Myths vs facts: tTG IgA and gut health

tTG IgA (tissue transglutaminase antibodies) is a highly specific biomarker for celiac disease, not a general gut health indicator. A positive result suggests an autoimmune reaction to gluten, but diagnosis requires duodenal biopsy confirmation. Common myths: 1) tTG IgA is a general 'gut health check' – false; it only screens for celiac disease. 2) A negative test rules out other gut issues – no; IBS, Crohn's, or food intolerances are not detected. 3) tTG IgA can be altered by diet – while levels drop on a gluten-free diet, the test is designed for diagnosis, not monitoring (IgG-based tests are better for follow-up). Evidence is human-strong: guidelines (ESPGHAN, ACG) recommend tTG IgA as the primary screening test for celiac disease, with ~93% sensitivity and >96% specificity. Caveats: IgA deficiency (1:500) causes false negatives; IgG-based testing is then required. Consumer DNA tests rarely include tTG IgA – it is a clinical blood test. If offered by companies like MyBody-X, caution is warranted: interpretation without a physician can lead to misdiagnosis. Bottom line: tTG IgA is a valuable but narrow marker – not a panacea for gut health.