Is APOE useful for gut health?

The APOE gene variant (especially ε4) is primarily known for its role in lipid metabolism and Alzheimer's disease risk. There is no established direct benefit for gut health. Some animal studies suggest APOE may influence gut microbiome composition, but the evidence is only mechanistic and not yet confirmed in humans. Therefore, APOE genetic testing is not useful for gut health optimization. Proven strategies like fiber intake, probiotics, and balanced nutrition are far more relevant. Evidence: mechanistic/unclear.