Intestinal permeability is sometimes to referred to as “leaky gut”. It is a condition in which the lining of the small intestine becomes damaged, causing partially digested food particles, waste products and bacteria to “leak” through the intestinal wall.
Normally the intestinal lining acts a barrier between the digestive system contents and the bloodstream. The cells that make up the lining are held together by connections called tight junctions. When these tight junctions become damaged the particles that leak through can interact with immune cells, triggering a reaction. This reaction can lead to symptoms such as headaches, brain fog, irritable bowel, fatigue, joint pain, low mood, and anxiety. It can also contribute to the worsening of existing inflammatory or autoimmune conditions such as rheumatoid arthritis, lupus, multiple sclerosis and psoriasis.
What causes increased intestinal permeability?
Leaky gut can occur whenever there is irritation in the gut or ongoing inflammation. Alcohol, aspirin and painkillers such as ibuprofen are well-known irritants of the bowel lining. They can damage the tight junctions between the cells, allowing some substances to pass through the gaps and into the bloodstream.
Inflammatory digestive conditions such as Crohn’s disease, coeliac disease and food sensitivities are also associated with leaky gut. As are an infection of the intestines by parasites or microbes.
Chemotherapy medicines, radiotherapy to the abdomen and immunosuppressing medications are all also known leaky gut triggers.
Laboratory analysis of intestinal permeability
Cyrex Array 2 measures intestinal permeability to large molecules which inflame the immune system and identifies the damaging route through the intestinal barrier.
It tests for the following antibodies.
- Occludin/Zonulin IgG
- Occludin/Zonulin IgA
- Occludin/Zonulin IgM
- Actomyosin IgA
- Lipopolysaccharides (LPS) IgG
- Lipopolysaccharides (LPS) IgA
- Lipopolysaccharides (LPS) IgM
Zonulin and occulin are proteins that open up the tight junctions of the intestinal wall, regulating how permeable the gut is. Researchers first discovered zonulin while studying intestinal infection cholera. It has since been shown that gluten can trigger zonulin release and cause the gut to become more permeable in people reactive to gluten.
As the gut becomes inflamed and breaks down during leaky gut, the immune system makes antibodies to zonulin and occludin. One way to evaluate leaky gut is to test for elevated zonulin-occludin antibodies.
Actomyosin antibodies are an indicator of intestinal destruction. Actomyosin is a complex of proteins that make up muscle fibres and contributes to contractions in the intestine. Antibodies to actomyosin signal a breakdown of the membrane lining the digestive tract and hence leaky gut.
Actomyosin antibodies indicate gut damage is severe enough to break through the cells, not just open the spaces between cells. This type of damage takes longer to repair.
The test also looks at antibodies to lipopolysaccharides (LPS). These are compound in the membranes of harmful bacteria that trigger inflammation. Immune cells in the mucosal lining do not normally interact with LPS when the gut barrier is healthy. It’s only when the gut barrier becomes permeable that the immune system will see the LPS and produce antibodies, so this is another marker we can measure to identify leaky gut.
LPS antibodies also signify an overgrowth of harmful bacteria in the digestive tract.
The antibodies to zonulin, occludin, actomyosin, and LPS are measurable with a blood test. This is a simple way to confirm that leaky gut is the cause of your symptoms. You can also confirm whether you have corrected the problem with a follow-up test.
Is recommended for people who:
- Regularly use gut irritants such as aspirin, ibuprofen or alcohol
- Suffer autoimmune disease
- Have an inflammatory digestive condition or intestinal infection
- Present multiple symptoms such as headaches, digestive disturbance, joint pain and mood changes
- Complain of food sensitivity and intolerance.
- Have undertaken a course of chemotherapy, radiotherapy or those on immunosuppressing medications