Bamboo rats (Rhizomys pruinosus) are among the few mammals that lives on a bamboo-based diet which is mainly composed of lignocellulose. However, the mechanisms of adaptation of their gut microbiome and metabolic systems in the degradation of lignocellulose are largely unknown. Here, we conducted a multi-omics analysis on bamboo rats to investigate the interaction between their gut microbiomes and metabolic systems in the pre- and post-weaning periods, and observed significant relationships between dietary types, gut microbiome, serum metabolome and host gene expression. For comparison, published gut microbial data from the famous bamboo-eating giant panda (Ailuropoda melanoleuca) were also used for analysis. We found that the adaptation of the gut microbiome of the bamboo rat to a lignocellulose diet is related to a member switch in the order Bacteroidales from family Bacteroidaceae to family Muribaculaceae, while for the famous bamboo-eating giant panda, several aerobes and facultative anaerobes increase after weaning. The conversion of bacteria with an increased relative abundance in bamboo rats after weaning enriched diverse carbohydrate-active enzymes (CAZymes) associated with lignocellulose degradation and functionally enhanced the biosynthesis of amino acids and B vitamins. Meanwhile, the circulating concentration of short-chain fatty acids (SCFAs) derived metabolites and the metabolic capacity of linoleic acid in the host were significantly elevated. Our findings suggest that fatty acid metabolism, including linoleic acid and SCFAs, are the main energy sources for bamboo rats in response to the low-nutrient bamboo diet.

竹鼠( Rhizomys pruinosus ) 是少数以主要由木质纤维素组成的竹子为食的哺乳动物之一。然而，其肠道微生物组和代谢系统在木质纤维素降解过程中的适应机制在很大程度上是未知的。在这里，我们对竹鼠进行了多组学分析，以研究其肠道微生物组与断奶前后代谢系统之间的相互作用，并观察到饮食类型、肠道微生物组、血清代谢组和宿主基因表达之间的显着关系. 为了进行比较，已发表的著名食竹大熊猫 ( Ailuropoda melanoleuca ) 的肠道微生物数据) 也用于分析。我们发现竹鼠肠道微生物组对木质纤维素饮食的适应与拟杆菌目从拟杆菌科到木杆菌科的成员转换有关，而对于著名的食竹大熊猫，断奶后几种需氧菌和兼性厌氧菌增加。竹鼠断奶后相对丰度增加的细菌转化丰富了与木质纤维素降解相关的多种碳水化合物活性酶 (CAZymes)，并在功能上增强了氨基酸和 B 族维生素的生物合成。同时，宿主体内短链脂肪酸（SCFAs）衍生代谢物的循环浓度和亚油酸的代谢能力显着升高。我们的研究结果表明，脂肪酸代谢，包括亚油酸和短链脂肪酸，是竹鼠响应低营养竹子饮食的主要能量来源。