What role does Cortisol play in Darmgesundheit?

Cortisol, the primary stress hormone, influences gut health via the gut-brain axis. Chronically elevated cortisol can impair the intestinal barrier (leaky gut), alter gut motility, and shift the microbiome composition, often reducing beneficial bacteria. It may also promote intestinal inflammation. However, most evidence comes from animal models and observational human studies; direct causal evidence in humans is limited. A single cortisol measurement (saliva, blood) is insufficient to assess gut health, as diet, sleep, and psychological stress also play major roles. Consumer tests like MyBody-X that include cortisol should be interpreted as part of a holistic assessment, not as a standalone diagnostic. Evidence: mechanistic with moderate human support. Caveat: not clinically validated for gut health as a single marker.