Zonulin: A Way to Test for Leaky Gut

Our small intestines are designed to absorb small molecules and keep bigger ones from entering our circulation, where they can trigger immune responses and lead to inflammation and autoimmune disease.

Dr. Alessio Fasano, back in 2000, discovered zonulin (represented by the blue circular objects in the drawing above), a protein which controls the tight junctions between the cells in the intestinal wall.  He found that levels go up in infection, as the body flushes out toxins.  Once the infection passes, zonulin levels fall.

Fasano discovered also that when Celiacs ate gluten, their zonulin levels rose, making their guts too permeable.  Gluten and other molecules passed through, triggering an autoimmune response.  Fasano and others who study zonulin have found that non-Celiacs who react to gluten and others with bacterial imbalance (dysbiosis) can also have high levels.   High zonulin levels are seen in people with IBS, autoimmune disease, and inflammatory bowel disease (Crohn’s and Ulcerative Colitis).

Leaky Gut happens when the tight junctions mentioned above are loosened and larger molecules such as proteins and bacteria can “leak” across the intestinal wall.  Once in the bloodstream, these particles can bind to immune cells, triggering an immune response, which can cause inflammation and tissue damage.

I recommend the Zonulin test along with the FIT Test to check for Leaky Gut and for the food sensitivities that may also be causing GI symptoms.  The cost for the Zonulin test is $195.  Insurance reimbursement is not available at this time.