Chances are, you’ve heard of leaky gut. Perhaps you’ve been told that this condition isn’t real. Mainstream Western medicine doesn’t really give this condition a lot of thought, despite the fact that there is a substantial amount of evidence-based literature to suggest that increased intestinal permeability is a thing, and it is a problem. But before we get into that, let me first explain the anatomy of a normal, healthy gut.
Our small intestine is the portion of our GI tract that comes immediately after the stomach. It is nearly 20 feet long and approximately 1 inch in diameter. And it’s size serves a purpose – it creates a ton of surface area, which increases the likelihood of nutrient absorption. There are three parts of the small intestine: the duodenum (about 10 inches long), the jejunum (nearly 8 feet long) and the ileum (about 12 feet long). Now, without getting too in-depth, the most superficial layer of the small intestine (the mucosa) is covered in these finger-like projections called villi that are about 1 millimeter in length (see below). The villi are covered with microvilli, which are even smaller projections off of villi and they further increase the surface area, in order to facilitate nutrient absorption. Think of villi as fingers and microvilli as hairs on the fingers. These villi are comprised of simple columnar epithelium cells. What this means is that there is one single layer of cells, bound together by tight junctions, which prevent certain substances from readily passing through. We have to absorb nutrients from our GI tract into our blood stream, and this happens through diffusion, osmosis and active transport. If you don’t remember high school biology, all you need to know is that our body is able to absorb the nutrients it needs from our GI tract. Meanwhile, harmful things (like bacteria) are kept out of our blood via tight junctions. You still with me? Good.

So, leaky gut is the condition that develops when these tight junctions are compromised. How does this happen? Well, we can blame a protein called zonulin. Zonulin changes the permeability of the gut lining by decreasing the integrity of tight juntions. Then, bacteria, toxins and undigested food are able to pass through the lumen of the GI and directly into the blood stream. The result? An immune response in the form of antibody activation, which can lead to migraines, eczema, fatigue, food allergies, and GI upset (abdominal pain, diarrhea, bloating, and gas). The inflammatory response that results from leaky gut can also exacerbate musculoskeletal pain. Recurrent infections/illness may also be indicative of leaky gut.
Source: https://commons.wikimedia.org/wiki/File:Selective_permeability_routes_in_epithelium.svg
What contributes to the development of leaky gut? Studies have shown that zonulin is released in response to the presence of bacteria and gluten in the small intestine. So, high levels of gluten intake can certainly play a role, as can overgrowth of bacteria (e.g. in the case of Small Intestine Bacteria Overgrowth, or SIBO). But, other things have also been shown to negatively affect the permeability of the intestine: excessive sugar intake, alcohol consumption and repeated use of Non-Steroidal Anti-Inflammatory Drugs.
So, why should we care about this? Well, if the symptoms aren’t reason enough, you can actually develop intolerances to certain foods if leaky gut persists! Think about it: if undigested food particles are getting absorbed into your blood and then are being attacked by your immune system repeatedly, this may eventually trigger full-blown allergic reactions when you consume those foods. Personally, I developed an intolerance to nightshades, which was a real shame because I love tomatoes.
So, what can we do to heal our gut? First and foremost, we have to give our bodies the right environments to heal. That means cutting out anything that triggers an immune response. Don’t know what your sensitivities are? Elimination diets are one way to identify what you respond to. This takes effort and diligence, but is totally doable. Keep a diary. Do you have abdominal discomfort, headaches or a runny nose after eating certain foods? If so, you may be sensitive to them. A good starting point is to cut out gluten, dairy and alcohol. Also, keep your sugar intake to a minimum. Check out the FODMAP list – often times people have sensitivities to “healthy” foods that you normally wouldn’t think to eliminate. You can also see an allergist, nutrition therapist/holistic nutritionist or naturopathic doctor to definitively determine what your body is responding to.
I recommend the following supplements, which facilitate gut healing: glutamine, quercetin, deglycyrrhizinated licorice (DGL), marshmallow root and aloe vera. I also ensure that my clients are getting plenty of vitamin A (found in cod liver oil, leafy greens, eggs and yellow/orange fruits and veggies), vitamin D (eat some salmon and/or get 20 minutes of unprotected sunlight) and zinc (found in red meats and oysters; supplement if needed, but know that zinc supplements may upset your stomach). Deficiencies in vitamin A, vitamin D and zinc may perpetuate increased intestinal permeability. I personally love to drink bone broth on an empty stomach; its collagen content promotes healing.
Oh, and try to work on your stress. We all know by now that stress leads to inflammation. And global inflammation WILL impair gut healing.
If you’re dealing with chronic pain, recurrent infections, frequent GI upset and constant fatigue, I encourage you to take a long, hard look at your diet. Chances are, your symptoms may be due to (or perpetuated by) inflammation in your diet, and possibly increased intestinal permeability.
Have questions about leaky gut? Leave them below!