Myths vs facts: Leaky Gut Test and Sport

The idea that a 'leaky gut' test (e.g., zonulin, LPS, α-1-antitrypsin) can reliably assess intestinal permeability or athletic performance is not supported by robust science. Most commercial tests measure surrogate markers that correlate poorly with the actual gut barrier function, and there are no validated reference ranges for athletes. While intense exercise can transiently increase gut permeability, a positive test does not indicate a clinically relevant disorder. Many companies exploit this uncertainty to sell expensive supplements. The evidence for using such tests in sports is predominantly marketing-driven. A more evidence-based approach is to monitor symptoms (bloating, diarrhea, fatigue) and consult a gastroenterologist if needed, rather than relying on unstandardized home tests.