Suspect You Have A "Leaky Gut"? Causes, Symptoms & Top Treatments

Ancient medical traditions, ranging from Ayurveda to the teachings of Hippocrates, have long recognized the central role that the gut plays in overall health. However, it's only recently that Western medicine has acknowledged gut barrier dysfunction as a critical factor not only in digestive health but also in chronic allergic, inflammatory, and autoimmune diseases.

As the largest interface between the body and the environment, the gut barrier consists of the mucus layer, gut microbiome, epithelial cells lining the gastrointestinal tract, and immune cells. Therefore, what we consume represents our greatest environmental exposure1. The vital function of the gut barrier is to selectively absorb nutrients while preventing the entry of harmful substances into the bloodstream and surrounding tissues.

Disruptions in the gut barrier, caused by factors such as low-fiber diets, dysbiosis2, antibiotics, and alcohol, can lead to a compromised ability to selectively filter harmful substances.

"Leaky gut" is a colloquial term that refers to increased intestinal permeability, where tight junctions between the epithelial cells lining the gut become less secure. Tight junctions serve as glue between the cells of the gut barrier lining and thus play a crucial role in creating a strong connection between the cells of the gut lining.

However, in the case of leaky gut, these junctions may become less secure, resulting in larger gaps or leaks in the gut barrier whereby undesirable or inflammatory substances can pass through into the deeper tissues or bloodstream.

While there is scientific evidence supporting the role of intestinal permeability in certain conditions, the term "leaky gut" is often used more broadly and may not yet have a universally accepted definition in the medical community. Some researchers prefer the term "intestinal permeability" to describe the phenomenon more precisely.

Although there is insufficient definitive evidence to classify so-called leaky gut as an independent disease, significant ongoing research indicates that intestinal hyperpermeability occurs before the onset of some chronic disorders4. Studies indicate that those who have asymptomatic intestinal permeability have a higher likelihood of developing illnesses such as Crohn's disease in the future5, for example.

Various possible risk factors6 are linked to gut barrier dysfunction, including food choices (such as the Western diet), lifestyle variables such as chronic stress, poor sleep, certain pharmaceutical drugs, inflammation, and environmental exposures. 

For example, consuming a diet high in processed foods and sugars and low in fiber7 can contribute to gut inflammation and permeability. Disruption of the balance between beneficial and harmful bacteria in the gut, or dysbiosis, can also compromise the integrity of the intestinal barrier.

The stereotypical Western diet is low in fiber and high in ultra-processed foods.

A diet lacking in fiber diminishes the thickness of the protective mucus layer lining9 the gastrointestinal tract, resulting in heightened intestinal permeability.

Individuals who consume a Western diet and have a daily fiber intake of less than 15 grams suffer changes in their gut flora10 and a decrease in the generation of short-chain fatty acids, which are important health-promoting microbial end products of fermentation. This, in turn, has an impact on mucus formation and the control of tight junctions. A diet low in fiber not only decreases the thickness of mucus but also alters the way the gut microbiota processes nutrients, resulting in the breakdown of the protective mucus layer in the gut and, occasionally, an increase in the population of microorganisms that can degrade mucus.

Highly processed foods frequently contain various chemicals, preservatives, sweeteners, and other chemical substances. Several studies suggest that these chemicals may potentially influence the health and permeability of the gut11 too. Furthermore, certain chemicals included in many processed meals are linked to impairments in the integrity of the intestinal barrier12.

In addition, emulsifiers are compounds that stabilize and homogenize mixes of liquids that are usually unable to combine, such as oil and water. They are frequently found in processed foods and baked products. Processed foods often include these substances to enhance texture and artificially extend shelf life, resulting in increased difficulty in digestion and additional stress on the gastrointestinal system. Several studies have found13 a correlation between consuming a diet rich in processed foods containing emulsifiers and experiencing adverse effects on metabolic health and inflammation.

There's a complex interplay between the gut microbiota and gut barrier function. Gut dysbiosis, which refers to an imbalance of bacteria in our gut, has the potential to disturb the function of the intestinal barrier. The generation of metabolites by our gut microbiota also has a direct impact on both immune responses and the function of the gut barrier14.

Research indicates that specific microbial metabolites and types of microorganisms15 have the capacity to enhance the permeability of the gut. Some studies suggest that certain microbes can influence the expression of tight junction proteins16, which are crucial for maintaining the integrity of the gut barrier. Disruptions to tight junctions can lead to increased intestinal permeability. Zonulin, a protein that modulates tight junctions, has been identified as a key player in regulating intestinal permeability17. Elevated levels of zonulin are associated with increased gut permeability18.

Scientific consensus supports consuming a diet rich in whole foods (vegetables, fruits, whole grains, nuts, seeds), fiber, and antioxidants to promote a healthy gut environment and reduce inflammation19.

Include gut-supportive foods like fermented foods (kimchi, sauerkraut, yogurt, miso), collagen supplements, and bone broth.