Leaky Gut Syndrome - make a reliable diagnosis with Zonulin

The development of many chronic diseases is due to the complex interplay of food allergens, microorganisms, the gut epithelium and the immune system. However, the most crucial role plays a permeable intestinal mucosa - the leaky gut syndrome.

Zonulin as a marker is suitable for the determination of a leaky gut in the following diseases:

  •     Allergic diseases
  •     Autoimmune diseases
  •     IBS
  •     Insulin-dependent diabetes mellitus, metabolic syndrome, fatty liver
  •     Multiple Sclerosis
  •     Coeliac disease

The leaky gut syndrome is defined as an unphysiological permeability of the intestinal mucosa. Thus, fat-insoluble substances, microbes and their fragments, incompletely digested nutrients and pollutants pass the mucosa and enter the blood circulation. This inflow burdens the liver and triggers immunological reactions.

Zonulin regulates the permeability of the gut mucosa

The regulator protein Zonulin is a suitable marker to determine the permeability of the intestinal mucosa. Zonulin regulates the exchange of fluids, macromolecules and leukocytes between the bloodstream and the intestinal lumen. It also protects the subepithelial layers. Various stimuli are responsible for the excess production of zonulin which is then excreted into the intestinal lumen and into the blood. Such stimuli may be direct contact with bacteria, a defective mucosal layer and contact with gliadin. Zonulin binds to receptors on the surface of the intestinal epithelial cells and triggers a signal cascade by which the cytoskeleton of the cell contracts. As a result, the Tight junctions open. If the zonulin-mediated opening of the tight junctions is repeated and intensified, the leaky gut syndrome develops.

Reference range
Stool: borderline value >78,0 ng/ml Stool
Serum: borderline value >48,0 ng/ml Serum

Tight junctions - the gates of the mucosa

The tight junctions are narrow bands of membrane proteins which are networked around each epithelial cell. Similar to a velcro, they close the gap between the cells and thus form an intercellular diffusion barrier.

The regulated opening of the tight junctions allows selective transport of amino acids, sugars, fatty acids and immunoglobulins. Digested food proteins, bacterial endotoxins or Candida antigens can also pass through open tight junctions.