Stress Feedback Loop

A stressor activates the sympathetic nervous system and HPA axis, increasing cortisol. IL-6 can reactivate the HPA axis and reduce glucocorticoid receptor expression, weakening cortisol feedback control. Glucocorticoid receptors normally help shut down stress activation after a threat passes. The article distinguishes cortisol from pathological stress and does not claim that B. longum 1714 suppresses cortisol production. In an unhealthy gut, cortisol can worsen gut permeability and allow more LPS into circulation.