Sleep and the gut microbiota in preschool-aged children.

Sleep plays a significant role in the mental and physical development of children. Emerging evidence in animals and human adults indicates a relationship between sleep and the gut microbiota; however, it is unclear whether the sleep of preschoolers during a key developmental period, associates with features of their gut microbiota. The objective of this study was to assess the relationship between sleep and gut microbiota in preschool-aged children (4.37 ± 0.48 years, n = 143). Sleep measures included total night-time sleep (TST), sleep efficiency (SE), and wake-time after sleep onset (WASO) assessed using actigraphy. Beta-diversity differences between children with low and high TST (p = .048) suggest gut microbiota community differences. Particularly, relative abundance of Bifidobacterium was higher in the high TST group and Bacteroides, was higher in children who had greater SE and less WASO (LDA score >2). In contrast, some Lachnospiraceae members including Blautia and Coprococcus 1 were associated with shorter night-time sleep duration and less efficiency, respectively. We also found a group of fecal metabolites, including specific neuroactive compounds and immunomodulating metabolites were associated with greater sleep efficiency and less time awake at night. Notably, tryptophan and its metabolizing products were higher in children who had higher SE or lower WASO (LDA score >2); concentration of propionate was higher in children with less WASO (p = .036). Overall, our results reveal a novel association between sleep and gut microbiota in preschool-aged children. Longer night-time sleep and greater sleep efficiency were associated with specific commensal bacteria that may regulate sleep through modulating neurotransmitter metabolism and the immune system.