Common mistakes around Gluten Test

A common mistake with gluten testing is taking the test while already on a gluten-free diet. Many tests (e.g., anti-tissue transglutaminase antibodies) require prior gluten exposure; otherwise, false negatives are likely. Interpretation is also often misleading: a positive antibody test alone does not confirm celiac disease – a duodenal biopsy is required. Moreover, many people confuse celiac disease (an autoimmune condition) with non-celiac gluten sensitivity (NCGS), for which no validated biomarker exists. Direct-to-consumer home tests often market 'gluten intolerance' without clear differentiation. The evidence for such tests is weak; they can lead to unnecessary diets or missed diagnoses. Another mistake: tests for IgG antibodies against gluten (instead of IgA) are commonly offered but have no clinical validity for celiac disease. Bottom line: Before any gluten test, consult a doctor, especially if celiac disease is suspected. The evidence is clear: only IgA-based tests (tTG) plus biopsy are the gold standard.