Poor sleep has become a severe social problem with negative consequences not only for health, but also for individual economic decision making. In children, poor sleep may even have farther-reaching consequences, e.g. telomere shortage through physiological stress; intertwinement of disturbed sleep and psychiatric disorders; and a sleep-dependent increase in dietary intake as a possible source of obesity. Importantly, sleep is closely tied to brain maturation, in animals as well as humans. For example, epidemiological data show that short, fragmented, or poorly consolidated sleep in infancy predicts later cognitive and psychosocial problems.
It is now widely accepted that homeostatic and circadian sleep regulation time biological processes to environmental and physiological needs. Essentially, there is tremendous potential associated with the circadian system for improving human health by timing sleep-wake / feeding-fasting cycles, and regulating cellular signaling pathways. Stimulating healthy sleep regulation in a vulnerable developmental period is thus promising not only for treating regulatory problems, but also for fostering healthy cognitive development.
Empirical work in the past decade has caused a shift in view from sleep as a pure behavior towards sleep as localized neurophysiological and cellular recovery process – a connotation that opens up new avenues. Importantly, bacterial symbionts partially regulate the gene expression landscape of the human host, and first indications suggest that bacteria also influence host sleep regulation. Bacterial signatures, particularly those in the gut, undergo a sequential change in the first months of life. Groundbreaking insights have uncovered that gut bacteria are linked to behavior, brain plasticity and brain development.
Sleep and bacteria are thus promising health targets. Both independently modulate brain maturation and behavior. We explore their maturation and potential risk for developmental disorders with an ongoing longitudinal study throughout the early human lifespan.