The outer layer of your gastrointestinal (GI) tract is a film of mucus and bacteria, and a protein called zonulin regulates how tightly the cells are linked together. These spaces between your gut's outermost cells are called intestinal tight junctions, and they act as the safeguard between your intestines and your bloodstream. When zonulin is functioning properly, your GI tight junctions keep things that don't belong in your bloodstream out—which includes toxins, allergens, undigested food particles, and bacteria. However, when zonulin malfunction occurs, you end up with leaky gut and sometimes a full-blown autoimmune disorder because the materials slip through the blood steam and start causing inflammation throughout the body.
It might surprise you to hear that some people suffering from leaky gut don't experience any symptoms at all. However, in general, if the amount of food and toxin leakage is small, symptoms are generally confined to the gastrointestinal tract. In fact, many people who have received a diagnosis of irritable bowel syndrome actually have leaky gut. Typical leaky gut symptoms mimic those of irritable bowel syndrome, including gas, cramping, bloating, and diarrhea or constipation. When we see more leakage (generally when there is more damage to the tight junctions), we find more systemic symptoms, which can include joint pain, rashes, difficulty sleeping, cognitive dysfunction, fatigue, and asthma. Eventually, these symptoms can even lead to autoimmune disorders such as Crohn's disease, rheumatoid arthritis, psoriasis, and type 1 diabetes.
Obviously, none of these scenarios are ideal. So let's review the common causes of leaky gut and what you can do to prevent it: