The microbiome stabilizes circadian rhythms in the gut

Area of Science:

• Circadian Biology
• Microbiome Research
• Drosophila melanogaster as a model organism

Background:

• The gut microbiome influences host physiology and health.
• Circadian clocks widely regulate host physiology.
• Interactions between the gut microbiome and host circadian rhythms are not fully understood.

Purpose of the Study:

• To investigate the interaction between the gut microbiome and circadian rhythms in Drosophila.
• To determine how timed feeding and microbiome status affect gut gene expression and host physiology.

Main Methods:

• Utilized Drosophila melanogaster models with and without functional circadian clocks (per mutants).
• Employed timed feeding (TF) and microbiome manipulation (germ-free conditions).
• Analyzed gut transcriptome cycling, gene expression amplitude, histone acetylation, and stress sensitivity.

Main Results:

• The gut microbiome did not cycle under ad libitum feeding but showed limited cycling with TF in clockless flies.
• Both TF and microbiome loss independently and jointly altered the gut cycling transcriptome composition.
• TF and microbiome loss increased the amplitude of rhythmic gene expression, with TF effects linked to histone acetylation.
• Timed feeding increased animal sensitivity to stress.
• Germ-free flies exhibited faster resetting of circadian rhythms following light:dark cycle shifts.

Conclusions:

• The gut microbiome plays a role in stabilizing host gut circadian rhythms.
• The microbiome may prevent rapid physiological fluctuations in response to environmental changes.
• Interplay between timed feeding, microbiome, and circadian rhythms impacts gene expression and stress response.