Dogs have long been celebrated as beloved companions. However, recent studies suggest they may also improve our well-being by influencing our microbiomes. Experiments conducted on mice indicate that dog owners possess unique bacterial species that promote both empathic and social behaviors.

It’s evident that pets significantly enhance life satisfaction while also impacting our gut microbiome. Research highlights how this microbiome affects our mental health and plays a role in shaping our personalities. With dogs often topping the list of preferred pets, Takefumi Kikusui and his team from Azabu University in Japan sought to investigate whether pets influence our microbiomes and enhance our overall well-being.

To delve into this, researchers analyzed a survey where caregivers of 343 adolescents aged 12 to 14 in Tokyo reported on their social behaviors, including feelings of loneliness, tendencies toward aggression, and peer interactions. It was noted that approximately a third of these adolescents own pet dogs.

Findings revealed that, on average, dog owners perceived themselves as less socially withdrawn and exhibited less aggressive tendencies compared to their non-dog-owning peers. The research team also examined potential influencing factors such as gender and household income.

Saliva samples indicated that several types of streptococcus bacteria were more abundant among adolescents who owned dogs, which is associated with lower levels of depressive symptoms.

“Engaging frequently with your dog exposes you to their microorganisms (like licking),” explains Gerald Clarke from University College Cork, Dublin, Ireland. These bacteria can migrate to the gastrointestinal tract, potentially causing infections. They can also produce anti-inflammatory substances like short-chain fatty acids, which may improve mental health.

An essential part of the study involved transplanting oral microbes from dog owners and non-dog owners into germ-free mice. Fecal analysis showed that the introduced microorganisms successfully colonized the mice’s intestines.

In subsequent weeks, the researchers conducted various behavioral tests on the mice. In one test, a mouse was placed in a cage alongside another mouse trapped in a tube. Results indicated that mice transplanted with microbes from dog owners were significantly more inclined to interact with the tube than those who received microbes from non-dog owners.

This behavior suggests that the original mice displayed greater empathy and a willingness to help, Kikusui noted. Recent research has also revealed that mice can assist their pregnant partners in giving birth and even provide rudimentary first aid.

In another experiment, dog-owner transplants exhibited a tendency to sniff unknown mice in their cages more frequently than the other groups, indicating increased sociability, according to Clarke. “Such social behaviors can have implications across species, including humans,” he asserts. “Robust social networks are beneficial for mental health; having limited social exposure can be detrimental.”

Gaining further insights into these microbial shifts and developing probiotics that replicate these effects could potentially benefit individuals without dogs, Clarke suggests. However, studies in other regions with different microbial exposures are necessary.