The duodenal epithelium plays a pivotal role in the uptake and transport of dietary nutrients while simultaneously acting as physical and biochemical barrier to protect against harmful bacteria and antigens. In the case of functional dyspepsia (FD), the duodenum is of particular interest, due to observed local immune involvement and the proximity to the stomach and exposure to acidopeptic secretions. Recent observations in FD pathophysiology, including those reported by Beeckmans et al in this issue of the journal, have identified a loss of barrier function in the duodenal epithelium, an altered duodenal microbiome and alterations in intestinal bile acid pools. Because FD symptoms coincide with food intake and, thus, secretion of bile acids, these findings may indicate loss or imbalance of bile-acid-microbiota-epithelial homeostasis as a process driving FD. Here, we review the evidence linking these observations to FD symptoms.

中文翻译：

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十二指肠胆汁酸是肠粘膜稳态和疾病的决定因素。

十二指肠上皮在饮食营养的吸收和运输中起着关键作用，同时还充当物理和生化屏障，以防御有害细菌和抗原。在功能性消化不良（FD）的情况下，十二指肠特别重要，这是由于观察到的局部免疫受累以及与胃的接近以及暴露于胃酸分泌物。FD病理生理学的最新发现，包括Beeckmans等人在本期杂志上所报道的发现，已发现十二指肠上皮的屏障功能丧失，十二指肠微生物组改变和肠内胆汁酸池改变。由于FD症状与食物摄入以及胆汁酸的分泌同时发生，这些发现可能表明胆汁酸-微生物-上皮稳态的丧失或失衡是驱动FD的过程。在这里，我们回顾了将这些观察结果与FD症状联系起来的证据。