Dogs and us Share More Than a Friendship: We Have the Same Intestinal Flora Recently, scientists attempted to prove there is a link between obesity and our intestinal flora. Because pigs and mice share a bunch of physiological aspects with us, they are the most used animals in health studies. But this time, scientists wanted to include dogs. These dogs followed a healthy diet and then unhealthy diet, and then, scientists analyzed the bacterium of dogs' drops. They were surprised by two things: dogs had the same bacteria as human beings and their intestinal flora also reacted to unhealthy food as human beings. This study proves that the link between dogs and humans is stronger than we thought. They don't know why we share the same intestinal flora with dogs but the main theory is that we have eaten the same food for more than 10.000 years.