Studies on rodents indicate the daily oscillations of the gut microbiota have biological implications for host. However, the responses of fluctuating gut microbes to the dynamic nutrient substrates are not fully clear. In the study, we found that the feed intake, nutrient substrates, microbiota and metabolites in the colon underwent asynchronous oscillation within a day. Short-chain fatty acids (SCFAs) including acetate, propionate, butyrate and valerate peaked during T24 ~ T27 (Timepoint 24, 12:00 pm, T27, 03:00 am) whereas branched SCFAs isobutyrate and isovalerate peaked during T09 ~ T12. Further extended local similarity analysis (eLSA) revealed that the fluctuation of feed intake dynamically correlated with the colonic carbon substrates which further influenced the oscillation of sugar metabolites and acetate, propionate, butyrate and valerate with a certain time shift. The relative abundance of primary degrader Ruminococcaceae taxa was highly related to the dynamics of the carbon substrates whereas the fluctuations of secondary degraders Lactobacillaceae and Streptococcaceae taxa were highly correlated with the sugar metabolites. Meanwhile, colonic nitrogen substrates were correlated with branched amino acids and the branched SCFAs. Furthermore, we validated the evolution of gut microbes under different carbohydrate and protein combinations by using an in vitro fermentation experiment. The study pictured the dynamics of the micro-ecological environment within a day which highlights the implications of the temporal dimension in studies related to the gut microbiota. Feed intake, more precisely substrate intake, is highly correlated with microbial evolution, which makes it possible to develop chronotherapies targeting the gut microbiota through nutrition intervention.

对啮齿动物的研究表明，肠道微生物群的日常波动对宿主具有生物学意义。然而，波动的肠道微生物对动态营养底物的反应尚不完全清楚。在研究中，我们发现结肠中的采食量、营养底物、微生物群和代谢物在一天内发生异步振荡。包括乙酸盐、丙酸盐、丁酸盐和戊酸盐在内的短链脂肪酸 (SCFA) 在 T24 ~ T27（时间点 24、12:00 pm、T27、03:00 am）期间达到峰值，而支链 SCFA 异丁酸盐和异戊酸盐在 T09 ~ T12 期间达到峰值。进一步扩展局部相似性分析（eLSA）显示，采食量的波动与结肠碳底物动态相关，进一步影响糖代谢物以及乙酸、丙酸、丁酸和戊酸的振荡，并具有一定的时移。初级降解菌瘤胃球菌科类群的相对丰度与碳底物的动态高度相关，而二级降解菌乳杆菌科和链球菌科类群的相对丰度与糖代谢物高度相关。同时，结肠氮底物与支链氨基酸和支链 SCFA 相关。此外，我们通过体外发酵实验验证了不同碳水化合物和蛋白质组合下肠道微生物的进化。该研究描绘了一天内微生态环境的动态，强调了时间维度在肠道微生物群相关研究中的影响。饲料摄入量，更准确地说是底物摄入量，与微生物进化高度相关，这使得通过营养干预开发针对肠道微生物群的时间疗法成为可能。