The Impact of Minor Sleep Schedule Adjustments on Gut Health

Maintaining regular sleep patterns may support your gut health, according to a new study.

Researchers from King’s College London found that keeping a consistent sleep schedule by going to bed and waking up around the same time each day may help people avoid “social jet lag.”

Social jet lag, or going to sleep and waking up at very different times during the week, compared to the weekend, can have negative health effects. The research team also found that quality of rest impacted people’s social jet lag.

The new study of roughly 1,000 adults, published earlier this month in the European Journal of Nutrition, analyzed participants’ blood, stool, and gut microbiome, comparing those who maintained a regular sleep schedule to those who did not.

Researchers found that even a 90-minute difference in the timing of the midpoint of sleep impacted gut microbiome composition.

“We were surprised to find a persistent relationship between social jet lag and species living in the gut, independent of age,” Kate Bermingham, PhD, Senior Scientist at ZOE, postdoctoral researcher at Kings College London, and lead researcher on the study told Health.

“We found that a change of 90-minutes either side of the usual sleep midpoint has a significant association with worse markers of diet and microbiome health,” she said.

The research team concluded that three of the six microorganisms found in the guts of those with social jet lag were associated with poor health conditions, such as obesity, inflammation, stroke risk, and cardiovascular risk.

Social jet lag is thought to affect more than 40% of the UK population, and is most common in teenagers and young adults, tapering with age. The study found that older sleepers were some of the best at keeping their sleep schedule consistent.

Food choices also played a major role in participants' overall gut health.

In addition to having their sleep recorded and stool collected, participants recorded everything they ate in a food questionnaire. Roughly 16% of the participants had social jet lag and were more likely to eat a diet heavy with potato chips, sugary drinks, and fewer fruits or vegetables.

“Poor quality sleep impacts choices—and people crave higher carb or sugary foods,” Bermingham said.

She explained that the research team found that snacking after 9 PM was negatively associated with metabolic health markers; eating late at night could result in less time for the gut to repair as necessary.

“Without sufficient sleep, our gut biome suffers, and insufficient sleep coupled with eating late at night may be more detrimental to health,” she said.

According to the study, heavily-disrupted sleep was one of the main culprits of social jet lag.

These often include individuals who work unorthodox shifts, whose jobs require them to work at night and sleep during the day, sometimes resuming normal sunrise-to-sundown wake schedules on the weekends.

“While night-shift workers may find it difficult to reach for whole foods instead of high-calorie convenience foods, doing so might help,” Ying-Chieh Tsai, PhD, biochemist, gut-microbiome expert, and chief scientist at Bened Life who was not involved in the study said.

“Fiber-rich prebiotic foods may increase gut microbial diversity and help decrease sleep disturbances,” he said.

Regardless of when you’re able to go to sleep, Tsai recommends that individuals still aim for seven to eight hours of sleep, creating the morning as night by investing in blackout curtains or using a sleeping mask, and being mindful of when their last caffeinated beverage was.

He also advises that with new technology it’s easy to set bed and wake times and lock other apps on your phone during that time, to ensure your sleep is uninterrupted.

“It can be tempting to skimp on sleep to emulate a traditional 9 to 5 schedule, especially if you have children or are taking care of elderly family members, however, that may be detrimental to health,” Tsai said.

Previous studies have also suggested that irregular sleep could yield negative health outcomes like mental fatigue and higher levels of inflammation and stroke risk.

One report found that regularly sleeping more than nine hours per night raises the risk of stroke; another recent study found that sleep deprivation leads to changes in gut microbiome composition.

While the relationship between sleep, diet, and gut health is complex, researchers behind the study at King’s College had actionable recommendations.

They include going to bed and getting up at the same time every day of the week, regardless of work schedule, and eating a healthy diet that promotes gut well-being.

“The key takeaway is to create a consistent sleep schedule and aim to go to sleep and wake up around the same time, as often as possible,” Bermingham said. “Consistency is more important than perfection.”

Tsai firstly recommends avoiding blue light from LED screens before bed, as these reduce melatonin secretion.

He also recommends prioritizing a healthy diet by eating your final meal of the day two to three hours before bedtime to reduce gastroesophageal reflux disease (GERD) and increase the chances of getting quality sleep. Eating a meal or big snack too close to bedtime can disrupt your sleep cycle and increase stomach aches.

“Your diet impacts not only your own body but also the microorganisms that inhabit your gut,” Tsai said.

It’s not just meal times you should consider, but what you’re putting in your body over the course of the day that can also make a huge difference in your gut health.

“When you eat healthy foods that contain prebiotic fiber, this feeds the good bacteria in your gut, allowing them to thrive,” Tsai said. “They, in turn, produce molecules that can be helpful in keeping the digestive tract healthy, and in reducing inflammation in the gut.”