Myths vs facts: Stuhlprobe and allergy

The notion that a stool sample can diagnose allergies is a widespread myth, often promoted by direct-to-consumer (DTC) companies. In reality, stool tests typically measure IgG antibodies to foods, which indicate immune exposure, not true allergy. True allergies (Type I) are mediated by IgE and require blood or skin prick tests. IgG tests yield many false positives and are not recommended by professional bodies like the European Academy of Allergy and Clinical Immunology (EAACI). Furthermore, there are no standardized reference ranges for stool-based allergy markers. Stool analysis can be useful for gastrointestinal conditions (e.g., calprotectin for inflammation), but not for allergy diagnosis. Consumers should avoid relying on such tests and consult an allergist for proper evaluation. The evidence is clear: stool tests for allergies are marketing, not evidence-based medicine.