Chapter 2 | Review & Discussion | The Mind Gut Connection by Emeran Mayer, MD
Our Gut Mirrors our Emotions
Most of us can recognize human emotions. By this, I mean we can usually tell if another individual is happy, sad, or upset. I can usually tell if my wife is upset by the look on her face. I’m sure all of you have the same sort of ability when it comes to reading the emotions of loved ones, or sometimes even perfect strangers. In chapter two, Dr. Mayer talks about this common ability, and how emotions are tied to different regions of the gastrointestinal tract which is influenced by the brain’s limbic system. The limbic system is the region of the brain that controls emotions and memory, which makes this a very intriguing connection.
Emotions are Tied to the Gut
When we are emotionally upset, our stomach will go into vigorous convulsions and deliver more stomach acid. A similar sort of reaction happens when we are angry or anxious. On the contrary, when we are depressed, hardly any movement occurs in our intestines. The point is that our gut will mimic the emotions that we are experiencing because the gut is tied to the brain. We’ve all felt butterflies in our stomach when we’re nervous, or had a gut feeling about something, so we intuitively know that this is true.
A large percentage of people in the US suffer from some sort of gut brain disorder. These disorders range from irritable bowel syndrome, to indigestion, to chronic heartburn. We spend a large amount of money and resources to treat these ailments, yet we are not understanding that the cause of these gut issues may be tied to the gut brain connection.
The Man Who Couldn't Stop Vomiting
Dr. Mayer tells us an account of a young man named Bill that literally could not stop vomiting. He saw several doctors and none of them could diagnose the condition. It was destroying this young man’s life, as he was forced to drop out of college and spend countless hours at doctors offices and emergency rooms.
Bill’s mother finally consulted Dr. Google and self diagnosed him with cyclical vomiting syndrome. As Dr. Mayer states, prolonged stress can cause a major imbalance in the body. This causes the brain region known as the hypothalamus, which coordinates all our vital functions, to release a molecule known as corticotropin releasing factor or CRF. This molecule sends the body into a stress response mode and can raise anxiety. It also causes the gut to become leakier, which can result in diarrhea or severe belly pain. In Bill’s case, he had intense vomiting.
It was later found that Bill did indeed have cyclical vomiting syndrome. This was an extreme example of how a stressed mind can cause very powerful reactions to the gut and body. Also, it was alarming that Bill had such a hard time being diagnosed. Most likely this is because too many doctors are unaware of how powerful the gut brain connection really is.
The Second Brain
So what happens to food after we eat it? I mean, how do we actually digest food? As we eat, our stomach fills up with concentrated hydrochloric acid. This acid is strong enough to dissolve metal, so If you are planning on a heavy metal diet, your stomach has you covered. As food enters your stomach, strong forces break up food into tiny particles. The gallbladder and pancreas inject bile and enzymes into the small intestine to help digest fat. After food enters your stomach, it travels to the small intestine where the enzymes and bile break down the food into nutrients that can be absorbed into the rest of your body.
The digestive process continues with contractions known as peristalsis moving food through the digestive tract. Between meals, your digestive system is maintained by the migrating motor complex, which moves anything out of the stomach that it wasn’t able to break down. This reflex functions like your gut’s housekeeping wave, and it happens when you are sleeping and switches off once you eat again. Your gut’s motor functions handle all of these reactions without the help of your brain, but instead use a network of 50 million nerve cells embedded in the gastrointestinal system known as the enteric nerve system or ENS. Again, the reflex is an automatic function that is not dependent on your brain, but is instead hardwired within your enteric nervous system. However, your brain’s emotions can hinder this entire process….so that means we have an automatic process in place that can be disrupted by our emotions. I personally find it very interesting.
Initial Study of Gut Reaction through a Gunshot Wound
In the early 1800’s, Alexis St. Martin was shot by a musket at close range, leaving a hand-sized hole in his abdomen. The wound also left his stomach visible with a smaller, finger-sized hole. Under the care of Dr. William Beaumont, St. Martin’s life was spared but he was treated with a gastric fistula, leaving a permanent hole in his body. The procedure allowed Dr. Beaumont to study his stomach and digestion in real time, an interesting “benefit” of the gunshot wound. Dr. Beaumont was able to insert various foods into St. Martin’s stomach to witness the breakdown of the food under various conditions, which came to be the first study of its kind. Notably, when St. Martin became angry, his digestion slowed. When he was under distress, his intestines became more active. This data correlates with more modern, recent studies about how emotions relate to digestion.
Enteric Nervous System, the Brain, and the Gut
As mentioned earlier, our enteric nervous system is on autopilot. It handles all of our gut functions automatically, unless there is some sort of emergency signal, such as a strong emotion, sent from the brain. This type of signal will interrupt the normal autopilot behavior. Then the brain will send signals to release stress hormones like cortisol and adrenaline. Once the emergency has passed, the autopilot functionality of the enteric nervous system resumes. It can be noted that in a depressed or anxious person, the gut cells adapt to the repeated stress messages sent by the brain, causing the gut to be more sensitive to stress. This may also cause these people to be physically hypersensitive to stress.
We learned that a primitive brain system, called the limbic system, gets activated when we get angry, scared, hungry, or thirsty. When we feel these emotions, our brain sends signals to the GI-tract to rid itself of its contents so our body can conserve the energy that may have been used for digestion. If you’ve ever needed to go to the bathroom before a public speaking event, this would be the reason why. Other hormones like dopamine or oxytocin may also be released and will promote an overall sense of well-being. The master switch we mentioned earlier that ties it all together is called CRF, or the corticotropin releasing factor. If you have digestive issues with certain foods, your mind may be relating a past stressful event to that food. This connection is very strong and can last for years.
Our bodies and minds are extremely complex, yet highly organized. We must better understand the relationship between the mind and the gut to become masters of these connections, and to help ourselves control both our physical and mental well-being.
Join us on this journey and check out the book for yourself! Read along with us if you like. You can then comment and share your views on this book and the subject of the gut and mind connection.
