The sun always rises. And when it does, it kickstarts a cascade of activity across life on Earth. Plants transform light into nutrients, honey bees start foraging for food, and certain types of algae and bacteria begin the process of photosynthesis. We, too, operate in tight synchronicity with sunlight thanks to our bodies’ circadian rhythms.

These internal clocks play a foundational role in our sleep-wake cycle and when we feel energized vs. tired. But their influence doesn’t stop there. Chronobiology research shows that there is also a strong circadian component to our gut health, meaning that our intestinal microbes shift alongside external cues like sunlight and temperature.

Here’s an overview of your gut’s circadian rhythm—and how it might help explain why you always feel constipated while traveling to new time zones, why your stomach is a mess after a night of poor sleep, and why you have trouble digesting food late at night.

Your Microbiome Has Its Own Circadian Clock

The sun always rises. And when it does, it kickstarts a cascade of activity across life on Earth. Plants transform light into nutrients, honey bees start foraging for food, and certain types of algae and bacteria begin the process of photosynthesis. We, too, operate in tight synchronicity with sunlight thanks to our bodies’ circadian rhythms.

These internal clocks play a foundational role in our sleep-wake cycle and when we feel energized vs. tired. But their influence doesn’t stop there. Chronobiology research shows that there is also a strong circadian component to our gut health, meaning that our intestinal microbes shift alongside external cues like sunlight and temperature.

Here’s an overview of your gut’s circadian rhythm—and how it might help explain why you always feel constipated while traveling to new time zones, why your stomach is a mess after a night of poor sleep, and why you have trouble digesting food late at night.