The gastrointestinal tract has remarkable capacity to withstand considerable insults from exposure to abrasive food particles, chemicals, allergens, and pathogenic microbes. Maintaining a robust epithelial barrier sequesters these potentially harmful substances in the lumen, preventing absorption into the systemic circulation. Normal functioning of this barrier is central in diverse physiological processes including digestion, immunity, inflammation, and gut-brain signaling. One crucial component of the barrier is the mucus layer covering the epithelium. There is increased appreciation of the importance of mucus in maintenance of the gut barrier, and how dysregulation of the mucus layer contributes to several common gastrointestinal pathologies. This manuscript reviews the physical and chemical properties of mucus, its maintenance and turnover, and its role in maintaining gut barrier integrity. The dynamic interactions of the mucus layer within the gut ecosystem are illustrated by highlighting how a weakened mucus layer or defective mucus production facilitate pathogenic microbial colonization and mucosal biofilm formation. These may potentially contribute to the pathogenesis of gastrointestinal diseases such as inflammatory bowel diseases or result in secretion and mucosal damage and inflammation in bile acid diarrhea. A final goal is to review how certain dietary factors, especially low-fiber diets and emulsifiers common in Western diets, can harm the mucus layer. This report summarizes evidence from preclinical and human studies that document damage to the mucus layer, and reviews approaches, including diets and probiotics, that promote a healthy mucus layer and break down pathogenic biofilms, thereby potentially preventing and/or treating gastrointestinal diseases that impact mucosal integrity.

中文翻译：

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肠道粘液：胃肠道健康和疾病中肠道粘液和生物膜的生理学、饮食和治疗


胃肠道具有显着的能力，可以承受因暴露于磨蚀性食物颗粒、化学物质、过敏原和病原微生物而造成的大量伤害。维持强大的上皮屏障将这些潜在有害物质隔离在管腔中，防止吸收到体循环中。该屏障的正常功能在各种生理过程中至关重要，包括消化、免疫、炎症和肠脑信号传导。屏障的一个关键组成部分是覆盖上皮的粘液层。人们越来越认识到粘液在维持肠道屏障方面的重要性，以及粘液层失调如何导致几种常见的胃肠道疾病。本手稿综述了粘液的物理和化学特性、其维持和周转，以及它在维持肠道屏障完整性中的作用。通过强调减弱的粘液层或有缺陷的粘液产生如何促进病原微生物定植和粘膜生物膜形成，说明了肠道生态系统中粘液层的动态相互作用。这些可能导致胃肠道疾病（如炎症性肠病）的发病机制，或导致胆汁酸性腹泻的分泌和粘膜损伤以及炎症。最终目标是回顾某些饮食因素，尤其是西方饮食中常见的低纤维饮食和乳化剂，如何损害粘液层。 本报告总结了来自临床前和人类研究的证据，这些证据记录了粘液层的损伤，并回顾了促进健康粘液层和分解病原生物膜的方法，包括饮食和益生菌，从而可能预防和/或治疗影响粘膜完整性的胃肠道疾病。