Myths vs facts: MTHFR and Darmgesundheit

MTHFR variants (C677T, A1298C) are common and affect folate metabolism, but the direct link to gut health is scientifically weak. Myths often claim that MTHFR mutations cause leaky gut, IBS, or food intolerances – there is no robust evidence for this. Facts: MTHFR influences homocysteine levels and methylation, which may indirectly modulate gut barrier and microbiome, but effects are small and not clinically actionable. Many individuals with MTHFR variants have completely normal gut function. Gut health is primarily driven by diet, stress, medications, and microbiome composition. A DNA test alone is insufficient for recommendations. Supplementing with active folate (5-MTHF) instead of folic acid may be reasonable for certain variants, but not specifically for gut health. Caveat: No randomized trials demonstrate a causal effect of MTHFR on gut health. Evidence: mixed/unclear. Sources: No specific PMIDs in context; general guidelines on MTHFR and methylation.