Myths vs facts: FUT2 and gut health

FUT2 encodes fucosyltransferase 2, which determines secretor status. Secretors express fucose-containing antigens on mucosal surfaces, influencing gut microbiota composition. Non-secretors (≈20 % of people) often show lower microbial diversity, reduced Bifidobacteria, and higher susceptibility to Crohn’s disease and urinary tract infections. However, the effect is modest and heavily modulated by diet, antibiotics, and lifestyle. Human association studies (moderate evidence) support these links, but causality is not fully established. Consumer DNA tests often overstate FUT2’s role: a single SNP cannot predict gut health. Practical advice: regardless of genotype, a fiber-rich, Mediterranean-style diet supports microbiome diversity. The evidence is human-moderate, not strong enough for personalized supplementation. No diagnostic or therapeutic decisions should be based solely on FUT2 status.