Dog lovers often speak about the joy, comfort, and companionship pets bring to their lives. But scientists now say the benefits of growing up with dogs may go deeper—down to your gut.
A new study by Sinai Health and the University of Toronto reveals that children who live with dogs between the ages of five and fifteen are more likely to have a healthier gut and a lower risk of developing Crohn’s disease later in life. The findings, published in Clinical Gastroenterology and Hepatology, could pave the way for new strategies in preventing inflammatory bowel disease (IBD).
How Can Dogs Improve Gut Health?
“The idea behind predicting someone’s risk of disease is that you can then also begin to understand who you might want to do something to try and prevent disease,” said Dr. Kenneth Croitoru, lead researcher and clinician-scientist at the Lunenfeld-Tanenbaum Research Institute.
Croitoru and co-author Dr. Williams Turpin led the study at Mount Sinai Hospital’s Centre for Inflammatory Bowel Disease. Their research explored dozens of environmental factors—dog ownership stood out as a potential protector of the gut.
While the study doesn’t yet explain why, researchers found children exposed to dogs had better gut microbiome composition, gut permeability, and blood biomarkers—factors linked to lower inflammation and disease risk.
A Family Dog May Protect Against Crohn’s
Crohn’s disease is a chronic condition caused by inflammation in the gastrointestinal tract. It affects over 300,000 Canadians, with cases in children under 10 having doubled since 1995. Although genetics play a strong role, environmental influences like diet and household pets can make a difference.
The study also found that living in a large family during infancy reduced Crohn’s risk, while contact with birds appeared to increase it. These findings emphasize how early-life environments can shape long-term health outcomes.
“We have established associations between environmental factors and Crohn’s and are now trying to understand how these environmental factors affect the triggering of the disease,” Croitoru explained.
The GEM Project and What Comes Next
These insights are part of the Genetic, Environmental, and Microbial (GEM) Project—one of the largest ongoing studies of Crohn’s disease in the world. The GEM Project has tracked over 5,000 healthy relatives of Crohn’s patients since 2008 across countries like Canada, Australia, and Israel.
In those 15 years, over 120 participants have gone on to develop Crohn’s. Researchers are comparing the medical and lifestyle data of those who did and didn’t develop the disease to predict risk.
Another Mount Sinai researcher, Dr. Sun-Ho Lee, recently used this data to create an “integrative risk score” using machine learning that predicts Crohn’s disease with high accuracy.
But Croitoru’s vision goes beyond risk prediction.
“We want to move from understanding who is at risk to actually preventing the disease from happening,” he said.
His team is now working on interventions, including dietary supplements aimed at promoting a healthier microbiome from an early age.
Dog Ownership Could Lead to Personalized Health Plans
“By integrating genetic, environmental, and microbial data, Dr. Croitoru and colleagues are paving the way towards personalized intervention strategies that could significantly reduce the incidence of Crohn’s disease,” said Anne-Claude Gingras, director of LTRI and vice-president of research at Sinai Health.
For now, the findings suggest that the benefits of growing up with dogs may be more powerful than once believed—not just emotionally, but biologically.
