The Gut-Brain Connection
Turns out the idiom, "gut feeling" is more than just a way to describe your intuition. If you've ever felt "butterflies" in your stomach when you're nervous or "listened to your gut" when making a big decision, you're likely getting messages from the lining of your digestive system, known as the enteric nervous system (ENS) or "second brain."
While the second brain can't perform complex thinking tasks, it can regulate our digestion and communicate with the central nervous system, or the main brain. This interplay between the trillions of tiny microbes that live in our gut and the nervous system is known as the gut-brain axis. Scientists have described the gut-brain axis as a communication superhighway that carries vital messages back-and-forth along the vagus nerve, linking emotional and cognitive centers of the brain with intestinal functions.
Although research is still emerging, studies have found that a healthy gut influences a healthy brain. For example, we know that microbes in the gut produce a variety of key brain neurotransmitters, such as dopamine, glutamate, GABA, and serotonin, which are the body's chemical messengers. In fact, 95% of the body's "happy hormone," serotonin, comes from the gut.
When communication between the gut and brain are disrupted, it can interfere with the production and signaling of these "feel-good" chemicals, contributing to depression, anxiety and even neurological disorders. What's more, studies have found higher rates of anxiety and depression in patients with GI disorders like irritable bowel syndrome and ulcerative colitis suggesting that dysfunction of the gut-brain axis is bidirectional.
So how do we prevent disruptions in the gut-brain axis to benefit our mental health?
Diversify Your Diet
Consuming a wide variety of fiber-rich foods, fruits, vegetables, whole grains, and fermented foods can enhance the diversity of your gut microbiota. These foods provide prebiotics (fiber that feeds beneficial gut bacteria) and probiotics (live beneficial bacteria) that support a healthy gut. Eating foods like yogurt, kimchi, sauerkraut, kefir, and tempeh can introduce beneficial bacteria into your gut as well as omega 3 fatty acids, which have anti-inflammatory properties and may help relieve depression.
Don't Be Afraid of Spices
Many spices, like turmeric and saffron, also have rich antioxidant and anti-inflammatory properties. In addition, spices like cloves, cinnamon and nutmeg contain nutrients that sharpen memory, reduce stress and may even improve sleep.
Reduce Stress
Chronic stress can negatively affect the balance of gut bacteria. Practicing stress-reducing techniques such as mindfulness exercises, physical exercise, and getting quality sleep can positively impact your gut microbiome. Adequate sleep is not only essential to good mental health, but also helps maintain a healthy balance of gut bacteria and supports overall digestive health.
Avoid Antibiotics
Antibiotics can disrupt the balance of good and bad bacteria in your gut. While they're essential in fighting certain infections, unnecessary use should be avoided. Probiotic supplements can be beneficial in maintaining gut health, especially after antibiotic use or during times of digestive upset. However, the best way to add probiotics to your diet is through food.
For another look at good-mood foods, check out the psychobiotic pyramid, created by John Cryan, Ph.D. and Ted Dinan, Ph.D., authors of The Psychobiotic Revolution.