What to watch with FUT2 and fatigue?

FUT2 (fucosyltransferase 2) determines your secretor status and influences gut microbiota composition and vitamin B12 absorption. Non-secretors (certain FUT2 variants) have a higher risk of low B12 levels, which can cause fatigue. They are also more susceptible to certain infections (e.g., norovirus) that may lead to exhaustion. However, the evidence is moderate (observational) and a direct causal link between FUT2 and fatigue is not established. If you experience persistent fatigue, have your B12 levels and other causes checked by a doctor. A DNA test alone is insufficient for diagnosis.