Is Leaky Gut Test useful for Müdigkeit?

The usefulness of a Leaky Gut Test for fatigue is not supported by strong scientific evidence. The concept of 'leaky gut' (increased intestinal permeability) is debated; no standardized, validated biomarkers exist for routine diagnosis. Direct-to-consumer tests (e.g., stool zonulin) have limited evidence and are not part of clinical guidelines. Fatigue has many potential causes: iron deficiency, thyroid dysfunction, poor sleep, stress, infections, or chronic inflammation. A single gut permeability test cannot replace a thorough medical workup. Even if permeability is elevated, it is unclear whether it causes fatigue or is merely an epiphenomenon. The evidence level is 'unclear'. Anyone experiencing persistent fatigue should first consult a physician for basic lab tests (CBC, ferritin, vitamin D, TSH, CRP). A Leaky Gut Test may be considered only as part of a broader, integrative assessment, but not as a standalone diagnostic tool.