Good sleep and a healthy gut flora – what can we learn from research?

Sleep deprivation is one of the most common health related problems in modern society. Almost as much as 20 % of the global population have trouble sleeping. And anyone who’s ever suffered from sleep deprivation is familiar with the stress and agony it can cause and how it affects your everyday life. Sleep deprivation does not only make you tired and cause stress. Research shows a connection between how you sleep and your gut flora, where lack of sleep has a negative impact on your gut. But the upside is that a good night’s sleep works wonders for your gut health, and that you can improve your sleep by taking care of your gut.

Good sleep quality improves your gut health

It is common to associate good sleep with how many hours of sleep you get. But it is actually the quality of your sleep that is important. A study published in Plos One, an American magazine, shows a connection between our sleep quality and our gut flora. The study was performed on people who slept with an advanced measuring instrument attached to their bodies to measure the quality of their sleep. When the sleep quality was determined, researchers measured the number of good bacteria in the gut. The results showed that the people with the best sleep quality had a healthier gut flora with more good bacteria.

Irregular sleep can damage your gut flora

A study made at Weizmann Institute of Science in Rehovot, Israel, found a connection between irregular sleep and an unbalanced gut flora. Researchers studied fecal samples from mice living in a lab, and subsequently also tested a smaller group of humans affected by jetlag.

When studying the fecal samples, it was found that the activity in the gut flora varied from daytime to nighttime. During the day, when the mice were active, the gut bacteria focused mainly on digestion and repairing the DNA. During nighttime when the mice were sleeping, the bacteria shifted focus to getting rid of toxins, repairing and restoring different parts of the gut flora. For the mice who had irregular sleeping patterns, the shifts of focus and activity in the gut flora happened to a lesser extent. This indicates a connection between irregular sleeping patterns and the constitution and functions in the gut flora.

The part of the study focusing on humans showed that jetlag caused an increased amount of a specific bacteria which is more common amongst people suffering from obesity and diabetes. This bacteria is also associated with weight gain, increased blood sugar levels and a higher body fat percentage. When returning to more regular sleeping patterns, the participants in the study showed reduced levels of the unhealthy bacteria and a restored balance in the gut flora.

Taking care of your gut flora and digestion has a positive impact on your sleep

As it shows, your sleep and your gut flora need each other to function. We have already established that poor sleep will have a negative effect on your gut health. But the good news is that by taking care of your gut and strengthening your gut flora, you can improve the quality of your sleep. The good bacteria in the gut regulate the stress levels in our bodies and produce hormones that are essential for our wellbeing and how we sleep. Melatonin is often referred to as the sleep hormone, since it makes us feel tired. To be able to produce melatonin, our bodies need another hormone – serotonin. This is our “happy hormone” that affects how we feel, our cognitive functions and is essential for how we sleep. As much as 95 % of the serotonin is produced in the gut, hence taking care of your gut health is important for your mood, cognition and sleep quality.

Prebiotics – essential for better sleep and a healthier gut

Prebiotics, that can be found in for example green bananas, Jerusalem artichokes, onions, garlic and asparagus, is a good way to boost the good bacteria in your gut and thereby improving your sleep. Studies have also shown a direct connection between good sleep and prebiotics, where a diet high in prebiotics made falling asleep easier and improved the sleep cycle. Prebiotics also stimulate the growth of healthy gut bacteria that actively reduce stress levels, and thereby help us sleep better.


Study published in the medical journal Plos One by American researchers at Nova Southeastern University: University

Thompson, R.S., Roller, R., Mika, A., Greenwood, B.N. . . . Fleshner, M. (2017). Dietary Prebiotics and Bioactive Milk Fractions Improve NREM Sleep, Enhance REM Sleep Rebound and Attenuate the Stress-Induced Decrease in Diurnal Temperature and Gut Microbial Alpha Diversity. Frontiers in Behavioral Neuroscience, 10(240). doi: 10.3389/fnbeh.2016.00240

Schmidt, K., Cowen, P.J., Harmer, C.J., Tzortzis, G., Errington, S., Burnet, P.W. (2015). Prebiotic intake reduces the waking cortisol response and alters emotional bias in healthy volunteers. Psychopharmacology, 232(10), 1793-801. doi: 10.1007/s00213-014-3810-0

Study by S Eran Elinav, immunologist specialized in the microbiome at Weizmann Institute of Science in Rehovot, Israel:Science Mag

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