Feeling butterflies in the belly before a big meeting or binging on chocolate to soothe a broken heart, humans have always known how emotions affect the digestive system, and vice versa.
Now, neurobiologists are confirming what many distressed people already know firsthand: there’s a powerful link between the brain and the gut.
That connection is so deep that scientists are now calling the digestive system our second brain.
The brain in the head and the one in the stomach constantly communicate through a bundle of chemical and neural pathways called the gut-brain axis — a messaging system so direct that treating disorders affecting one of these brains can alleviate symptoms in the other.
The Gut-Brain Axis: A Message System
The gastrointestinal tract is responsible for breaking down food, extracting nutrients and eliminating waste. But this system, collectively called the gut, also contains two extra layers of over 100 million cells whose job doesn’t involve processing food.
This structure, called the enteric nervous system, is responsible for just one thing: sending messages between gut and brain through chemical signals passed via the central nervous system. These chemicals are responsible for things like the “fight or flight” response of accelerated heart rate and shallow breathing – but also for sudden trips to the bathroom in a tense situation.
The enteric nervous system is just one pathway on the gut-brain axis. Along with our own human cells, the gut also hosts a vast colony of microorganisms including bacteria, fungi and even parasites. With millions of strains concentrated largely in the intestines, these organisms make up ninety percent of the body’s total cell count
Called the gut, or enteric, biome, this colony is home to benign bacteria such as lactobacillus, which helps digestion. But the gut biome also contains potentially harmful ones like H. pylori, which if unchecked can lead to ulcers, infections and inflammation. These organisms also communicate with the brain by sending signals along the vagus nerve and through chemical pathways related to the immune system.
Two-Way Tools for Healing
The intimate connection between gut and brain makes it possible to heal maladies of both, in often surprising ways. Stubborn cases of digestive conditions such as irritable bowel syndrome and colitis can improve with mental health treatments such as cognitive therapy and antidepressants. Mindfulness and meditation practices intended to reduce anxiety are also being used to reduce the severity of digestive issues triggered by stress.
Treating the gut also helps ease emotional problems. New studies suggest that adding probiotic supplements to the diet to support a healthy gut biome can reduce anxiety and relieve symptoms of depression. Dietary changes such as swapping simple carbohydrates, bad fats and processed foods for lean protein, vegetables and fruits can also help boost mood and ease depression. In the same way, fish oil supplements and other healthy fats can calm anxiety and improve memory.
The secrets of the gut brain axis are still being discovered. But new research reveals that the powerful and immediate communication between our first and second brains is a potent tool for healing both systems – and going with your gut may be a key to staying well.