Repeated sleep disruption in mice leads to persistent shifts in the fecal microbiome and metabolome

It has been established in recent years that the gut microbiome plays a role in health and disease, potentially via alterations in metabolites that influence host physiology. Although sleep disruption and gut dysbiosis have been associated with many of the same diseases, studies investigating the gut microbiome in the context of sleep disruption have yielded inconsistent results, and have not assessed the fecal metabolome. We exposed mice to five days of sleep disruption followed by four days of ad libitum recovery sleep, and assessed the fecal microbiome and fecal metabolome at multiple timepoints using 16S rRNA gene amplicons and untargeted LC-MS/MS mass spectrometry. We found global shifts in both the microbiome and metabolome in the sleep-disrupted group on the second day of recovery sleep, when most sleep parameters had recovered to baseline levels. We observed an increase in the Firmicutes:Bacteroidetes ratio, along with decreases in the genus Lactobacillus, phylum Actinobacteria, and genus Bifidobacterium in sleep-disrupted mice compared to control mice. The latter two taxa remained low at the fourth day post-sleep disruption. We also identified multiple classes of fecal metabolites that were differentially abundant in sleep-disrupted mice, some of which are physiologically relevant and commonly influenced by the microbiome. This included bile acids, and inference of microbial functional gene content suggested reduced levels of the microbial bile salt hydrolase gene in sleep-disrupted mice. Overall, this study adds to the evidence base linking disrupted sleep to the gut microbiome and expands it to the fecal metabolome, identifying sleep disruption-sensitive bacterial taxa and classes of metabolites that may serve as therapeutic targets to improve health after poor sleep.

近年来已有研究证实，肠道微生物组（gut microbiome）可通过调控影响宿主生理的代谢物改变，在健康与疾病发生过程中发挥作用。尽管睡眠紊乱与肠道菌群失调（gut dysbiosis）已被证实与诸多相同疾病存在关联，但针对睡眠紊乱背景下肠道微生物组的相关研究所得结果并不一致，且尚未有研究对粪便代谢组（fecal metabolome）进行系统性评估。本研究将小鼠暴露于为期5天的睡眠紊乱环境中，随后给予4天的自由恢复睡眠（ad libitum recovery sleep），并通过16S rRNA基因扩增子（16S rRNA gene amplicons）与非靶向LC-MS/MS质谱法（untargeted LC-MS/MS mass spectrometry），在多个时间点对粪便微生物组（fecal microbiome）与粪便代谢组进行检测分析。我们发现，在恢复睡眠的第二天（此时多数睡眠参数已恢复至基线水平），睡眠紊乱组小鼠的微生物组与代谢组均发生了全局变化。与对照组小鼠相比，该组小鼠的厚壁菌门（Firmicutes）与拟杆菌门（Bacteroidetes）的丰度比值升高，同时乳杆菌属（Lactobacillus）、放线菌门（Actinobacteria）及双歧杆菌属（Bifidobacterium）的丰度出现显著下降。后两类类群在睡眠紊乱后的第4天仍维持较低丰度。我们还鉴定出睡眠紊乱组小鼠中存在多种丰度存在显著差异的粪便代谢物，其中部分代谢物具有生理相关性，且通常受微生物组调控，其中包括胆汁酸（bile acids）。对微生物功能基因含量的推断显示，睡眠紊乱组小鼠体内的微生物胆汁盐水解酶（microbial bile salt hydrolase）基因的表达水平有所降低。总体而言，本研究进一步丰富了睡眠紊乱与肠道微生物组之间关联的证据基础，并将研究范畴拓展至粪便代谢组，鉴定出对睡眠紊乱敏感的细菌类群与代谢物类别，这些物质或可作为改善不良睡眠后健康状态的潜在治疗靶点。