This important paper increased our scientific understanding of the mechanism by which a host's circadian clock can affect metabolism and health. Leone, et al. showed that both gut microbiota composition and metabolite production fluctuated daily in mice and that these changes were associated with host circadian rhythms and were modifiable by diet.
Collection and sequencing of fecal material as a proxy of gut microbial content is becoming more and more frequent for clinical and/or research studies.