What should I know about nahrungserganzungsmittel test?

A 'dietary supplement test' (often marketed as DNA or microbiome test) claims to provide personalized supplement recommendations. However, the scientific basis is generally weak. While certain genetic variants do influence nutrient metabolism – e.g., MTHFR C677T (rs1801133) for folate or FUT2 for Bifidobacteria – the effect is usually small and often compensated by diet and lifestyle. Most people with such a variant do not require high-dose supplements. Clinical guidelines recommend routine supplementation only for confirmed deficiencies or specific risk groups (e.g., folic acid before pregnancy). Many direct-to-consumer tests overstate their predictive power and rely on association studies without causal evidence. Independent validation is often lacking. A responsible approach: discuss results with a doctor or dietitian before buying supplements. Beware of high doses of fat-soluble vitamins or trace minerals, which can be toxic. Bottom line: these tests may offer rough hints, but not reliable treatment instructions.