Once again we return to the story of how important it is to have a healthy gut barrier. The main job of the GI mucosal layer is to allow in health-promoting nutrients and to prevent the passage of damaging molecules such as yeast, bacteria, and chemicals into systemic circulation. It also protects the stomach from stomach acid and ingested toxins, drugs, alcohol, and infectious pathogens.
When the GI mucosa is damaged, molecules of all types can bypass the body's first line of defense. "Leaky Gut" is the name given to the condition in which the barrier is damaged and damaging substances can slip around the cells and into circulation. We see this occuring in patients with intestinal inflammation, food allergies and intolerances, and celiac. In a study of 200 children with cow's milk allergy, there was a significant number that tested positive for intestinal permeability. Poor nutrient intake or absorption will also affect intestinal permeability. Abnormal intestinal permeability has also been observed in patients undergoing chemo and radiation, most likely due to the killing of proliferating cells.
So, how do we test for Leaky Gut? This can be done one of two ways:
- Urine Challenge Test- This measures the recovery of two nonmetabolizable sugars: lactulose and mannitol. Their different molecular weights enable evaluation of transcellular and paracellular absorption. This is done with a a first morning urine sample. A premeasured lactulose/mannitol drink is ingested and then urine is collected for the following 6 hours. Total urine volume is measured, and both samples are assessed for recovery of the two sugars and their ratio of L:M.
- Blood Draw- This is done to assess levels of zonulin, occludin, actomyosin, and lipopolysaccharides in the blood. These should not be present in the bloodstream and indicate if the breach is by way of transcellular or paracellular pathways. This is a measure of immune response as it is an antibody measurement.
Intestinal barrier integrity plays a significant role in the overall health and well-being of patients.
Who should be tested?
- Anyone with a family history of autoimmunity or neurodegeneration.
- Those with gut dysbiosis.
- Those suspected of intestinal mucosal damage.
- Those who complain of food allergy and intolerance.
- Those who present with several symptoms.
- Those who may suspect they have blood-brain barrier permeability, depression, or neuroimmunity.