Deaver Jessica A, Eum Sung Y, Toborek Michal
Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, United States.
Front Microbiol. 2018 Apr 13;9:737. doi: 10.3389/fmicb.2018.00737. eCollection 2018.
Disrupted circadian rhythms and alterations of the gut microbiome composition were proposed to affect host health. Therefore, the aim of this research was to identify whether these events are connected and if circadian rhythm disruption by abnormal light-dark (LD) cycles affects microbial community gene expression and host vulnerability to intestinal dysfunction. Mice were subjected to either a 4-week period of constant 24-h light or of normal 12-h LD cycles. Stool samples were collected at the beginning and after the circadian rhythm disruption. A metatranscriptomic analysis revealed an increase in , a bacterial species known to decrease gut barrier integrity, and a decrease in , a bacterium that helps maintain the intestinal epithelial cell layer, after circadian rhythm disruption. In addition, genes involved in pathways promoting host beneficial immune responses were downregulated, while genes involved in the synthesis and transportation of the endotoxin lipopolysaccharide were upregulated in mice with disrupted circadian cycles. Importantly, these mice were also more prone to dysfunction of the intestinal barrier. These results further elucidate the impact of light-cycle disruption on the gut microbiome and its connection with increased incidence of disease in response to circadian rhythm disturbances.
昼夜节律紊乱和肠道微生物群组成的改变被认为会影响宿主健康。因此，本研究的目的是确定这些事件是否相关，以及异常的明暗（LD）周期导致的昼夜节律紊乱是否会影响微生物群落基因表达和宿主对肠道功能障碍的易感性。将小鼠置于持续24小时光照或正常12小时LD周期下4周。在昼夜节律紊乱开始时和之后采集粪便样本。宏转录组分析显示，昼夜节律紊乱后，已知会降低肠道屏障完整性的一种细菌物种增加，而有助于维持肠上皮细胞层的一种细菌减少。此外，在昼夜节律紊乱的小鼠中，参与促进宿主有益免疫反应途径的基因下调，而参与内毒素脂多糖合成和运输的基因上调。重要的是，这些小鼠也更容易出现肠道屏障功能障碍。这些结果进一步阐明了光周期破坏对肠道微生物群的影响及其与昼夜节律紊乱导致疾病发病率增加的关联。
