Chronic blue light-emitting diode exposure harvests gut dysbiosis related to cholesterol dysregulation

Abstract

Abstract Background Night shift workers may be associated with circadian dysregulation and metabolic diseases. Mounting evidences illuminate that gut microbiota, circadian clock, and metabolic system are tightly co-evolved. In regarding with artificial light at night (ALAN) has been linking to circadian disruption and causal metabolic diseases, the present study therefore aims to explore the impact of chronic exposure of specific type and different exposing time of light-emitting diodes (LEDs) on the gut microbiota and associated physiological changes. Results Male C57BL/6 mice were exposed to blue or white LED lighting at two exposure time (i.e., 3.6J/cm2 or 7.2J/cm2) from 11 to 44 weeks at ZT13.5-14. 16S rRNA sequencing was used to analyze related gut microbial compositions. Blue LED lighting specifically decreased alpha diversity at both 27 and 44 weeks (p = 0.007 and 0.013). Low dosage of both types of LED lighting did not cause significant changes of microbial compositions. Furthermore, the low irradiance of both blue and white LED illuminations significantly increased serum cholesterol, but not triglyceride. The ratio of beneficial to harmful bacteria was significantly increased at a high irradiance of blue light. This ratio was negatively correlated with serum cholesterol but positively correlated with bile acid biosynthesis. Conclusion Our results revealed that chronic blue LED lighting would promote gut dysbiosis and dysregulate cholesterol metabolism without any additional confounding factors. In addition, the effects of chronic blue LED lighting on shaping gut microbiota in response to optic stress through the brain-gut axis shed a new insight into the link between the host and gut microorganisms to circadian clock and cholesterol metabolism.