The ever-changing roles of serotonin

Area of Science:

• Neuroendocrinology
• Gastroenterology
• Metabolic Health

Background:

• Serotonin (5-HT) traditionally functions as a neurotransmitter and hormone regulating mood, sleep, anxiety, and gastrointestinal motility.
• Emerging research highlights serotonin's role as a metabolic hormone influencing glucose homeostasis and adiposity, with links to metabolic diseases.
• Peripheral serotonin is primarily produced by gut enterochromaffin (EC) cells, which sense nutrients and gut microbiota.

Purpose of the Study:

• To review the traditional and modern functions of serotonin.
• To highlight the emerging pathway of gut microbiota influencing host health via serotonin.
• To focus on the peripheral roles of serotonin and its interaction with gut microbiota.

Main Methods:

• Literature review of studies on serotonin synthesis, function, and metabolism.
• Analysis of the interaction between gut microbiota and enterochromaffin cells.
• Examination of evidence linking gut-derived serotonin to host homeostasis.

Main Results:

• Serotonin (5-HT) has diverse roles, including central neurotransmission and peripheral hormone regulation.
• Enteroendocrine EC cells are key producers of peripheral serotonin, responding to luminal contents.
• Gut microbiota composition and activity dynamically modulate EC cell function and serotonin production.

Conclusions:

• The gut microbiota significantly influences host physiology through interactions with EC cells and serotonin pathways.
• Understanding the gut-serotonin-microbiota axis is crucial for addressing metabolic diseases.
• Further research into this axis may reveal novel therapeutic targets for metabolic and gastrointestinal disorders.