The Oscillating Gut Microbiome and Its Effects on Host Circadian Biology.
Level 5 - mechanism / opinion, no new human data
Narrative review summarizing mechanistic, pre-clinical, and translational research without a systematic search methodology
PubMed 35576592 · doi:10.1146/annurev-nutr-062320-111321
What was done
This narrative review synthesizes literature on diurnal fluctuations in the gut microbiota. It reviews the characteristics and origins of microbiome rhythms, the pathways of host-microbiome circadian communication, and the potential implications of disrupted microbiome oscillations for human health and disease.
What was found
The abstract reports no primary data, sample sizes, or quantitative effect estimates. It summarizes conceptual findings that gut microbial functions—such as digestion, metabolite synthesis, and immune modulation—exhibit diurnal variation driven by compositional and biogeographical shifts that interact bidirectionally with host circadian clocks.
Why it matters
This work highlights the temporal dimension of host-microbe interactions, showing that microbiome function is dynamic across the 24-hour cycle rather than static.
Limits
As a narrative review, it lacks systematic search criteria or quality grading of included studies. The underlying evidence heavily relies on mechanistic pathways and animal models, and no empirical human trial data are reported in the abstract.
Cited by
- supports The composition of the gut microbiome exhibits circadian rhythmicity, fluctuating in bacterial populations between bedtime and morning.