Evidence check: FADS1 in the context of gut health

FADS1 encodes delta-5-desaturase, a key enzyme in the omega-3 and omega-6 fatty acid cascade. Genetic variants (e.g., rs174537) affect the conversion of alpha-linolenic acid (ALA) to EPA and DHA. Lower enzyme activity can lead to reduced EPA/DHA levels, which may promote inflammation – a known risk factor for impaired gut barrier function and dysbiosis. However, direct human studies linking FADS1 variants to specific gut health outcomes (microbiome composition, permeability) are scarce. The evidence is largely mechanistic and derived from GWAS on fatty acid levels. Individual SNP interpretation is not clinically actionable. Adequate intake of preformed long-chain omega-3s (e.g., from fatty fish) may be beneficial for risk allele carriers, but this does not replace medical advice. Overall: weak to moderate evidence for a direct gut effect.