skeleton model with gastrointestinal organs and a text bubble saying how does leaky gut start?

Leaky gut, or intestinal permeability, describes the loss of intestinal barrier function where things leak through that shouldn’t.

Our intestinal tract is complex – it’s responsible for the digestion and absorption of the nutrients we consume, but it’s also exposed to food antigens, commensal bacteria, pathogens and toxins [1]. We have a specialized barrier to selectively block certain things, but absorb others.

A quick review of leaky gut is seen in the video below. Click here to learn more about leaky gut.

Causes of Leaky Gut

Diet Induced Leaky Gut

There are many dietary influences known to cause leaky gut or intestinal permeability. The exact mechanisms aren’t always known, but we know there is a cause and effect relationship.

  • Low Fiber: triggers mucus-degrading bacteria [2]
  • Low Vitamin D: vitamin D is recognized to protect against intestinal permeability by inducing the expression of two proteins which keep things intact. Vitamin D can come from sunlight, but also certain foods.
  • Western-style diet
    • Diets excessively high in fats, carbs and proteins are associated with excess amounts of circulating bacterial wall lipopolysaccharide. This is associated with systemic inflammation as well [3].
  • High Fructose: diets high in fructose are also associated with loss of tight junction proteins occludin and ZO-1 [4]. This is mainly from high fructose corn syrup, and not fructose from fruit.
  • Hyperglycemia (high blood sugar): drives intestinal barrier dysfunction and risk of infection [5] by affecting the integrity of tight junctions and intestinal and splenic immune system. High blood sugar also increases infection [5], which you’ll see below is another cause of leaky gut.
  • Increased use of industrial food processing and food additives: increased intestinal permeability seen with additives including sugar, metal oxide nanoparticles, surfactants and sodium chloride [6]
  • Alcohol consumption: chronic consumption is known to lead to intestinal barrier dysfunction, alterations in quality and quantity of gut microbiota, lipopolysaccharide translocation, and alcoholic liver disease [1]. Most of the changes pertaining to intestinal permeability arise from changes to gut bacteria.


As we age, certain gut changes are inevitable, including changes to gut bacteria. These age-related have been shown to result in increased intestinal permeability, systemic inflammation and immune dysfunction [7]. Luckily supplementation and proper medical assessment allows for proper intervention.

Stress-Induced Leaky Gut

The gut and brain have very strong connections. During times of stress, we see reduced gut healing. If the gut doesn’t heal properly, intestinal permeability or leaky gut may ensue.

Major stressors, such as burns, are well documented to have profound changes to gut permeability [1].


Various alterations to the gut microbiome are associated with leaky gut/intestinal permeability. We’ve seen associations between leaky gut and protozoan infections [8], H. pylori, and a wide range of other intestinal infections [1]. Certain bacteria are known to increase leaky gut by disrupting connective proteins called TJ protein ZO-1 [1].

Even SIBO, which is an overgrowth of bacteria (good or bad) in the small bowel, has been shown to induce leaky gut.

Oxidative Stress / Hypoxia / pH Alterations

A constant supply of oxygen is crucial for every cell in our body, including our gut. Disturbed oxygen supply can affect normal gut balance. Oxidative stress is damage induced by oxygen free radicals, and hypoxia is diminished oxygen supply. Basically, reduced oxygen supply or oxidative stress can both lead to leaky gut. The degree of hypoxia found in the intestinal mucosa is exacerbated significantly in inflammatory bowel disease, leading to a more extensive and severe hypoxia, and subsequently leaky gut [9] [10]. pH alterations can come about when there is oxidative stress or reduced oxygen. When the pH changes, this too can lead to leaky gut [10].

Proinflammatory Cytokines

Sometimes due to infections or dysbiosis, inflammation is its own driving force behind intestinal permeability [11] [10].

graphic with digestive system showing the mechanisms of leaky gut, including diet, stress, alcohol, infections, dysbiosis, oxidative stress, inflammation, hypoxia, and altered gut pH


Understanding the multitude of causative factors behind leaky gut is valuable. Since many of these are lifestyle factors (such as diet), simple changes can be made to have profound effects. Also, by understanding how leaky gut arises, we can supplement appropriately. Several nutrients may be helpful for intestinal permeability or leaky gut; be sure to talk to your naturopath to learn how to do it safely.


Interested in learning more?

Read on in our series of articles on Gut Health!

About the Author - Dr. Johann de Chickera

man facing camera

Dr. Johann is a fully licensed Naturopathic Doctor. His approach emphasizes the importance of living a healthy lifestyle and improving one’s health naturally. Dr. Johann obtained a Doctor of Naturopathy at the Canadian College of Naturopathic Medicine (CCNM). Education at CCNM is a vigorous four years, with a curriculum involving biomedical sciences, physical diagnosis, clinical nutrition, traditional Chinese medicine and acupuncture, botanical (herbal) medicine, physical medicine, homeopathy and lifestyle management.

While Dr. Johann has a general practice, he focuses on fertility, hormonal imbalances, gut health, and autoimmune disease.

To book in please call us at (519) 442-2206 or click here.

Leave a Comment