Questions people ask about DNA Test Basis

Consumer DNA tests can provide insights into genetic predispositions, but they are often not diagnostic. Evidence quality varies widely: lactase persistence (rs4988235) has strong human evidence, while tests for sports nutrition or food intolerances are often based on mechanistic or marketing data. Microbiome tests cannot diagnose food allergies—clinical allergy testing remains the gold standard. Markers like zonulin or LPS for 'leaky gut' are not validated. For iron deficiency in children, a blood ferritin test is superior to DNA testing because genetic effects are small. APOE e4 (rs429358) moderately increases Alzheimer's risk but is not deterministic. Many tests overstate their utility. Always consult a doctor or genetic counselor before changing supplements or diet based on home tests. Personal tolerance and clinical findings matter most.