We’ve all had the experience of physically feeling our emotional states — “butterflies” in our stomachs, our insides tied in “knots,” or even the less palpable, but no less powerful “gut feeling.” How does this work? How do our bodies have wisdom, giving us direct signs and physical information that relate to our emotional states of being?
We learned in Part 1 and Part 2 of our gut health series how integral the gut is to overall physical health and how to best support it. In this third and final installment, we’ll delve into a surprising aspect of this invaluable system: how it operates as our second brain.
You may find yourself wondering how a collection of organs responsible for digestion can also function as a brain. The gastrointestinal (GI) tract is not only full of bacteria and digestive enzymes; it’s also lined with roughly 100 million nerve cells – collectively known as the Enteric Nervous System, (ENS). While the ENS does regulate the digestive process, it is also in constant communication with the brain, and vice versa.
The nerve cells that make up the ENS create signals that are sent via neurotransmitters along the vagus nerve (the longest cranial nerve in the body) to the brain. From the gut up, the signals communicate to the brain how healthy the gut—and by extension, the immune system—is. From the brain down, they can impact the effectiveness of the digestive process (which is how stress contributes to poor digestion and fear can ignite sudden bowel issues).
The “second brain” comes into play because these communications don’t just impact digestion. Preliminary research shows that if the gut contains an overwhelming amount of bad bacteria (due to poor diet, environmental toxins, etc.) and is consequently inflamed, it will send chemical messages to the brain that can impact our moods, emotions and stress levels—and not in a good way.
Fascinatingly, some of the many chemicals that the gut’s microorganisms secrete are the same chemicals that regulate mood—which are often associated with the brain. Serotonin, for example, is well known to govern happiness and anxiety levels. What is lesser known is that 90% of the serotonin in your body is produced in the gut! Additionally, the gut’s microorganisms produce an estimated 50% of the dopamine in our bodies, which helps control the brain’s reward and pleasure responses. They also generate glutamate - a neurotransmitter that is responsible for memory creation and thought processes. Depression, anxiety and lack of mental clarity are all linked to insufficient production of these chemicals.
Our bodies contain intricate systems that work in relationship with one another; the gut-brain axis is a prime example, which researchers are just beginning to fully understand. How empowering is it to know that you can help heal your gut by simply reducing the stress in your life - by meditating, spending time in nature, taking intentional deep breaths throughout your day, or disconnecting from technology? Even further, you can support your moods and mental clarity by eating nourishing foods that contribute to your gut’s optimal functioning! I know it’s science, but quite frankly, it sounds like magic to me.
1. David Perlmutter, "Healthy Gut, Healthy Brain."
2. Douglas Lord, M.D., “Your Body’s Second Brain – The Importance of Gut Health.”
3. Johns Hopkins Medicine, "The Brain-Gut Connection."
4. Peter Andrey Smith, The New York Times, "Can the Bacteria in Your Gut Explain Your Mood?"