels of two types of microbes linked with lower risks of obesity and allergic diseases.

But the timing has to be right.

“There’s definitely a critical window of time when gut immunity and microbes co-develop, and when disruptions to the process result in changes to gut immunity,"

said Anita Kozyrskyj, a pediatric epidemiologist at University of Alberta and one of the world’s leading researchers on gut microbes.

Ruminococcus And Oscillospira

The team analyzed fecal matter samples collected from 746 infants in the Canadian Healthy Infant Longitudinal Development study. They found that the bacteria Ruminococcus and Oscillospira was abundant in babies exposed to pet dander. Those two bacteria have been found to be associated with reduced childhood allergies and obesity.

“The abundance of these two bacteria were increased twofold when there was a pet in the house,” said Kozyrskyj.

Exposure to dirt and bacteria early in life — for example, in a dog’s fur and on its paws — might create early immunity, though the researchers aren’t sure whether the effect occurs from bacteria on pets or from human transfer by touching the pets, according to Kozyrskyj.

Pet exposure was shown to affect the gut microbiome indirectly — from dog to mother to unborn baby — during pregnancy as well as during the first three months of the baby’s life. In other words, even if the dog had been given away for adoption just before the woman gave birth, the healthy microbiome exchange could still take place.

“It’s not far-fetched that the pharmaceutical industry will try to create a supplement of these microbiomes, much like was done with probiotics,” Kozyrskyj said.

The study was funded by the Canadian Institutes of Health Research and the Allergy, Genes and Environment Network (AllerGen NCE).

Hein M. Tun, Theodore Konya, Tim K. Takaro, Jeffrey R. Brook, Radha Chari, Catherine J. Field, David S. Guttman, Allan B. Becker, Piush J. Mandhane, Stuart E. Turvey, Padmaja Subbarao, Malcolm R. Sears, James A. Scott, Anita L. Kozyrskyj, and the CHILD Study Investigators Exposure to household furry pets influences the gut microbiota of infant at 3–4 months following various birth scenarios Microbiome 2017 5:40 DOI: 10.1186/s40168-017-0254-x

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