Unwinding the mysteries of our bowels
You know the expression “go with your gut?” Have you ever made a decision based on a gut feeling? How about butterflies in your stomach– have you ever had those? Ever been so nervous that it made you nauseous? Have you ever hated someone’s guts?
You aren’t imagining things– there’s actually some pretty interesting science suggesting that our guts and brains are connected in ways that you may have never thought possible. We really do feel emotions in our digestive systems, so it might make sense to pay attention to your gut feelings.
I recently watched a documentary about the marvels of the human gut and its connection to our minds and emotions. Intrigued, I decided that I wanted to find out more.
I did some reading about the gut-brain connection and compiled some facts that I think are useful to know:
The gut was the original brain
Eukaryote cells first started figuring out how to digest things about two billion years ago, during the Proterozoic Era.
Some of the Earth’s earliest multi-celled organisms consisted of basically only a digestive system shaped liked bags two cells thick. These later evolved into tube-shaped creatures like roundworms. Stomachs started evolving around the end of the Proterozoic, about 542 million years ago.
Human fetuses start out looking like a primitive gut as well, around the 16th day of development. It almost seems like having a gut is more essential to being a living organism than having a regular brain.
The gut has its own nervous system
Did you know that your stomach’s brain has as almost as many neurons as an entire cat?
As powerful as the brains of many small animals, the enteric nervous system is a spiderweb of 500 million neurons that rule the gastrointestinal tract.
The ENS is smart enough to act independently of other systems like the sympathetic and parasympathetic nervous systems, and is often called “The Second Brain.” This brain usually communicates with your other brain through the vagus nerve– but can still operate even if the vagus nerve is severed.
The gut and the brain are connected
There’s so much biochemical signaling going on between your belly and your noggin that there’s even a name for the system: the gut-brain axis.
The vagus nerve is the largest lane on the gut-brain superhighway, sending signals in both directions. The connection is strengthened by chemicals called neurotransmitters, which produce feelings and emotions in the brain.
Gut microbes make chemicals that affect the brain
The huge population of microfauna in your gut also produces many other chemicals that affect the brain, mind, and emotions.
Microbes play an important role in the immune system, controlling what is absorbed into the body and what is excreted as waste. They produce short-chain fatty acids and amino acids, which also affect the brain in a myriad of ways.
The connection is clear- the gut is essential in many processes that regulate our mood and emotions. If your gut isn’t healthy, it makes sense that you’re feeling bad in other ways.
You can care for your gut-brain connection
One way to help the health of your gut and brain is by consuming bacteria called probiotics.
A study found that feeding mice probiotics reduced the level of stress hormones in their blood. Another found a reduction of the stress hormone cortisol in humans after three weeks of a certain probiotic.
You can also eat a diet that benefits your gut-brain connection. Fermented foods like yogurt and sauerkraut contain beneficial microbes that can aid your gut, and high-fiber foods like seeds, nuts and vegetables can aid your friendly bacteria.
Eating Omega-3s like the ones found in fish, walnuts, and chia seeds can help your gut bacteria as well as reducing the risk of certain brain disorders.
Eating foods high in tryptophan like turkey eggs, and cheese can help your gut fauna make serotonin– a chemical that produces feelings of happiness and contentment.
In fact, about 90% of the body’s serotonin exists in the gut, along with about 50% of the dopamine. Dopamine is responsible for helping us regulate mood, attention, and emotional responses, as well as aiding us in taking action towards goals by affecting pleasure and reward systems in the brain.
Understanding how our bodies and minds connect is a powerful way to learn to care for both. Now that I know my gut and brain are connected, I’m going to pay closer attention to both my food and mood.
How about you?
Anyway, happy eating– and remember to go with your gut.
Originally published on medium.com on October 3rd, 2019.
Esoteric Epistemology 