What does the Zonulin test measure?

Why is Zonulin measured?

Faecal zonulin is used in functional and integrative gastroenterology as a marker of intestinal tight-junction integrity and barrier function. Elevations are interpreted as evidence of increased intestinal permeability ('leaky gut'), a contested but increasingly studied mechanism in coeliac disease, inflammatory bowel disease, irritable bowel syndrome, and systemic conditions including autoimmunity and metabolic dysfunction. Because zonulin assays lack standardisation and measure a family of proteins rather than a single molecule, results should be interpreted cautiously and in the context of the clinical picture rather than as diagnostic.

Reference ranges

Standard reference

Laboratory-specific; Genova reports functional thresholds rather than population-derived reference intervals.

Functional medicine optimal

Functional-medicine practitioners often aim for values at the lower end of the laboratory's reference range, though optimal thresholds are not established by consensus guidelines.

Units

ng/mL, µg/g stool, ng/mL or ng/g

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.