Harvard Health calls it a “medical mystery” and “mysterious ailment.” It’s been linked to everything from gut troubles, autoimmune diseases, and even mental health concerns.
I’m talking about “leaky gut” or “intestinal permeability”—have you heard of it?
Many doctors and the established medical community may not recognize it, but there is growing research to suggest it is associated with many health conditions.
What exactly is “leaky gut?” Do you have it? How does it happen? What can you do about it?
What is “leaky gut?”
Your gut (gastrointestinal system) is more than just a 30-foot-long muscular tube that starts at your mouth and ends with the anus. It’s a vast and complex system with many functions. It breaks down food into smaller digestible bits and nutrients, like vitamin A, D, C, etc. It keeps moving those nutrients to the small intestine which is the major site of absorption.
Inside the intestines, you have a very important mucous lining which lets our bodies absorb what we need from food and beverages but also protects us by keeping out harmful substances. This ability to selectively allow some things in our gut to be absorbed while keeping others out is only possible if the mucous lining cells are working properly and physically joined together very tightly. The bonds that keep the mucous cells tightly together are called “tight junctions.”
Leaky gut happens when the tight junctions aren’t so tight anymore. This mucous barrier becomes irritated and weakened, causing tiny holes to appear. These perforations allow things, like toxins, microorganisms, food particles, and bad bacteria, that would normally stay out of the bloodstream, now get into the bloodstream. When these get into the bloodstream, your immune system is triggered to start fighting them as “foreign invaders”. This is similar to how your immune system starts fighting the cold virus and causes inflammation. This immune reaction is normal and helps keep you healthy. Remember, 70% of your immune system is in your gut.
Do you have a leaky gut?
The symptoms of leaky gut are similar to those of other digestive conditions like inflammatory bowel disease, celiac disease, and Crohn's disease. Symptoms can include diarrhea, constipation, cramps, bloating, food sensitivities, or nutrient deficiencies.
But, because the food particles, toxins, and bacteria have been absorbed into the bloodstream which travels throughout your body, symptoms can appear anywhere. Studies show that leaky gut may feel like fatigue, headaches, confusion, difficulty concentrating, joint pain, or skin problems (e.g., acne, rashes, eczema). Leaky gut is also linked with diabetes, polycystic ovarian syndrome, liver disease, chronic fatigue syndrome, and autoimmune diseases such as lupus and multiple sclerosis. There may even be links to anxiety and depression. Many of these gut and non-gut symptoms and conditions are linked to chronic inflammation, but more research is needed to understand how they are connected.
Even if you have some of these symptoms, the fact is, it’s very difficult to diagnose a leaky gut, nor how leaky it is. This means that, while there are some biomarker tests, there isn’t a reliable diagnostic test available just yet. So, it’s difficult to say whether your symptoms are from leaky gut, or whether leaky gut is a symptom of another issue.
What causes leaky gut?
It’s not 100% clear what causes those bonds to loosen and result in tiny perforations in the gut barrier. In fact, we’re just starting to understand how the gut barrier functions and there is a lot of ongoing research.
Part of leaky gut may be due to the genes you inherit from your parents. It can also be from chronic diseases, gut infections, medications or chronic overuse of alcohol or NSAIDs (aspirin and ibuprofen). Leaky gut is also linked to eating a diet that is low in veggies, fruits, nuts, and other gut-friendly fiber (adults should aim for 25-30 g of fiber per day). It can also be from consuming too much added sugar, excess grain/starchy carbohydrates and saturated fat. Leaky gut may even result from an imbalance and diversity in the numbers of your gut-friendly microbes. Stress is huge in disrupting the chemical balances in the gut.
Also, as you age your cells can get damaged more easily and heal slowly, including the cells that line your gut. This can leave you more susceptible to weakening the mucous lining.
What can you do about it?
One way to approach a suspected leaky gut is to address inflammation and eat a more gut-friendly diet. This means reducing excessive alcohol and processed foods that tend to be high in fat and sugar or artificial sweeteners. It’s also a good idea to avoid foods that you are allergic or sensitive to. For example, if you have diagnosed celiac disease or gluten sensitivity, you want to be sure to stay away from gluten, as exposing your gut to it can cause a large inflammatory response.
Instead, enjoy more foods rich in gut-friendly probiotics and fiber which is a prebiotic, or food for your friendly gut microbes. These include
fruits and vegetables (e.g., berries, oranges, broccoli, carrots, zucchini and more)
nuts and seeds (e.g., walnuts, cashews, and chia, flax seeds)
yogurt or kefir
fermented foods (e.g., kimchi, sauerkraut, and miso)
Whole grains (e.g., oats, corn, and quinoa)
Pro Tip: If you’re going to proactively increase your fiber intake, do it over several days or weeks, starting with 1 teaspoon because sudden increases in fiber can cause gas, bloating, and other gut discomforts; especially, if you do not drink enough water. If you have IBS, talk to your doctor, or by scheduling with me to see if certain fibers may worsen your condition and which are recommended.
Also, regular exercise can help your digestive system. This means taking even a 15- or 20-minute walk after you eat to help you digest your food. And don’t forget the importance of stress management, quality sleep, and not smoking.
If you are experiencing digestive symptoms like bloating, gas, irregular bowel activity, or brain fog, among other symptoms
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Harvard Health. (2018). Putting a stop to leaky gut. Retrieved from
Harvard Health. (2018). Putting a stop to leaky gut: What can you do about this mysterious ailment? Retrieved from
Leech, B., Schloss, J. & Steel, J. (2019). Association between increased intestinal permeability and disease: A systematic review. Advances in Integrative Medicine. 6(1), 23-34. https://doi.org/10.1016/j.aimed.2018.08.003
Mayo Clinic. (2016). Food sensitivities may affect gut barrier function. Retrieved from
Medical News Today. (2019). What to know about leaky gut syndrome. Retrieved from
Medical News Today. (2019). What is the best diet for leaky gut syndrome? Retrieved from https://www.medicalnewstoday.com/articles/326102.php
Medscape. (2019). Is 'Leaky Gut' the Root of All Ills? Retrieved from
Mu, Q., Kirby, J., Reilly, C. M., & Luo, X. M. (2017). Leaky Gut As a Danger Signal for Autoimmune Diseases. Frontiers in immunology, 8, 598. doi:10.3389/fimmu.2017.00598
National Institutes of Health News in Health. (2017, May). Keeping Your Gut in Check. Retrieved from https://newsinhealth.nih.gov/2017/05/keeping-your-gut-check
Obrenovich M. (2018). Leaky Gut, Leaky Brain? Microorganisms, 6(4), 107. doi:10.3390/microorganisms6040107
US Department of Health and Human Services and US Department of Agriculture. (2015). Dietary Guidelines for Americans 2015-2020, eighth edition. Appendix 7. Nutritional Goals for Age-Sex Groups Based on Dietary Reference Intakes and Dietary Guidelines Recommendations. Retrieved from