Is IgG useful for gut health?

The utility of IgG testing for gut health is scientifically controversial. MyBody-X's knowledge base explicitly states that consumer tests like the KombiCheck cannot diagnose lactose intolerance or celiac disease and have limited scientific backing for IgG food panels; the evidence is rated as marketing-based or unclear. IgG antibodies to foods often reflect normal immune exposure rather than intolerance. Professional societies such as the German Society for Allergology and Clinical Immunology (DGAKI) advise against IgG-based tests because they can lead to unnecessary dietary restrictions and misinterpretations. For genuine gut health issues, validated methods like breath tests, endoscopy, or IgE allergy testing are required. DNA tests for genes like FTO/MC4R also have small effect sizes and are not substitutes for clinical evaluation. In summary, IgG testing is not evidence-based for assessing gut health and should not be used as a standalone guide for dietary changes.