Leaky gut is a term that refers to an increase in your intestinal permeability.[1] In other words, the tight junction of your intestinal walls begins to loosen and form holes. Normally, there are small gaps to allow smaller, beneficial particles to pass through and keep out the harmful substances. But these widened gaps (holes) allow larger particles such as toxins, harmful bacteria, and undigested food to cross through and enter the bloodstream.[2]
Certain lifestyle factors and ailments can disrupt the balance in your gut depleting beneficial bacteria and leading to the overgrowth of harmful bacteria. This imbalance can disrupt the integrity of your gut’s protective lining[1].
Though not a true medical term, “leaky gut” refers to a compromised (hole-y) gut lining and its association with various diseases — both intestinal and systemic (that which affects the entire body)[3].
Read on to learn more about leaky gut, its potential causes and manifestations, and what you can do to heal your gut.
Symptoms
“Leaky gut” is not medically recognized as a disease or condition.[3] But an increase in your intestinal permeability might lead to symptoms like bloating, cramps, and fatigue, according to a 2019 review. It may also trigger food allergies, sensitivities, and headaches. It can occur alongside serious conditions such as autoimmune diseases, diabetes, inflammatory bowel disease (IBD), multiple sclerosis, and mood disorders like depression. [1]
Related Conditions
A leaky gut might have a role in inflammatory issues in specific organs or throughout your body. Gut issues can affect skin health, potentially triggering acne, psoriasis, eczema, and dermatitis. This increased permeability in your gut barrier may also co-exist with heart disease and related conditions, as harmful substances can enter the bloodstream more easily.[8]
Digestive disorders are often associated with leaky gut. These include acute pancreatitis, celiac disease, fatty liver disease, and inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease, as well as irritable bowel syndrome.[8] And while there is no direct correlation between Leaky Gut and GERD (chronic acid reflux), both conditions share inflammatory distress, signs of imbalance in your gut microbiota, and potential immune system disruption.
Furthermore, immune disorders and neurological diseases may also be connected to issues of gut permeability.[8]
Causes
Chronic stress, unhealthy eating habits, and using antibiotics or NSAIDs (such as aspirin or ibuprofen) can disrupt your gut’s ideal balance. The imbalance can deplete healthy bacteria and lead to an overgrowth of harmful bacteria, which can tear into your gut’s lining.[1]
Certain diseases can also cause issue with your gut lining’s integrity. People with gluten sensitivity or celiac disease are likely to have a leaky gut. Gluten has a protein called gliadin that triggers the release of zonulin (a protein your body synthesizes in your liver). Zonulin widens the gaps in your gut’s lining.[4]
Other disease-related substances, like interleukin 13 and tumor necrosis factor, can also mess with the tight junctions of your gut lining. These substances are pro-inflammatory, which can upset the bacterial balance in your gut. They also make pathways that allow the gut lining to stretch and become more prone to leakage.[5]
Measuring Gut Permeability
Leaky gut may be the cause or effect of various health issues.[1] Since leaky gut is not recognized medically as a disease, it is not a condition that is diagnosed.[3]
However, compromised intestinal permeability may be measured using probes that can’t pass through the intestinal wall in a normal, healthy state. A person swallows the probes to see if they cross the intestinal barrier. If they cross, they will pass into the bloodstream and filter through the kidneys. Thus, it is assumed that they have crossed if they are excreted through the urine.{5,6}
Testing with two probes, lactulose and mannitol, may be useful. Lactulose is large and can only cross a leaky barrier. Whereas, mannitol is much smaller and can pass through a tighter, less permeable, surface area. By measuring the ratio of lactulose to mannitol excreted in the urine, the extent of intestinal permeability can be determined. A higher ratio of lactulose to mannitol suggests a greater degree of permeability.[5,6]
How to Restore Leaky Gut
There are no approved medications designed to specifically target and restore gut barrier function. However, some potential medications have been considered. Adalimumab and infliximab are two anti-inflammatory medications that have shown progress in effectively treating IBS (inflammatory bowel syndrome), a condition that often coincides with a leaky gut.[7]
Another potential treatment for restoring the gut barrier is Divertin, a small molecule that has shown potential to restore gut barrier function in experimental models. It is also suggested that Divertin may reduce disease progression in chronic inflammatory disease.[7] Increased intestinal permeability may result from chronic inflammatory disease states.
Research is still emerging as to whether or not increased gut permeability alone is sufficient to cause disease in an otherwise healthy person.[5,6] And, while inflammatory diseases may result in leaky gut, there isn’t sufficient evidence to prove that resolving a leaky gut might be a remedy or cure.
That said, current dietary considerations for leaky gut include avoiding foods that disrupt a healthy gut barrier and consuming those foods that protect it.[7] Read more about these foods in the section below entitled: How to Prevent a Leaky Gut.
Dietary Recommendations for Leaky Gut
What you eat may have a role in preventing leaky gut. Nutrients like vitamins A and D, zinc, and the amino acids methionine and glutamine, can help strengthen your gut lining.[1] These nutrients can be found in a variety of plant foods. Probiotics and fermented foods that contain them, as well as anti-inflammatory omega 3s may also be beneficial[8].
As such, eating a Mediterranean diet may help to prevent a leaky gut. This diet focuses on vegetables, legumes, fruits, and nuts, which have fiber, vitamins, minerals, and antioxidants that keep your gut healthy. The nutrients in these foods also help maintain the tight junctions in your gut lining and support the mucus layer that protects it. The diet also includes fish and olives, which are sources of gut-protective omega 3s.[9]
On the other hand, too much fat, emulsifiers (substances in processed foods to bind its ingredients), and inflammatory proteins like gliadins found in wheat gluten can weaken your gut lining[1]. Too much fat can promote more bile acids, which make your gut lining more permeable. It can also cause inflammation and reduce the healthy bacteria in your gut. Some emulsifiers can make the mucus layer in your gut thinner, which can harm the proteins that support your gut lining.[7]
In Summary
Leaky gut is not a medical diagnosis, but it is a term that reflects a compromise in your gut barrier and its normally tight junction. Increased permeability in the gut barrier means larger and particles such as toxins, harmful bacteria, and undigested foods can enter and pass into the bloodstream. This can upset the healthy balance in your gut and potentially affect other areas of your body.
Chronic stress, unhealthy eating habits, and use of antibiotics, aspirin, or ibuprofen can impact your gut health and its protective lining. And a more penetrable gut lining may co-exist with a number of diseases from digestive disorders to heart disease.
While there are no approved medications to help tighten the gut’s barrier, a heart-healthy diet such as the Mediterranean dietary plan may provide nutrients that can fortify and strengthen the gut’s lining.
More human research is necessary to determine if resolving leaky gut can help remedy or cure inflammatory disease.
References:
- Camilleri M. Leaky gut: Mechanisms, measurement and clinical implications in humans. Gut. 2019;68(8):1516-1526. doi:10.1136/gutjnl-2019-318427
- Khoshbin K, Camilleri M. Effects of dietary components on intestinal permeability in health and disease. Am J Physiol Gastrointest Liver Physiol. 2020;319(5). doi:10.1152/ajpgi.00245.2020
- Odenwald MA, Turner JR. The intestinal epithelial barrier: A therapeutic target?Nat Rev Gastroenterol Hepatol. 2016;14(1):9-21. doi:10.1038/nrgastro.2016.169
- Hollon J, Puppa E, Greenwald B, Goldberg E, Guerrerio A, Fasano A. Effect of gliadin on permeability of intestinal biopsy explants from celiac disease patients and patients with non-celiac gluten sensitivity. Nutrients. 2015;7(3):1565-1576. doi:10.3390/nu7031565
- Odenwald MA, Turner JR. Intestinal permeability defects: Is it time to treat?Clinical Gastroenterol Hepatol. 2013;11(9):1075-1083. doi:10.1016/j.cgh.2013.07.001
- Odenwald MA, Turner JR. Intestinal permeability defects: Is it time to treat?Clin Gastroenterol Hepatol. 2013;11(9):1075-1083. doi:10.1016/j.cgh.2013.07.001
- Camilleri M, Vella A. What to do about the leaky gut. Gut. 2021;71(2):424-435. doi:10.1136/gutjnl-2021-325428
- Liang L, Saunders C, Sanossian N. Food, gut barrier dysfunction, and related diseases: A new target for future individualized disease prevention and management. Food Sci Nutr. 2023;11(4):1671-1704. doi:10.1002/fsn3.3229
- Nagpal R, Shively CA, Register TC, Craft S, Yadav H. Gut microbiome-mediterranean diet interactions in improving host health. F1000Research. 2019;8:699. doi:10.12688/f1000research.18992.1po
