The neurohumoral signaling systems of the gastrointestinal (GI) tract are considered the most significant of the peripheral inputs controlling both food intake in the short term and energy balance over a longer time course. The importance of the GI tract in the control of energy balance is underscored by the marked beneficial effects of bariatric surgeries for the treatment of obesity. Despite their effectiveness, the mechanisms of bariatric surgery remain to be fully elucidated. Considerable new evidence points to the importance of gut–brain communication, gut barrier function and microbial signaling as three of the most important mechanisms of bariatric surgery-induced weight loss. These mechanisms are reviewed in the present article and the accompanying four papers.

胃肠道（GI）的神经体液信号系统被认为是控制短期食物摄入和较长时间过程中能量平衡的最重要的外周输入。减肥手术对治疗肥胖症的显着有益作用强调了胃肠道在控制能量平衡中的重要性。尽管减肥手术很有效，但其机制仍有待充分阐明。大量新证据表明肠脑通讯、肠道屏障功能和微生物信号传导的重要性，它们是减肥手术引起的减肥的三个最重要机制。本文和随附的四篇论文对这些机制进行了回顾。