Neurobiology of Sleep and Microbiomics in Aging
Authors:   Department of Psychiatry, University of Arkansas for Medical Sciences, 4801 W. Markham St, Little Rock, AR 72205, USA, Larson-Prior Linda J. ,   Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, 4801 W. Markham St, Little Rock, AR 72205, USA,   Department of Neurology, University of Arkansas for Medical Sciences, 4801 W. Markham St, Little Rock, AR 72205, USA, Azhar Gohar ,   Donald W. Reynolds Department of Geriatrics, University of Arkansas for Medical Sciences, 613 Elm St., Little Rock, AR 72205, USA, Davila David G. ,   Central Arkansas Veterans Healthcare System Sleep Center, 4300 W. 7th St., 111SL/LR, Little Rock, AR 72205, USA, Jun Se-Ran ,   Department of Biomedical Informatics, University of Arkansas for Medical Sciences, 501 Jack Stephens Dr., Little Rock, AR 72205, USA, Kemp Aaron S. ,   Department of Psychiatry, University of Arkansas for Medical Sciences, 4801 W. Markham St, Little Rock, AR 72205, USA, Nookaew Intawat ,   Department of Biomedical Informatics, University of Arkansas for Medical Sciences, 501 Jack Stephens Dr., Little Rock, AR 72205, USA, Wei Jeanne Y. ,   Donald W. Reynolds Department of Geriatrics, University of Arkansas for Medical Sciences, 613 Elm St., Little Rock, AR 72205, USA,   Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, 613 Elm St., Little Rock, AR 72205, USA, Wassenaar Trudy M. ,   Molecular Microbiology and Genomics Consultants, 55576 Zotzenheim, Germany
Published: April 2017

(1) Background: The daily rhythms of life on earth are governed by a central clock located in the hypothalamus and entrained primarily by light. By virtue of its connections to a myriad of other clocks located both in the brain and in peripheral organs and cells, this clock provides a timing signal based on the light/dark cycle by which organismal physiology and behaviour are governed. Disturbances of these natural rhythms have multiple downstream effects, frequently resulting in dysregulations of sleep and wake cycles, energy homeostatic signalling and decreased stability of the gut microbiome. With increasing age, changes in these natural rhythms are common, and distinguishing changes associated with healthy aging from those associated with pathological aging is an important and growing avenue of investigation in which the recognition of the interdependence of these systems is critical. (2) Aims: In this review, we focus on the importance of better understanding the integration of these signals and their physiological and behavioural outputs in an aging population in which sleep durations are frequently shortened and dietary choices highly varied and frequently nutritionally poor. (3) Conclusions: The gut-brain-microbiome axis is a critical regulator of health across the lifespan such that dysregulation at any point along this axis impacts organismal function. As yet, the impact of age alone on this system is not fully understood. However, it is clear that age-related dysfunctions including the development of frailty and the increased risk for neurological disease are intertwined with the health of the gut-brain-microbiome axis.