The Gut Influences … Everything
Our gastrointestinal (GI) tract influences so much of our bodies and many doctors overlook its complexity and not to mention its importance. In this article I will introduce you to the gastrointestinal tract connections throughout the body. The big three include immunity, endocrine (hormones) and nervous system.
IMMUNITY
Researchers speculate that 70% of the body's immune system resides within the GI tract. This is AMAZING!! Not only does our gut have the enormous responsibility of breaking down food into minute particles, initiating the release of digestive enzymes, and absorbing nutrients to provide energy for our entire body but it is the gatekeeper for pathogens wanting to invade your body.
The body is equipped with two sides of an immune system, equally important TH-1 and TH-2. T-Helper (TH) 1 is mainly stimulated after having a virus or bacterial infection. Most of these cells die off within 7 - 10 days, this is why your average cold last a week to 10 days. TH-2 is a main source of antibody production.(2) So for people who never claim to get sick, this is a big RED FLAG for us indicating that this person does not have a fully functioning nervous system because it cannot even initiate an immune response. Because lets face it, who does not get exposed to something everyday on this earth whether it be bacteria, virus, mold, spoiled food, uncooked food, allergens, environmental toxins, etc.?
HORMONE INFLUENCE:
Hormones are typically made by endocrine and exocrine glands such as the thyroid, pancreas, adrenals and ovaries/testes. However, most hormones are activated and secreted by the gastrointestinal tract.
Thyroid hormone for instance makes approximately 93% T4 (inactive thyroid hormone) and 7% T3 (active thyroid hormone). So in the ideal, healthy patient this is what the current research literature is saying: Once the thyroid has produced T4, it is metabolized peripherally from the thyroid into a combination of T3 hormones by the enzyme 5’ deiodinase, mostly in the liver. Approximately 40% of the available T4 is converted into T3, 20% is converted into reverse T3 (rT3) which is irreversibly inactive, and 20 % is converted into T3 sulfate (T3S) and triodothyroacetic acid (T3AC).
T3S and T3AC are inactive thyroid hormones until they circulate into the gastrointestinal tract and are acted upon by intestinal enzymes which make active T3 hormone.(3)
Hormones such as estrogen and testosterone after being used by their target cells must be broken down from their original structures and detach or cleave metabolites that may be reused by the body. This breaking of metabolites is done in the liver. So in simple, here is the process. The hormone is used and thrown into the venous circulation which is then delivered to the liver. The liver breaks off all the useful parts of the discarded hormone and passes on the rest, this is phase I of liver detoxification. Phase II conjugates the discarded hormone, puts a tag on it, which says “no good or go to dump.” The discarded hormone then gets dropped into the trash which we call phase III or biliary elimination. The gallbladder or biliary system then dumps the trash into the colon where it can be properly discarded as feces.
Complications arise when the body is able to break the bond from phase II (conjugation) releasing the discarded hormone back into circulation. This is one example of how estrogen and testosterone (pending the sex of the patient) may increase to unhealthy levels. This is one explanation of hormone sensitive tissues becoming prolific or cancerous.
NERVOUS SYSTEM INFLUENCE:
“The hormones of the gastrointestinal tract have a greater impact than neurological connections,” stated by Arthur Guyton’s 11th Edition of Medical Physiology. This is a profound statement when we as doctors stop and think about it. The big kick today in medicine is caring for the brain, have to rejuvenate the brain, have to keep the brain active and healthy.
Well my first question to this school of thought is... “Where does the brain get its nutrients from?”
Anybody??
Well we eat food and it gets digested in … THE GUT!!
Ask yourself a question, “what is the goal of taking one of the best supplements on the market if your body is unable to break it down and use the nutrients it provides?”
In our office we recommend patients taking the 2100 Gastrointestinal Profile which looks at Predominant bacteria, Digestion, Immunity, Pathogens (i.e. Yeast/Fungi, Opportunistic, Parasites & Pathogenic), Beneficial Short Chain Fatty Acids, pH, and Absorption. With an in depth look at these factors we are able to address the patient’s needs in a systematic and objective point of view.
Hmmm... sounds reasonable?
The GI tract is a complex and dynamic ecosystem due to the interplay between peristaltic movement, food particles, host cells and defence molecules and a vast array of resident microbes and their secreted products. The microbial population, estimated to total about 10^14th bacteria, is 10 to 20 times greater than the total number of cells in the human body. It has been estimated that between 500 to 1000 bacterial species inhabit the GI tract.(1)
Many of these microbes play key roles in the thyroid metabolism, digestive enzymes, calorie expenditures, vitamins and mineral, and SO MANY MORE!! In the diagram below it shows how hormones influence the rate of food intake. The upper part of the stomach releases Ghrelin which sends signals to the brain to increase food intake while Obestatin, Cholecystokinin (CCK), Oxyntomodulin (OXN) and more suppresses appetite. All these indicators effect nuclei in the brainstem, mainly in the medulla oblongata which may also alter sexual behavior and motivation. So to summarize the microbial environment can alter your brain’s chemistry enough to affect satisfaction during meals, sexual behavior and self-drive.
SUMMARY:
The gastrointestinal tract is key in balancing an unstable system. An unstable system being imbalance in hormones, obesity, brain fog, chronic allergies, chronic skin issues, chronic pain patterns, chronic fatigue, and the list goes on and on. There is a new era starting to be recognized and that is how dynamic and important the gastrointestinal tract is. No one part is greater than the sum of its parts but when all else has failed look to the gut.
References:
1. Gastrointestinal Microbiota and Regulation of the Immune System. Gary B. Huffnagle and Mairi C. Noverr. Copyright 2008 Landes Bioscience and Springer Science+Business Media.
2. Th1/Th2 Cells. http://www.ncbi.nlm.nih.gov/pubmed/10579123
3. Functional Blood Chemistry Manual. Dr. Datis Kharrazian. Copyright 2005
