The community of microorganisms inhabiting the gastrointestinal tract of monogastric herbivores played critical roles in the absorption of nutrients and keeping the host healthy. However, its establishment at different age groups has not been quantitatively and functionally examined. The knowledge of microbial colonization and its function in the intestinal tract of different-age donkeys is still limited. By applying the V3–V4 region of the bacterial 16S rRNA gene and functional prediction on fecal samples from different-age donkeys, we characterized the gut microbiota during the different age groups. In contrast to the adult donkeys, the gut microbiota diversity and richness of the young donkeys showed significantly less resemblance. The microbial data showed that diversity and richness increased with age, but a highly individual variation of microbial composition was observed at month 1. Principal coordinate analysis (PCoA) revealed a significant difference across five time points in the feces. The abundance of Bacteroides, Lactobacillus, and Odoribacter tended to decrease, while the proportion of Streptococcus was significantly increased with age. For functional prediction, the relative abundance of pathways had a significant difference in the feces across different age groups, for example, Terpenoids and Polyketides and Folding, Sorting, and Degradation (P < 0.05 or P < 0.01). The analysis of beta diversity (PCoA and LEfSe) and microbial functions predicted with PICRUSt (NSTIs) clearly divided the donkeys into foals (≤3 months old) and adults (≥7 months old). Microbial community composition and structure had distinctive features at each age group, in accordance with functional stability of the microbiota. Our findings established a framework for understanding the composition and function of the fecal microbiota to differ between young and adult donkeys.

居住在单胃食草动物胃肠道中的微生物群落在吸收养分和保持宿主健康方面起着关键作用。但是，尚未对它在不同年龄段的建立情况进行定量和功能检查。微生物定植及其在不同年龄驴的肠道中的功能的知识仍然有限。通过应用细菌16S rRNA基因的V3-V4区域和对不同年龄驴的粪便样本进行功能预测，我们表征了不同年龄组的肠道菌群。与成年驴相比，幼驴的肠道菌群多样性和丰富性表现出明显更少的相似性。微生物数据表明，多样性和丰富度会随着年龄的增长而增加，但是在第1个月观察到微生物组成的高度个体差异。主坐标分析（PCoA）显示，粪便中五个时间点的差异显着。丰富的拟杆菌属， 乳杆菌和 臭杆菌 趋于减少，而 链球菌随着年龄的增长明显增加。对于功能预测，不同年龄组的粪便中途径的相对丰度存在显着差异，例如，萜类化合物和聚酮化合物以及折叠，分类和降解（P <0.05或 P<0.01）。用PICRUSt（NSTIs）预测的β多样性（PCoA和LEfSe）和微生物功能分析清楚地将驴分为驹（≤3个月大）和成年驹（≥7个月）。根据微生物群的功能稳定性，每个年龄段的微生物群落组成和结构都有其独特的特征。我们的发现建立了一个框架，用于了解粪驴微生物群的组成和功能，以使其在成年驴和成年驴之间有所不同。