The bacterial bunch: Parents, kids and dogs trade microbes

As much as dog owners love their children, they tend to share more of themselves, at least in terms of bacteria, with their canine cohorts rather than their kids.

That is just one finding of a new study led by the University of Colorado Boulder that looked at the types and transfer modes of microbes from the guts, tongues, foreheads and palms (or paws) of members of 60 American families, including canines. Identifying how such bacterial communities can be affected by environmental exposure may help scientists better understand how they can be manipulated to prevent or treat disease, say CU-Boulder Associate Professor Rob Knight and CU-Boulder doctoral student Se Jin Song, the study leaders.

Knight and his team sampled 159 people and 36 dogs. Seventeen of the 60 families had children at home ranging in age from 6 months to 18 years, 17 families had one or more dogs and no children, eight families had both children and dogs and 18 families had neither children nor dogs. Each family consisted of at least one couple between the ages of 26 and 87, and all of the children in the study were biologically related to the couples in the study. 

The team swabbed various parts of the body to obtain microbial samples on the couples, children and dogs.  For humans, the team looked at the tongue, forehead, right and left palm and fecal samples to detect individual microbial communities. Dogs were sampled similarly, except that fur was sampled instead of skin on the forehead and all four paws were swabbed for bacteria in the absence of canine palms.

“One of the biggest surprises was that we could detect such a strong connection between their owners and pets,” said Knight, also a faculty member at CU-Boulder’s BioFrontiers Institute and an Early Career Howard Hughes Medical Institute Scientist. “In fact, the microbial connection seems to be stronger between parents and family dogs than between parents and their children.”

Another surprise from the study: If you want to share more of your skin bacteria with your spouse, get a dog.

A paper on the subject was published today in the new online science and biomedical journal, eLIFE, a joint initiative of the Howard Hughes Medical Institute, the Max Planck Society and the Wellcome Trust Fund.

Read the full press release here.

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