Leaky gut (intestinal permeability syndrome)
An abnormal increase in intestinal permeability allowing unwanted substances (bacteria, toxins, food antigens) to cross the gut barrier and enter the bloodstream.
The gut wall is a sophisticated barrier made of a single layer of epithelial cells (enterocytes) joined by tight junctions. These junctions are regulated by proteins such as zonula occludens-1 (ZO-1) and occludin. Intestinal permeability is dynamic and controlled: it must allow nutrients to be absorbed while blocking harmful molecules.
In dysbiosis or chronic inflammation, myosin light chain kinases (MLCK) increase and weaken the tight junctions, raising permeability. Lipopolysaccharides (LPS) from gram-negative bacteria then leak into the bloodstream, triggering a systemic inflammatory response.
A fresh angle: leaky gut is often over-diagnosed by naturopaths, but the links to autoimmune diseases (type 1 diabetes, multiple sclerosis, rheumatoid arthritis, lupus, Crohn’s disease) are scientifically validated. A 2021 study (Kinashi et al., Frontiers in Immunology) shows that dysbiosis plus leaky gut creates a vicious circle: intestinal permeability exposes the immune system to antigens, which triggers autoimmune reactions that in turn worsen the dysbiosis.
Restoration: adding glutamine (an amino acid used by enterocytes) and L-glutamine as a supplement may help, but restoration comes first and foremost through nutrition (removing irritants, increasing prebiotics) and stress management.