The brainy folk (aka researchers) at the University of Arizona reckon the microbes in a dog’s gut could have a probiotic effect on the human body—encouraging the growth of good bacteria.

Does chillin’ with your canine comrade leave you feeling all warm and fuzzy inside? Can’t resist puckering up and giving your pooch a kiss? Maybe it’s the positive microorganisms working their magic!

The researchers are gearing up to prove that the microbes exchanged between dogs and people, through the dog’s saliva, have a positive probiotic effect (a bit like yoghurt!), which helps boost our overall wellbeing.

“We've co-evolved with dogs over the millennia, but nobody really understands what it is about this dog-human relationship that makes us feel good about being around dogs," says Kim Kelly, an anthropology doctoral student and one of the primary investigators on the study.

"Is it just that they're fuzzy and we like to pet them, or is there something else going on under the skin? The question really is: Has the relationship between dogs and humans gotten under the skin? And we believe it has,” she says.

Participants in the study will be 50 years of age or older and will not have lived with a dog in the last six months. Initially they will have their gut bacteria, exercise levels, diet and immune function evaluated. They will then be teamed up with a pooch from the humane society and will live with it in their home for three months. The initial tests will be repeated each month to see if there is a positive response in the gut microflora in both the human and the dog.

The pooch and participant’s general health and wellbeing will also be assessed.

The university is currently seeking volunteers and funding to get the study up and running and to prove once and for all that a dog really is a man’s (or woman’s) best friend!