Evidence check: CYP2D6 in the context of gut health

CYP2D6 is a liver enzyme involved in metabolizing many drugs and some endogenous compounds. Its direct role in gut health is not well established. While CYP2D6 contributes to serotonin metabolism, which influences gut motility and the gut-brain axis, the effect of common genetic variants on gut microbiota or intestinal barrier function is weak and inconsistent. Most consumer DNA tests report CYP2D6 variants for drug response (e.g., antidepressants, beta-blockers), not for digestive health. Claims linking CYP2D6 SNPs to gut health are speculative and lack robust human evidence. Evidence grade: unclear. Caveat: Do not change diet or lifestyle based solely on a CYP2D6 test. For gut issues, focus on proven strategies like fiber, probiotics, and stress management, and consult a healthcare professional.