Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan.
Milk Science Research Institute, Megmilk Snow Brand Co., Ltd, Kawagoe, Saitama, Japan.
Genes Cells. 2023 Jun;28(6):433-446. doi: 10.1111/gtc.13025. Epub 2023 Mar 28.
Commensal microbes influence various aspects of vertebrate and invertebrate brain function. We previously reported that Lactiplantibacillus plantarum SBT2227 promotes sleep in the fruit fly, Drosophila melanogaster. However, how widely the sleep-promoting effects are conserved in gut bacterial species remains unknown. In this study, we orally administered human intestinal and food-associated bacterial species (39 in total) to flies and investigated their effects on sleep. Six species of bacteria were found to have significant sleep-promoting effects. Of these, we further investigated Bifidobacterium adolescentis, which had the greatest sleep-promoting effect, and found that the strength of the sleep effect varied among strains of the same bacterial species. The B. adolescentis strains BA2786 and BA003 showed strong and weak effects on sleep, respectively. Transcriptome characteristics compared between the heads of flies treated with BA2786 or BA003 revealed that the gene expression of the insulin-like receptor (InR) was increased in BA2786-fed flies. Furthermore, a heterozygous mutation in InR suppressed the sleep-promoting effect of BA2786. These results suggest that orally administered sleep-promoting bacteria (at least BA2786), may act on insulin signaling to modulate brain function for sleep.
共生微生物影响脊椎动物和无脊椎动物大脑功能的各个方面。我们之前报道过植物乳杆菌 SBT2227 可促进果蝇的睡眠。然而，肠道细菌物种的促睡眠作用在多大程度上是保守的仍不清楚。在这项研究中，我们给果蝇口服了人类肠道和食物相关的细菌物种（共 39 种），并研究了它们对睡眠的影响。发现有 6 种细菌具有显著的促睡眠作用。在这些细菌中，我们进一步研究了具有最大促睡眠作用的青春双歧杆菌，并发现同一种细菌的不同菌株的促睡眠效果存在差异。双歧杆菌 BA2786 和 BA003 菌株分别具有较强和较弱的促睡眠作用。比较用 BA2786 或 BA003 处理的果蝇头部的转录组特征表明，胰岛素样受体 (InR) 的基因表达在 BA2786 喂养的果蝇中增加。此外，InR 的杂合突变抑制了 BA2786 的促睡眠作用。这些结果表明，口服的促睡眠细菌（至少 BA2786）可能通过胰岛素信号通路作用于大脑功能以调节睡眠。
