Lin Ching-Yen, Cross Tzu-Wen L, Swanson Kelly S
Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA.
Department of Animal Sciences, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA.
Anim Microbiome. 2025 Jan 6;7(1):2. doi: 10.1186/s42523-024-00368-7.
The gastrointestinal (GI) microbiota plays a crucial role in host health and disease in dogs, but the knowledge regarding the mucosal associated microbiota along the GI tract is limited in dogs. Therefore, the objective of this study was to characterize the phylogeny and predicted functional capacity of microbiota residing on the gut mucosa across five GI regions of healthy young adult and geriatric dogs fed different diets. Twelve weanling (8 weeks old) and 12 senior (11.1 years old) beagles were randomly assigned to be fed an animal product-based diet or plant product-based diet for 12 months. At that time, mucosal samples from the stomach, duodenum, jejunum, ileum, and mid-colon were collected. DNA was extracted and the hypervariable region 4 (V4) of the 16S rRNA gene was amplified to assess microbiota using Illumina MiSeq sequencing. Data were analyzed using QIIME 1.9.1. and Statistical Analyses of Metagenomic Profiles software 2.1.3. Gene predictions were made using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States. Taxonomic assessment revealed a greater (p < 0.05) species richness in the mid-colon compared with other segments. Principal coordinates analysis of weighted UniFrac distances demonstrated distinct clusters of stomach, ileum, and mid-colon samples, indicating the presence of unique microbial communities in these regions. The predominant phyla in all five segments were Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria and Fusobacteria, but their relative abundances varied between segments. Proteobacteria had a decreasing relative abundance from the stomach to mid-colon (q < 0.05). The ileum had the highest while the stomach had the lowest relative abundance of Firmicutes (q < 0.05). The duodenum had a higher abundance of Bacteroidetes than the stomach and ileum (q < 0.05). The mid-colon had a higher Fusobacteria relative abundance than other regions (q < 0.05). The predicted functional capacities of the microbiota in the stomach differed from those in the other segments. Age and diet of dog did not significantly impact the taxonomy or predicted functional capacities of the mucosal microbiota. In conclusion, our findings demonstrate distinct characteristics of the mucosal microbiota across various segments of canine GI tract.
胃肠道（GI）微生物群在犬类宿主健康和疾病中起着至关重要的作用，但关于犬类胃肠道黏膜相关微生物群的知识有限。因此，本研究的目的是描述喂食不同饮食的健康年轻成年犬和老年犬五个胃肠道区域肠道黏膜上微生物群的系统发育和预测功能能力。将12只断奶幼犬（8周龄）和12只老年犬（11.1岁）比格犬随机分配，分别喂食基于动物产品的饮食或基于植物产品的饮食12个月。届时，收集胃、十二指肠、空肠、回肠和结肠中段的黏膜样本。提取DNA，并扩增16S rRNA基因的高变区4（V4），使用Illumina MiSeq测序评估微生物群。使用QIIME 1.9.1和宏基因组谱统计分析软件2.1.3对数据进行分析。使用未观察状态重建的群落系统发育研究进行基因预测。分类学评估显示，与其他节段相比，结肠中段的物种丰富度更高（p < 0.05）。加权UniFrac距离的主坐标分析表明，胃、回肠和结肠中段样本形成不同的聚类，表明这些区域存在独特的微生物群落。所有五个节段中的主要菌门为变形菌门、厚壁菌门、拟杆菌门、放线菌门和梭杆菌门，但它们的相对丰度在不同节段有所不同。从胃到结肠中段，变形菌门的相对丰度逐渐降低（q < 0.05）。回肠中厚壁菌门的相对丰度最高，而胃中最低（q < 0.05）。十二指肠中拟杆菌门的丰度高于胃和回肠（q < 0.05）。结肠中段梭杆菌门的相对丰度高于其他区域（q < 0.05）。胃中微生物群的预测功能能力与其他节段不同。犬的年龄和饮食对黏膜微生物群的分类学或预测功能能力没有显著影响。总之，我们的研究结果表明犬类胃肠道各节段的黏膜微生物群具有不同特征。
