The University of Arizona has launched a study designed to explore whether dogs promote the growth of probiotics--the so-called good bacteria--in their owners. Probiotics reside in the human (and canine) gut and are believed to enhance digestion and immunity. During the study, which is the first from the university's Human-Animal Interaction Research Initiative, each volunteer will be paired with a pound dog for three months, during which both human and dog gut bacteria and physical activity will be measured. Researchers will note changes in the physical and mental health of all participants, and volunteers will be able to adopt the dogs after the study. Release