Can FUT2 help with Müdigkeit?

The question of whether FUT2 can help with fatigue cannot be directly answered from the provided information. FUT2 (fucosyltransferase 2) determines secretor status and influences vitamin B12 absorption and gut microbiome composition. Vitamin B12 deficiency can cause fatigue, and certain FUT2 variants are associated with lower B12 levels. However, the effect is moderate and not clinically relevant in all carriers. The provided contexts contain no specific studies or data on FUT2 and fatigue. Therefore, the evidence is rated as 'unclear', based on mechanistic reasoning rather than direct clinical research. A genetic test may offer clues but does not replace medical evaluation for persistent fatigue.