If you had to guess the organ that has undue influence on your emotions, your mood, even your choices, what would you guess? The brain? Sure, but what else? The heart—that mythological seat of the soul? Not quite. The stomach? You’re getting warmer. Would you believe it’s the large and small intestine, collectively known as the gut? More specifically, it’s the trillions of bacteria—the microbiota—that live in your gut. Each of us carries up to four and a half pounds of bacteria around in our guts at any given time. More than 100 trillion microbes live down there. That’s as many cells as make up the rest of your body.
Now, this crowd is mostly good guys, and they do important work, to the extent that some scientists advocate classifying these collective microbiota as its own organ. Aside from helping digest our food, they protect us from disease, neutralize some of the toxic by-products of the digestive process, and make it harder for bad bacteria to set up shop. In short, your gut does way more than just digest everything from Cheetos to camembert.
But it turns out gut bacteria may also affect how we feel. Who knew the next frontier in mental well-being would lead right to the toilet? With that lovely image in mind, here are 3 big ways our microbiota are connected to our mental health.