Gut-derived serotonin and its emerging roles in immune function, inflammation, metabolism and the gut-brain axis

Purpose of review To shed light on the recently uncovered diverse role of serotonin (5-hydroxytryptamine; 5-HT) in the regulation of immune functions, inflammation, metabolism, and gut-brain axis. Recent findings Peripheral 5-HT which accounts for approximately 95% of the total is largely synthesized in the gut by enterochromaffin cells. Enterochromaffin cells release 5-HT in response to various stimuli including microbial products. Released 5-HT influences secretomotor, sensory and immune functions as well as inflammatory processes in the gut. 5-HT released from enterochromaffin cells enters circulation and is taken up and concentrated in platelets. 5-HT released from the activated platelets interacts with different organs to alter their metabolic activity. 5-HT also serves as a link in the gut-brain axis. Emerging evidence regarding the role of peripheral 5-HT in the regulation of various physiological and pathophysiological conditions opens up new targets for researchers to explore and for clinicians to treat and manage different diseases associated with the altered 5-HT signalling.

Automated summary

Recent research has highlighted the significant role of peripheral serotonin in immune functions, inflammation, metabolism, and gut-brain axis regulation. This neurotransmitter is mainly produced in the gut and influences various physiological and pathophysiological conditions by interacting with different organs. This discovery paves the way for new research targets and potential treatment strategies for diseases related to serotonin signaling.