You try to eat a balanced diet, move your body often and get enough sleep, all in the name of good health. But what if we told you that it’s not really you who is in control—but tiny organisms that control your body’s functions?
Each of us coexist with more than 100 trillion microbes, mostly bacteria, that live on us and within us, shares Will DePaolo, Ph.D., director of the UW Medicine Center for Microbiome Sciences & Therapeutics.
“For every human cell there’s that same number of bacteria,” says DePaolo.
Together, these microbes make up the human microbiome. And each part of you, like your skin, bodily fluids, lungs and gastrointestinal tracts, have their own vastly different community of bacteria, known as a microbiota. Scientists like DePaolo have been particularly interested in studying the gut microbiota because of the links they’re uncovering between the gut and the immune system, brain and behavior.
Learning more about the intricate connection between the gut and the brain—or the gut-brain axis—is helping researchers understand how what you eat and think can affect how you feel—and what you can do about it.
The Conversation: How Your Gut Talks to Your Brain
As you go about your daily life, you’re having little conversations with yourself all day long. But it’s not just the self-chatter that’s going on in your head. Your belly and your brain talk to one another constantly—like when it’s time for a snack.
“The microbiome is going to send signals saying we should be eating,” says DePaolo. “I’ve heard us talked about as walking sacks of bacteria. They’re telling us when we’re hungry by sending signals to the brain. Leptin, a hormone associated with hunger and satiation, is influenced by the microbiome as well.”