Peripheral serotonin: cultivating companionship with gut microbiota in intestinal homeostasis

Serotonin, also known as 5-hydroxytryptamine (5-HT), is an evolutionarily ancient and phylogenetically conserved monoamine that regulates multifaceted physiological functions in mammals. 5-HT was, at one time, most extensively studied as a neurotransmitter within the central nervous system but is now known to regulate nonneuronal functions including immune responses in an autocrine-paracrine-endocrine manner. Compelling evidence from …