What is meant by leaky gut syndrome?

When the protective function of the intestinal wall is impaired, it has serious consequences for our body. This condition, known in naturopathy as leaky gut syndrome, plays a particularly important role in the English-speaking health sector.

How does nutrient absorption in the intestines work in healthy people?

Our digestive tract is completely lined with a layer of mucous membrane (mucosa). To give you an idea of its enormous size, here is a comparison: At 372 square meters, the mucous membrane of our intestines has an area almost twice as large as a tennis court.

The mucosal tissue is extremely dense, which is why intestinal contents cannot pass through it on their own. In this way, our body prevents dangerous microorganisms and allergy-causing substances (allergens) from crossing the intestinal wall and entering the body.¹

After digestion, most food components are absorbed through the intestinal villi in the small intestine. This process, known as absorption, is largely active: With the help of transport proteins, our body moves carbohydrates, proteins, fats, vitamins, and other micronutrients through the intestinal mucosa into the lymphatic and circulatory systems.²

Water, electrolytes, and micronutrients such as vitamin B12 can pass through the intestinal wall at the so-called tight junctions (in German: tight connections).

Tight junctions are small gaps located between the individual cells of the intestinal mucosa. They are normally completely impermeable to food components, bacteria, and allergens.

Numerous scientific studies indicate that, in certain diseases, the sealing at the tight junctions no longer functions properly. This leads to increased permeability (permeability) of the intestinal mucosa, which is also referred to in English as leaky gut.

What exactly is leaky gut syndrome?

The term leaky gut syndrome is used mainly by practitioners who apply naturopathic treatment methods. In recent years, groundbreaking research findings have led an increasing number of scientists and doctors to recognize increased intestinal permeability as a possible cause of disease.^3-5

Nevertheless, you may be met with an incredulous furrowed brow when you bring up the topic of leaky gut with your general practitioner.

What do naturopaths and doctors with additional qualifications in naturopathic medicine mean by leaky gut syndrome?

When the tight junctions in the intestinal wall become enlarged due to various factors, bacteria, allergens, or other harmful substances can pass through these sites by diffusion into the bloodstream. This phenomenon is known as leaky gut.

As a result of increased intestinal mucosal permeability, the body activates the immune system. A localized inflammation often develops initially and spreads to other regions of the body over time.

The initial symptoms of leaky gut syndrome include:⁴

• Digestive problems
• Bloating
• Fatigue
• Food intolerance, allergy
• Skin problems

Why do some people develop a leaky gut?

The exact cause of leaky gut syndrome has not yet been clarified. It has long been known that the protein zonulin regulates intestinal mucosal permeability.⁶

When zonulin is activated in people with a corresponding sensitivity, it can lead to increased intestinal permeability. Italian scientist Prof. Dr. Alessio Fasano—currently working at the University of Maryland School of Medicine in Baltimore—identified two factors that trigger the release of zonulin: certain intestinal bacteria and gluten.⁷

According to current scientific studies, further factors could also play a role in the development of leaky gut syndrome:

• Intestinal dysbiosis (dysbiosis)⁸
• Consumption of fructose and other carbohydrates (sugar)⁹
• Long-term use of certain painkillers (nonsteroidal anti-inflammatory drugs, NSAIDs)¹⁰
• An inadequate supply of vitamin A, vitamin D, and zinc^{10, 11-13}
• Regular heavy alcohol consumption¹⁴
• Chronic inflammation¹⁵
• Excessive stress¹⁶
• Intestinal colonization with Candida fungi¹⁷

What are the possible consequences of leaky gut syndrome?

Current scientific research shows a connection between increased intestinal permeability and various chronic diseases.⁶

1. Irritable bowel syndrome

Doctors use the term irritable bowel syndrome (irritable colon) to describe a disorder of intestinal function that is often accompanied by constipation, bloating, diarrhea, or abdominal pain. In clinical studies, scientists at McMaster University in Hamilton, Canada, and the world-renowned Mayo Clinic demonstrated that people with irritable bowel syndrome have increased intestinal permeability.^18,19

Leaky gut syndrome is particularly pronounced when diarrhea is the predominant symptom.²¹ In medicine, this variant of irritable bowel syndrome is called the diarrhea-predominant type.²⁰

2. Crohn’s disease

Crohn’s disease is a chronic inflammatory bowel disease that can affect any part of the digestive tract. In 2012, a research team from the University of Alberta in Edmonton, Canada, demonstrated that intestinal barrier permeability is significantly increased in patients with Crohn’s disease.²¹

Leaky gut can be detected not only in affected individuals. Close first-degree relatives also often have increased intestinal mucosal permeability, even when they do not have Crohn’s disease.²²

This discovery suggests that inherited intestinal permeability could be one of the main causes of the development of Crohn’s disease..²³

3. Celiac disease

The term celiac disease describes an autoimmune disease of the gastrointestinal tract characterized by gluten intolerance. American researchers at the University of Maryland in Baltimore found that patients with celiac disease have a more permeable intestinal wall than healthy individuals.²⁴

Immediately after consuming gluten-containing foods, intestinal permeability increases significantly in affected individuals.²⁵

4. Food allergy

Clinical studies by scientists from the Hospital Center Regional University in the French overseas department of Guadeloupe and the University of Bari Medical School in Bari, Italy, show that patients with an allergy to certain foods often also have increased intestinal mucosal permeability.^26,27

With a leaky gut, food components cross the intestinal barrier and enter the body. This process triggers an immune response that doctors diagnose as a food allergy. In a 2009 review, American scientists from the University of Cincinnati reached the following conclusion:

“Clinical and experimental evidence shows that impaired intestinal barrier function is an important factor contributing to a predisposition to diseases such as food allergies, inflammatory bowel disease, and celiac disease.”²⁸

5. Type 1 diabetes mellitus

Several indications suggest that leaky gut plays a significant role in the development of type 1 diabetes.³

This disease is considered to be caused by the destruction of the insulin-producing beta cells in the pancreas by the immune system itself. Finnish and Dutch scientists see a direct connection between the autoimmune reaction and certain substances that leak from the intestines in leaky gut syndrome.^{29, 30}

As part of a clinical study with 339 participants, an American research group from the University of Maryland School of Medicine in Baltimore found that 42 percent of people with type 1 diabetes had elevated zonulin levels. Among patients with prediabetes, the so-called prediabetes, as many as 70 percent had excessively high zonulin levels.³¹

As mentioned above, zonulin regulates the permeability of the intestinal wall. A significant increase in this biomolecule therefore indicates leaky gut syndrome.

What you can do about a leaky gut

Increased intestinal permeability is not an unavoidable fate: All measures that promote gut health also counteract the development of leaky gut.

If you suspect that you or your child has an overly permeable intestinal wall, there are several things you can do about it. The following measures have proven beneficial for improving the environment in your gut and properly stimulating your gut flora:³²

If you use a medication such as aspirin, diclofenac, ibuprofen, or another nonsteroidal anti-inflammatory drug on a long-term basis, please ask your family doctor for a different medication. As already indicated above, these active ingredients promote the development of leaky gut syndrome.

References