A High Grain Diet Dynamically Shifted the Composition of Mucosa-Associated Microbiota and Induced Mucosal Injuries in the Colon of Sheep.
A High Grain Diet Dynamically Shifted the Composition of Mucosa-Associated Microbiota and Induced Mucosal Injuries in the Colon of Sheep.
复制标题
高谷物饮食动态改变了绵羊结肠粘膜相关微生物群的组成并诱发粘膜损伤
DOI：
10.3389/fmicb.2017.02080
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发表时间：
2017
影响因子：
5.2
通讯作者：
Mao S
中科院分区：
文献类型：
--
作者：
Wang Y;Xu L;Liu J;Zhu W;Mao S
本研究调查了饲喂高谷物（HG）饮食的绵羊结肠中粘膜相关微生物群组成和粘膜形态的动态变化。将20只雄性绵羊随机分为4组（每组n = 5）。第一组饲喂干草日粮。其余3组分别饲喂HG饲料7（HG 7）、14（HG 14）和28（HG 28）d。收集结肠直肠样品以测定pH以及挥发性脂肪酸（VFA）和乳酸的浓度。对结肠粘膜取样以使用Illumina MiSeq测序表征细菌群落，并使用定量实时PCR确定细胞因子和紧密连接蛋白基因的mRNA表达水平。结果表明，随着时间的推移，结肠pH值呈线性下降（P = 0.007），总VFA浓度呈线性上升（P < 0.001）。微生物分析表明，HG饮食线性降低（P < 0.050）结肠微生物群的多样性和丰富度。主坐标分析结果表明，结肠粘膜相关的细菌群落的四个组显着转移与饲喂HG饮食的天数。在属的水平上，HG喂养显着增加了一些类群的相对丰度，包括普雷沃氏菌，粪球菌，罗斯拜瑞氏菌属，梭菌_sensu_stricto_1，并降低密螺旋体的比例，这些类群的百分比不受影响的天数喂HG饮食。显微镜检查显示高糖喂养导致了粘膜上皮损伤。RT-PCR结果显示，随着饲喂HG饲料天数的增加，Claudin-1（P = 0.038）、IL-1β（P = 0.045）、IL-6（P = 0.050）和TNF-α（P = 0.020）的mRNA表达量呈线性增加。相关性分析显示结肠黏膜细胞因子mRNA表达与黏膜细菌组成之间存在显著相关性。一般来说，HG喂养增加结肠发酵和改变结肠粘膜细菌群落，最终导致结肠粘膜损伤并导致结肠功能障碍，并且这些变化在至少4周内逐渐发生。
This study investigated the dynamic shifts in mucosa-associated microbiota composition and mucosal morphology in the colon of sheep fed a high grain (HG) diet. A total of 20 male sheep were randomly assigned to four groups (n = 5 for each). The sheep in first group received hay diet. The animals in other 3 groups were fed an HG diet for 7 (HG7), 14 (HG14), or 28 (HG28) days, respectively. Colonic digesta samples were collected to determine the pH and the concentrations of volatile fatty acid (VFA) and lactate. The colonic mucosa was sampled to characterize the bacterial communities using Illumina MiSeq sequencing and to determine mRNA expression levels of cytokines and tight junction protein genes using quantitative real-time PCR. As time advanced, results revealed that colonic pH linearly decreased (P = 0.007), and the concentrations of total VFA linearly increased (P < 0.001). Microbial analysis showed that an HG diet linearly reduced (P < 0.050) the diversity and richness of the colonic microbiota. The principal coordinate analysis results showed that the colonic mucosa-associated bacterial communities of the four groups significantly shifted with number of days fed an HG diet. At the genus level, HG feeding significantly increased the relative abundance of some taxa including Prevotella, Coprococcus, Roseburia, and Clostridium_sensu_stricto_1, and decreased the proportion of Treponema, and the percentage of these taxa was not affected by days fed an HG diet. The microscopic examination showed that HG feeding caused the mucosal epithelial injury. The RT-PCR results showed that the mRNA expression of claudin-1 (P = 0.038), IL-1β (P = 0.045), IL-6 (P = 0.050), and TNF-α (P = 0.020) increased linearly with number of days fed an HG diet. The correlation analysis revealed significant correlation between the colonic mucosal mRNA expression of cytokines and mucosal bacterial composition. Generally, HG feeding increased colonic fermentation and altered colonic mucosal bacterial communities, which eventually caused colonic mucosal damage and led to colonic dysfunction, and these changes occurred gradually over at least 4 weeks.