Daily cycles of gut bacteria vary by sex and the body’s internal clock

The abundance of Bacteroidetes in the fecal microbiota of mice exhibits circadian rhythmicity, particularly in female mice.

• Circadian rhythms affect physiological and metabolic processes in mammals, including the fecal microbiota.
• Deep sequencing analysis revealed that both the total amount of fecal bacteria and the composition of microbiota vary with the time of day.
• Disruption of the circadian clock by deleting the Bmal1 gene eliminated rhythmic patterns in fecal microbiota for both male and female mice.
• Bmal1 deletion led to changes in bacterial populations, with varying impacts based on the sex of the mice.
• Sexual differences play a role in how the host circadian clock influences microbial composition.

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