What is the Gut-Brain Axis?
The Gut-Brain Axis (GBA) is the system responsible for communication/regulation between the brain, the central nervous system (CNS), and the intestinal environment of the gut. Both the gut and the brain function through the enteric (relating to or occurring in the intestine) nervous system (ENS), and therefore any experienced stress and the symptoms that appear with that stress affect gastrointestinal (GI) function. The ENS holds so much power in the ability to function optimally in relation to the brain, it is now considered by some to be the third subdivision of the ANS (the other two being sympathetic (fight or flight) and parasympathetic (rest and digest). If we are in a state of stress or anxiety, our parasympathetic nervous system is down, and our sympathetic is up. When this occurs, functions of the intestinal tract such as activating smooth muscle contraction, regulating pH, etc. are not able to perform properly and we suffer. IT’S ALL RELATED FOLKS.
Effects of Stress on the Functions of the GI System (The GBA at Work)
I would like to dive a little deeper into what is happening with the functions of the GI tract when we are in a sympathetic, or stressed out state, and why this is not an ideal state to be in while eating. These findings reiterate the correlation between the gut and the brain. First, however, I would like to illustrate some important differences in individuals suffering from functional gastrointestinal disorders (FGIDS, ex. IBS), which makes the achievement of the rest and digest state even more imperative than for healthy controls.
Response to Stress in Individuals with FGIDs vs. Healthy Controls
When an individual (with or without an FGID) is exposed to an emotional stressor, there is a decrease in parasympathetic vagal tone, and an increase in heart rate, which is leading them towards sympathetic dominance. This is exacerbated in people with IBS (the most common FGID) because they have been shown to have increased visceral hypersensitivity (pain within the inner organs) as compared to individuals who do not suffer from IBS when experiencing pain, stress, or triggers. This fact alone makes it even more imperative that individuals with IBS achieve a parasympathetic state. Findings using Positron Emission Tomography (a technique used to observe metabolic processes in the body) have shown that those with IBS experience greater activation of the prefrontal cortex which leads to an enhanced state of sensory sensitivity which may bring about anxiety, enhanced recall of emotional trauma, as well as increased pain perception in response to stress.
Stress-Induced Changes in Esophageal Motility (GERD)
Esophageal spasms are often triggered by physiological and psychological stressors. Anxiety increases the perception of reflux symptoms, and many patients (64%) with gastroesophageal reflux disease (GERD) report that their symptoms are exacerbated by stress. There is an increased incidence of psychiatric diagnosis in patients with esophageal motility disorders (namely anxiety and depression).
Normal Gastric Motility vs. Stress-Induced Changes in Gastric Motility
A “normal” response to food entering the stomach is receptive relaxation. Incoming food is accommodated by smooth muscle relaxation, which is much more easily achieved in the parasympathetic state. In normal gastric motility, there will be around 3 contractions per minute of the gastric smooth muscle. When a stressor is introduced during feeding, the sympathetic system overpowers the parasympathetic, and gastric contractions (typically 3 per minute) slow to only one per minute. In a sympathetic state, the entire stomach undergoes weaker contraction, and blood is shunted to the brain and extremities instead of the gut because the brain and extremities take priority during sympathetic dominance (think about this from an evolutionary standpoint). This means that digestion has now taken the back seat and is at the bottom of the priority list when in reality we want it to be at the top while of the list when we are consuming a meal.
Stress-Induced Changes in Salivary Secretion
Salivary flow decreases with sympathetic dominance, and amylase (the enzyme responsible for converting starch and glycogen into simple sugars) increases. With increased amylase may come increased levels of cortisol or catecholamines, thus encouraging a strong stress response which may the body up for elevated fat-storage.
The parasympathetic tone is reduced when we feel rushed during a meal when we watch something upsetting such as the news during a meal, or if we are stressed out trying to answer emails, stay up to date with social media, or argue with a loved one during a meal. There is no arguing that it is optimal to eat in a relaxing atmosphere with no distractions so that you are able to focus on what you are eating, remain in a parasympathetic state, and ultimately set your body up for normal/proper digestive functioning.
If you would consider yourself a perfectionist, you may be at greater risk for sympathetic dominance, which will degrade the digestive process. So pretty much you should CHILL.
Breathing through your mouth which makes it impossible to breathe while chewing can increase the sympathetic response, which can lead to aerophagia and therefore to abdominal bloating and pain due to excessive volume of air in the digestive tract.
Take Away Points and Suggestions
In order to prime yourself for optimal digestion… slow down and relax. Make sure that the atmosphere in which you are eating is relaxed and as free of distraction as possible. I like to recommend taking 3-5 deep breaths regardless of how relaxed you feel before a meal to activate the parasympathetic system even further. I suggest not eating while driving, as even subconscious stress (you know you have road rage) can lead to increased sympathetic tone. Eating at the dinner table consistently is a good way to train your mind and body to recognize that it is time to eat (as opposed to eating on a couch in front of the tv). While eating, you should be able to acknowledge whether or not you are actually enjoying what you are ingesting, and food should be chewed down to liquid. If you finish a meal and don’t even recall how it tasted, you are not engaged properly. Improving digestion can be done for FREE by acknowledging your surroundings and feelings BEFORE and during a meal.
If you try the above tips and find that you need a little extra help, a supplement that I would recommend for supporting digestion is Opti-Greens 50 by 1st Phorm. This product is a greens powder that is low temperature processed, provides your vegetable servings for the day, and has properties of enzymes that can help the digestive process. Overall, this product can aid in regulating digestion, decreasing bloat, and increasing overall immune function.
If you are interested in more specific probiotic supplementation, I highly encourage you to seek out a professional that can assist you in choosing the right strain and CFU’s for your particular symptoms. Probiotics are not something that you can just pick at random!
Of course, if you experience abnormal symptoms after implementing some of the strategies in this newsletter, consult a professional to seek further evaluation and treatment options.