Liu Yue, Liu Chang, Wu Hao, Meng Qingxiang, Zhou Zhenming
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China.
Front Microbiol. 2022 Apr 21;13:862151. doi: 10.3389/fmicb.2022.862151. eCollection 2022.
The gastrointestinal tract (GIT) contains complex microbial communities and plays an essential role in the overall health of the host. Previous studies of beef cattle feed efficiency have primarily concentrated on the ruminal microbiota because it plays a key role in energy production and nutrient supply in the host. Although the small intestine is the important site of post-ruminal digestion and absorption of nutrients, only a few studies have explored the relationship between the microbial populations in the small intestine and feed efficiency. Moreover, variations in GIT metabolites contribute to differences in feed efficiency. The objective of this study was to investigate relationships among bacterial populations of duodenum, jejunum, ileum; microbial metabolites; and RFI phenotype of beef cattle. We carried out by using Illumina MiSeq sequencing of the 16S rRNA V3-V4 region and liquid chromatography-mass spectrometry (LC-MS). In the duodenum, the relative abundances of Firmicutes ( < 0.01), , , , , ( < 0.05), and ( < 0.05) were higher in the low residual feed intake (LRFI) group compared with the high residual feed intake (HRFI) group, whereas the HRFI group had higher abundances of Proteobacteria and ( < 0.01). In the jejunum, the relative abundances of and were higher in the LRFI group ( < 0.05). In the ileum, the relative abundances of ( < 0.01), , , and were also higher in the LRFI group ( < 0.05). Moreover, the genera , and were negatively associated with RFI, while the genus was positively associated with RFI. The metabolomics analysis revealed that the LRFI group significantly improved protein digestion and absorption, as well as glycerophospholipid metabolism in the duodenum, jejunum, ileum. The correlation between intestinal microorganisms and metabolites revealed that some microorganisms play an important role in amino acid metabolism, glycerophospholipid metabolism, nutrient digestion and absorption, and antioxidant enhancement. The present study provides a better understanding of the small intestinal microbiota and metabolites of beef cattle with different RFI phenotypes and the relationships among them, which are potentially important for the improvement of beef cattle feed efficiency.
胃肠道（GIT）包含复杂的微生物群落，对宿主的整体健康起着至关重要的作用。先前关于肉牛饲料效率的研究主要集中在瘤胃微生物群，因为它在宿主的能量产生和营养供应中起关键作用。尽管小肠是瘤胃后营养物质消化和吸收的重要部位，但只有少数研究探讨了小肠微生物种群与饲料效率之间的关系。此外，胃肠道代谢产物的变化导致饲料效率的差异。本研究的目的是调查肉牛十二指肠、空肠、回肠的细菌种群、微生物代谢产物和剩余采食量（RFI）表型之间的关系。我们通过对16S rRNA V3-V4区域进行Illumina MiSeq测序和液相色谱-质谱联用（LC-MS）来开展研究。在十二指肠中，低剩余采食量（LRFI）组的厚壁菌门（<0.01）、[此处原文缺失部分菌属名称]、[此处原文缺失部分菌属名称]、[此处原文缺失部分菌属名称]、[此处原文缺失部分菌属名称]、[此处原文缺失部分菌属名称]（<0.05）和[此处原文缺失部分菌属名称]（<0.05）的相对丰度高于高剩余采食量（HRFI）组，而HRFI组的变形菌门和[此处原文缺失部分菌属名称]（<0.01）丰度更高。在空肠中，LRFI组[此处原文缺失部分菌属名称]和[此处原文缺失部分菌属名称]的相对丰度更高（<0.05）。在回肠中，LRFI组[此处原文缺失部分菌属名称]（<0.01）、[此处原文缺失部分菌属名称]、[此处原文缺失部分菌属名称]和[此处原文缺失部分菌属名称]的相对丰度也更高（<0.05）。此外，[此处原文缺失部分菌属名称]属、[此处原文缺失部分菌属名称]属和[此处原文缺失部分菌属名称]属与RFI呈负相关，而[此处原文缺失部分菌属名称]属与RFI呈正相关。代谢组学分析表明，LRFI组显著改善了十二指肠、空肠、回肠中的蛋白质消化吸收以及甘油磷脂代谢。肠道微生物与代谢产物之间的相关性表明，一些微生物在氨基酸代谢、甘油磷脂代谢、营养物质消化吸收和抗氧化增强中起重要作用。本研究更好地了解了具有不同RFI表型的肉牛小肠微生物群和代谢产物以及它们之间的关系，这对提高肉牛饲料效率可能具有重要意义。
