How are FUT2 and Allergie related?

The provided context does not contain any direct information about the relationship between FUT2 and allergies. FUT2 (fucosyltransferase 2) is a gene that controls the secretion of ABO blood group antigens into body fluids and is associated with gut microbiota composition. Some studies outside this context suggest a possible role of FUT2 variants in allergic diseases, potentially through modulation of mucosal immunity or microbial colonization. However, the evidence is inconsistent and insufficient for clinical recommendations. Without specific sources or validated data from the given material, the evidence level must be marked as unclear. Consumers should be aware that direct-to-consumer tests linking FUT2 to allergies currently lack robust scientific backing.