Jill Carnahan, M.D., wrote an article for her blog called, “Zonulin: A Discovery That Changed The Way That We View Inflammation, Autoimmune Disease and Cancer.”
From the article:
Zonulin opens up the spaces between the cells of the intestinal lining. That normally occurs, in order for nutrient and other molecules to get in and out of the intestine. However, when leaky gut is present, the spaces between the cells open up too much allowing larger protein molecules to get into the bloodstream where an immunologic reaction can take place. Once that happens, the body is primed to react to those proteins each and every time they appear. It can also cause leakage of intestinal contents, like bacteria into the immune system creating inflammation and overloading the liver’s ability to filter out this garbage.
Based on Dr. Fasano’s research, we know that the two most powerful triggers to open the zonulin door are gluten and gut bacteria in the small intestine. Gliadin causes zonulin levels to increase both in those people who have celiac disease and those who do not. As the zonulin level rises, the seal between the intestinal cells diminishes, opening up spaces between cells that allow all sorts of things to pass right through. This is called “leaky gut”. Its as if the security guard that keeps the bad guys out is taking a nap! Sometimes large food molecules will pass through to the immune system. The immune system thinks they are foreign invaders and will mount an immune response leading to food sensitivities. In addition this immune activation leads to more damage to the intestinal cells (called enterocytes) and the gut becomes more inflamed and more permeable or “leaky”. As the damage continues, the microvilli that line the intestines and absorb nutrients become damaged, leading to other nutrient deficiencies.