There's nothing like a smooch from our pup. Some love it; others call it gross. But some believe dog kisses might actually keep us healthy.
"There's a lot of evidence that pets help people emotionally," explains Dr. Charles Raison, psychiatrist and researcher at the University of Arizona.
Dr. Raison and his team are studying whether dogs -- specifically dog kisses -- can offer humans a physical health boost.
"We think the dog kiss on the skin, or the oral cavity, there's a transfer, and that transfer is like taking a probiotic, and taking very complex probiotic," continued Raison.
It's all thanks to communities of bacteria called microbiota. These organisms live in us and on us, and their effect can reach our brain and impact how we think and feel.
The question now: How do dog kisses help balance good bacteria with bad bacteria in our gut? The theory is that the probiotic effect can protect us from chronic conditions like asthma and allergies, as well as hard-to-treat drug-resistant disease caused by superbugs.
"We know dogs make people feel better. We want to understand the mechanism that they make people feel better and if turns out that some of making people better is changing the gut composition. Not only does that provide novel ways of thinking why dogs are important," said Raison, "If we understand what they do in the gut, maybe it will devise other ways other probiotic ways of doing the same things, and that might someday be antidepressants."
Some may wonder if dogs can make us sick. Dr. Raison says in the past, dogs carried far more parasites and people more frequently became infected with worms. Now dogs are healthier so it's far less likely.
Even so, he believes, the parasites dogs passed onto humans may have had a beneficial effect, priming our immune systems so they would not overreact later, leading to life-threatening allergies and auto-immune disease. It's called the "hygiene hypothesis."
The current study involves adults over the age of 50. Results are expected by next year.
His next study will involve children at a very early age. He hopes to place dogs in homes of children who may be at risk of not having enough good bacteria in their guts. That might include babies born by cesarean section or those who were hospitalized.
Dr. Raison: http://psychiatry.arizona.edu/raison
Hygiene Hypothesis: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2841828/pdf/cei0160-0001.pdf