Other studies have shown that dogs and their owners share much of the same gut bacteria over time, which helps people ward off allergies. Another study by Finnish scientists found that babies in homes with dogs were found to have fewer colds, fewer ear infections, and need fewer antibiotics in their first year of life than babies raised in pet-free homes.

As positive as the effects of microbes may be from dog saliva, other studies have shown that there are also potential negative effects from kissing a pet. Some research indicates that pets could pass on gum disease, where as others are investigating the potential for animals to pass on antibiotic-resistant infections to humans.

That said, the multi-disciplinary study planned at the University of Arizona sounds fascinating. That dogs may actually help humans feel better on a biological level is an exciting notion. Researchers are currently looking for participants over 50 years old and have not lived with a dog for a period of time.

The individuals will be paired with a dog from the humane society and live with the animal in their home for three months. Researchers will evaluate both the participants' and dogs gut bacteria, diet, physical activity levels and immune function prior to them living together.

Over the three months tests will be repeated to measure if there have been any positive impacts on gut microflora in either the humans or the dogs.

The researchers will also look for evidence of any changes in the humans’ and dogs’  health and emotional well-being.