What does this mean? For healthy individuals without celiac disease or gluten sensitivity (where their bodies are producing antibodies against gluten), the damage to individual cells and the junctions between them that can be caused by gluten is relatively fast to heal, anywhere from a few days to 3 weeks. For these healthy individuals, most of this time is likely asymptomatic. Many people report symptoms that only last from a couple of hours to a couple of days after gluten exposure. This also means that healthy individuals should be able to heal their guts completely after following a 30-day paleo challenge such as a Whole30. For those with confounding factors, healing is slower. Confounding factors are numerous and include gluten sensitivity (where the body is producing antibodies against gluten which increases inflammation and slows healing), celiac disease (an autoimmune condition), uncontrolled inflammation in the gut (which could be caused by food allergies, food sensitivities or diseases such as Inflammatory Bowel Disease), nutritional deficiencies (which can be caused by having a very inflamed and damaged gut, but slows healing because not all of the raw materials needed to repair are available), gut dysbiosis (the wrong type, amount and/or location of microorganisms in the gut), infections, stress, body-wide inflammation, and chronically elevated insulin. How much do these confounding factors slow healing? The extreme end of the spectrum is those with Celiac Disease, an autoimmune condition triggered by gluten exposure. One hallmark of Celiac Disease is a shortening or blunting of the intestinal villi which is observed by performing a biopsy of the small intestine (they are typically 3-5 times longer in healthy individuals than those with Celiac Disease). For those with celiac disease, one study showed that only 66% of patients had a normal intestinal biopsy after 5 years on a gluten-free diet 6. This means that even after 5 years, 34% of Celiac Disease sufferers had not recovered. There are no good similar studies evaluating intestinal repair in people with non-celiac gluten-sensitivity, but medical professionals who specialize in treating gluten-sensitivity report time frames of approximately 1½-2 years 7.