Research shows that babies who are breastfed have a more diverse gut microbiome (or collection of microorganisms in the gastrointestinal tract) than babies who are formula fed. But a recent Henry Ford Health study indicates that prenatal dog exposure may increase the diversity of gut bacteria in babies who are formula fed, especially between the ages of three and six months old.
“Our gut microbiome is connected to our health in so many ways,” says Edward Zoratti, M.D., an allergist at Henry Ford Health. “In fact, the number of microbes in our gut greatly outnumbers the cells in our body.
“Several research reports show that children who grow up with dogs have reduced allergies and asthma—so we started this study to find out why. We think it’s because of this diverse gut bacteria that dogs contribute to. Gut diversity in early life is likely important to stimulating the immune system to protect against asthma and allergies.”
The study focused on people who had a dog at least six months prior to—and throughout—pregnancy, suggesting that dog exposure even before birth may benefit babies. In addition to having more diverse gut microbes, among formula-fed children, having a dog was associated with a higher abundance of several potentially beneficial types of bacteria.
“We know breastfeeding supplies some microbial diversity,” says Dr. Zoratti. “Breast milk is not sterile. It contains bacteria and substances that may promote the growth of certain bacteria in the stomach, which babies who are formula fed may be missing. But this study found having a dog may make up for that.”
How Animals Affect Our Gut Microbiome
Dogs may not be the only animal to impact our health: Dr. Zoratti says children who grow up on active farms are less likely to have allergies—and there are little to no allergies among the Amish population.
“The first year of life is crucial for the immune system,” says Dr. Zoratti. “Microbes that inhabit the gut are changing rapidly. Our immune system makes significant developments and matures over that first year of life. That’s why we think having a dog in the house early on is so impactful.”
Reviewed by Edward Zoratti, M.D., an allergist at Henry Ford Health. He specializes in allergy, asthma and clinical immunology and sees patients at Henry Ford Medical Center—Fairlane and Henry Ford Medical Center—Sterling Heights.