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Leaky gut, leaky brain: the role of zonulin

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In recent years an amazing discovery has advanced our understanding of intestinal permeability.

In 2000, Dr Alessio Fasano and his team discovered a molecule responsible for modulating intestinal tight junctions (TJs) known as zonulin. To date, zonulin is the only human protein known to reversibly regulate intestinal permeability.

Based on Dr Fasano’s research, we now know two key triggers that augment zonulin expression with implications for the development of numerous autoimmune conditions, including coeliac disease (CD) and type 1 diabetes. These triggers are gluten and gut bacteria.

Gliadin from gluten causes zonulin levels to increase both in those people who have CD and those who do not. Changes in gut microbiota have also been observed to trigger the zonulin pathway leading to a loss of intestinal barrier function. This results in the passage of harmful molecules into the bloodstream and the activation of inflammatory and autoimmune processes. It is also conceivable that zonulin participates in the physiological regulation of intercellular TJs of the vascular endothelium, including the blood-brain barrier (BBB) with wide implications for mood and cognition.

In this infographic we review zonulin research, what this means for the development of disease and the protective actions of probiotics and zinc.


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Melissa Lee
Melissa is a designer turned nutritionist, who has combined the two modalities to create purposeful designs for various health publications and websites. Having initially studied Multimedia Systems Design, she then went on to complete a BHSc in Nutritional Medicine which led to her involvement in the integrative medicine industry and eventually to FX Medicine.