Intestinal Permeability
Plain-English definitions of microbiome research vocabulary — the terms you'll see across articles, testing services, and probiotic claims.
The property of the intestinal lining that controls what passes from the gut into the bloodstream. Increased permeability (sometimes called "leaky gut") allows harmful substances to enter circulation, triggering immune responses.
Related terms
Lipopolysaccharide (LPS)
A component of the outer membrane of gram-negative bacteria. When LPS enters the bloodstream through a compromised intestinal barrier, it triggers inflammation — a key mechanism linking gut health to systemic disease.
Dysbiosis
An imbalance in the composition or function of the microbiome, typically characterised by reduced diversity, loss of beneficial bacteria, or overgrowth of potentially harmful species.