Abstract

The objective of this study was to evaluate the effect of undernutrition on colonic microbiota and fermentation in pregnant ewes. Sixteen ewes bearing multiple fetuses for 115 days in the control (CON) and severe feed restriction (SFR) groups were fed 100% and 30% level of ad libitum feed intake, respectively. After 15-day treatment, all ewes were sacrificed to collect colonic digesta samples to extract DNA for 16S rRNA sequencing and to detect fermentation parameters. Our data showed that SFR increased (P < 0.05) the levels of colonic propionate, isobutyrate, butyrate, isovalerate, and valerate, and slightly decreased (P < 0.1) colonic pH. The mole proportions of isobutyrate, butyrate, and isovalerate were increased (P < 0.05) upon SFR while that of acetate was decreased (P < 0.05). Hematoxylin-eosin staining sections exhibited the disorderly, irregular, and loose arrangement and part sloughing of colonic epithelial cells. Furthermore, SFR decreased (P < 0.05) the diversity of colonic microbiota and changed the microbial communities. At the genus level, SFR increased (P < 0.05) the abundance of unclassified Peptococcaceae and decreased (P < 0.05) the abundances of Ruminococcus, unclassified Ruminococcaceae, and unclassified VadinBB60. Additionally, the abundances of Ruminococcus and unclassified Ruminococcaceae were positively correlated (P < 0.05) with the acetate proportion while the abundance of unclassified Peptococcaceae was negatively correlated (P < 0.05) with the percentages of isobutyrate, butyrate, and isovalerate. In summary, SFR diminished the diversity of bacteria, affected the composition of bacterial communities, and finally changed the colonic fermentation pattern and epithelial histomorphology in pregnant ewes.

Key Points

• Undernutrition changed colonic bacterial diversity and composition in pregnant ewes.

• Microbial alteration affected colonic fermentation pattern and parameters.

• Alteration of colonic microbiota and fermentation damaged epithelium histomorphology.

Graphical abstract

中文翻译：

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营养不良改变了怀孕母羊的结肠发酵和与消化相关的细菌群落。

摘要

这项研究的目的是评估营养不足对孕妇母羊结肠微生物群和发酵的影响。对照组（CON）和严格限饲（SFR）组的16头多胎胎儿在115日龄内分别采食了100％和30％的随意采食量。处理15天后，将所有母羊处死以收集结肠消化物样品，以提取DNA进行16S rRNA测序并检测发酵参数。我们的数据表明，SFR增加 了结肠丙酸，异丁酸，丁酸，异戊酸和戊酸的水平（P <0.05），而 结肠pH值略有降低（P <0.1）。异丁酸酯，丁酸酯和异戊酸酯的摩尔比例增加（P SFR时<0.05），而乙酸盐则降低（P  <0.05）。苏木精-伊红染色切片显示结肠上皮细胞无序，不规则和松散排列以及部分脱落。此外，SFR降低了（P  <0.05）结肠微生物群的多样性，并改变了微生物群落。在属水平，SFR升高（P  <0.05）的丰度非保密的Peptococcaceae和降低（P  <0.05）的丰度瘤胃球菌，未分类Ruminococcaceae，和未分类VadinBB60。此外，丰富的Ruminococcus和未分类瘤胃球菌科 与乙酸盐含量呈正相关（P <0.05），而未分类的肽球菌科的丰度 与异丁酸酯，丁酸酯和异戊酸酯的含量呈负相关（P <0.05）。总之，SFR减少了细菌的多样性，影响了细菌群落的组成，并最终改变了怀孕母羊的结肠发酵模式和上皮组织形态。

关键点

•营养不良改变了怀孕母羊的结肠细菌多样性和组成。

•微生物改变会影响结肠的发酵模式和参数。

•结肠菌群的改变和发酵破坏了上皮的组织形态。

图形概要