The rationale for this novel approach to enhancing health and well-being in the elderly comes from several lines of evidence. First, one recent study shows that family members share as much or more of the composition of their microbiota with their dogs as they do with each other (Song et al. 2013). This shows that the introduction of dogs into home environments has a profound impact on the human microbiota. Second, many studies show that children raised with dogs are less likely than others to develop a range of immune-mediated disorders, including asthma and allergies (Ownby et al. 2002; Almqvist et al. 2003; Havstad et al. 2011). This suggests that dogs can serve as probiotics for children by appropriately training their immune systems not to produce inflammation in response to harmless stimuli. Thus, what is not known, and what this study is designed to explore, is whether dogs might also improve the physical and mental health of elderly adults by improving the structure and function of their microbiota. This is a proof of concept / pilot study. Should results from this study suggest that there is indeed a positive benefit/relationship to canine companionship to the microbiota of elderly human companions, the investigators plan to implement a larger, full-scale clinical trial to investigate this phenomenon.