Luo Yunfeng, Luo Liangming, Xia Mengle, Liu Qian, Zhang Guosong
Discipline of Chinese and Western Integrative Medicine, Jiangxi University of Chinese Medicine, Nanchang, China.
Jiangxi University of Chinese Medicine, Nanchang, China.
Front Microbiol. 2025 Apr 17;16:1551693. doi: 10.3389/fmicb.2025.1551693. eCollection 2025.
The gut contains a diverse array of commensal microorganisms, forming a vital biological barrier within the intestine that contributes to the overall intestinal mucosal barrier. However, research on the rectal barrier during early development remains limited. This study aims to investigate the relationship between intestinal microbiota and rectal barrier function in young rats.
We evaluated the rectal barrier structure and function in rats at 2-, 4-, and 10-week-old. Methodology included histological analysis, Muc2 expression quantification, immunofluorescence localization of tight junction proteins (ZO-1, Occludin, Claudins), blood glucose monitoring after rectal insulin administration, and 16S rDNA sequencing of rectal microbiota. Spearman correlation analysis was used to explore mechanisms linking age-dependent changes in rectal permeability to microbiota dynamics.
Physiological rectal permeability was significantly higher in 2-week-old rats compared to 4- and 10-week-old rats ( < 0.01), although systemic biomarkers (LPS, D-LA, and LBP) showed no significant differences. The rectal microbiota exhibited marked age-dependent shifts in composition, /-diversity, and metabolic pathways, with increased abundance of beneficial taxa (e.g., Muribaculaceae, Akkermansia) in older rats. Correlation analysis revealed strong associations between reduced permeability, elevated Occludin expression, and microbiota maturation ( = 0.65, < 0.001).
This study demonstrates that age-dependent maturation of the rectal barrier is closely linked to microbiota composition and tight junction protein expression, providing insights into developmental mechanisms and potential strategies for pediatric rectal drug delivery.
肠道中含有各种各样的共生微生物，在肠道内形成了一个重要的生物屏障，有助于整体肠道黏膜屏障。然而，早期发育过程中直肠屏障的研究仍然有限。本研究旨在探讨幼鼠肠道微生物群与直肠屏障功能之间的关系。
我们评估了2周龄、4周龄和10周龄大鼠的直肠屏障结构和功能。方法包括组织学分析、Muc2表达定量、紧密连接蛋白（ZO-1、闭合蛋白、Claudins）的免疫荧光定位、直肠注射胰岛素后的血糖监测以及直肠微生物群的16S rDNA测序。采用Spearman相关性分析来探索直肠通透性随年龄变化与微生物群动态之间的联系机制。
与4周龄和10周龄大鼠相比，2周龄大鼠的生理性直肠通透性显著更高（<0.01），尽管全身生物标志物（LPS、D-LA和LBP）没有显著差异。直肠微生物群在组成、α-多样性和代谢途径方面表现出明显的年龄依赖性变化，老年大鼠中有益类群（如毛螺菌科、阿克曼氏菌）的丰度增加。相关性分析显示通透性降低、闭合蛋白表达升高与微生物群成熟之间存在强关联（=0.65，<0.001）。
本研究表明，直肠屏障的年龄依赖性成熟与微生物群组成和紧密连接蛋白表达密切相关，为儿科直肠给药的发育机制和潜在策略提供了见解。
