Light, fat, and commensals
The gut microbiota facilitates energy harvest from food and transfers it into fat storage. Working in mice, Wang et al. found that an epithelial cell circadian transcription factor, NFIL3, is involved in regulating body composition through lipid uptake. Flagellin and lipopolysaccharide produced by certain microbes tuned the amplitude of oscillation of NFIL3 through innate lymphoid cell (ILC3) signaling, STAT3, and the epithelial cell clock. Such interactions may help to explain why circadian clock disruptions in humans, arising from shift work or international travel, frequently track with metabolic diseases, including obesity, diabetes, and cardiovascular disease.
Abstract
The intestinal microbiota has been identified as an environmental factor that markedly affects energy storage and body-fat accumulation in mammals, yet the underlying mechanisms remain unclear. Here we show that the microbiota regulates body composition through the circadian transcription factor NFIL3. Nfil3transcription oscillates diurnally in intestinal epithelial cells, and the amplitude of the circadian oscillation is controlled by the microbiota through group 3 innate lymphoid cells, STAT3 (signal transducer and activator of transcription 3), and the epithelial cell circadian clock. NFIL3 controls expression of a circadian lipid metabolic program and regulates lipid absorption and export in intestinal epithelial cells. These findings provide mechanistic insight into how the intestinal microbiota regulates body composition and establish NFIL3 as an essential molecular link among the microbiota, the circadian clock, and host metabolism.
DOI: 10.1126/science.aan0677
