What to watch with IgG and gut health?

When it comes to IgG and gut health, caution is warranted. Many direct-to-consumer tests measure IgG antibodies to foods and market them as indicators of food intolerances or sensitivities. However, the scientific evidence is weak: IgG levels often reflect normal immune exposure, not pathology. Major allergy and immunology societies (e.g., EAACI, AAAAI) advise against using IgG tests for diagnosing food intolerances. They can lead to unnecessary dietary restrictions and nutritional deficiencies. For gut health, more validated markers include fecal calprotectin (inflammation), zonulin (intestinal permeability), and stool tests for pathogens. A comprehensive approach—symptom diary, medical history, and supervised elimination diets—is more evidence-based. Caveat: Do not self-treat based on IgG results; consult a gastroenterologist or dietitian.