With the activity of intestinal stem cells and continuous turnover, the gut epithelium is one of the most dynamic tissues in animals. Due to its simple yet conserved tissue structure and enteric cell composition as well as advanced genetic and histologic techniques, Drosophila serves as a valuable model system for investigating the regulation of intestinal stem cells. The Drosophila gut epithelium is in constant contact with indigenous microbiota and encounters externally introduced "non-self" substances, including foodborne pathogens. Therefore, in addition to its role in digestion and nutrient absorption, another essential function of the gut epithelium is to control the expansion of microbes while maintaining its structural integrity, necessitating a tissue turnover process involving intestinal stem cell activity. As a result, the microbiome and pathogens serve as important factors in regulating intestinal tissue turnover. In this manuscript, I discuss crucial discoveries revealing the interaction between gut microbes and the host's innate immune system, closely associated with the regulation of intestinal stem cell proliferation and differentiation, ultimately contributing to epithelial homeostasis.

中文翻译：

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宿主-微生物相互作用调节果蝇的肠道干细胞和组织更新。

由于肠道干细胞的活性和不断更新，肠道上皮是动物中最具活力的组织之一。由于其简单而保守的组织结构和肠细胞组成以及先进的遗传和组织学技术，果蝇成为研究肠干细胞调节的有价值的模型系统。果蝇肠道上皮与本地微生物群不断接触，并遇到外部引入的“非自身”物质，包括食源性病原体。因此，除了在消化和营养吸收方面的作用外，肠道上皮的另一个重要功能是控制微生物的扩张，同时保持其结构完整性，从而需要涉及肠道干细胞活性的组织周转过程。因此，微生物组和病原体是调节肠道组织更新的重要因素。在这篇手稿中，我讨论了揭示肠道微生物与宿主先天免疫系统之间相互作用的重要发现，该相互作用与肠道干细胞增殖和分化的调节密切相关，最终有助于上皮稳态。