Second Brain Explained
New research proves that the gut and brain are interconnected more than we previously thought. These discoveries have enormous potential to help people with gut issues with help from their brains and support our brain or mood issues with help from their gut.
Imagine if eating differently could elevate your moods or improve your brain and mental health. (It can.) Or if reducing stress can also reduce gut symptoms. (It does.)
Sounds interesting? Learn about the gut-brain axis and how you can leverage this new research to improve your gut and brain.
Your gut is (partially) controlled by your brain.
Gut (GI/digestive)disorders can cause pain, bloating, or discomfort. They impact over 35 percent of people at some point in life—affecting women more than men. Often, these gut issues don’t have an apparent or easily diagnosable physical cause so they can be challenging to Doctors and relieve symptoms.
We already know that our brains control some of our digestive processes. For example, research has found that even thinking about eating can cause the stomach to release juices to get itself ready for food. Your gut is also sensitive to emotions. You may recall feeling anxious and nauseous or “knots” or “butterflies” in your stomach.
Several studies show that stress may be a meaningful—often overlooked—reason for gut issues. Harvard Health says, “Stress can trigger and worsen gastrointestinal pain and other symptoms, and vice versa.”
This is why it’s essential to look at your stress and emotions if you have gut issues. Many studies have found that stress reduction techniques can significantly improve gut symptoms compared to conventional medical treatment alone.
Before we go over how to do this, let’s look at a bit more of the biology behind the gut-brain axis.
Your nervous systems
There are two main parts of your “main” nervous system. One is the part we can consciously control, like when we move our muscles to walk around, chew our food, or swim laps. This is called the somatic nervous system.
The other part of our nervous system controls everything we can’t control but need to survive. These include processes that happen automatically in the background: breathing, heart beating, sweating, or shivering. This part of the nervous system is called the autonomic nervous system (because it works automatically).
The autonomic system regulates our body’s functions by either speeding things up or slowing them down. When things are sped up, like when our “fight or flight” reactions kick in, this is done by the sympathetic part. We feel this happening when we sense danger (real or not) and get stressed. Our heart beats faster, and we breathe heavier. We’re preparing to fight or flee, so our body focuses on ensuring our muscles get enough blood and oxygen to working hard.
On the other hand, slowing things down is done by the parasympathetic part. This happens when we’re relaxing or after the danger has passed and we start to calm down. Our heart, lungs, and muscles rest, and our digestive systems do their jobs much better. In this phase, we’re secreting more digestive juices to break down food, absorbing more nutrients, and having lower levels of inflammation in our gut. That’s why this is called the “rest and digest” phase.
Both arms of the autonomic nervous system—the sympathetic and parasympathetic—interact with the GI tract/digestive system. This means that when our body is stressed, we can experience gut symptoms, and when we’re relaxed, our digestion does what it’s meant to do.
Your GI tract/digestive system is your “second brain.”
In addition to your “main” nervous system, your gut [GI tract/digestive system] has its nervous system called the enteric nervous system. The enteric nervous system spans your whole digestive tract from your esophagus along your stomach, intestines, and colon. This nervous system is sometimes referred to as the “second brain” because it works the same way as the “main” one. It has 100 million nerve cells (called neurons) that communicate with each other using biochemicals called neurotransmitters.
Your enteric nervous system gets input from both the sympathetic and parasympathetic nervous systems, so it can speed up or slow down when it has to. It also has a “mind” of its own and can function independently of them.
This complex system is essential because of how complicated our digestive processes are. For example, after we eat, the neurons in our enteric system tell the stomach and intestines muscle cells to contract to move food to the next part. As our GI tract/digestive system] does this, our enteric nervous system uses neurotransmitters to communicate with the central nervous system.
Your enteric nervous system is also very closely linked to your immune system. This is because many germs [bacteria/pathogens] can enter the body through the mouth and end up in the gut. You have a sizeable immune presence there to help fight them off before they become a more significant problem and infect other body parts. The immune system cells provide another path for the gut to communicate with the brain. They relay information like when they detect an infection or when your stomach is bloated, so your brain knows.
Even the friendly gut microbes (gut microbiota) that help us digest and make certain nutrients play a role in communicating with the brain. They make neurotransmitters, some of which are known to influence our moods.
The gut-brain axis
This intimate and complex connection between your gut and brain is called the gut-brain axis. And we now know that the signals go in both directions: from your brain down to your gut and from your gut up to your brain.
This is where we see the link between digestive issues and the brain, stress, and mood issues.
When someone is stressed enough to get into the “fight or flight” reaction, digestion slows down to allow the muscles to fight or flee. The same physical reaction appears whether the stress is from a real threat or a perceived one. This means that your body reacts the same whether you’re facing an actual life-threatening situation or whether you’re super-stressed about a looming deadline. This disruption of the digestive process can cause pain, nausea, or other related issues.
Meanwhile, it’s known that experiencing solid or frequent digestive issues can increase stress levels and moods. People with depression and anxiety have more GI symptoms, and vice versa.
How stress and emotions affect your gut
Because of these strong connections between the gut and the brain, it’s easy to see how stress and other emotions can affect the gut. Fear, sadness, anger, or feeling anxious or depression are often felt in the GI tracts/digestive systems. When they cause our digestive systems to speed up (or slow down) too much, this can influence pain and bloat. It can also allow germs to cross the gut lining and enter the bloodstream, activating our immune systems. It can increase inflammation in the gut or even change the microbiota.
This is why stress and strong emotions can contribute to or worsen several GI/digestive issues such as Crohn’s disease, colitis, irritable bowel syndrome (IBS), gastroesophageal reflux disease (GERD), food allergies, or sensitivities.
Then, these gut issues are communicated to the brain, increasing the stress response and affecting our moods.
This loop of stress and gut issues and more stress and more gut issues becomes a vicious cycle.
New research shows that changes to the gut’s inflammation or microbiome can strongly affect many other body parts, not just the brain and mood. They’re also associated with depression and heart disease.
How to eat and de-stress for better gut and brain health
What you eat can have a significant impact on your health. This is particularly true when it comes to the microbiome. Your gut health improves when you eat a higher-fiber, more plant-based diet. That’s because it provides your friendly gut microbes with their preferred foods so they can grow and thrive. Probiotic foods that include health-promoting bacteria are also recommended. Reducing the amount of sugar and conventionally farmed red meat you eat can also help. These can lead to a healthier microbiome by helping to maintain a diverse community of many species of microbes to maximize your health. They can also lower gut [GI/digestive] inflammation levels and reduce the risk of depression and heart disease.
For better gut and brain/mental health, eat more:
Whole grains
Yogurt
Eat less:
Sugar
Overall Processed Conventional Red meat it stand out
What about stress?
Evidence suggests that some stress reduction techniques or psychotherapy may help people who experience gut [GI/digestive] issues. They can lower the sympathetic “fight or flight” response, enhance the parasympathetic “rest and digest” response, and even reduce inflammation.
Some of the stress-reduction techniques I love and recommend are:
Guided meditation
Deep breathing before each meal
Mindfulness
Relaxation
Hypnosis
Yoga
Your gut, brain, and mood will thank you!
References
Cleveland Clinic. (2016, October 6). Gut-Brain Connection. Retrieved from
https://my.clevelandclinic.org/health/treatments/16358-gut-brain-connection
Harvard Health. (n.d.). The gut-brain connection. Retrieved from
https://www.health.harvard.edu/diseases-and-conditions/the-gut-brain-connection
Harvard Health. (2019, August 21). Stress and the sensitive gut. Retrieved from
https://www.health.harvard.edu/newsletter_article/stress-and-the-sensitive-gut
Harvard Health. (2019, April 11). Brain-gut connection explains why integrative treatments can help relieve digestive ailments. Retrieved from
The University of Calgary. (2018, December 1). Can a meal be medicine? How what we eat affects our gut health, which affects our wellness. Retrieved from
https://explore.ucalgary.ca/gut-health-microbiome-and-our-wellnes
