The Gut and the Immune System
“All disease begins in the gut.”
It was over 2,000 years ago that Hippocrates said this, and science continues to affirm that a large majority of illness can be linked back to the gut.
This is not the case 100% of the time of course, since most genetic diseases are present at birth. Some genetic diseases are activated later in life, however. Science has found that genes can express in 30,000 different ways, and the way in which they express are affected by lifestyle and are a result of the state of the immune system. Thus, even some genetic diseases can be prevented.
A large percentage of the immune system is comprised in the gut. (I have seen many numbers thrown around, from 70-90%.) The immune system is many systems that work together to attack and detox: white blood cells, antibodies, chemicals and proteins, lymph, bone marrow, certain organs, and bacteria. Most of this occurs within the gut.
We have a lot of healthy bacteria lining our intestinal tracts. I like to think of these bacteria as the Good Army, because there are trillions of them fighting for us daily to keep us well and healthy.
It really is huge. To put it into perspective, we have about 37.2 trillion cells that make up our entire body, and approximately 39 trillion live bacteria living in our guts. (Per the most current information, though this number is still just an educated estimate.)
With a very large part of our immune system residing in our guts, a compromised gut is basically a recipe for a compromised immune system.
Immunity refers to the body’s ability to keep illness and disease away. If you have a strong immune system, then your body will capable of keeping itself healthy by fighting that which causes illness.
Therefore, a compromised immune system means that your body does not have good immunity. It will not have a strong ability to fight off infection, disease and illness.
Not every case of a compromised immune system is the same. Some cases are mild while others are more severe.
Signs of a compromised immune system include (but are not limited to): chronic illness, food and environmental/seasonal allergies, chronic inflammation, chronic sinusitis, cancer, and contracting acute illnesses that tend to linger longer than they should.
If your immune system is compromised, it means that your gut health has been compromised, as this is where the majority of the immune system is contained.
A gut that functions properly and creates stable homeostasis is a healthy gut. You cannot be healthy without a healthy gut. When the gut has become compromised, it fails to properly (if at all) do its job. To explain a long story short, the three primary functions of the gut are:
- Digestion of foods and conversion into vitamins
- Absorption of nutrients
- Prevention of toxins and pathogens from entering the body
It’s pretty much a no-brainer that if these functions are not working well, health will decline and illness and disease will result.
A healthy gut is one with a balance of good bacteria. When the Good Army of bacteria has been weakened and the prevailing bacteria in the gut is “bad”, this allows for an overgrowth of yeast, molds, and fungus – as well as many digestive symptoms, like bloating, foul-smelling gas, distention, pain, constipation, diarrhea, and a “leaky gut.”
Like I said before, you cannot be healthy without a healthy gut.
Of course the question is then, why the gut? How does the gut become compromised in the first place?
The answer is: STRESS.
Stress: The (nearly) Silent Killer
In short, the bugger called stress is the response by the adrenal glands to any physiological or psychological threat. (Meaning physical stress and/or mental/emotional stress.)
How this response happens is first the brain perceives the circumstance as threatening. The sympathetic nervous system (SNS) takes charge of the threat, and mobilizes the fight-or-flight response. This reaction initiates a release of catecholamines from the adrenal glands.
Catecholamines are the neurotransmitters and hormones produced by the adrenal glands, such as adrenaline, norepinephrine, and cortisol.
These catecholamines prepare your body to fight or to flee from the threat. Many bodily functions are activated, such as:
- An increase in heart rate, which results in an increased delivery of oxygen and nutrients to the brain and the muscles to prepare them for the stress.
- An increase in glucose, released from the liver into the bloodstream to provide more energy to the muscles.
- Widening of the airways (bronchioles) in the lungs to allow more air, which increases oxygen supply to the blood and the rest of the body.
- Dilatation of the pupils, which is often observed when you are surprised or threatened.
- Slowing down of digestive activity, which helps conserve your body’s energy that can be used to defend itself against stress. Thus you have decreased nutrient absorption, decreased oxygenation to your gut, as much as four times less blood flow to your digestive system (which leads to decreased metabolism), and decreased enzymatic output in your gut as much as 20,000-fold!
- These stress hormones (along with poor digestion) also inhibit other systems of the body such as growth, reproduction and the immune system (of course, since much of the immune system is comprised of the gut).
This stress response is all good and great when you are in the woods and come face to face with a big ol’ bear. You then have the ability to fight or flee, whichever you think is your best bet at survival. (I would definitely run.) But in this day and age, stress is everywhere. And the body doesn’t differentiate between different kinds of stress. The reaction is the same to each and every stressor.
We are constantly bombarded with stress of every kind from every direction. And it’s a big problem if your stress becomes chronic.
When stress is constant in your life, your body continues to pour out stress hormones. Any time your mind perceives a threat, it will automatically activate the fight-or-flight response. If the stressor never goes away, the fight-or-flight response will remain on constantly. You can become trapped in the fight-or-flight response—the stress hormones constantly coursing through your body and the effects of the fight-or-flight response taking a toll on your health and life.
The fight-or-flight response is a lifesaving mechanism; when you are in danger, that is. This physical response can help you survive in dangerous situations, or in critical situations (such as losing a limb). Once in a blue moon in short bursts, your body can withstand the effects of the stress response fairly well. But a constant, chronic state of stress will wear down your body and most definitely affect your health.
Chronic stress could be a week of stress that then ends up in a weekend with a cold, or it could be months and years of constant stress, resulting in debilitating illness and disease.
Chronic stress is usually long-lasting, enduring, and often relentless.
Chronic stress affects your bodies in many negative ways. As shown above, many bodily functions are activated when the fight-or-flight response is in session, and these functions are not necessary for daily life. In fact, they make life miserable and use up reserves, causing poor health.
The hormones themselves take a toll on the body.
As stated at www.adrenalfatigue.org, I quote:
- Higher and more prolonged levels of circulating cortisol (like those associated with chronic stress) have been shown to have negative effects, such as:
- Impaired cognitive performance
- Dampened thyroid function
- Blood sugar imbalances, such as hyperglycemia
- Decreased bone density
- Sleep disruption
- Decreased muscle mass
- Elevated blood pressure
- Lowered immune function
- Slow wound healing
- Increased abdominal fat, which has a stronger correlation to certain health problems than fat deposited in other areas of the body. Some of the health problems associated with increased stomach fat are heart attacks, strokes, higher levels of “bad” cholesterol (LDL) and lower levels of “good” cholesterol (HDL), which can lead to other health problems.
The adrenal glands only hold so much cortisol and adrenaline. This is called your “reserves.” Those who seem to be able to handle a lot more stress, have more reserves. Those who have less are most likely already experiencing more stress to begin with, thus they cannot handle much more before their reserves begin to get further depleted.
Cortisol is used to balance and keep many functions under control. You need this hormone for proper health and homeostasis. Under chronic stress however, the reserves become depleted and these functions begin to suffer.
As quoted once again from www.adrenalfatigue.org,
“Chronically lower levels of circulating cortisol (as in adrenal fatigue) have been associated with negative effects, such as:
- Brain fog, cloudy-headedness and mild depression
- Low thyroid function
- Blood sugar imbalances, such as hypoglycemia
- Fatigue – especially morning and mid-afternoon fatigue
- Sleep disruption
- Low blood pressure
- Lowered immune function
- Lowered immune function
This is not new information or alternative wisdom. See similar info at the Mayo Clinic Website. Despite this, conventional and Western medicine prefers to ignore the role of stress on our wellbeing.
As stated above, stress directly affects the digestive tract. When the stress mechanism has been triggered, digestive activity slows down in order to conserve the body’s energy to be used to defend itself against stress. Thus you have decreased nutrient absorption, decreased oxygenation to your gut, as much as four times less blood flow to your digestive system (which leads to a decreased metabolism), and decreased enzymatic output in your gut as much as 20,000-fold.
This means that you are not digesting food well and your entire body begins to suffer from the lack of proper nutrients. There is a reason why we eat multiple times per day, but when under chronic stress, this very basic process is no longer fruitful.
When our digestion suffers, secretions (stomach acid in addition to enzymes) needed for digestion are decreased. Food begins to sit for extended amounts of time in the stomach. Food can even become putrid and rotten due to improper stomach acid output and cause bloating and belching.
When digestion has been compromised, the gut itself begins to go down hill. The very walls of the intestinal tract become weakened, thin and porous, allowing particles of undigested food to leak through into the blood stream. This is called Leaky Gut Syndrome. Inflammation can result, causing physical symptoms in the rest of the body such as joint pain, headaches, back aches, fybromialgia symptoms, fatigue and more.
Stress affects the contractions of the digestive muscles and the microbiota (our gut bacteria). Further symptoms of gurgling, constipation, diarrhea, IBS, and more can result from indigestion.
The numerous issues that occur from Leaky Gut Syndrome can further trigger the stress response, and a vicious cycle follows that further deteriorates the health of the body.