What is the leaky gut syndrome?

With the Leaky gut Syndrome, the intestinal wall is no longer properly intact, which means that pro-inflammatory substances enter the organism. The disease often develops insidiously via primary diseases. The actual protective mechanisms of the intestinal mucosa can no longer recognise what should and should not be absorbed, which means that pro-inflammatory substances enter the body. Fortunately, however, Leaky gut can be cured by dietary adjustments - because the intestinal mucosa is constantly renewing itself.


In brief: What is the Leaky gut Syndrome?    

The intestinal mucosa has a huge surface, which contains small passages for the nutrients to be absorbed into the bloodstream. In order to ensure that only the desired substances actually get there, there are barriers at the passages. These ensure that no potential promoters of inflammation and disease enter the organism. It is possible, however, that the intestinal barriers are damaged by various influences and that the intestine thus becomes permeable to foreign substances. It is therefore a leaky intestine as it is commonly known.

A short digression to the digestive tract

Digestion begins in the mouth: we break down food with our teeth and our saliva is mixed with enzymes that partially break down more complex carbohydrates, for example. Fatty acids are also predigested and the probiotic bacteria contained in the oral flora protect us from pathogens1.   
The mixture then passes through the oesophagus into the stomach, where the high acidity destroys any remaining pathogens and important enzymes such as pepsin break down the proteins.
In the small intestine all fatty acids are then emulsified with bile and carbohydrates are completely broken down into simple sugars. Indigestible carbohydrates, known as dietary fibres, are further released into the large intestine where they nourish probiotic intestinal bacteria.

Proteins are also broken down in the small intestine into smaller units, the amino acids. This leaves fatty acids, amino acids and simple sugars. These are ultimately the forms of macronutrients that our intestinal mucosa can absorb2.       


The intestinal mucosa: Protective shield and bridge for the absorption of nutrients at the same time

The small intestine, or rather its inner surface, has a total area of more than 300m2, which corresponds to the size of a tennis court. Its special shape – consisting of microscopically small protrusions – makes this possible. In the vernacular these folds are called intestinal villi, or the short biological medical term for them would be villi.

Each of these intestinal villi contains even smaller protuberances, which are also called brush border because of their shape. The brush border is virtually the surface of the epithelial cells on the inner side of the intestine, these cells are responsible for the transport or absorption of nutrients into the blood2. The epithelial cells adhere to each other, their contact points are called tight junctions.
The tight junctions serve on the one hand mechanically by connecting and stabilizing the cells. On the other hand they make themselves useful as a barrier, so that no parasites and harmful substances can enter the bloodstream3. Another protective shield is located directly in front of the intestinal wall, because it is surrounded by a special layer of mucus. This consists of special antibodies that prevent the penetration of pathogens. In addition, in a healthy intestine there is a probiotic intestinal flora, which contains numerous good intestinal bacteria that destroy pathogenic microorganisms4.  

In simple terms, the following could be said: On the inside of the small intestine there are small passages through which vital nutrients from food enter the bloodstream. These passages are controlled by various mechanisms such as protective microorganisms, a layer of mucus and the structure of the passages.


In case of the leaky gut syndrome, the intestinal barrier is no longer properly intact

The intestinal barrier, which was described in the last section, can be damaged by various influences. In this case, part of the protective mechanisms or, in the worst case, all three are destroyed. Without the natural protection, substances that do not belong there can enter the bloodstream. Especially if the function of the tight junctions is weakened, this has fatal consequences for the health of the intestine. This is exactly when we speak of the Leaky gut Syndrome. The intestinal wall is permeable or full of holes.

Causes of the leaky gut syndrome

Especially potential allergens from daily food can irritate the intestines. Gluten, lactose, fructose, industrially processed fats and antinutrients contained in pulses and cereals are inflammation promoters5,6,8. Lectins, for example, are among these antinutrients. They are found particularly in beans, lentils, peanuts and gluten-containing cereals. They inhibit digestive enzymes, which prevents the macronutrients from being broken down completely.

Thus they remain as too large components and cannot be properly absorbed. However, you can avoid this problem by soaking pulses in water with a dash of lemon overnight and rinsing them well the next day before cooking.

In addition, exposure to toxins, heavy metals, a lack of immune defence cells and noxious substances such as alcohol can promote the development of a porous intestine5.

Chronic inflammatory bowel diseases such as Crohn's disease and ulcerative colitis or even pancreatic insufficiency that have been persisting for a long time can also attack the bowel mucosa, the microbiome and ultimately also the tight junctions6. Bacterial toxins, parasites and drugs can upset the balance of the intestinal microbiome6. Antibiotics in particular have a serious negative influence there, because they destroy not only the pathogenic bacteria but also those that protect us.7.
It is also evident that chronic stress, long-lasting or recurring inflammation in the mouth and amalgam fillings, as well as dietary habits have a major influence on an intact intestinal barrier.9.


What are possible symptoms for the leaky gut syndrome?

As the intestine now becomes permeable for pathogenic and inflammatory substances, the immune system must constantly react. The body must intercept the substances that now enter. At some point, the immune system can no longer regenerate due to the overload: Chronic inflammation develops6. This can lead to weight gain, but also to weight loss and fat-like deposits in the tissue.

Other actively felt symptoms are diarrhoea, flatulence, migraine, constipation and lymphoedema. The skin on the outside of the body also tends to show symptoms of illness, acne or neurodermatitis being the most common of these. It can also lead to poorer absorption of micronutrients, which can also result in anaemia due to iron deficiency. Cramps, weakness are frequent companions. Other food intolerances or allergies can also develop7.    
Furthermore, an association between the Leaky gut syndrome and autoimmune diseases, depression and diabetes mellitus has been found8.


Diagnosis – how can it be determinated whether a Leaky gut syndrome is present?

The diagnostic tools for typical intestinal diseases from traditional medicine, such as sonography and colonoscopy, are not helpful in determining the presence of porous bowel7 . It is possible to take a blood sample from the doctor to determine whether the body's own regulatory protein zonulin is overactive.

This protein initiates the opening of the tight junctions, i.e. the intestinal barrier. If it is in a conspicuously increased concentration in the blood, this is an indicator of gluten intolerance. However, according to current scientific studies, the reference ranges are not yet sufficiently decisive, which makes this test rather useless. In addition, celiac disease is not a compulsive companion of the porous intestine5.    
In order to determine the leaky disease well, a feces sample is therefore best suited5. In Germany, you do not even have to see a doctor for this, but you can order a home kit directly from specialized laboratories and send in the sample yourself. The evaluation can then be viewed online and a detailed diagnosis can be obtained via a personal account. 

With this it can be determined directly whether the intestine is permeable. In addition, precursors, or potential leaky gut syndrome promoters can be detected in time. For example, an imbalance in the composition of intestinal bacteria Text Microorganisms Link or various inflammation markers are visible in the evaluation of the stool sample.


Treatment, prevention and nutrition

The leaky gut syndrome can be treated mainly by the right nutrition. If the body is supplied with the right nutrients, it is able to heal the bowel and repair the leaks in the bowel. The intestinal cells are constantly renewing themselves. A nutritional adjustment is the best and most sustainable therapy for a leaking intestine:

Potential allergens such as cow's milk, gluten-containing cereals, industrially processed fats and convenience food link articles Convenience food with many unnatural additives should be avoided if possible.

The following foods support the intestinal mucosa or the intestinal barrier in their therapy, but are also recommended as a preventive measure:


Meat broth

Meat broth is traditionally obtained by cooking the bones and cartilage of chicken and beef. The boiling process releases certain amino acids and minerals from the animal bones.
The most important of these amino acids are proline and glycine. Proline and glycine are crucial for the production of collagen.

If the body does not produce enough collagen, then the skin becomes flabby and you get wrinkles. The same thing happens to the tissue of our intestines, it gets flabby.

Proline and glycine help to repair the intestine so that it does not let through any unwanted molecules. Meat broth also contains the amino acid L-glutamine. This acts like a bandage for the intestine. Meat Broth is a natural therapy for Leaky gut syndrome.



Kefir is one of the strongest probiotic foods of all. For the cure of Leaky gut syndrome, goat milk kefir should be preferred to cow's milk products as goat milk is most similar to human breast milk and cow's milk intolerance is widespread. Even better would be the completely vegan variant: coconut kefir, which can now be found in selected organic markets.
Kefir contains specific probiotics such as Lactobacillus. The Lactobacillus expels bad bacteria, yeast and fungi from the intestines and helps the good bacteria to multiply. A deficit of probiotics should definitely be compensated for in order to heal a leaking intestine.


Fermented vegetables 

Fermented vegetables, such as sauerkraut or kimchi, also contain bacteria that drive away the bad bacteria in the intestines and restore the balance of the microbiome.
In addition, however, the organic acids are the optimal breeding ground for the "good" bacteria in the intestine. They create, so to speak, an optimal intestinal environment in which the intestinal probiotics can sprout.


Psyllium husks

They consist of dietary fibres that are not absorbed by the intestines and can be used as energy sources or storage for ours. In return, they rub the intestinal mucosa, which causes it to produce more protective mucus. On the other hand, they serve the good intestinal bacteria as food.


Bitter substances

Grapefruit, bitter herbs, artichoke and chicory salad contain various bitter substances. These stimulate enzymes in the mouth, which have a positive influence on the oral flora. Above all, they stimulate the bile to produce more bile acid, which is crucial for the emulsification of fats. It is important to chew the bitter foods well, because only when they are perceived by the taste receptors in the mouth will nerve impulses be transmitted to the brain, stimulating the bile to do so.










Nischwitz, Dr. Dominik (2019): In aller Munde – Biologische Zahnmedizin. München: Mosaik Verlag.

Campbell, Neil A. und Reece, Jane B.(2015): Biologie. München: Pearson. 8. aktualisierte Ausgabe. S. 1228-1233.

Doccheck Flexikon: Tight Junction. [https://flexikon.doccheck.com/de/Tight%20junction; 30.10.2019].

Reizdarm: Darmbarriere. [https://www.reizdarm.net/lexikon/darmbarriere; 30.10.2019].

Schmidt, Karlheinz (2015): Das Leaky-gut-Syndrom – Grundlagen und Labordiagnostik. Stuttgart: Hippokrates Verlag MVS Medizinverlage Stuttgart GmbH & Co.

Rüffer, Andreas; Eckert, Michaela & Martin, Miriam (2015): Ist der Darm noch dicht? Das Leaky-gut-Syndrom.

Spiller, Wolfgang & Oldhaver, Mathias (2015): Mit hochdosierten Probiotika gegen Missverhältnisse in der Darmflora.

Mutschler, Dr. med. Rainer (2013): Ein Umdenken in der Medizin tut not – Mitochondrien in den Mittelpunkt stellen: Die Wege der Mitochondrialen Medizin. Speyer: OM & Ernährung. Nr. 142. F70-F72.

Nischwitz, Dr. Dominik (2017): Leaky gut - die Basics - chronische Entzündung im Magen-Darm-Trakt [https://www.youtube.com/watch?v=r6ClAPCoUNA; 30.10.2019].


Ines Schulz
Ines Maria Schulz, geboren am 01.12.1992 in Basel, Schweiz hat auch dort den Master Of Education in Biologie und WAH abgeschlossen, womit sie den Grundstein für das Verständnis von Physiologie und Anatomie sowie Ernährungslehre gesetzt hat. Zudem ist sie ausgebildete Sportlehrerin für die Grundschule. Seit zwei Jahren ist sie Coach bei MTM Personal Training, dem erfolgreichsten Personal Training Studio in Berlin. Dort unterstützt sie täglich Kunden, die ihr maximales Potential bezüglich mentaler und physischer Gesundheit und ihrer Leistungsfähigkeit ausschöpfen möchten. In Kooperation mit Ärzten wie Dr. Dominik Nischwitz und einem Labor für Darmgesundheit sowie dem ständigen Austausch im Team kann sie ihre Kunden optimal über Training, Ernährung, Mikronährstoffe und Lifestyle beraten. Für MTM hat sie bereits ein Frühstücksbuch und einen grossen Teil eines Lifestyle Booklets verfasst. Zudem schreibt sie wöchentlich den Newsletter, in dem Ernährungstipps und von ihr kreierte Rezepte veröffentlicht werden. Ines hat bei verschiedensten erfolgreichen Coaches und Fachpersonen Seminare und Zertifikate absolviert und erweitert stetig ihre Kompetenz. Für Supz Nutrition ist die junge Trainerin seit Januar 2019 mit dem Verfassen von Blogartikeln aktiv.

Häufig gestellte Fragen

What can be done about the so-called leaky gut syndrome?
Go on an elimination diet and support the intestinal flora with the right foods: Avoid anything potentially allergenic, especially the major allergens. Cereals containing gluten, dairy products, legumes such as soya, lentils, peanuts and beans. Sugar, artificial sweeteners and industrially processed foods also have a negative influence on the microbiome.
What is a leaky good anyway, what does it mean?
Leaky gut means, translated, porous intestine. In Leaky Gut Syndrome, the intestinal wall is no longer properly intact, which means that substances that promote inflammation enter the organism. The disease often develops insidiously via primary diseases. The actual protective mechanisms of the intestinal mucosa can no longer recognise what should and should not be absorbed, which means that pro-inflammatory substances enter the body.
Which foods help with the leaky gut syndrome?
1. meat broth: It contains the structural protein collagen, which strengthens our tissue, nails, bones, skin and hair. Collagen can therefore also strengthen the intestinal mucosa. 2. kefir: Kefir contains specific probiotics such as Lactobacillus, which expels pathogenic bacteria, yeast and fungi from the intestines and helps to multiply the good bacteria. Goat or coconut kefir should be preferred over cow's milk products, as cow's milk can cause further inflammation in the intestines. 3. fermented vegetables: Fermented vegetables such as sauerkraut or kimchi also contain bacteria that drive away the bad bacteria in the intestines and restore the balance of the microbiome. 4. psyllium husks: Since the good intestinal bacteria feed on dietary fiber such as psyllium husks or inulin, this food can help to increase the small intestinal carriers. 5. bitter substances: They stimulate the bile to produce more bile acid, which is essential for fat digestion. Fat is a central component of cell walls, including the intestinal mucosa, which keeps them intact.

The fields marked with * are required.