A recent study from the Department of Child Rehabilitation in China uncovered some interesting differences in the gut microbiomes of kids who go to bed early compared to those who stay up late. Spoiler alert: if you’re letting your kid burn the midnight oil, they might be missing out on some important bacteria.

The research showed that children who hit the sack earlier had more diversity in their gut bacteria—basically, their stomachs were home to a wider variety of microorganisms, and that’s a good thing. One of the main players in this bacterial bonanza is Akkermansia muciniphila. This beneficial bacterium is linked to gut health and even cognitive functions, meaning it could potentially be helping these early sleepers with more than just digestion.

We already know that sleep is vital for kids, and other studies have shown it boosts academic performance, helps them grow, and even keeps their body mass index (BMI) in a healthy range. This latest study decided to dig deeper, focusing on how sleep schedules affect gut health. The study published in Scientific Reports analyzed the fecal samples (yes, poop) of 88 healthy kids aged 2 to 14.

The kids were divided into two groups: those who fell asleep before 9:30 p.m. and those who stayed up later. Over two weeks, their sleep habits were tracked—everything from how long it took to fall asleep, how often they woke up at night, and even how well they slept.

What did they find? The early sleepers had more of that Akkermansia muciniphila, as well as other bacteria like Holdemania filiformis and Firmicutes bacterium CAG-95. There was also an increase in Streptococcus sp. A12, Weissella confusa, Clostridium sp. CAG-253 and Eubacterium siraeum in the early-to-bed group. Some fungi, like CAG-83, were even higher in these kids. In the world of gut health, that’s basically a win.

The late-night crew, on the other hand, didn’t show as much of this microbial diversity. Fewer beneficial bacteria mean their gut health might not be as good, which could have long-term impacts on things like metabolism, cognitive functions, and even mood.

At a broader level, the study found that certain bacteria correlated with sleep quality. For example, Akkermansia muciniphila and Alistipes finegoldii were linked to how long it took to fall asleep, while Clostridium sp. CAG-253 had a negative association with sleep onset latency (basically, the longer it took to fall asleep, the less of these bacteria showed up). Even more interesting, Alistipes finegoldii was positively associated with total sleep duration but negatively tied to things like dream frequency and sleep efficiency.

When they dug into metabolic data, early sleepers showed increased activity in pathways related to amino acid metabolism and neurotransmitter regulation. Translation? These kids might be benefiting from better brain development and function, thanks in part to their early bedtimes.

The researchers pointed out that their findings don’t necessarily prove that an early bedtime directly causes these changes in gut bacteria. It’s possible that the gut microbiome itself could be influencing sleep patterns instead. Still, the results open the door to exploring new treatments for sleep disorders in children by targeting gut health.

There’s definitely more to explore here. The links between sleep, gut health, and brain function could offer new insights into how we deal with sleep problems, as well as how we understand the connection between our digestive system and our cognitive function.

In short, the next time you consider letting your kid stay up late, just remember that their gut bacteria might have other plans. And who knows, those early bedtimes might be doing more for their brains than you think.