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  • Writer's pictureOrsolya Szathmari

Understanding Increased Intestinal Permeability: The Impact on Your Health and Wellness

Understanding Intestinal Hyper-Permeability

Intestinal hyper-permeability, often referred to as "leaky gut," is a condition where the lining of the small intestine becomes damaged, allowing undigested food particles, toxins, and pathogens to "leak" through the intestines into the bloodstream. The intestinal wall is a semipermeable barrier that plays a crucial dual role: it facilitates the absorption of nutrients and water while preventing harmful substances from entering the body. This barrier function is maintained by tight junctions between epithelial cells, which act as the first line of defense against pathogens. When these tight junctions become compromised, various unwanted substances can pass into the bloodstream, potentially leading to inflammation and a host of health issues.

Causes of Increased Intestinal Permeability

Intestinal hyper-permeability can be triggered by several dietary and lifestyle factors.

Different foods, pathogens, smoking, alcohol and stress might play a role.

Certain dietary components, particularly lectins, are known to damage the intestinal lining. Lectins are anti-nutrients found in many plant foods such as legumes, nightshades, certain grains, and vegetables. They can disrupt the tight junctions in the intestinal wall, leading to increased permeability.

Other dietary factors that can contribute to leaky gut include grains, cereals, nuts, seeds, dairy products, vegetable oils, alcohol, coffee, tea, medications, and most dietary supplements. These substances can irritate the gut lining and exacerbate intestinal permeability.

Health Consequences of Intestinal Hyper-Permeability

Increased intestinal permeability is associated with a range of chronic diseases. Conditions such as irritable bowel syndrome (IBS), Crohn’s disease, ulcerative colitis, celiac disease, chronic liver disease, diabetes, food allergies and sensitivities, polycystic ovarian syndrome, and various autoimmune disorders have all been linked to leaky gut. The presence of a hyper-permeable gut can lead to systemic inflammation and exacerbate these conditions.

Conversely, maintaining low intestinal permeability is associated with reduced inflammation and improvements in many health conditions. A healthy intestinal barrier supports overall wellness by preventing the infiltration of harmful substances into the bloodstream.

Symptoms of Intestinal Hyper-Permeability

Common symptoms associated with leaky gut include bloating, diarrhea, constipation, headaches, skin problems (such as rashes, eczema, and acne), nutritional deficiencies, brain fog, chronic inflammation, hormonal imbalances, chronic pain, chronic fatigue syndrome, fibromyalgia, obesity, and various mental health conditions. These symptoms arise due to the body's reaction to foreign particles entering the bloodstream, triggering immune responses and inflammation.


The process of digestion begins with the breakdown of proteins into peptides and then into amino acids. Ideally, only amino acids should be absorbed by the gut. However, this process can be disrupted by various factors such as natural plant toxins like lectins, food additives, chemicals, drugs, or even a lack of digestive enzymes. When the digestive process is impaired, partially undigested foods, proteins, and peptides reach the gut, leading to a cascade of problems.

These proteins and peptides have the ability to modify the gut microbiome. This process will lead to increased endogenous lipopolysaccharides (LPS) production. LPS are endotoxins produced by gut bacteria, that cause inflammation and damage the tight junctions between intestinal cells. This damage increases intestinal permeability, allowing partially digested proteins to cross the mucosal barrier.

Once these proteins penetrate the mucosal layer, they can migrate into regional lymph nodes and the bloodstream. There, they may bind to tissues, triggering an immune response. The immune system perceives these proteins as foreign invaders and attack them, which can lead to autoimmunity.

A significant portion of our immune system resides in the gut, making it a critical interface between our external environment and internal anatomy. This connection underscores the importance of gut health in maintaining overall immune system balance and preventing autoimmune diseases.

Strategies to Improve Gut Health

Improving gut health involves avoiding foods and substances that damage the gut lining while incorporating nutrients that support healing. One dietary intervention that has shown promise in reversing intestinal hyper-permeability is the Paleolithic-Ketogenic Diet. This diet focuses on consuming high quality red meat and animal fats and avoiding plant foods to help reduce inflammation and promote gut healing.

Other interventions, such as pre- and probiotic supplementation, colostrum, the FODMAP diet, and the popular Paleolithic diet, have shown varying degrees of success. The key to improving gut health lies in avoiding harmful toxins, achieving ketosis, and obtaining essential nutrients from the diet.

Beneficial Effects of Nutrients on Intestinal Integrity

A synergistic combination of vitamins, minerals, and the right proportion of macronutrients from bioavailable sources is essential for maintaining intestinal integrity. Vitamins A and D are particularly important in regulating gastrointestinal homeostasis. These vitamins support the integrity of the intestinal epithelial barrier, modulate the immune system, and influence the gut microbiota. Notably, these vitamins are found in animal foods, underscoring the importance of a nutrient-dense diet in maintaining gut health.


Currently, there is no medication that can reverse pathological intestinal permeability. The most effective method for restoring the epithelial barrier is through dietary interventions, particularly those that emphasize a high-fat, animal-based diet. By focusing on nutrient-dense foods and avoiding substances that harm the gut lining, individuals can improve their intestinal health and potentially alleviate the symptoms associated with leaky gut.


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  6. Favourable effects of consuming a Paleolithic-type diet on characteristics of the metabolic syndrome: a randomized controlled pilot-study

  7. The intestinal barrier: a fundamental role in health and disease

  8. Reframing Nutritional Microbiota Studies To Reflect an Inherent Metabolic Flexibility of the Human Gut: a Narrative Review Focusing on High-Fat Diets

  9. The intestinal barrier: a fundamental role in health and disease


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