The Gut-Brain Connection

The Enteric Nervous System

(The Brain of the Gut)

Scientists in the relatively new field of neurogastroenterology are studying what a British doctor described in 1921 and labeled as the enteric nervous system (sometimes called the intrinsic nervous system). The terms second brain or brain of the gut are modern slang expressions for this system. There are research notes about this neuro-network as early as the late 1800’s.

What is the enteric nervous system?

The enteric nervous system is a sub-division of the autonomic nervous system. This system consists of a mesh-like highway of neurons that together govern the function of the gastrointestinal system. The enteric nervous system consists of, depending on the size of your body and the development of this system, between one hundred million and 500 million neurons. This is far less than the number of neurons in the brain. It’s about equal to the neurons in the spinal cord or in the parasympathetic nervous system.

Where is the enteric nervous system located?

The neurons of the enteric nervous system run from the taste buds of the tongue through the entire alimentary canal (digestive tract) all the way to the anus. Rather than try to pack 500 million additional neurons into our brains and spinal cords and then sending long connections to the gastro-intestinal tract, the Creator placed the circuitry needed for digestion right where each digestive function occurs.

Why is this system referred to as a “second brain”?

Brains have certain components, characteristics, and functions. The brain in the gut has all of these. The brain in our head is meant to exert control over our physical systems, our thoughts, and our behavior. That is what brains do. The brain in our gut exerts control over the functions of our digestive organs and, it would seem, is a factor in our emotional state. It is certain that, too often, our digestive systems are very responsive to our mood of the moment. There is good science behind the idea that our gut may be a contributing factor to our moods.

This second brain can operate independently of the brain and spinal cord. At other times it communicates with the central nervous system through the parasympathetic nervous system. The vagus nerve (cranial nerve #10) is the neural pathway for this communication. Amazingly when the vagus nerve is cut anywhere between the brain and the abdomen, the enteric nervous system continues to function just fine on its own.

The enteric nervous systems consists of more than 30 different neurotransmitters. Many of these message bearing chemicals are the same ones found in the brain. For example, more than 90% of the body’s serotonin is produced and found in the gut. About 50% of the body’s supply of dopamine is also found there.

What is the role of serotonin in digestion?

A specialized cell squirts serotonin into receptor sites on the walls of the small intestine. The reception of the serotonin sends signals communicating the need for a variety of digestive enzymes to be produced and dispatched as needed.

Here are a few examples of things affected by serotonin levels in your digestive tract:

1) Serotonin levels affect the peristalsis of the bowel, controlling how fast and how efficiently food moves through your digestive system.

2) It impacts fluid and mucus levels in your intestinal tract. Fluid levels, also impact constipation and diarrhea, keeping them both from negatively affecting your life. Excess mucus in the bowel can coat the walls and create even further problems with serotonin levels.

3) Serotonin is a neurotransmitter. As such it controls how sensitive your bowels are when there are digestive issues going on. Sensitivity in your digestive system also communicates to you when you have had enough—or too much—to eat. Poor gut health is a contributing factor to over-eating and weight issues. Over-sensitivity creates pain, and usually, a great deal of pain.

In a healthy person, the serotonin released to start the digestive process is immediately swept out of the bowel when its work is done. Certain drugs, among them chemotherapy drugs, cause excess amounts of serotonin to be released into the gut and slow the processes by which it is removed when its work is finished. The result of all of this excess serotonin is the nausea and vomiting associated with chemotherapy treatments. Some anti-depressants and anti-anxiety medications also create problems with serotonin levels.

What is the role of serotonin in Irritable Bowel Syndrome?

Improper serotonin levels may also contribute to IBS (irritable bowel syndrome). Certainly during episodes of severe cramping with either diarrhea or constipation, testing reveals that serotonin levels are far from where they should be. When those with IBS experience constipation they often have lower levels of serotonin. As a result the muscles in their rectums are less responsive and they’re more likely to have hard or lumpy stools. High levels of serotonin in IBS sufferers usually instigates diarrhea. The persons rectum becomes more reactive, with loose or watery stools.

People with this serious and painful bowel disorder often suffer from depression and a range of anxiety disorders along with their digestive problems. IBS has too often been considered a psychosomatic rather than a physically driven disease. Ongoing research into this connection is showing several conclusive connections. In fact, a problem in the gut may be the trigger for problem in the emotions. Perhaps this connection is a two-way street, with emotions impacting gut health and gut health impacting the emotions.

Is there a connection between neurotransmitters, our emotions, and beneficial bacteria in the digestive system?

There is! Butterflies in the stomach before a stressful presentation or interview or diarrhea the night before a big exam are examples of the connections between these two “brains”. Stress is known to overstimulate nerves in the esophagus and trachea, causing the feelings of choking and lack of air that are part of panic attacks.

People with bowel disorders often suffer from depression, a range of anxiety issues, and digestive problems. People are told, too often, that they are ill because they are stressed or are letting their emotions ruin their indigestion. Perhaps they are telling them so, accomplishes nothing unless workable strategies are provided for managing these gut-health driven emotions.

Dr. Natasha Campbell-McBride has successfully demonstrated a link between beneficial bacteria in the gut and the functioning of the brain. Scientific research is suggesting that nourishing your intestinal tract is very important for optimal brain functioning.

Dr. Campbell-McBride refers to the work that she does with these connections and the problems they create as Gut and Psychology Syndrome (knows by the acronym GAPS). She has worked with hundreds of children and adults with varied neurological and psychiatric conditions including autistic spectrum disorders, ADD/ADHD, schizophrenia, dyslexia, depression, and bi-polar disorder. She emphasizes that as the health of the intestinal tract improves there is marked improvement in these disorders.

Dr. Campbell-McBride has linked the health of the mother’s intestinal tract during the pregnancy to the health of infants who later struggle with these disorders. If mom does not have proper levels of good bacteria during the pregnancy, it is unlikely that the baby will have a proper digestive flora either. Many aspects of our lifestyle lived by so many people contribute to the destruction of the necessary flora in the gut of both the mother and the infant.

Why is is important to maintain beneficial bacteria in our intestinal tract?

Beneficial bacteria in the gut keeps the walls of the large and small intestines clean. This allows for serotonin production, proper reception of serotonin signals, and the removal of serotonin when its work is done. Clean intestinal walls allow the many other neurotransmitters of the enteric nervous system to do their jobs also. (Serotonin is only one of many of these neurotransmitters in the intestinal tract.)

Clean intestinal walls are also essential in keeping sludge from interfering with absorption of nutrients in the small intestine. The house-keeping done by bacteria also prevents pockets of fecal matter from forming (diverticulitis).  As well as keeps toxins from reabsorbing from the intestines back into the blood and then moving from the blood throughout the entire body.

Antibiotics, which  are meaning to kill harmful bacteria, are not in the least discriminating. They kill at random. As the normal levels of various bacteria in the intestinal tract get out of balance, more aggressive bacterial strains flourish. Candida albicans is a naturally occurring and necessary bacteria for gut health. It is only when it gets too prevalent and prominent that the nasty thing called a candida infection occurs. This is only one of the problems that antibiotic use creates. When things are out of balance in the intestinal tract, the digestive system, instead of being a source of nourishment, becomes a major source of toxicity in the blood, then in the liver, and finally in the body as a whole.

Rebuilding the intestinal tract

When the flora in the digestive system is out-of-balance, it needs rebuilding by the replenishing of good, health-promoting bacteria. Taking a good probiotic supplement and digestive enzymes can be a good place to start.

Fermented foods are an excellent way to boost the good bacteria in the gut and return intestinal flora to well-balanced levels. These foods also gently detox the entire digestive system. Fermented foods are some of the chelating agents available and help the body rid itself of a wide range of toxins, including heavy metals.

Naturally fermented foods include yogurt (the right kinds), kefir, sauerkraut, kimchi, and pickles.

As long as the fermented foods that you are consuming are of good quality with healthy bacterial colonies, only small quantities will be necessary. It is probably more important to have a small amount with each meal every day than to gorge yourself on fermented foods only once in a while. Be aware that not all commercially fermented foods have retained their integrity. Fermenting your own vegetables at home can maximize the replenishment of the flora in the gut.

The GAPS diet, while quite extreme, can rebuild the gut from even the worst of states and has proven beneficial in rebuilding the intestinal tract permanently. Information for this regimen is on-line. This diet begins with very simple foods that reduce inflammation. Rebuilding the gut and eliminate the poisons which destroyed the gut in the first place.

What are some other functions of the enteric nervous system as it relates to digestion?

There are so many! We cannot possible talk about them all but let’s talk about at least some of them.

First

Let’s talk about a nerve bundle near the end of the colon. This bunch of nerve fibers communicates directly with the brain via the 10th cranial nerve—the vagus nerve—as we discussed earlier. One function of this nerve plexus is to receive signals from the stomach whenever food is ingesting. This signal instructs the colon to evacuate immediately and sends a signal to the brain in the head filled with information about further dietary needs and whether or not any additional food is required at the moment.

A healthy enteric nervous system should create a bowel movement every time we put food into our mouths. A bowel movement every time food is ingesting is normal and healthy; anything less than this is the beginnings of constipation. Snacking all day—grazing I have heard it called—is recommended by some. My experiences as a foot zone therapist for many years, tells me that the continual ingestion of snacks confuses and tires this aspect of the nervous system. The result is constipation, food cravings, and over-eating.

Second

When we are stressing, perceived or real, the hormones  give us the extra strength and energy we might need, have a disturbing effect on the intestines. The barrier between the lumen, the interior of the gut where food is digesting, and the rest of the bowel becomes more permeable. Toxic waste, undigested proteins, and other undesirables move out into the tissues responsible for peristalsis or serotonin removal molecules. These toxic substances not moving forward through the bowel are damaging and destroying it. The intestinal tract sends a distress call to our brain which responds by activating immune cells called mast cells.

Mast cells release histamines and other inflammatory agents to aid the enteric nervous system in expelling the intruders. Inflammation and diarrhea are the results. Inflammation in tissues are tender and sore, pain also occurs. Further, the inflammation makes the sensory neurons in the intestinal tract fire more often—far more often—producing a kind of sensory hyperactivity, an over-active bowel.

Does the enteric nervous system play a role in anything but digestion?

This system is far too complex and extensive to be only a system  in design to make sure things move out of the colon in a timely manner. Like any good “brain” it performs a multitude of functions. One of those is controlling insulin production.

Receptor sites on the tongue (some of the taste buds, in other words) detect “sweetness”. Signals sending back and forth to identify sources of energy producing glucose in the digestive system. The distribution of glucose, especially in the gut, plays a vital part in the regulation of insulin and the other hormones that establish and maintain blood sugar levels.

A great many—way more than half by any scientific estimation—of the fibers in the vagus nerve carry information from the viscera to the brain, and not the other way around.

What information is relaying and how does this information affect the various components and functions of the brain?

Mentioning above, the digestive system plays a role in mental and emotional health. Study after study shows concern more than just IBS. The connection between these two brains and our emotional state is manifesting in many ailments—some of which are physical and others that are more psychosomatic. If we understand diseases better we will find that many begin in one area or the other—emotions or digestive issues—but very quickly manifesting in both as distress signals are sending out and assisting with the problem it is seeking for.

Learning disabilities, depression, anxiety, ulcers, ulcerative colitis, a variety of other inflammatory conditions throughout the body, bone mass and density problems, and Parkinson’s disease are among the list of diseases manifesting symptoms in the brain and along the GI tract at the same time. Some initial findings seem to indicate that serotonin seeping from the gut areas may even play a part in autism.

What causes or contributes to malfunctions in the enteric nervous system?

Malfunctions in the enteric nervous system are in link to early surgical traumas such as circumcision or hernia surgeries in infants. Shock and trauma situations later in life may also trigger either hyper- or hypo- activity in this system. Scientific studies show poor diet, parasites, drugs and many other things are issues with the enteric nervous system.

Diabetes can result in enteric nervous system malfunction and enteric nervous system malfunction can worsen a diabetic state.

Cooperation between our two brains is essential. Our two brains—the one in our gut and the one in our head—must cooperate with each other if we are to be healthy. If they do not, according to Dr. Michael Gershon who has devoted his life to understanding the human digestive system. “Then there is chaos in the gut and misery in the head. . .”.  We cannot experience an emotion or think a thought without a biological correlation in our body. The enteric nervous system deeply affects our daily emotions, it would seem. Our emotions affect our digestive systems just as strongly.

What essential oils (and an alternative product or two) would be beneficial to the enteric nervous system?

The obvious answer to this question is, “any oil or supplement that supports brain, nervous system or digestive health. If a blend does all three at the same time, so much the better. The goal of any good blend is to accomplish healing on more than one plane. There are Butterfly blends that work with all of these systems at the same time. They are in design with the nervous system and digestive tract—both together—in mind. Below is a short discussion of a few of these blends.

^LeJulia

^LeJulia is the first blend I would reach for if there was the slightest chance that any portion of the digestive issue could have an emotional driver or two. ^LeJulia calms and soothes the emotions, allowing the “knots” in the stomach to dissolve away. Caraway, a single oil in this blend, is listed as both a nervine and a digestive oil. It seems to communicate with the enteric nervous system in alleviating intestinal spasms and encouraging normal effective peristalsis. Orange is likely the most gentle nervine in the oil world and with lavender and Roman chamomile also present, this blend is amazingly effective and amazingly mild.

^LeEZ Traveler

^LeEZ Traveler was originally created by a former employee to cope with the emotions connected to flying that she simply knew were going to make an upcoming trip planned by a loving husband absolutely dreadful. It is an amazing emotional blend—calming and comforting—and settles the stomach as well. Frankincense is known to be of benefit any time a physical ailment is caused, or worsened by, nervous tension or emotional trauma. ^LeEZ Traveler also contains some unique, less common, digestive oils. Myrrh, for example, improves the secretion of bile and peppermint, known for its effectiveness in settling an upset stomach, is also world-renowned as a remedy for bowel disorders of any kind.

^LeInside Out

This oil, ^LeInside Out, while usually considered more a physical blend for more physical issues such as intestinal and stomach flu or food poisoning, is useful on a emotional level for helping us sort out and let go any emotions tied to our digestive issues.

^LeGrace

It was designed as an emotionally supportive oil with the heart and cardiovascular system in mind.  ^LeGrace has proven itself effective in relieving the underlying emotions of digestive system issues, particularly those centered in the gut.

^LeQuietEssence

This is one of the best—and gentlest—nervine blends in the Butterfly line-up. Not mentioned specifically for digestive issues. It is useful here, in part, because of its antispasmodic properties. ^LeQuietEssence is a wonderful way to relieve the pain of over-stimulation of peristalsis. Because the blend contains St. John’s wort, rue, and valerian—all in very small quantities—it must be listed as cautioned for pregnancy. I (a midwife) would use it properly diluted, with caution, not contraindicated, if the occasion indicated a need.

^LeSynopsis

^LeSynopsis contains many of the best digestive oils in the essential oil repertory combined with essential oils that are specific to the emotional drivers of digestive and colon issues. Synopsis has a special affinity for both the small and large intestines. This is a great blend for indigestion, bloating of the stomach or intestinal area, constipation, and diarrhea.

Some possible emotional drivers of digestive issues include holding on to the past. Needing to be in control. Lack of trust and cooperation in an important relationship, and feelings of fear or rejection.

Any strong essential oils in this blend are only in minute amounts. The synergistic effect of the whole will alleviate it. A bit of caution during pregnancy is a must.

^LeRevitalize

^LeRevitalize is one of my favorite blends for just about everything. A mild and gentle liver cleanser, ^LeRevitalize replenishes inner stores of strength and increases stamina and vitality. This is an excellent blend for any lymphatic congestion or situation where the over-production of mucus plays a part.

^LeAboutFace

^LeAboutFace is comprised of frankincense in several varieties, can always be counted on when any situation is caused or made worse by nervous tension. Palo Santo is a member of the same botanical family as the frankincenses but the essential oil is distilled from the heartwood rather than being created from the resin. The use of the heartwood completely alters the medicinal properties of this essential oil.  Setting it apart as an oil for lending us strength and firmness regarding our own core beliefs. Any wood essential oil strengthens our roots while helping us reach for inspiration from Heavenly sources. Opoponax, as a member of the myrrh family, improves the secretion of bile and has a drying action on mucus build-up in both the lungs and the intestinal tract. Opoponax is also strongly anti-inflammatory.

^LeIntention

Is a very mild blend to use for improving digestive functions. ^LeIntention works by gently cleansing and toning the liver, preventing gallbladder inflammation and the production of gallstones. This oil is a very mild blend—containing only grapefruit, lime, orange sweet, and vanilla.

^LeLetting Go

It does just what it says. ^LeLetting Go helps us let go of emotions. It helps with situations that we are holding onto that are creating such physical problems as constipation. Letting go of emotional baggage can have an energizing effect on the colon, kidneys, liver, and the gall-bladder.

^LeLiteN

It is included here because it seems to limit the intensity of food cravings.  ^LeLiteN helps us eliminate snacking that is upsetting to the nerve plexus that controls the timing of bowel elimination.  ^LeLiteN is the perfect choice for any situation where one might turn to food for comfort or encouragement. The combination of cinnamon, cassia, ginger, and peppermint increases energy levels. Lime and peppermint soothe the digestive tract.

Silica

Silica, taken as a homeopathic or blessed water, can have a profound effect on stomach and digestive disorders. Most disorders of the stomach and digestive tract involve degradation of the lining of the gastro-intestinal tract. Silica is an essential element that is absolutely necessary for rebuilding and maintaining these delicate tissues. Silica involves many other functions in the body but those are topics for another day. The homeopathic remedy, especially in cell salt potency, encourages the absorption of the silica found naturally in foods we eat. You can find Silica in whole grains, oatmeal, brown rice, bananas, mangoes, green beans, and spinach—to name just a few sources.