What role does IgE play in Darmgesundheit?

IgE (Immunoglobulin E) is primarily known for its role in allergic reactions and defense against parasites. In the gut, IgE contributes to immune surveillance by binding to mast cells and basophils. Upon allergen exposure (e.g., pollen, food proteins), it triggers histamine release and inflammation, leading to symptoms like diarrhea, cramps, or nausea. In food allergies (e.g., peanut, milk), IgE is directly involved in pathogenesis. However, IgE's role in general gut health (barrier function, microbiome) is less clear. Elevated IgE levels in stool or blood may indicate an allergic tendency but are not specific markers for gut dysfunction. Many commercial tests (e.g., IgG-based intolerance tests) do not measure IgE, and their scientific basis is weak. An IgE test for food allergies is only useful when there is a clear clinical suspicion and should be interpreted by an allergist. The evidence for IgE in gut health is strong for allergies but weak for non-allergic gut issues. Caveat: A positive IgE test does not automatically mean a clinically relevant allergy – oral food challenge remains the gold standard.