The Gastrointestinal Tract
You may not have thought of it like this before but the gastrointestinal tract is technically outside the body. It is basically a long tube with one opening at the mouth and another at the anus. Just like the skin protects the body from the external environment, so too does the GI tract, with respect to everything that is ingested.
The main functions of the GI tract are as follows:
- Digests foods
- Absorbs the products of digestion so they can be converted into energy and proteins.
- Carries nutrients like vitamins and minerals across the intestinal lining, into the bloodstream.
- Contains a major part of the chemical detoxification system of the body.
- Contains antibodies that protect the body against infection.
The healthy gastrointestinal tract absorbs only the small molecules like those that are product of complete digestion. These molecules are the amino acids, simple sugars, fatty acids, vitamins, and minerals that the body requires for all the processes of life to function properly. The intestines, small intestine in particular, only allow these substances to enter the body due to the fact that the cells that make up the intestinal wall are tightly packed together. The intestines also contain special proteins called 'carrier proteins' that are responsible for binding to certain nutrients and transporting them through the intestinal wall and into the bloodstream.
So what is a Leaky Gut Syndrome?
Leaky Gut Syndrome (LGS) is the name given to a condition in which the ability of the intestinal wall to keep out large and undesirable molecules is reduced. Hence the name, as substances that are normally kept outside the body and within the intestines, are "leaking" across the intestinal wall and into the body as a whole. This happens when the spaces between the cells of the intestinal wall become enlarged for various reasons.
Leaky Gut Syndrome is hardly ever tested for or diagnosed by doctors in general practice but there are vast amounts of research implicating altered permeability of the intestinal wall in a large number of illnesses. To illustrate this, the following definition for leaky gut syndrome is taken from Allergy Induced Autism, a UK based Autism charity.
Leaky Gut Syndrome is "an increase in permeability of the intestinal mucosa to luminal macromolecules, antigens and toxins associated with inflammatory degenerative and/or atrophic mucosal damage".
To simplify a few of these terms that may be unfamiliar:
Mucosa - The intestinal wall
Lumina - The space within the walls of the intestine
Macromolecules - Large molecules
What causes Leaky Gut Syndrome
There are quite a large number of factors that can increase the permeability of the intestinal wall. The most common are:
- Alcohol and caffeine - These irritate the gut wall.
- Candida and Gut dysbiosis - Caused by antibiotic use etc.
- Drugs - The worst offenders include NSAID's (non-steroidal anti-inflammatory drugs), antacids and pain med's like aspirin and ibuprofen.
- A diet high in refined carbohydrate.
- Environmental contaminants
- Food additives
- Insufficient digestive enzymes
- Chronic stress - Stress reduces blood flow to the gut leaving it unable to repair itself.
- Other gastrointestinal disease.
- Poor liver function resulting in inflammatory toxins being excreted into the intestines in bile.
Testing for Leaky Gut Syndrome
The same test used by medical researchers to detect changes in intestinal permeability is now available inexpensively to consumers and can be easily completed at home. Basically the test involves providing urine samples before and after drinking a solution containing the non-metabolised sugars mannitol and lactulose. These are then mailed to the lab in a pre-paid envelope.
The lab analyzes the urine samples for levels of mannitol and lactulose. Since lactulose is not normally absorbed in significant quantities an abnormally high result suggests leaky gut syndrome. Mannitol is absorbed by the intestinal cells to some degree so a low result may indicate malabsorption but a high result again suggests leaky gut syndrome, especially when combined with high lactulose recovery.
For more information see the Intestinal Permeability (IP) Test review page.
What happens when you have a Leaky Gut Syndrome?
A leaky gut results in many problems that affect the whole body:
Gastrointestinal Symptoms - The most obvious problems resulting from a leaky gut are probably digestive symptoms like bloating, flatulence and abdominal discomfort.
Large food particles can pass into the bloodstream - The immune system assumes these particles are dangerous foreign material and creates antibodies against them. This leads to the situation where large numbers of different foods set of an immune reaction every time they are eaten. These antibodies may also attack the bodies own cells that are structurally similar to the large food molecules. This leads to auto-immune disease.
Nutritional deficiencies - Although you might expect that having a leaky gut would mean you can absorb more nutrients, this is not the case. This is because the 'carrier proteins' that were mentioned earlier, are damaged when the gut becomes inflamed and more permeable. This means that the nutrients can't get across the intestinal wall and nutritional deficiencies result.
Increased absorption of toxins - This places a great strain on the liver and as detoxification enzymes become depleted, more and more toxins are able to circulate to all parts of the body in the bloodstream. In severe cases leaky gut can lead to liver inflammation and toxic hepatitis. These toxins circulating in the blood can result in any number of symptoms from foggy thinking to skin rashes as well as inflammation of various tissues and organs. Multiple Chemical Sensitivities are the end result of a high toxic load as the nervous system becomes sensitized.
The gut's immune function is impaired - When the gut wall is inflamed the antibodies (IgA) that protect the gut are adversely affected. This reduces its ability to fight off potentially pathogenic bacteria, parasites and yeast like candida.
Gut microorganisms can enter the body - When the intestinal lining is inflamed, the bacteria that usually reside within the intestine are able to "translocate". This means that they can pass across the gut wall and into the bloodstream, from where they can cause infection anywhere in the body, causing havoc for the immune system.
As you can imagine, all of this can lead to any number of seemingly unrelated symptoms affecting every organ system in the body. Leaky Gut Syndrome has also been linked with having a causative role in a large number of distinct illnesses. Many of these are auto-immune diseases, which means the immune system attacks the body's own cells. Leaky gut syndrome plays a role in these types of illness because it increases immune reactions to food particles and then cross reactivity may occur meaning that the immune system attacks body tissues that are chemically similar to the foods to which it has become sensitized. Here are a small number of the many diseases in which leaky gut syndrome may have a role:
- Rheumatoid Arthritis
- Multiple Sclerosis
- Crohn's Disease
- Addison's Disease
Leaky Gut Syndrome and Environmental Illnesses
Leaky gut syndrome is likely to play a part in all of the environmental illnesses. All of these illnesses are characterized by a high frequency of allergy, symptoms brought on by chemical exposure, subclinical nutritional deficiencies and gastrointestinal symptoms. The increased toxic load on the body produced by a leaky gut has the general effect of making the nervous and immune systems hyperstimulated. Neuroimmune dysfunction, or more specifically, neuroimmune hyperactivity, is implicated in all the leading theories about the etiology of environmental illnesses like CFS and fibromyalgia.