Intestinal epithelial homeostasis plays an important role in intestinal morphology and function. However, the developmental changes in intestinal epithelial cell turnover in piglets during early weaning are unknown so far. Thus, the aim of this work was to detect changes in piglet gut development from weaning to post-weaning d 14. Accordingly, 40 piglets were used in the present study, and 8 piglets were randomly selected for sampling at d 0, 1, 3, 7 and 14 post-weaning, respectively. The results showed that weaning stress significantly affected small intestinal morphological architecture, and this impact was the worst on d 3, and then returned to normal on d 14. Furthermore, the number of the marker of proliferation Ki-67 (Ki67) positive cells was decreased on d 1 and 3, and then recovered on d 14 (P < 0.001). Also, weaning strikingly increased jejunal epithelial cell shedding on d 1 to 7 compared on d 0 (P < 0.05). Moreover, weaning remarkably affected the number of small intestinal enterocytes, goblets and endocrine cells (P < 0.05), and there were also significant differences in genes expression related to proliferation and differentiation (P < 0.05). Additionally, the mechanistic target of rapamycin (mTOR) phosphorylation level was higher on d 3 (P < 0.05). However, the Wingless/Int1 (WNT)/β-catenin pathway was not influenced by post-weaning days. Taken together, weaning induced noteworthy changes in intestinal epithelial cell proliferation, differentiation and shedding, and the mTOR signaling pathway was involved in this process. Our findings provide a cellular mechanism for intestinal developmental changes during weaning periods. This may provide nutritionists with better insight into designing efficient in-feed alternatives for preventing the unfavorable gut development in weaning piglets.

肠上皮稳态在肠道形态和功能中起重要作用。然而，目前尚不清楚断奶早期仔猪肠道上皮细胞更新的发育变化。因此，这项工作的目的是检测从断奶到断奶后第 14 天仔猪肠道发育的变化。因此，在本研究中使用了 40 头仔猪，并在第 0、1、3 天随机选择了 8 头仔猪进行采样，断奶后分别为 7 和 14。结果表明，断奶应激显着影响小肠形态结构，这种影响在第3天最严重，第14天恢复正常。此外，增殖标志物Ki-67（Ki67）阳性细胞的数量为在第 1 天和第 3 天下降，然后在第 14 天恢复（P < 0.001)。此外，与第 0 天相比，断奶后第 1 天至第 7 天的空肠上皮细胞脱落显着增加（P  < 0.05）。此外，断奶对小肠肠细胞、杯状细胞和内分泌细胞的数量有显着影响（P  < 0.05），与增殖和分化相关的基因表达也存在显着差异（P  < 0.05）。此外，雷帕霉素 (mTOR) 磷酸化水平的机制靶点在第 3 天较高（P < 0.05)。然而，Wingless/Int1 (WNT)/β-catenin 通路不受断奶后天数的影响。总之，断奶诱导了肠上皮细胞增殖、分化和脱落的显着变化，mTOR信号通路参与了这一过程。我们的研究结果为断奶期间肠道发育变化提供了细胞机制。这可能为营养学家提供更好的洞察力来设计有效的饲料替代品，以防止断奶仔猪肠道发育不良。