This comprehensive set of studies, by researchers in Israel, showed that intestinal microbiota in mice and humans show diurnal changes in composition and function. The changes happen on the scale of hours, and are influenced by the host’s feeding rhythms.It is already known that chronic jet lag and shift work is associated with dysbiosis. Here, researchers induced jet lag and showed that the resulting disruptions to the intestinal microbiota promoted metabolic imbalances. The jet-lag-induced dysbiosis in both mice and humans promoted glucose intolerance and obesity, which was transferrable to germ-free mice through fecal transplantation.
The studies provide evidence of daily rhythms of microbiota change that coordinate across the metaorganism. The finding that host microbiota fluctuate over a matter of hours has implications for future microbiota studies; it suggests that samples should be taken from subjects at a consistent time of day to control for these changes.
See science writer Ed Yong’s blog post on the research here.
Thaiss et al., Transkingdom Control of Microbiota Diurnal Oscillations Promotes Metabolic Homeostasis, Cell (2014), http://dx.doi.org/10.1016/j.cell.2014.09.048