kissing your dog is actually good for your health.
They are holding a study with people over 50 to test if kissing your dog adds good bacteria to your gut like yogurt does - adding good probiotics to your stomach - and therefore is actually good for your health.
It's something that real dog lovers have known for a long time.
In addition to that they are testing at the same time during this study the emotional as well as physical well being of the humans to see if living with a dog has improved and given any evidence of change in both the dogs' and the humans overall health and well being.
It's all part of the "Human Animal Interaction Research Initiative" that sounds pretty interesting -