We all know that the brain is our command center. It uses the vagus nerve to communicate with most of the body including the majority of the digestive tract. It also communicates fight or flight which is why you might feel your heart race, get short of breath, or a knot in your stomach or vomit when you become very stressed or nervous.
What science has learned is that 80-90% of the nerves in the enteric nervous system (region from esophagus to anus) go from the gut to the brain. The enteric system is so advanced with an extensive network of more than one hundred million neurons – more than the number of nerves in the spinal chord – that even if you cut the vagus nerve it will continue digestion on its own without the direction of the brain. That’s pretty impressive!
Before the modern age of food safety we had to determine if food was safe, if it could provide fuel, etc. The direct communication from the gut tells us this information. This is why our body releases dopamine, the feel good chemical, when it eats fat and sugar. Both excellent fuel sources. Our gut is telling us that it likes these fuel-rich sources in order to prevent fuel scarcity in the body. Remember, our primitive body wants to store as much energy as possible in case of long periods of famine.
Not only does the gut communicate to the brain, its microbes also produce about 50% of the body’s dopamine and 90% of its serotonin, a neurotransmitter that affects, mood, appetite and digestion, sleep, and memory. These microbes manipulate us for their own survival. They continue to send signals to brain to tell you to eat the food they love and that ensure their survival. What this means is that whether we eat foods that are more or less healthy for us, we populate the gut with the bacteria that prefers that food source – then those bacteria tell our brain (via the gut) to eat more. Have you ever noticed that when you eat more clean and healthy your body tells you it wants more? Cleaner, healthier foods promote more energy, focus and better sleep. Your body also craves more of the same when you have eaten sugar, fat or salt laden foods. The more of something you eat the more you want it.
Studies on laboratory mice with no bacteria to colonize their gut have shown that introducing good bacteria into the gut improved their serotonin levels. Mice fed a specific bacteria showed improvements in stress levels and improved memory and learning. Then when researches severed the vagus nerve those improvements disappeared, showing that the origin of those improvements came from the gut. What this is telling us is that our mood, sleep and memory are directly impacted by the foods we eat. So next time you are glum or tired be sure to let your brain make the true food choice and pick an option that is healthy, clean, fibrous and lean.
Originally published at www.nicolehollar.com