With this, immunologists have made strides in understanding how to try to prevent autoimmune diseases, and one area in particular that has gained increased attention is the gut. Here, we’ll take a closer look at how the gut might play a role in autoimmune diseases and see how you can maintain a healthy gut in order to try to prevent those diseases from flourishing.
Leaky gut and autoimmune diseases
The expression “leaky gut” has long been bandied around on the fringes of medicine, being blamed for everything from brain fog to weight gain. But although mainstream medics have usually dismissed the idea as a bit cranky, opinion has started to shift in the face of increasing evidence that autoimmune diseases are indeed linked to increased intestinal permeability.1
But what exactly is a leaky gut? To understand this, we need to consider what a healthy gut looks like. Our small intestine, the surface of which when stretched out is about the equivalent size of a tennis court, has a lining that, when working properly, forms a tight barrier that controls what gets absorbed into the bloodstream. When functioning healthily, this would include fully digested protein (amino acids), broken down fats, and carbohydrates (simple sugars), as well as vitamins and minerals.
However, when the functioning unhealthily, the gut lining itself will has junctions between the cells, allowing improperly digested food, toxins and bad bacteria to penetrate the tissues beneath. This is bad because when substances such as partially digested proteins cross into the bloodstream, the immune system may recognise them as the enemy and gun into action. This can lead to inflammation and changes in the balance of gut bacteria, ultimately leading to a higher risk of autoimmune diseases.
What causes your gut to be too permeable?
How exactly does the small intestine become damaged? There are a few theories that try to explain this, but here are the three main ones:
An exaggerated immune response to foreign particles often has a strong genetic element.2 It’s thought that in genetically susceptible people the overactive immune system may activate several pathways involved in intestinal permeability.
There’s plenty of evidence that the standard western diet, which is low in fibre, but high in sugar and saturated fats, may lead to increased permeability of the gut.3 This is thought to happen by the diet promoting inflammation and unhealthy changes in the balance of bacteria in your gut. If you’re a heavy drinker, you might also become susceptible to increasing gut permeability.4
There are a number of more general factors that may play a role and this is particularly true for certain medications.5 Drugs that may cause a problem can include antibiotics, particularly if you’ve been prescribed several courses, in addition to non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and diclofenac, which can damage the gut wall.
Bolstering your gut barrier
The bottom line is that our modern lifestyle seems to be a major contributor to leaky gut. This is positive, though, as it means that it’s largely preventable through some simple changes. What can you do to bolster your gut health and help to prevent your body from autoimmune disease?
First, it's worth mentioning that there are a lot of quite extreme claims made on the internet for diets and supplements that supposedly restore the intestinal barrier and that suggests that healing your leaky gut will cure things like eczema, psoriasis, and inflammatory bowel disease. Unfortunately, the current research suggests that it’s far more complex than that.
There are a number of general rules and tips to follow that can help to maintain a healthier gut, and potentially strengthen yourself against the threat of autoimmune diseases:
Try a gluten free trial: although only a small percentage of people are gluten intolerant, you may be one of them if you have an autoimmune disease. Under the supervision of a nutritionist, it can be at least useful to trial a gluten-free diet for a month or so to see what happens to your symptoms. Be sure to replace wheat with alternative high fibre grains and make sure you don’t remove gluten if you think you may actually have coeliac disease, as to obtain an accurate diagnosis of this condition requires you to be consuming gluten at the time you are tested for it. It’s important do this under the supervision of a nutritionist to avoid nutritional deficiencies and to go back to a normal diet if there isn’t any improvement.
- Cut out highly processed foods: diets high in calorie-dense fatty foods, fast releasing carbohydrates are drivers of inflammation, weight gain, and metabolic disease. But they also influence and change the balance of your gut bacteria, which could affect how leaky your gut is, at least theoretically. As a general rule, aim to fill half of your plate at every meal with fruit and vegetables.
- Take a quality probiotic: it’s thought that the balance of bacteria in the gut can influence intestinal permeability, so it’s worth taking a probiotic to tip your gut microbiota in a healthier direction.6 It’s not yet understood exactly what strains or dosage are beneficial for humans, but a good guide is to choose one that provides a minimum of five billion live bacteria and researched strains, such as Lactobacillus acidophilus, Lactobacillus plantarum and Bifidobacterium lactis.
- Vitamin D: this vitamin is also potentially useful to help maintain a healthy gut, with some evidence suggesting it protects the intestinal lining, especially among those with Inflammatory Bowel Disease (IBD), though the role of the vitamin is still unclear.6
Ultimately, if you want to tackle issues that arise from autoimmune diseases the first place to start is with what you eat and drink, in addition to eliminating any negative lifestyle factors, like smoking or drinking to excess. This may not only help to keep your gut in tip-top shape, but it can also help to take you that one step further in tackling the problem of autoimmune diseases.
If you'd like to read more about the benefits of keeping a healthy gut, as well as find more information on how you can promote good gut health, then head over to our Gut Health advice centre.
1Mu, Q., Kirby, J., Reilly, C. M., and Luo, X. M. (2017). Leaky Gut As a Danger Signal for Autoimmune Diseases. Frontiers in Immunology, 08(598).
2Fassano, A. (2012). Leaky gut and autoimmune diseases. Clinical Reviews in Allergy & Immunology, 42(01).
3Bischoff, S. C., Barbara, G., Buurman, W., et al. (2014). Intestinal permeability - a new target for disease prevention and therapy. BMC Gastroenterology, 14(189).
4Massey, V. L., and Arteel, G. E. (2012). Acute Alcohol-Induced Liver Injury. Frontiers in Physiology, 03(193).
5de Punder, K., and Pruimboom, L. (2015). Stress Induces Endotoxemia and Low-Grade Inflammation by Increasing Barrier Permeability. Frontiers in Immunology, 06(223).
6Michielan, A., and D’incà, R. (2015). Intestinal Permeability in Inflammatory Bowel Disease: Pathogenesis, Clinical Evaluation, and Therapy of Leaky Gut. Mediators of Inflammation, 05.