Serotonin (5-hydroxytryptamine or 5-HT) once most extensively studied as a neurotransmitter of the central nervous system, is seen to be predominantly secreted in the gut. About 95% of 5-HT is estimated to be found in gut mainly within the enterochromaffin cells whereas about 5% is found in the brain. 5-HT is an important enteric signaling molecule and is well known for playing a key role in sensory-motor and secretory functions in the gut. In recent times, studies uncovering various new functions of gut-derived 5-HT indicate that many more are yet to be discovered in coming days. Recent studies revealed that 5-HT plays a pivotal role in immune cell activation and generation/perpetuation of inflammation in the gut. In addition to its various roles in the gut, there are now emerging evidences that suggest an important role of gut-derived 5-HT in other biological processes beyond the gut, such as bone remodeling and metabolic homeostasis. This review focuses to briefly summarize the accumulated and newly updated role of 5-HT in the maintenance of normal gut physiology and in the pathogenesis of inflammation in the gut. The collected information about this multifaceted signaling molecule may aid in distinguishing its good and bad effects which may lead to the development of novel strategies to overcome the unwanted effect, such as in inflammatory bowel disease.

曾经被广泛研究为中枢神经系统神经递质的5-羟色胺（5-羟色胺或5-HT）主要在肠道中分泌。估计约有95％的5-HT主要在肠嗜铬细胞内发现于肠内，而约5％则见于脑内。5-HT是重要的肠信号转导分子，并且众所周知在肠的感觉运动和分泌功能中起关键作用。近年来，发现肠源性5-HT的各种新功能的研究表明，未来几天仍将发现更多功能。最近的研究表明，5-HT在免疫细胞激活和肠道炎症的产生/持久中起着关键作用。除了在肠道中的各种作用外，现在有新出现的证据表明，肠道衍生的5-HT在肠道以外的其他生物过程（例如骨骼重塑和代谢稳态）中起着重要作用。这篇综述的重点是简要总结5-HT在维持正常肠道生理和肠道炎症的过程中的累积作用和新近更新的作用。收集到的有关此多方面信号分子的信息可能有助于区分其好坏，这可能导致开发出克服不良作用的新策略，例如在炎症性肠病中。这篇综述的重点是简要总结5-HT在维持正常肠道生理和肠道炎症的过程中的累积作用和新近更新的作用。收集到的有关此多方面信号分子的信息可能有助于区分其好坏，这可能导致开发出克服不良作用的新策略，例如在炎症性肠病中。这篇综述的重点是简要总结5-HT在维持正常肠道生理和肠道炎症的过程中的累积作用和新近更新的作用。收集到的有关此多方面信号分子的信息可能有助于区分其好坏，这可能导致开发出克服不良作用的新策略，例如在炎症性肠病中。