Happy Friday, my friends! I figured I would start this post off with a little food for thought and a scientific #FactFriday. 70-80% of our immune systems are located in our gut. If you have ever felt “butterflies in your stomach” when nervous or “gone with your gut” to make a decision, you are most likely getting these feelings from an unexpected source: your little second brain. Hidden among the walls of the digestive system, this “little second brain” is revolutionizing medicine’s understanding of the links between digestion, mood, overall health, and the way you think.
According to the John’s Hopkins University School of Medicine, scientists are referring this “little second brain” in your gut the enteric nervous system (ENS)… and it is not so little. The ENS is two thin layers of more than 100 million nerve cells lining your gastrointestinal tract from your esophagus to your rectum.
What Power Does The Gut Brain Have?
Unlike the big brain in your skull that everyone knows about, the ENS is unable to balance your checkbook or compose a love note. “Its main role is controlling digestion, from swallowing to the release of enzymes that break down food to the control of blood flow that helps with nutrient absorption to elimination,” says Jay Pasricha, M.D., director of the Johns Hopkins Center for Neurogastroenterology, whose research on the enteric nervous system has triggered international attention. “The enteric nervous system doesn’t seem capable of thought as we know it, but it communicates back and forth with our big brain—with profound results.”
The ENS may trigger big emotional shifts experienced by people coping with irritable bowel syndrome (IBS) and functional bowel problems such as constipation, diarrhea, bloating, and upset stomach. “For decades, researchers and doctors thought that anxiety and depression contributed to these problems. But our studies and others show that it may also be the other way around,” Pasricha says. Researchers are finding scientific evidence that irritation in the gastrointestinal system may send signals to the central nervous system (CNS) that cause mood changes.
“These new findings may explain why a higher-than-normal percentage of people with IBS and functional bowel problems develop depression and anxiety,” Pasricha states. “That’s important, because up to 30 to 40 percent of the population has functional bowel problems at some point.”
Understanding the Gut = Finding New Treatments
This new understanding of the ENS-CNS connection helps explain the effectiveness of IBS and bowel-disorder treatments such as anti-depressants and mind-body therapies like cognitive behavioral therapy (CBT) and medical hypnotherapy. “Our two brains ‘talk’ to each other, so therapies that help one may help the other,” Pasricha says. “In a way, gastroenterologists [doctors who specialize in digestive conditions] are like counselors looking for ways to soothe the second brain.”
Gastroenterologists may prescribe certain antidepressants for IBS, for example – not because they think the problem is all in a patient’s head, but because these medications calm symptoms in some cases by acting on nerve cells in the gut, Pasricha explains. “Psychological interventions like CBT may also help to improve communications between the big brain and the brain in our gut,” he says.
There Is Still So Much More To Discover
Pasricha said that research suggests that digestive-system activity may affect cognition as well. “This is an area that needs more research, something we hope to do here at Johns Hopkins,” he says. Discovering how signals from the digestive system affect metabolism, raising or reducing risk for health conditions like Type II Diabetes, is another area of interest. “This involves interactions between nerve signals, gut hormones and microbiota—the bacteria that live in the digestive system,” Pasricha says.