Evidence check: Leaky Gut Test in the context of longevity

The concept of a 'leaky gut' test in the context of longevity lacks strong scientific support. While intestinal permeability is a recognized phenomenon in certain gastrointestinal diseases (e.g., celiac, Crohn's), its role as a driver of human aging is not established by rigorous evidence. Commercial tests often measure markers like zonulin, lactulose/mannitol ratio, or endotoxin antibodies, but these assays are not standardized, lack validated reference ranges for healthy populations, and are not recommended by major medical societies for longevity assessment. Furthermore, results can be confounded by diet, medications, stress, and transient inflammation. Without concurrent inflammatory markers (e.g., CRP, IL-6), a single 'leaky gut' result is ambiguous. The evidence base linking gut permeability to longevity is primarily mechanistic or based on animal models, not human clinical trials. Therefore, such tests are best considered experimental or marketing tools. For consumers interested in longevity, established biomarkers (CRP, HbA1c, lipids) and lifestyle interventions (diet, exercise, sleep) are more evidence-based approaches.