As an essential part of the immune system, mast cells (MCs) play an important role in the pathogenesis of irritable bowel syndrome (IBS). Accumulating evidence has identified altered MC count and density in intestinal mucosa of patients with IBS; however, conflicting findings yield inconsistent conclusions. Currently, most studies have suggested intestinal MC infiltration in IBS patients. Considering the pivotal role of MCs in IBS, it is necessary to achieve a better understanding about the pathological changes in the intestine. The risk factors for IBS, including dietary habits, psychological factors, infection, and dysbiosis, are implicated to induce intestinal MC infiltration. Mechanistically, food may trigger immune‐related allergic reactions and affect the intestinal microbiota activity. Some exogenous pathogens and altered profile of commensal bacteria promote intestinal MC recruitment through promoted release of chemokines from epithelial cells or direct activation of the immune system. In addition, psychological factors may affect the microenvironment where MCs live. MCs have been proven to interact with the enteric neurons and other immunocytes, evidenced by the close proximity of MCs to neurons and regional altered immune system components. A variety of mediators released by the enteric neurons, immunocytes, and MCs per se, such as neurotrophins, neuropeptides, cytokines, and chemokines, may have stimulant effects on MCs by modulating the survival, proliferation, and recruitment process of MCs in the intestine. In this review, the associations between IBS and intestinal MC density and the underlying mechanisms are discussed.

中文翻译：

---

肠道肥大细胞浸润在肠易激综合征中的作用

作为免疫系统的重要组成部分，肥大细胞 (MC) 在肠易激综合征 (IBS) 的发病机制中起重要作用。越来越多的证据已经确定了 IBS 患者肠粘膜中 MC 计数和密度的改变；然而，相互矛盾的发现会产生不一致的结论。目前，大多数研究表明 IBS 患者存在肠道 MC 浸润。考虑到 MCs 在 IBS 中的关键作用，有必要更好地了解肠道的病理变化。IBS 的危险因素，包括饮食习惯、心理因素、感染和生态失调，都与诱导肠道 MC 浸润有关。从机制上讲，食物可能会引发免疫相关的过敏反应并影响肠道微生物群的活动。一些外源性病原体和共生细菌的改变通过促进上皮细胞释放趋化因子或直接激活免疫系统来促进肠道 MC 募集。此外，心理因素可能会影响 MC 生活的微环境。MCs 已被证明与肠道神经元和其他免疫细胞相互作用，这可以通过 MCs 与神经元和区域改变的免疫系统组件的紧密接近来证明。肠神经元、免疫细胞和 MCs 本身释放的多种介质，如神经营养因子、神经肽、细胞因子和趋化因子，可能通过调节 MCs 在肠道中的存活、增殖和募集过程对 MCs 产生刺激作用。在这篇综述中，讨论了 IBS 与肠道 MC 密度之间的关联及其潜在机制。