Cortisol

Direct Effects on the Microbiome#

P. gingivalis virulence: Cortisol promotes surface translocation of Porphyromonas gingivalis in a concentration-dependent manner, upregulating T9SS-associated genes and fimbrial proteins.^{[1]Kim et al. 2022 — Cortisol Promotes Surface Translocation of Porphyromonas gingivalisHey-Min Kim, Christina Magda Rothenberger, Mary Ellen Davey · 2022Open reference 1 ↓} This is the most direct evidence of a stress hormone activating a specific pathogen's virulence program.

Catecholamine-responsive bacteria: Cortisol's downstream catecholamines (norepinephrine) are sensed by enteric bacteria, promoting growth and virulence factor expression in Enterobacteriaceae. Immunosuppression: Cortisol suppresses secretory IgA, mucosal immune cell function, and tight junction integrity—removing immune barriers to pathogen expansion.

Stress-Disease Connections#

Periodontitis: Salivary cortisol elevated in periodontitis (>0.15 µM vs. 0.02 µM healthy); directly activates P. gingivalis migration.^{[1]Kim et al. 2022 — Cortisol Promotes Surface Translocation of Porphyromonas gingivalisHey-Min Kim, Christina Magda Rothenberger, Mary Ellen Davey · 2022Open reference 1 ↓}

Depression: HPA axis dysregulation is a core feature of MDD; cortisol drives gut Dysbiosis → Endotoxemia → neuroinflammation.^{[2]Graves' disease as a driver of depression: a mechanistic insightSiegmann EM, Muller HHO, Luecke C et al. · 2020Open reference 2 ↓}

PPD: Cortisol dysregulation postpartum compounds estrogen/progesterone withdrawal.^{[3]Suryawanshi 2022 — A Comprehensive Review on Postpartum DepressionOm Suryawanshi, Sandhya Pajai · 2022Open reference 3 ↓[4]Silva-Fernandes 2024 — Inflammatory Biomarkers and Perinatal Depression: A Systematic ReviewAnabela Silva-Fernandes, Ana Conde, Margarida Marques et al. · 2024Open reference 4 ↓} PMDD: Cortisol-GABA-Allopregnanolone axis disruption.^{[5]Cheng 2025 — Neuroinflammation in PMS and PMDD (Review)Cheng et al. · 2025Open reference 5 ↓}