A little known micro-system of nerve fibers exists in and around the gut called the enteric nervous system (ENS). Sometimes referred to as the 2nd brain, it talks continuously to the central nervous system as well independently regulating the GI tract. There are as many neurons in this system than the spine and 5X more than in your brain!
The health of the gut directly influences affect, motivation, emotions and cognitive functions. The gut 'brain' actually has neurotransmitters that communicate back and forth to and from the central and autonomic nervous systems. 90%-95% of the body's serotonin (a neurotransmitter that regulates mood such as depression) is found in the gut! GABA, also a mood altering substance in the body, is found in the gut. Irritation of the gut may signal the brain to cause mood changes as well as cognitive disturbances, fear, anxiety and pain.
The main 'freeway' of this bidirectional highway is the vagus nerve. This is the longest nerve in the body, running from the brain through the heart to the gut. It runs from the medulla oblongata to the colon. Stimulation of this nerve can cause decreases in heart rate and one can lose consciousness. This nerve can be stimulated by bearing down while going to the bathroom, pressure on the side of the neck or shockingly cold water on the face or head.
So keeping the gut microbiome healthy literally translates into a healthy brain!
Nutrition Tips for Healthy Guts:
Omega-3 fats: These fats are found in oily fish and also in high quantities in the human brain. Studies in humans and animals show that omega-3s can increase good bacteria in the gut and reduce risk of brain disorders.
Fermented foods: Yogurt, kefir, sauerkraut and cheese all contain healthy microbes such as lactic acid bacteria. Fermented foods have been shown to alter brain activity.
High-fiber foods: Whole grains, nuts, seeds, fruits and vegetables all contain prebiotic fibers that are good for your gut bacteria. Prebiotics can reduce stress hormone in humans.
Polyphenol-rich foods: Cocoa, green tea, olive oil and coffee all contain polyphenols, which are plant chemicals that are digested by your gut bacteria. Polyphenols increase healthy gut bacteria and may improve cognition.
Tryptophan-rich foods: Tryptophan is an amino acid that is converted into the neurotransmitter serotonin. Foods that are high in tryptophan include turkey, eggs and cheese.