Is tTG IgA useful for Darmgesundheit?

The tTG IgA test (anti-tissue transglutaminase IgA) is a well-established serological marker for celiac disease, an autoimmune condition triggered by gluten that damages the small intestinal lining. It is highly useful for diagnosing celiac disease, but not for general gut health without specific suspicion. The test has high sensitivity and specificity when measured together with total IgA. A positive result requires confirmation by duodenal biopsy. In IgA deficiency, the test can be falsely negative; then IgG-based tests (tTG-IgG, DGP-IgG) are indicated. For other gut issues like IBS or SIBO, tTG IgA is not appropriate. Evidence is strong (human), but the test is only meaningful in a clinical context. Note: Do not self-interpret without medical guidance.