Same physiology; same problemsThink back to a time when you ate something that didn’t agree with you. It didn’t take long to get a bloated sensation, then a severe gas pressure build up, then cramping pains, and the intense feeling of misery in your head right before you found a toilet and spray painted the inner bowl with a nice shade of brown. Ok, maybe that’s a bit dramatic but I’m sure you can relate to that experience at least once? You must have wondered what the heck was going on inside of you for all that to happen!
The above situation is an example of the interconnected web-like nature of our body that I had described in the previous post. What few people realize or remember is that we have what is considered a learning and thinking BRAIN inside of our gut, composed of more neurons that what is found in the spinal cord – that’s over 100 million! The commonly used name for this gut brain - you might remember from your biology classes - is the ENTERIC NERVOUS SYSTEM (ENS), a division of the autonomic nervous system. Look it up on a search engine and you will see that the ENS is found branching throughout the sheaths of tissue that line the esophagus, stomach, small intestine, and colon in an amazing way. Perhaps just as important to the gut brain as all the nerves is the trillions of bacteria that make a home in our gut lining to aid in digestion, production of neurotransmitters, and defense. More on this later.
Why a brain in the gut?Evolutionarily-speaking, the gut brain is the first brain that we inherited from a time when organisms were aquatic and simple, perhaps feeding on smaller organisms as they floated by and got trapped. Later on as feeder organisms evolved into more complex creatures that had to find food and mates, the central nervous system and brain were developed. In the study of human and mammalian development, it can be seen that the enteric nervous system (ENS) and the central nervous system (CNS) form out of separate sections of the neural crest and are later loosely connected through a cable called the vagus nerve. Functionally, a big job is assigned to the gut brain, as it needs to coordinate digestion from breakdown to nutrient absorption, and it produces a majority of the neurotransmitters for gut function and organ development/rebuild (90% of serotonin plus a majority of over 30 others). The neurotransmitter production is in large part under influence of the probiotics – the live bacteria – in the intestinal mucosa.
The connections between the central brain and the gut brainGoing from the brain stem down to the gut, the vagus nerve connects the CNS to command-receiving neurons in the ENS followed by interneurons that respond to them and then spread into the myenteric plexus and submucosal plexus gut layers. The CNS sends commands by altering the rate of firing down the vagus nerve and the command-receiving neurons get a change of status and alter in the way they stimulate the interneurons. Looking at this setup at first glance, it seems that the CNS does most of the communicating. However, closer inspection of the vagus nerve from research finds that 90 percent of its fibers carry information in the other direction from the ENS to the CNS. The central brains gets a lot of information from the gut but sends few commands back – as if the central brain is a lazy CEO that hates to micromanage or get too involved in the messy business of digestion.
The central brain and the gut brain systems are also connected through the circulatory system, which connects all things, and between them all are two barriers that protect and help maintain control of each system. A blood-brain barrier (BBB) of tight-junctioned endothelial cells around blood vessels prevents harmful substances from coming in contact with the CNS, while only allowing special cells and substances that provide nutrients and important function through. Following a very similar design, a gut-immune barrier (GIB) of tight-junctioned intestinal epithelial cells are in place to limit the entry of environmental pathogens and toxins from the digestion system into the blood, and actively transport the right nutrients in the right directions. So each brain produces it’s own neurotransmitters and can function independently from the other, but to complicate the function and the communication between them, we can get leaky barriers both at the gut and the brain. One of the many causes that is common? Inflammation.
Cross-talk between the central brain and the gut brainHere is what we more or less know so far about the interactions between our two brains from experiments on stress and from drug-therapy. When the central brain is under stress, it releases surges of stress hormones like noradrenaline (norephinephrine) and cortisol which cause the vagus nerve to fire hard and fast which turns up the production of serotonin in the gut’s enterochromaffin cells of the alimentary canal. Serotonin is used to regulate digestive organ function and with too much around, the gut is overstimulated and diarrhea results or a person’s esophagus contracts such that they “choke” with emotion or have trouble swallowing. Certain stress signals from the brain have been shown to affect the nerves firing between the stomach and the esophagus resulting in stomach heartburn. In the case of extreme stress, the central brain sends signals to immunological mast cells in the plexus to create inflammatory chemicals (histamines, prostaglandins and the like) normally produced to protect the gut. Unfortunately the results of these stress signals are always nasty things like cramping, and diarrhea. Of course with the gut talking back to the brain the thoughts that enter conscious awareness are pain and bloatedness.
A growing body of research is now showing evidence of the gut affecting mood and the central brain’s thoughts. In one study, disruptions to intestinal bacteria or the digestive organs were shown to cause depression and anxiety. A pesky bacterium called Clostridium difficile, which not only causes gastrointestinal symptoms, has also been directly linked to the brain disorder Autism as one of the primary causes. Other studies have shown that deficiencies in certain nutrients like folic acid and selenium cause depression and bad moods, respectively.
It seems there is always a mirrored cause-effect relationship between the CNS and the ENS. MDs have known for many decades that small doses of the anti-depression drug Prozac can treat chronic constipation, while large doses cause nausea and constipation so severe that the colon freezes shut. Very similar effects are experienced in people using hard drugs like morphine and heroin, and the gut brain can also get addicted to these opiates since it has the receptors. In the same way, when someone has a central nervous system disease like Alzheimer’s or Parkinson’s, there are nerves in the gut brain that also get sick.
It’s no wonder that we get “gut feelings” – the gut brain is also full of the same major neurotransmitters found in the brain: serotonin, dopamine, gamma-aminobutyric acid (GABA), and noradrenaline (norepinephrine). Ok enough talk about all the scientific details and examples; now on to the cool meaningful stuff!
What implications does this dual brain relationship hold for health and happiness?Given this dual brain design of our physical body and it’s connection with emotion (plus the susceptibility to problems) it’s important to keep a critical balance of supportive nutrients, digestive acids/enzymes, and probiotics in the GI system in order to function well and feel healthy and happy in the head.
Scientific studies on neurotransmitter function in the brain have lead to an understanding of the relationship between the relative levels of these neurotransmitters and the behaviour or mood it creates in the study subject. Below is a chart illustrating the aforementioned relationship dependent on balance:
Given that different foods contain different nutrients and that different neurotransmitters are formed from these nutrients, it should be very well possible to control your mood from the choice of food (or supplements) you ingest. For example, if one were aiming to increase their alertness/concentration as well as motivation/drive early in the day, they would be looking at a balance of noradrenaline and dopamine with little to no serotonin. That person might want to start their day with meat & nuts or eggs while holding off on sources of carbs. Meat is a great source of protein and contains a good level of tyrosine amino acid which is the source of noradrenaline and dopamine production. Nuts and eggs contain a good level of lecithin and choline which aid in the production of acetylcholine (not in the chart above) and linked to wakefulness, attentiveness and memory. The avoidance or minimization of carbohydrates early in the day is probably the best thing for that person too, as it leads to increased tryptophan and thus elevated serotonin production which could lead to moods such as anxiety/irritability or appetite/aggression depending on the balance. Had that person eaten only carbohydrates for their breakfast, the risk of them feeling fatigued and relaxed with obsessive compulsive thoughts is much higher. Try it and you will see for yourself!
What most adults and adolescents need to learn and remember is that we all have another brain in our gut, and take notes on how they react and feel after consuming different foods or a mixture of those foods. This way they have a better understanding and ability to control their feelings, mood, energy level and possibly behaviour -while avoiding an upset gut - all from the food and nutrient choices.
Here are the top 5 things I suggest for your gut brain health in order to ensure better overall health and happiness:
1. Avoid sensitive, allergenic, and inflammatory foods first, as much as possible! More than 75% of people have some kind of food sensitivity, usually numerous, that are causing irritations internally or manifesting externally. With the help of a naturopathic doctor, you can successfully screen for these sensitivities and allergies. You can also utilize an elimination diet to identify these foods via mood and energy change. Inflammatory foods include caffeine, refined sugars, trans fats, and processed foods with chemical additives. These foods will quickly destroy good gut bacteria and damage the intestinal epithelial cells causing leaky gut, and possibly leaky brain, and causing loss of normal control of the systems.
2. Repair internal gut damage with good nutrition, and provide nutrients that promote healing. Choose a diet rich in whole, unprocessed foods and fiber, from organic sources if possible. Take in additional nutrient supplements such as L-glutamine, the most abundant amino acid in the gut which can immediately battle inflammation and go into repair of a leaky gut. Other healing nutrients include quercetin, gamma linoleic acid (GLA), licorice root, turmeric, aloe vera, and Omega 3 fats (fish, fish oils, avocado, walnut, pecan, hemp, flax).
3. Improve your gut health with probiotics, prebiotics, and digestive enzymes. Healthy intestinal bacteria are crucial for proper immune system function, detoxification, neurotransmitter and hormone production, and prevention of bad bacteria and yeast. Be sure to get a high quality beneficial probiotic blend of lactobacillus acidophilus and bifidobacterium that can survive gut digestion and reach the intestines. Along with a probiotic you will need soluble prebiotics like plant/fruit inulins and pectins (fructooligosaccharides) and fatty acids like butyric acid (recall the benefits I mentioned previously of butter and heavy cream) that allow the probiotics to settle and flourish. Fermented vegetable foods from various ethnic groups are excellent prebiotics that stimulate the growth of a health promoting flora. Digestive enzymes including betaine HCl, pancreatin, protease, amylase, and lipase with meals ensure that you achieve an optimal stomach pH for proper enzymatic breakdown of solid food into absorbable nutrients as well as protect the gut against bad bacteria and other foreign invaders.
4. Work on reducing mental stress. Mental and emotional stress is damaging to the gut and the body so the less you experience, the better. Practicing relaxation techniques while you’re doing other everyday things can be one way to reduce stress. A couple of examples are meditating while commuting or using deep breathing techniques while doing housework. Guided imagery, or using soothing music or a therapeutic voice to help you imagine a scene in which you feel at peace and free, is a very useful technique for stress relief. Learning tai chi or yoga is also a great way to relax so that they can be used in the privacy of your office or in a park at lunchtime. The fear of what others might think when seen doing these things is another stress people have. It's time we stop worrying about what others think and start doing what is best for our own beings first.
5. Focus on love rather than fear. It is said that all thoughts you think, every word that you speak, and every action that you take falls under these two headings – love and fear. Like stress (which comes out of fear), fear has very destructive effects on the body and gut, including restriction of amino acid and gene expression. Love, on the other hand, has very healing effects, and opens more codons for amino acid expression as well as switching on more beneficial genes in our DNA. By consciously thinking, speaking, and acting out of love for self, others, and nature instead of acting out of fear of this and that, you are acting at a higher vibrational frequency of energy which can attract what you love back to you. By love I do not mean sex or possession or attachment, but merely helping another out of good will, sending out of care for another, or sending out of ideas/knowledge to benefit others. Some call it the 'Law of Attraction', but I call it unconditional love and when it is practiced, one begins to understand that we are born free knowing only love and we learn fear later which restricts us in so many ways. After some time of focusing on love, one unlearns fear and prejudice, becomes empowered, and realizes that there is nothing to fear and can achieve liberation again.
by Asim Khan