Disrupting daily feeding rhythms by distributing food intake evenly across 24 hours in mice significantly reduces the rhythmic expression of approximately 25% of colonic epithelial cell transcripts, including genes involved in steroid biosynthesis, bile secretion, and mineral absorption, demonstrating that feeding timing provides critical extrinsic cues for maintaining circadian gene regulation independent of the intrinsic cellular clock.

When food is eaten only at certain times of day, the gut receives pulses of fats and nutrients that trigger rhythmic signals in gut cells. These signals turn on and off genes that control fat processing, bile production, and mineral uptake. The same pulses also feed gut bacteria in a timed way, making them produce chemicals that further regulate those genes. When food is spread evenly throughout the day, these pulses disappear, the signals stop cycling, and the genes lose their daily rhythm.