Is Leaky Gut Test useful for fatigue?

Whether a leaky gut test is useful for fatigue requires careful scrutiny. The concept of increased intestinal permeability ('leaky gut') is scientifically debated, and no standardized, clinically validated test exists to reliably diagnose it. Most commercial tests measure markers like zonulin or lipopolysaccharides, but their link to fatigue is weak and not supported by robust evidence. Fatigue has many well-established causes: iron deficiency, vitamin B12 deficiency (influenced by FUT2 gene variants), thyroid dysfunction, poor sleep, or stress. A leaky gut test does not replace a proper medical workup for these common factors. The evidence base is largely marketing-driven; high-quality studies are lacking. A more useful approach is a basic blood panel (CBC, ferritin, B12, TSH) and possibly a microbiome test, though even that does not directly diagnose fatigue. Conclusion: Leaky gut testing is not evidence-based for fatigue and should not be relied upon.