Evidence check: Cortisol senken in the context of Darmgesundheit

The idea of lowering cortisol through gut health is rooted in the gut-brain axis: the gut microbiome, intestinal barrier, and vagus nerve influence the hypothalamic-pituitary-adrenal (HPA) axis. Some studies suggest that certain probiotics (e.g., Lactobacillus and Bifidobacterium strains) can modestly reduce morning cortisol in healthy individuals. However, effects are small, strain-specific, and not consistently replicated. A high-fiber diet may support gut barrier integrity and reduce inflammation via short-chain fatty acids (SCFAs), potentially dampening HPA axis activity. The evidence is mostly mechanistic or from animal models; large human RCTs are lacking. Commercial tests (DNA, microbiome) often claim to personalize cortisol-lowering strategies, but clinical validity is low. A single SNP or one-time microbiome snapshot cannot capture the complex, dynamic interplay. Chronically elevated cortisol requires medical evaluation. A healthy, fiber-rich diet and stress management are evidence-based approaches, independent of genetic testing.