Zonulin Stool Test

The zonulin marker assesses for hyperpermeability in the gut lining. The lining of the gut is composed of a single layer of cells that are held together by something called tight junctions. These tight junctions are meant to be able to open and close based upon the needs of the system at any particular time. Zonulin regulates the opening of the tight junctions. While this is desirable at times, certain types of infections and gliadin (the oft-problematic protein in gluten) can upregulate zonulin and create chronic intestinal hyperpermeability (aka leaky gut).t Zonulin may also be suggestive of a leaky brain beyond just a leaky gut.