The leaky gut syndrome has been reported to be on the rise in the recent past. The intestinal lining allows nutrients and biomolecules to get into and out of the intestines. However, in persons with the leaky gut syndrome, the intestinal walls have bigger spaces that allow larger protein molecules to get into the bloodstream causing a sequence of immunological reactions. Once this happens, the body will always get into this defensive state causing reactions every time the proteins are released into the bloodstream.

Besides leakage of proteins into the bloodstream, there is leakage of intestinal contents and this includes bacteria that cause inflammation and an overload of the liver. The doorway that leads to releases of the proteins into the bloodstream is the zonulin door.

What triggers opening of the zonulin door?

Bacteria and gluten are the main causes of the opening. Gluten is seen as the main trigger of the doorway opening because of the presence of gliadin. Gliadin increases zonulin levels in the intestinal walls for persons with or without celiac disease.

Regardless of an individual’s genetic predisposition, gliadin activates zonulin signaling pathways. When the zonulin levels are high, the intestinal walls are made more permeable and this is what is referred to loosely as the leaky gut syndrome.

Nutrient deficiencies develop when the condition continues and enterocytes and microvilli are damaged. The damage is also associated with immune activation increasing cases of food sensitivities.

What maintains a healthy gut?

A healthy gut is basically a sealed gut with healthy intestinal cells, and tight junction bonds between the healthy cells. These junctions aren’t static, but they prevent the intestines from being leaky. They generally enhance nutrient absorption, survey of the internal ecosystem, protection from infectious bugs and parasites, and they shuttle white blood cells into the gut from the bloodstream.

The Zonulin ELISA detection Assay

As mentioned above, the protein gliadin or alpha gliadin increases production of Zonulin that leads to release of macromolecules into the bloodstream from the gut. To determine the levels of zonulin present in the gut, a competitive ELISA assay is carried out.

In the test, the ZON ELISA testing kits and the assay technique employs monoclonal anti-ZON antibodies and an ZON-HRP conjugate. The assay sample and the buffers are then incubated with the HPR conjugate. After incubation, the substrates and the plates are washed then incubated with a substrate for Horse Radish Peroxidase enzyme. This enzyme substrate reaction forms a blue colored complex.

The color intensity of the complex is measured spectrophotometrically and the readings show the zonulin levels in the plasma sample, cell cultures, or serum.


Besides digestion and absorption, the intestinal walls also carry out an important role of trafficking macromolecules between the cells and the bloodstream. A barrier mechanism is involved and there are also the neuroendocrine networks and the tight intercellular junctions. Zonulin is the only modulator so far to be known to be involved in trafficking of the macromolecules and also in balancing or tipping off the immune balances. Deregulation of the Zonulin pathway leads to neoplastic disorders, inflammatory and autoimmune diseases.

Author's Bio: 

Walter Moore is a renowned biotechnologist. He runs a blog called ‘what is an ELISA kit’.
Visit his page to learn more about ELISA kits according to the targeted pathways and antibodies or biochemicals.