Chronic sleep fragmentation (SF) commonly occurs in human populations, and although it does not involve circadian shifts or sleep deprivation, it markedly alters feeding behaviors ultimately promoting obesity and insulin resistance. These symptoms are known to be related to the host gut microbiota. Mice were exposed to SF for 4 weeks and then allowed to recover for 2 weeks. Taxonomic profiles of fecal microbiota were obtained prospectively, and conventionalization experiments were performed in germ-free mice. Adipose tissue insulin sensitivity and inflammation, as well as circulating measures of inflammation, were assayed. Effect of fecal water on colonic epithelial permeability was also examined. Chronic SF-induced increased food intake and reversible gut microbiota changes characterized by the preferential growth of highly fermentative members of Lachnospiraceae and Ruminococcaceae and a decrease of Lactobacillaceae families. These lead to systemic and visceral white adipose tissue inflammation in addition to altered insulin sensitivity in mice, most likely via enhanced colonic epithelium barrier disruption. Conventionalization of germ-free mice with SF-derived microbiota confirmed these findings. Thus, SF-induced metabolic alterations may be mediated, in part, by concurrent changes in gut microbiota, thereby opening the way for gut microbiome-targeted therapeutics aimed at reducing the major end-organ morbidities of chronic SF.

More VEGF, more life—and health span: Advanced aging is celebrated but its ill effects, deterioration at the cell, tissue, and organ levels, are not. Grunewald et al . provide evidence for the vascular theory of aging, which reports that age-related decrease of vascular function is a driver of organismal aging at large (see the Perspective by Augustin and Kipnis). Vascular endothelial growth factor (VEGF) signaling insufficiency underlies this vascular insufficiency in aged mice. A modest compensatory increase in circulatory VEGF was sufficient to preserve a young-like vascular homeostasis, alleviate multiple adverse age-related processes, and ameliorate a host of age-associated pathologies in mice. —BAP

Study Objectives:. Sleep fragmentation (SF) is a common occurrence and constitutes a major characteristic of obstructive sleep apnea (OSA). SF has been

Study Objectives:The stress imposed by the COVID-19 pandemic and ensuing social isolation could adversely affect sleep. As sleep problems may persist and hurt health, it is important to identify wh...