Leaky Gut Syndrome: What Happens When the Intestine is Leaky?

Leaky gut syndrome is a condition that involves a permeable intestinal mucosa. This can not only lead to a variety of symptoms, but is also associated with a number of diseases.

What is Leaky Gut Syndrome?

Strictly speaking, the term “leaky gut” refers to the mucous membrane of the small intestine, which has tiny gaps in the case of leaky gut syndrome. These gaps result in the mucosa no longer being able to fully perform its protective barrier function (permeability).

Small Intestinal Mucosa: A Small Marvel

The mucosa of the small intestine (lat.: mucosa) is a small, highly complex and sensitive marvel with an ingenious anatomical fine structure. Its tasks are, firstly, to absorb all the important nutrients that enter the small intestine through food. And secondly, it fends off unwanted intruders. In short, the mucous membrane of the small intestine decides what is allowed to pass through the intestinal wall into the bloodstream and what is not.

The intestinal mucosa must be nourished well and free of inflammation in order to perform its tasks to the best of its ability.

Gaps: Access for Undesirable Substances

In a healthy intestine, the cells of the mucosa form a tight cellular network that defends against unwanted substances. The individual cells are sealed by tight junctions. If there are gaps in these tight junctions, this is called leaky gut syndrome. Unwanted substances that normally migrate further into the colon can then pass through the mucosa and straight into the bloodstream. When the substances pass over, the intestine activates its immune system, which causes the intestinal mucosa to become inflamed as a protective reaction. This, in turn, fires up the leaky gut syndrome even more.

In leaky gut syndrome, unwanted substances enter the bloodstream – these could be toxins, undigested food components, pathogens, and metabolic products.

The following figure shows a magnified version of the intricately folded mucosa of the small intestine step by step- starting from the transverse section of the small intestine to the microvilli, and showing the permeability (leaky gut).

Leaky gut syndrome

How Does Leaky Gut Syndrome Develop?

In most cases, leaky gut syndrome is caused by the interaction of a handful of factors. Basically, these include any disruptive factors that stress the protective systems of the small intestine (the mucus layer, mucous membrane, and intestinal flora), bring them out of balance, or cause inflammation.

Factors Contributing to the Development of Leaky Gut Syndrome:

  • Pro-inflammatory diet (especially high sugar consumption (1)
  • High alcohol consumption (2)
  • Consumption of foods that are incompatible with each other
  • A diet high in lectin
  • Painkillers (“non-steroidal, anti-inflammatory drugs” like ASA, ibuprofen, or diclofenac (3)
  • Antibiotics (4)
  • Toxins: Nicotine, heavy metals, environmental pollutants
  • Psychological stress (5)
  • Chronic inflammatory bowel diseases, like Crohn’s disease, ulcerative colitis (6)
  • Small intestine colonization SIBO (7)
  • Bacteria and viruses that cause diarrhea, e.g. salmonella or norovirus (8)
  • An increased Candida infestation in the intestine (9)

A natural and healthy lifestyle prevents leaky gut syndrome: A plant-based and gut-friendly diet, relaxation, and avoidance of environmental toxins and medications.

What Are the Symptoms of Leaky Gut Syndrome?

Because the symptoms are very non-specific and many of them are not directly related to the intestines, it can often be difficult to recognize leaky gut syndrome.

The following symptoms may be caused by leaky gut syndrome:

  • Susceptibility to infections
  • Digestive problems, like diarrhea, flatulence, abdominal pain
  • Food intolerances
  • Allergies
  • Asthma
  • Skin problems, like eczema, neurodermatitis, rashes
  • Migraine
  • Joint and muscle pain
  • Tiredness, fatigue
  • Nervousness
  • Mood swings, to the point of depression
  • Development of deficiency symptoms due to poorer nutrient absorption or increased nutrient losses, like zinc and iron deficiency

People affected by leaky gut syndrome often have a handful of symptoms, which frequently include digestive problems. With the help of a stool sample and also blood tests, a doctor or alternative practitioner who specializes in this can find out whether leaky gut syndrome is a factor.

Are you interessted in gaining a comprehensive understanding of the health benefits of a plant-based diet? Download the curriculum for our Holistic Nutrition Coach training program.

Curriculum Your Nutrition Academy

Which Diseases Can Leaky Gut Syndrome Promote?

While permeable mucosa is also a recognized condition in conventional medicine, many are still skeptical of its negative effects outside of the gut.

Studies point to correlations

Science is discovering more and more significant connections between leaky gut syndrome and various diseases. Whether leaky gut syndrome actually plays a triggering role in this, and how large a role, has not yet been adequately clarified.

However, one thing is certain – people with the following diseases are also affected with striking frequency by leaky gut syndrome:

  • Autoimmune diseases in general (10), including Hashimoto’s thyroiditis, rheumatoid arthritis, ankylosing spondylitis, and sarcoidosis
  • Inflammatory bowel diseases like Crohn’s disease and ulcerative colitis
  • Multiple sclerosis (11)
  • Celiac disease (12) (gluten intolerance)
  • Type 1 diabetes (13)
  • Autism (14)
  • Parkinson’s disease (15)
  • Irritable bowel syndrome (16)

The good news is that leaky gut syndrome is easily treatable and, as the gut heals, related symptoms disappear. Additionally, the possibility of developing diseases begins to decrease.

Nutrition for Leaky Gut Syndrome

Nutrition is an important pillar in leaky gut therapy. Basically, it’s all about eliminating irritating triggers and focusing more on healing foods.

Identify Triggers

A permeable gut can promote a number of intolerances. While some people react to histamine-containing foods, others get discomfort from too much fructose. A dietary protocol can help in finding out the individual triggers in order to avoid them, and thus spare the intestine.

However, it’s also been shown that most people who suffer from a leaky gut benefit from avoiding certain foods.

Avoid these foods

  • Animal-based foods, especially the ones containing lactose, like milk and dairy products
  • Cereal products containing gluten, like wheat, rye, spelt, etc.
  • Industrial sugar and white flour products
  • Alcohol
  • Lectins and phytic acid – it’s best to soak nuts and seeds, as well as soak, cook, or sprout legumes
  • Industrially processed foods with additives, like preservatives and flavor enhancers
  • Processed products that contain trans fatty acids, e.g. many baked goods, sweets, fried foods

Prefer natural foods

  • Fresh, organically grown vegetables and fruits, preferably seasonal and local
  • Vegetables and leafy greens rich in bitter substances, like wild herbs, chicory, artichoke, and endive
  • Dietary fiber serves as food for intestinal bacteria and is converted into short-chain fatty acids during “digestion.” These nourish the intestinal mucosa and counteract leaky gut.
  • Probiotic foods like fermented juices and fermented vegetables support the balance of the intestinal flora.
  • Turmeric, broccoli, blueberries, and green tea have a particularly anti-inflammatory effect – you can find detailed information on anti-inflammatory nutrition and other valuable foods here.
  • Omega-3 fatty acids, from linseed oil, soaked walnuts, hemp seeds, or flax seeds, for example, support the mucous membrane during regeneration.
  • Licorice root, marshmallow root tea, and aloe vera juice help with their mucus-forming properties.
  • Steamed vegetables are easier to digest than raw vegetables when you have a leaky gut. So it makes sense to eat cooked vegetables in the evening.
  • Not Vegan: Bone broth, and the amino acids glycine, proline, and glutamine that it contains, has a nourishing effect on the intestinal mucosa.


Eating to support a healthy intestine means first and foremost leaving out what’s unhealthy, and protecting the body from the countless microbiome-damaging substances within industrially processed foods. An anti-inflammatory diet rich in nutrients, fiber, and bitter substances supports the intestines and nourishes the intestinal flora and mucosa.


Would you like to join our unique, based on nutritional sciences and practice-oriented training program for gaining a high level of health?

We are more than happy to inform you about our training program on our website

Your Nutrition Academy Training Program

Ulrike Eder (Author)

Ulrike is a naturopath, Holistic Nutrition Coach, Hippocrates Lifestyle Medicine Coach and phytotherapist. Together with her husband, Jürgen, she leads the Holistic Nutrition Coach training program of Your Nutrition Academy.



Submit a Comment

Your email address will not be published. Required fields are marked *