Every decade there’s a groundswell of popular interest in some “unified field” explanation of chronic diseases. For a while, it was free radicals, then inflammation. Now it’s “leaky gut.” Surfing the Internet, you may get the impression that this “syndrome” is epidemic and the cause of most of our maladies. Many alternative medicine practitioners support this notion, as do marketers of supplements and treatments that are supposed to cure leaky gut.
Here’s how the leaky gut scenario goes. The large intestine contains trillions of bacteria (called our colonic microflora), many of which perform vital functions. If the intestine becomes injured—by certain medications (including aspirin and ibuprofen), chronic inflammation, high alcohol intake, stress, certain foods and so on—the tight junctions between cells in the lining loosen. This increased intestinal permeability allows “leakage” of bacteria (and/or the toxins they produce) and other substances into surrounding tissue and possibly the bloodstream. This, in turn, can supposedly cause, trigger or worsen everything from gas, cramping, eczema, joint pain, hives and food sensitivities to obesity, diabetes, heart failure, kidney and liver disease, autism, migraines, Crohn’s disease, ulcerative colitis, irritable bowel syndrome, diabetes, asthma, depression, acne and chronic fatigue, as well as celiac disease and other autoimmune diseases.
Recently, I reviewed the scientific literature on leaky gut and found hundreds of studies from the past 15 years suggesting potential implications for health. The most interesting research, I think, concerns the role leaky gut may play in certain autoimmune disorders. For instance, a paper in Clinical Reviews in Allergy & Immunology in 2011 noted how increased intestinal permeability may trigger autoimmune diseases such as rheumatoid arthritis and celiac disease by causing an abnormal immune response in genetically predisposed people. But even here, the evidence is very preliminary and largely theoretical.
There’s no question that human health is inextricably tied to our bacterial residents. Genetic, dietary, environmental and other factors help shape this microflora, its effects on our bodies, and intestinal permeability. Whether “leaky gut” actually causes chronic diseases, is a result of them, or merely accompanies them is still unknown. It’s an incredibly complex story, and one we’re only beginning to understand.
So don’t believe simplistic claims you may read online or hear on TV that leaky gut causes certain conditions or symptoms. Be especially wary if a practitioner says that “leaky gut syndrome” is the cause of all your ills and then prescribes a special diet, supplements (such as probiotics, colostrum or antioxidants) or treatments (such as colonic irrigation). There’s no evidence that these will help reduce intestinal permeability or the disorders purportedly linked to it.