wie testet man eine glutenunverträglichkeit — which blood markers matter?

Testing for gluten intolerance requires distinguishing celiac disease (an autoimmune condition) from non-celiac gluten sensitivity (NCGS). For celiac disease, established blood markers include tissue transglutaminase antibodies (tTG-IgA) as the primary screening test, along with endomysial antibodies (EMA) and deamidated gliadin peptides (DGP). A positive serology must be confirmed by duodenal biopsy. For NCGS, no validated biomarkers exist; diagnosis relies on exclusion and a controlled gluten challenge. Consumer DNA tests claiming to detect 'gluten intolerance genes' (e.g., HLA-DQ2/DQ8) are insufficient: these variants are necessary but not sufficient for celiac disease – many carriers never develop symptoms. Evidence for blood markers is strong for celiac disease but weak for NCGS. Without medical evaluation and biopsy, self-testing remains unreliable.