Reference entry
Zonulin
Plain-English definitions of microbiome research vocabulary — the terms you'll see across articles, testing services, and probiotic claims.
Glossary context
Defined
in the site-wide microbiome glossary
Definition
A protein that regulates the tight junctions between intestinal cells. Elevated zonulin levels increase intestinal permeability. Discovered by Alessio Fasano, zonulin is triggered by gluten exposure and certain bacteria, and is studied as a biomarker for gut barrier function.