Could pets offer “probiotic” benefits to their owners?
Researchers at the University of Pennsylvania School of Veterinary Medicine (Penn Vet) are set to investigate whether pets could be a source of microbiota that can help restore deficiencies in their owner’s gut microbiome (i.e. collection of microbes in the intestines).
The study, which has received funding from the Human Animal Bond Research Institute (HABRI), will follow pet owners (60 years or older) who are taking antibiotics for dental implant placement. Antibiotics disrupt the native gut microbiome, HABRI reports, which can result in adverse outcomes, ranging from mild diarrhea to severe “C. diff” (Clostridioides difficile) infection.
Researchers hypothesize the gut microbiomes of owners and their pets will resemble each other prior to the course of antibiotics, diverge during the disruption phase, then steadily converge during the recovery phase.
“A growing number of studies have documented the ability of animal contact to impact the human microbiome in ways that may help prevent certain types of disease, such as cardiovascular disease and asthma,” says principal investigator, Laurel Redding, VMD, PhD, DACVPM, an assistant professor of epidemiology at Penn Vet. “In conducting this study, our goal is to shed light on the microbial exchanges that occur between pets and pet owners and assess whether pets can mitigate disruption of their owner’s gut microbiome following antibiotic therapy.”
Researchers say the study’s results could support the promotion of contact between older adults and household pets, HABRI reports.
“HABRI is proud to fund research that will contribute to our understanding of the physiological health benefits of the human-animal bond,” says the group’s president, Steven Feldman. “We know pets and people are good for each other, and it’s exciting we can still discover new evidence underlying this powerful, mutually-beneficial relationship.”
In urban environments, allergic diseases are more common among dogs and their owners compared to those living in rural areas. Simultaneous allergic traits appear to be associated with the microbes found in the environment, but microbes relevant to health differ between dogs and humans.
In a joint research project known as DogEnvi, researchers from the University of Helsinki, the Finnish Environment Institute and the Finnish Institute for Health and Welfare have previously observed that dogs are more likely to have allergies when their owners suffer from allergic symptoms. In a new study, the researchers investigated whether such simultaneous presence of allergic traits is associated with gut or skin microbes shared by dogs and their owners. A total of 168 dog–owner pairs living in rural and urban environments participated in the study.
“Research shows that dogs and owners living in rural areas have a lower risk of developing an allergic disease compared to urban areas. We assumed that in rural areas both dogs and owners are exposed to health-promoting microbes. We found that the microbial exposure of both was different in rural and urban environments. For instance, the skin microbiota varied more between individuals in rural areas compared to their urban counterparts. A diverse and varying microbial exposure may be precisely what provides the associated health benefit,” says Senior Researcher Jenni Lehtimäki, PhD, from the Finnish Environment Institute.
The study demonstrated that the living environment had a markedly more significant effect on the skin microbiota than on that of the gut in dogs and humans. Dogs living in urban areas had on their skin more microbes typically found on human skin, which may be caused by the accumulation of microbes typical to humans indoors and in urban areas, a phenomenon that has been previously observed.
In a study conducted earlier, the researchers noticed that both the living environment and living habits affected the canine skin microbiota.
“The same was now observed in humans. For both dogs and humans, the risk of developing allergic diseases was at its lowest when the skin microbiota was shaped by a rural environment and a lifestyle that promotes microbial abundance. Such a lifestyle was associated with a number of different animals in the family, as well as larger family size,” says Professor Hannes Lohi from the University of Helsinki.
While the living environment appeared to alter the species of the skin microbiota as well as the risk of allergic diseases in both dogs and their owners, no single shared microbe in the environment had a link to allergies in both dogs and humans.
“We detected microbes associated with allergies in urban dogs, as well as microbes connected to health in rural dogs and humans, but these microbes were different in dogs and humans. It appears that the microbes in the living environment are important for the health of both dogs and humans, but due to the physiological differences of the species, the microbes that are relevant can vary,” Lehtimäki sums up.
DogEnvi, a multidisciplinary research project launched in 2014, is aimed at investigating the significance of the living environment to canine health. Under the project, a study on the link between canine gut microbiota, nutrition and allergies is being prepared. The project has received funding from the Jane and Aatos Erkko Foundation, among others.