With Leaky Gut syndrome, people tend to have wider gaps in between the cells of their intestinal wall than usual, caused by inflammation and bacterial imbalances. It is believed that changing your diet can help restore the bacterial imbalance and reduce inflammation that will be of great help in combating Leaky Gut.
So what are the best foods for leaky gut?
You will find that you need to eat the foods that will help the healthy gut bacteria grow and create a bigger diversity. This includes fresh fruits, cultured or fermented dairy products, healthy fats, lean meats, and fibrous and fermented vegetables. Try to avoid processed and refined junk foods and artificial sugars, as well as foods that are difficult to digest and cause bloating and flatulence.
Making these changes to your diet will not only help to improve your gut health, but it will also help reduce the risk of getting other conditions like inflammatory bowel disease or obesity. You will notice that changing your diet in a positive way will also help reduce uncomfortable symptoms like bloating, flatulence, constipation, and diarrhoea.
Understanding leaky gut syndrome
According to the scientific literature on the subject, it is very difficult to pinpoint a main culprit for this syndrome. They call the alternative medicine articles online “folklore” and make sure to point out that many diverse diseases like food intolerances, fibromyalgia, chronic fatigue syndrome, and autism all may have leaky gut in common, but that it is not the cause of these diseases.1 Despite it being a popular term in alternative medicine, Western medical professions do not seem to recognise it as a condition nor a valid diagnosis. Intestinal hyperpermeability would be the most likely name used in this case.1-3
Leaky Gut, or intestinal hyperpermeability, is a condition that features gaps in the lining of the intestinal walls. The epithelial cells that form this lining usually have small gaps, which allow the passage of small molecules like water, electrolytes, and nutrients into the bloodstream. Food and waste are too big and should not be able to pass through these gaps.
However, in leaky gut syndrome, inflammation of the intestinal lining and bacterial imbalances in the gut are causing these gaps to expand. You can see how this facilitates food and waste to leak into the bloodstream, causing a whole array of problems like inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS).1-3
Causes
Any inflammatory process may impair the integrity of the intestinal lining, as does an imbalance of the gut bacteria (gut dysbiosis) where the bad bacteria have overgrown the beneficial gut bacteria. Dietary components or bile acids can independently influence the barrier function of the intestinal lining. Additionally, allergens, stress and physical activity may also alter the functioning of the intestinal lining. It is important to note that having a genetic condition that leads your intestinal lining to have an impaired barrier function does not always lead to Leaky Gut Syndrome.1
What happens when you have leaky gut syndrome?
The intestinal lining has 3 different layers that form the barrier. From the inside out:
- The surface mucus is the first line of defence. It consists of 2 layers - the first inner layer has virtually no bacteria present and secretes peptides that are protective with antibacterial functions (e.g. defensins and lysozyme), whilst the second outer layer has an abundance of bacteria and bacterial products. This mucus layer is thicker in the colon than it is in the small bowel
- Then there is the epithelial layer. These epithelial cells have 3 sets of junctions on an intercellular level. They regulate the epithelial barrier function and intercellular transport
Currently, there are 3 distinct pathways known for their permeability:
- Leak pathway, which are regulated by the so-called tight junctions and define intestinal permeability
- Pore pathway, which works the same as the leak pathway
- Unrestricted pathway, which is associated with tissue damage leaks in case the lining is disease-stricken. This route is independent of the tight junctions and provides easy access for bacteria to the mucosa and then bloodstream
- Finally, the immune defence mechanisms in the mucosa, or lamina propria. This is where the innate and adapted (or acquired) immune system works to defend the tissue. There are different mechanisms that the immune system sets up to fight potential risks from external stimuli. One of these mechanisms is the production of proteins such as antibodies, cytokines and antigen presenting cells. IgA is an antibody produced by IgA secreting plasma cells to capture bacteria and cells secreting potent inflammatory proteins. Once the antibody captures the foreign element, it sends out a signal (cytokines)to “kill the intruders'' . Additionally, there are other proteins called antigen presenting cells that present a piece of these intruders and show them to other immune cells in the body so they can orchestrate a specific attack1,3
When food or waste passes through all of the physical barriers, it finally reaches the immune mechanisms in the tissues/blood, which can then lead to inflammation and tissue damage.1,2 This inflammation will have a clear impact on your digestive health.
Some believe the inflammation in the digestive tract can impact other systems e.g. joint pains, fatigue, skin issues, thyroid issues, migraines, autoimmune reactions etc. If you think you may suffer from a leaky gut or if you have made changes in your diet and still suffer from some symptoms that have been discussed here, you should seek medical advice as something more serious might be going on.
Symptoms
Symptoms associated with Leaky Gut Syndrome include: bloating, flatulence, indigestion, abdominal pain, diarrhoea, food sensitivities and intolerances, fatigue, headache, and joint aches.4
Who is at risk?
It is thought that people with digestive health issues are more prone to increased intestinal permeability, like coeliac disease, IBD and IBS, as they were thought to already have damaged the epithelial linings and loosened the tight junctions. Other diseases like HIV/AIDS can also cause intestinal injury, and when undergoing chemotherapy and/or radiation therapy, this will also damage your intestinal mucosa. You can also damage your lining yourself by chronic overuse of alcohol or non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and high-dose aspirin.4
Diagnosis
You may want to keep a food diary to figure out what foods could trigger your symptoms. This works best when you are on a restrictive diet and start adding potentially triggering foods back into your daily diet.
Considering that leaky gut syndrome is not medically recognised, your healthcare provider may or may not do some tests to gain insight in your intestinal permeability. Unfortunately, there is no standard test available to do this, which is one of the reasons why intestinal hyperpermeability is not a proper medical diagnosis yet. Lots of research is being performed on the topic, and these are some of the tests that might be performed according to the Cleveland Clinic.4
Firstly, there is a urine test where they give you a sweet tasting solution to drink. This drink contains different kinds of sugars which will have molecules of different sizes. The trick here is that some of them are not typically absorbed in the intestines. Kidneys filter your blood and remove waste products and you flush it out in your urine. Analysts will then measure the sugar levels in your urine to see which of the sugars made it through the intestinal wall.
Secondly, there is a blood test. Here they will check your blood to see if there are any signs of gut bacteria present like specific antibodies.
The last 2 tests are quite invasive, so it is safe to assume they will only be performed if the previous tests failed to give any answers.
Thirdly, a tissue biopsy can be taken from your intestinal tissue, which will then be examined in an Ussing chamber. This will allow an electrical current to measure ion transport across the intestinal barrier, which is parallel to water transport.
Lastly, they can make use of confocal microscopy. This is a very enhanced endoscopy exam that gives scientists the opportunity to look at your intestinal lining in high resolution and magnification. They will look for a contrast fluid that was previously injected into your vein to show up in your gut if there is a big enough gap in your intestinal wall.4
Treating leaky gut syndrome
Since leaky gut syndrome is not recognised medically, there is no official or evidence-based treatment.4,5 However, you can treat the symptoms caused by an inflammatory gastrointestinal disease by picking and borrowing from other known gastrointestinal diseases. For example, it is well-established that people with coeliac disease can restore the mucosal barrier of their intestinal lining by stopping their consumption gluten.6 People with Crohn’s disease can reduce their recurrent flares of intestinal inflammation by following a more restrictive but healthier diet and allowing their gut to heal. They can also be prescribed to take medication like steroids or anti-TNF agents.7
On that note, other things that have been found beneficial to reduce inflammation and restore the balance in your gut microbiome are:
- Beginning to removing the food groups that create problems in most diets like gluten, sugar and dairy
- Replacing these foods with foods that are less likely to cause irritation like fermented foods (kefir, yoghurt, sauerkraut, kimchi, etc.)
- To help heal and repair the damage done to the intestinal lining, you can take supplements such as L-glutamine, vitamin A and D, zinc and omega-3 fatty acids
- You need to increase the amount good bacteria in the gut, and this can be through the use of probiotics as you would after having finished a course of antibiotics
- Stay on your new diet to make sure there are more good bacteria living and thriving in your gut than there are bad ones 1,4,8,9
Some research has shown promising results when investigating a specific protein called Zonulin.10 It is described to be the only physiologic modulator of the above mentioned intercellular tight junctions, therefore helping to control the balance between tolerance responses and immune responses, or inflammation.10
Choosing the best foods for leaky gut
As stated before, you can choose to add probiotics and prebiotics to your diet. Probiotics are known to help maintain the health of your gut lining by making sure the wrong bacteria do not get the chance to overtake the good ones. Prebiotics are food for these good bacteria to ensure they keep growing - these are typically plant fibres. You can cook them to make sure the tough fibres will not add to your digestive problems.
Obviously, a healthy well-balanced diet is key to getting healthy and maintaining your gut health. Think lean meats, fatty fish, soups and bone broth, pasta, tofu and nuts, fermented dairy products like yoghurt and kefir, fermented vegetables like kimchi and sauerkraut. Make sure you stay well-hydrated too and drink lots of water.1,4,8,9
What foods to avoid?
It is sensible to keep a food diary to figure out which foods will upset your digestion. People with IBS are usually advised to follow a diet called the low FODMAP diet.
FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. These are a certain kind of carbs which are more difficult for people to digest. The low FODMAP diet will temporarily restrict intake of these carbs to give your gut lining a chance to restore itself and its healthy flora. While you are on this diet, you may be able to figure out which foods are triggering for you once you start introducing them back into your normal diet again.
Since you are trying to make sure your good gut bacteria thrive, make sure to stay away from dietary fats and sugars as they will only encourage the growth of the wrong bacteria. Cut out artificial sugar substitutes (like xylitol and sorbitol), alcohol and caffeine from your diet too.1,4,8,9
When to seek medical attention
Please speak to your doctor if you are suffering from symptoms despite having made changes in your diet. Ongoing inflammation in the intestines can cause malabsorption of important nutrients and could lead to other serious problems.
Summary
Leaky gut, or intestinal hyperpermeability, is a condition that features gaps in the lining of the intestinal walls due to inflammation or an imbalance between the good and bad bacteria in the gut microbiome. Leaky gut syndrome might be popular in alternative medicine, but the medical profession does not seem to recognise it as a condition nor a valid diagnosis. Symptoms associated with intestinal hyperpermeability include: bloating, flatulence, indigestion, abdominal pain, diarrhoea, food sensitivities and intolerances, fatigue, headache, and joint aches. It is advised to include prebiotics and probiotics to your daily diet, as well as reduce gluten, sugar and dairy. Also, lean meats, fatty fish, soups and bone broth, tofu, fermented foods and nuts are healthy choices to help deal with this intestinal issue.
References
- Camilleri, M. (2019). Leaky gut: mechanisms, measurement and clinical implications in humans. Gut, 68(8), 1516–1526. https://doi.org/10.1136/gutjnl-2019-318427
- Fukui, H. (2016). Increased intestinal permeability and decreased barrier function: Does it really influence the risk of inflammation? Inflammatory Intestinal Diseases, 1(3), 135–145. https://doi.org/10.1159/000447252
- Camilleri, M. (2021). What is the leaky gut? Clinical considerations in humans. Current Opinion in Clinical Nutrition and Metabolic Care, 24(5), 473–482. https://doi.org/10.1097/MCO.0000000000000778
- Alexander, C. (2013). Leaky gut syndrome: The invisible thief that steals your health and wellbeing-and what to do about it! Regency Publications.
- Odenwald, M. A., & Turner, J. R. (2017). The intestinal epithelial barrier: a therapeutic target? Nature Reviews. Gastroenterology & Hepatology, 14(1), 9–21. https://doi.org/10.1038/nrgastro.2016.169
- Griffiths, H. (2008). Coeliac disease: Nursing care and management. Wiley-Blackwell.
- Adegbola, S. O., Sahnan, K., Warusavitarne, J., Hart, A., & Tozer, P. (2018). Anti-TNF therapy in Crohn’s disease. International Journal of Molecular Sciences, 19(8), 2244. https://doi.org/10.3390/ijms19082244
- Usuda, H., Okamoto, T., & Wada, K. (2021). Leaky gut: Effect of dietary fiber and fats on microbiome and intestinal barrier. International Journal of Molecular Sciences, 22(14), 7613. https://doi.org/10.3390/ijms22147613
- Norman, A. (2019, October 21). Leaky gut diet: What to eat for better managment. Verywell Health. https://www.verywellhealth.com/leaky-gut-diet-4773680
- Sturgeon, C., & Fasano, A. (2016). Zonulin, a regulator of epithelial and endothelial barrier functions, and its involvement in chronic inflammatory diseases. Tissue Barriers, 4(4), e1251384. https://doi.org/10.1080/21688370.2016.1251384.