Solid diet supplementation in the early life stages of ruminants could improve rumen microbiota and tissue development. However, most studies focus on bacteria in the rumen content community. The microbiota attached on rumen epithelium are rarely investigated, and their correlations with rumen content bacteria and host transcripts are unknown. In this study, rumen digesta attached in the epithelium from goats in three diet regimes (milk replacer only, milk replacer supplemented concentrate and milk replacer supplemented concentrate plus alfalfa pellets) were collected for measurement of the epithelial microbiota using next generation sequencing. Correspondingly, the rumen tissues of the same animals were measured with the host transcriptome. The distinct microbial structures and compositions between rumen content and epithelial communities were associated with solid diet supplementation. Regarding rumen development in pre-weaning ruminants, a solid diet, especially its accompanying neutral detergent fibre nutrients, was the most significant driver that influenced the rumen microbiota and epithelium gene expression. Compared with content bacteria, rumen epithelial microbiota had a stronger association with the host transcriptome. The host transcriptome correlated with host phenotypes were associated with rumen epithelial microbiota and solid diet. This study reveals that the epithelial microbiota is crucial for proper rumen development, and solid diet could improve rumen development through both the rumen content and epithelial microbiota.

中文翻译：

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固体饮食在年轻反刍动物中操纵瘤胃上皮微生物群及其与宿主转录组的相互作用

在反刍动物生命的早期阶段补充固体饲料可以改善瘤胃微生物群和组织发育。然而，大多数研究都集中在瘤胃内容物群落中的细菌上。附着在瘤胃上皮上的微生物群很少被研究，它们与瘤胃内容细菌和宿主转录物的相关性尚不清楚。在本研究中，收集了三种饮食方案（仅代乳品、代乳粉补充浓缩物和代乳粉补充浓缩物加紫花苜蓿颗粒）中山羊上皮的瘤胃食糜，用于使用下一代测序测量上皮微生物群。相应地，用宿主转录组测量相同动物的瘤胃组织。瘤胃内容物和上皮群落之间不同的微生物结构和组成与固体日粮补充有关。关于断奶前反刍动物的瘤胃发育，固体饮食，尤其是其伴随的中性洗涤纤维营养素，是影响瘤胃微生物群和上皮基因表达的最重要驱动因素。与含量细菌相比，瘤胃上皮微生物群与宿主转录组的关联性更强。与宿主表型相关的宿主转录组与瘤胃上皮微生物群和固体饮食有关。这项研究表明，上皮微生物群对于瘤胃的正常发育至关重要，而固体饮食可以通过瘤胃含量和上皮微生物群来促进瘤胃发育。关于断奶前反刍动物的瘤胃发育，固体饮食，尤其是其伴随的中性洗涤纤维营养素，是影响瘤胃微生物群和上皮基因表达的最重要驱动因素。与含量细菌相比，瘤胃上皮微生物群与宿主转录组的关联性更强。与宿主表型相关的宿主转录组与瘤胃上皮微生物群和固体饮食有关。这项研究表明，上皮微生物群对于瘤胃的正常发育至关重要，而固体饮食可以通过瘤胃含量和上皮微生物群来促进瘤胃发育。关于断奶前反刍动物的瘤胃发育，固体饮食，尤其是其伴随的中性洗涤纤维营养素，是影响瘤胃微生物群和上皮基因表达的最重要驱动因素。与含量细菌相比，瘤胃上皮微生物群与宿主转录组的关联性更强。与宿主表型相关的宿主转录组与瘤胃上皮微生物群和固体饮食有关。这项研究表明，上皮微生物群对于瘤胃的正常发育至关重要，而固体饮食可以通过瘤胃含量和上皮微生物群来促进瘤胃发育。是影响瘤胃微生物群和上皮基因表达的最重要驱动因素。与含量细菌相比，瘤胃上皮微生物群与宿主转录组的关联性更强。与宿主表型相关的宿主转录组与瘤胃上皮微生物群和固体饮食有关。这项研究表明，上皮微生物群对于瘤胃的正常发育至关重要，而固体饮食可以通过瘤胃含量和上皮微生物群来促进瘤胃发育。是影响瘤胃微生物群和上皮基因表达的最重要驱动因素。与含量细菌相比，瘤胃上皮微生物群与宿主转录组的关联性更强。与宿主表型相关的宿主转录组与瘤胃上皮微生物群和固体饮食有关。这项研究表明，上皮微生物群对于瘤胃的正常发育至关重要，而固体饮食可以通过瘤胃含量和上皮微生物群来促进瘤胃发育。