You breathe in and out, over and over, slowly counting your breaths while you stare up at the ceiling. You move from one position to another, hoping you can get comfortable enough to drop off, until you finally have to admit to yourself that, as much as you want to, you can't sleep. Again.
There's nothing worse than feeling like you're sleepwalking through your days, waiting desperately for the moment that you can fall into bed and get some rest, only to find that once you get there you can't actually sleep. And yet, poor sleep is incredibly common, especially in the Western world. Nearly half of Americans get less than 6 hours of sleep a night, a full hour less than the low end of the recommended average of 7-9 hours a night.1
We've known about the results of sleep deprivation for a long time––it causes everything from low mood and unbalanced blood sugar to weight gain and more; increases the chances of accidents on the job; and devastates your willpower and ability for higher thinking—but research on solutions other than traditional sleep aids is relatively new.
However, recent studies indicate that we may have been overlooking a powerful ally for better sleep all this time: prebiotic fiber.
The Benefits of Prebiotics for Sleep
We already know that prebiotics—which are indigestible fibers found in plant-based foods like green bananas, Jerusalem artichokes, and acacia fiber—feed beneficial bacteria that impact your sleep cycle, giving them the energy and nutrients they need to thrive in your gut.
But recent research shows that prebiotics themselves have direct effects on the quality of your sleep, making it easier to fall asleep at the right time and move seamlessly through a healthy sleep cycle. In fact, a study from the University of Colorado found that rats who were fed a diet high in prebiotic fiber not only had healthier gut microbiomes, their bodies were also more likely to maintain the Circadian rhythms that signal the body when it's time to sleep, and they spent more time in restful Non-Rapid Eye Movement (nREM) sleep, as opposed to Rapid Eye Movement (REM) sleep.2
The study also found that prebiotics are "stress-protective," which means that they promote the growth of a specific mix of bacteria in your body that keeps your stress levels manageable, thereby promoting restful sleep. (This is backed up by other studies showing that people who eat a prebiotic-rich diet actually wake up with lower cortisol levels, feeling more alert but less stressed than those who don't get enough of these beneficial fibers.)3
Interestingly, prebiotics also appear to help your body bounce back from stressful or traumatic events, signalling it to spend more time in REM sleep after exposure to a stressor. This is a phenomenon called REM rebound, and people who are able to go through it after an intensely stressful experience appear to have a lower risk of experiencing lasting negative effects on their psychological health.
What's more, the study found that prebiotics increase what's called "alpha diversity" in your gut, which means that they increase both the number of bacterial species you have in your gut, and how evenly those species are distributed. To understand just what a big deal this is, you need to know a little bit about how sleep works, and the role that your gut microbiome plays in it.
How Your Gut Microbiome Impacts Your Sleep
Ideally, your body works on a regulated sleep/wake cycle that has you awake and alert for about 16 hours, and asleep for about 8 hours. This cycle is controlled by your suprachiasmatic nucleus, the "master clock" of your brain that is in charge of all of your Circadian rhythms––like cycles of body temperature, hormone production, digestion, and sleep (among other things)—that keep you alive and well.
When your Circadian rhythms are "in tune," everything works as it should. You wake up feeling refreshed, go about your day with steady energy levels, and gradually wind down in the evening, eventually falling into restful sleep that alternates between nREM and REM sleep at appropriate intervals. But when your rhythms get off, your body doesn't get the signals it needs to keep you awake or let you go to sleep at the right times, and your nREM and REM cycles get all mixed up, causing you to feel tired during the day and awake at night.
That's where the gut microbiome comes in. As a major player in the production of hormones and neurotransmitters that regulate the onset and architecture of sleep, your gut bacteria have a huge impact on when, how much, and how well you sleep. For example, they impact your:
• Serotonin. Your body needs serotonin to convert into melatonin, a hormone that makes you feel sleepy and encourages your digestive system to regularly contract in a pattern that keeps your Circadian rhythms in your brain on track. 90% of the serotonin in your body is produced in your gut, and your gut microbes regulate its production.4
• Cortisol and GABA. Both of these hormones are related to how you respond to stress. Cortisol is one of your "fight and flight" hormones; your body produces it when it sees a threat, which in the modern world can be any kind of stressor. Your gut microbes help keep your cortisol levels under control, and they encourage your body to produce GABA, a hormone that modulates your body's response to stress. And since stress not only makes it harder to shut your brain off at night, but also favors the growth of undesirable bacteria that can throw off your microbial balance, these two hormones are absolutely crucial for good sleep.
• Adenosine. This molecule contributes to you feeling sleepy as the day progresses: you wake up with relatively low levels of adenosine, which ideally increase as the day goes on. When they reach a certain level, your body knows its time to fall asleep––but this only happens when you have enough adenosine. Gut microbes both directly produce adenosine and break down other nutrients needed to make it.5
• IL-1b, TNFa, IL-18. These proteins signal your body when it's time to go into nREM sleep and may also determine when it's time to switch out of it into REM sleep. Your gut bacteria tell your intestinal cells to produce Interleukin-1 Beta (IL-1b) and Tumor Necrosis Factor Alpha (TNFa), and they also induce synthesis of Interleukin 18 (IL-18).6
All that sounds great, but the caveat is that your gut bacteria can only have these positive impacts when you have enough types of beneficial bacteria in large enough numbers. Unfortunately, most of us are regularly exposed to a whole range of things that can disrupt the balance of the microbiome. (Everything from a modern Western diet and spending too much time indoors to exposure to antibiotics in food and medication and the overzealous use of cleaning products puts your good guys at risk.)
Two other really common factors are stress and sleep deprivation. That's right, the relationship between your gut and your sleep goes both ways: improve your gut, and your sleep will benefit. But struggle with sleep, and your gut will also suffer...likely causing you to struggle with sleep.
The good news is, it's absolutely possible to break this cycle, increase your alpha diversity, and restore balance to your gut and peace to your nights––and prebiotics can be a foundational first step.
Gut-Friendly Tips for Healthy Sleep
With so many direct benefits to your sleep quality, it just makes sense to up your prebiotic intake. And when you consider the benefits that prebiotics bring your bacterial good guys, there's even more reason to start making them a part of your daily routine.
So make sure that you're giving your new bacterial allies the nutrition they need to thrive by getting as much prebiotic fiber as you can. Remember, prebiotics increase your gut's alpha diversity and since, like any ecosystem, your gut microbiome thrives on having a wide range of species, the more you can up your diversity, the better.
You've got lots of delicious options for prebiotic-rich foods, including onions, garlic, green bananas, Jerusalem artichokes, chicory, and dandelion greens––but it can be tricky to get the recommended 30g of daily prebiotic fiber from your diet alone. One easy way to make sure you're covering your bases is by incorporating a non-GMO prebiotic fiber blend like Hyperbiotics Prebiotic Powder, made with the perfect mix of fibers to feed your microbial friends.
While you're at it, repopulate your gut with beneficial species that can get your sleep cycles back on track. Your best bet here is a premium probiotic like PRO-15, which contains a curated mix of strains specifically associated with promoting good sleep, including L. rhamnosus, L. casei, L. gasseri, B. longum, and B. infantis, as well as other strains that can indirectly support your sleep by promoting nutrient absorption and managing your energy levels.7,8,9,10
Additionally, make sure that you're covering all your bases by practicing good sleep hygiene, and if you happen to be in the habit of using a sleep aid, see if you can work away from it. While they can be helpful in the short term, you're trying to get your body to self-regulate its cycles, and throwing in a chemical to artificially speed them up or slow them down can make it difficult for your body to reclaim its natural rhythms. (The common sleep aid diphenhydramine, for example, affects the way your body uses serotonin, which is critical for healthy sleep.)11 And you don't want to undermine all the good work your prebiotic fiber does by throwing off your hormone levels!
It's really hard to overstate the benefits of consistently getting high quality sleep: from your moods and your work performance to your overall health, it really is the foundation of a happy, healthy life. So make sure you're giving your body the prebiotic and probiotic support it needs to get those zzz's––it really can make all the difference.
1. National Sleep Foundation (2006). Sleep-Wake Cycle: Its Physiology and Impact on Health. Washington DC: United States.
2. 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
3. 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
4. Konturek, P.C., Brzozowski, T., Konturek, S.J. (2011). Gut clock: implication of circadian rhythms in the gastrointestinal tract. Journal of Physiology and Pharmacology, 62(2), 139-50.
5. Estrela, A.B., Abraham, W-R. (2011). Adenosine in the Inflamed Gut: A Janus Faced Compound. Current Medicinal Chemistry, 18(18), 2791-815. doi: 10.2174/092986711796011274
6. Galland, L. (2014). The Gut Microbiome and the Brain. Journal of Medicinal Food, 17(12), 1261–1272. doi: 10.1089/jmf.2014.7000
7. Huang, R., Wang, K., Hu, J. (2016). Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients, 8(8), 483. doi: 10.3390/nu8080483
8. Sawada, D., Kawai, T., Nishida, K., Kuwano, Y. . . . Rokutan, K. (2017). Daily intake of Lactobacillus gasseri CP2305 improves mental, physical, and sleep quality among Japanese medical students enrolled in a cadaver dissection course. Journal of Functional Foods, 31, 188-197. doi: 10.1016/j.jff.2017.01.042
9. Mairesse, J., Rodenas, C.L.G., Silletti, V., Cassano, T. . . . Maccari, S. (2011). Lactobacillus Reuteri DSM 17938 and Bifidobacterium Longum ATCC BAA-999 Normalize Sleep Patterns in Prenatal Stress Rats. Pediatric Research, 70, 797. doi: 10.1038/pr.2011.1022
10. Desbonnet, L., Garrett, L., Clarke, G., Bienenstock, J., & Dinan, T. G. (2008). The probiotic Bifidobacteria infantis: An assessment of potential antidepressant properties in the rat. Journal of Psychiatric Research, 43(2), 164-174.
11. Tanaka, T., Takasu, A., Yoshino, A., Terazumi, K. . . . Sakamoto, T. (2011). Diphenhydramine overdose mimicking serotonin syndrome. Psychiatry and Clinical Neurosciences, 65, 533–538. doi: 10.1111/j.1440-1819.2011.02234.x
Rachel Allen is a writer at Hyperbiotics who's absolutely obsessed with learning about how our bodies work. She's fascinated by the latest research on bacteria and the role they play in health, and loves to help others learn about how probiotics can help the body get back in balance. For more ideas on how you can benefit from the power of probiotics and live healthier days, be sure to subscribe to our newsletter. To learn more about how a healthy microbiome can enrich your life, subscribe to our newsletter.