The human physiology of well-being: A systematic review on the association between neurotransmitters, hormones, inflammatory markers, the microbiome and well-being

• Published in: Neuroscience and biobehavioral reviews Vol. 139; p. 104733
• Main Authors: de Vries, Lianne P., van de Weijer, Margot P., Bartels, Meike
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.08.2022
• Subjects: Hormones; Inflammatory markers; Microbiome; Neurotransmitters; Physiology; Well-being; Neurotransmitters; Physiology; Inflammatory markers; Well-being; Hormones; Microbiome; physiology; inflammatory markers; well-being; hormones; microbiome; neurotransmitters
• ISSN: 0149-7634; 1873-7528
• DOI: 10.1016/j.neubiorev.2022.104733

To understand the pathways through which well-being contributes to health, we performed a systematic review according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines on the association between well-being and physiological markers in four categories, neurotransmitters, hormones, inflammatory markers, and microbiome. We identified 91 studies. Neurotransmitter studies (knumber of studies=9) reported only a possible positive association between serotonin and well-being. For the hormone studies (k = 48), a lower momentary cortisol level was related to higher well-being (meta-analytic r = −0.06), and a steeper diurnal slope of cortisol levels. Inflammatory marker studies (k = 36) reported negative or non-significant relations with well-being, with meta-analytic estimates of respectively r = −0.07 and r = −0.05 for C-reactive protein and interleukin-6. Microbiome studies (k = 4) reported inconsistent associations between different bacteria abundance and well-being. The results indicate possible but small roles of serotonin, cortisol, and inflammatory markers in explaining differences in well-being. The inconsistent and limited results for other markers and microbiome require further research. Future directions for a complete picture of the physiological factors underlying well-being are proposed. •Higher blood levels of serotonin could be related to higher well-being.•Faster decrease of cortisol levels over the day is associated with higher well-being.•The levels of different inflammatory markers are negatively related to well-being.•An association between the microbiome composition and well-being is suggested.•More research to the physiological factors underlying well-being is needed.