Tiny microbes in the stomach may hold more power over behavior than you think.

We often imagine a dog’s personality as something shaped by training, environment, or maybe even genetics. But researchers are finding that some of the biggest influences on behavior may be invisible, living quietly in the gut. Those trillions of microbes could be whispering signals straight to the brain, fueling stress or calming nerves.
If your dog paces the floor during storms or trembles in crowded spaces, it might not just be temperament. Science is uncovering surprising connections between digestion and emotion, suggesting that solving anxiety could begin not with obedience classes, but with the balance of bacteria in the belly.