Rhee Sang H, Pothoulakis Charalabos, Mayer Emeran A
Inflammatory Bowel Disease Center, Division of Digestive Diseases, David Geffen School of Medicine, CA, USA.
Nat Rev Gastroenterol Hepatol. 2009 May;6(5):306-14. doi: 10.1038/nrgastro.2009.35.
While bidirectional brain-gut interactions are well known mechanisms for the regulation of gut function in both healthy and diseased states, a role of the enteric flora--including both commensal and pathogenic organisms--in these interactions has only been recognized in the past few years. The brain can influence commensal organisms (enteric microbiota) indirectly, via changes in gastrointestinal motility and secretion, and intestinal permeability, or directly, via signaling molecules released into the gut lumen from cells in the lamina propria (enterochromaffin cells, neurons, immune cells). Communication from enteric microbiota to the host can occur via multiple mechanisms, including epithelial-cell, receptor-mediated signaling and, when intestinal permeability is increased, through direct stimulation of host cells in the lamina propria. Enterochromaffin cells are important bidirectional transducers that regulate communication between the gut lumen and the nervous system. Vagal, afferent innervation of enterochromaffin cells provides a direct pathway for enterochromaffin-cell signaling to neuronal circuits, which may have an important role in pain and immune-response modulation, control of background emotions and other homeostatic functions. Disruption of the bidirectional interactions between the enteric microbiota and the nervous system may be involved in the pathophysiology of acute and chronic gastrointestinal disease states, including functional and inflammatory bowel disorders.
虽然双向脑-肠相互作用是健康和患病状态下调节肠道功能的已知机制，但包括共生菌和病原菌在内的肠道菌群在这些相互作用中的作用直到最近几年才被认识到。大脑可以通过胃肠道运动、分泌及肠道通透性的改变间接影响共生菌（肠道微生物群），也可以通过固有层细胞（肠嗜铬细胞、神经元、免疫细胞）释放到肠腔的信号分子直接影响。肠道微生物群与宿主之间的通信可以通过多种机制发生，包括上皮细胞、受体介导的信号传导，以及当肠道通透性增加时，通过直接刺激固有层中的宿主细胞。肠嗜铬细胞是调节肠腔与神经系统之间通信的重要双向传感器。肠嗜铬细胞的迷走传入神经支配为肠嗜铬细胞向神经回路的信号传导提供了一条直接途径，这可能在疼痛和免疫反应调节、背景情绪控制及其他稳态功能中发挥重要作用。肠道微生物群与神经系统之间双向相互作用的破坏可能参与急性和慢性胃肠疾病状态的病理生理过程，包括功能性和炎症性肠病。
