Effects of changing daylength and temperature on mouse gut microbiome

To better adapt to seasonal environmental changes, various physiology and behavior are seasonally regulated. The gut microbiome interacts with the physiology, behavior, and even diseases of the host animals including poultry, livestock and humans. Recently, seasonal changes in the gut microbiome composition have been reported in several species living under natural environment. However, available diet varies between different seasons under natural environment, and dietary contents significantly affect the compositions of microbiome. Understanding the seasonal regulatory mechanism of gut microbiome is important to understand seasonal adaptation strategy of animal. In the present study, we have examined the effects of changing day-length and temperature that mimic summer- and winter-conditions on gut microbiome using laboratory mice. Principal coordinate analysis and analysis of composition of microbiomes of 16S rRNA sequencing data demonstrated that microbiome of both cecum and large intestine show significant differences between summer- and winter-mimicking conditions. In line with previous studies, daily rhythm was also observed in the composition of microbiome. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States further predicted seasonal changes in several metabolic pathways. Our results clearly demonstrated that changing day-length and temperature can affect the composition of gut microbiome without changing the dietary contents.