Get to Know Your Enteric Nervous System: the Brain in Your Gut

It's more than a gut feeling: Your microbiome—that unique collection of microbes that lives in your gastrointestinal tract—plays a key role in your overall health. It's been tied to everything from your emotional well-being to how easily, or not, you maintain a healthy weight.

While the microbiome in the gut (there’s also one in your mouth, on your skin, and in your vagina) has garnered a great deal of attention, it’s also important to understand that it's not an isolated environment. It connects to the rest of your body through what's called the enteric nervous system (ENS). This signaling system makes it possible for your gut to communicate with your brain.

“There’s a connection from the enteric nervous system in the gut to the central nervous system and from the central nervous system to the enteric nervous system,” says Peggy Mason, PhD, professor of neurobiology at the University of Chicago. “The information goes both ways—and when things aren’t working in your gut, you feel it. It can change your mood.”

"When things aren’t working in your gut, you feel it. It can change your mood,” says Peggy Mason, PhD.

The gut and the brain are connected by the nerves that line the intestines, registering all sorts of chemical reactions taking place within your gut's microbiome. The most crucial job of your ENS is to move waste through your intestines. It's a relatively straightforward—but incredibly important—task performed day in and day out, with no conscious effort on your part (except for at the very end of the process). "That has to happen or you don’t live," says Dr. Mason. She notes that the enteric system is similar to the digestive system of many invertebrates; it's a very basic building block of our anatomy.

Though more information flows from the gut to the brain than the other way around, that sensation of butterflies in the stomach or diarrhea when you're feeling nervous is a clear, physical reminder of the link between the two.

That sensation of butterflies in the stomach or diarrhea when you're feeling nervous is a clear, physical reminder of the link between your gut and brain.

In a wellness landscape that includes services that will monitor your microbiome and help you modify it in pursuit of optimal well-being, Dr. Mason cautions that, while experts know that the ENS and the unique microbial fingerprint you play host to are important factors in your health, much more research is required to fully understand how it works. "The microbiome is probably not everything cracked up to be," she says. "But it's probably very, very important."

That doesn't mean you shouldn't think about your microbiome and what it's telling your brain via the enteric system when you're choosing what to eat. Research shows that a varied diet, with lots of fiber and probiotics—think fermented foods, yogurt, kombucha—encourages a diverse microbiome.

"It's not clear there is an optimal microbiome," says Dr. Mason. "Having a diverse mircobiome, though—the more diversity, the better, appears to be true."

Read up on the latest research regarding your gut health and anxiety. And here are more foods to eat for a healthy, diverse microbiome.