The Sleep Gut Connection Part 1: Imbalances
Scientists investigating the relationship between sleep and the microbiome are increasingly finding a dynamic connection between gut health and brain health. The microbial ecosystem may affect sleep and sleep-related physiological functions in a variety of ways, including altering the body’s sleep-wake cycle and affecting the hormones that regulate sleep and wakefulness. The quality of our sleep, in turn, may affect the health and diversity of our microbiome.
There’s constant interplay between the gut and the brain, which means that a disturbance in either can influence sleep. The intestinal microbiome actually promotes the release of many of the neurotransmitters — including dopamine, serotonin, and GABA — that help to regulate mood and promote sleep. Studies show a strong connection between imbalance of gut microbes and stress, anxiety, and depression, which in turn can trigger or exacerbate sleep disruptions. Research also links gut health to pain perception. An unhealthy microbiome appears to increase sensitivity to visceral pain, which then can make falling asleep and staying asleep much more difficult.
Just as an imbalanced gut can affect sleep, unhealthy sleep patterns can disrupt the microbiome, as in the common sleep disorder, obstructive sleep apnea. In one study, scientists put mice through a pattern of disrupted breathing that mimicked the effects of OSA. They found that the mice that lived with periods of OSA-like breathing for six weeks showed significant changes to the diversity and makeup of their microbiota.
Gut health also has a significant connection to hormones that affect sleep. Melatonin, the “darkness hormone”, is essential to sleep and a healthy sleep-wake cycle. Melatonin is actually produced in the gut as well as the brain, and evidence suggests intestinal melatonin may operate on a different cyclical rhythm than the pineal melatonin generated in the brain.
Additionally, cortisol is critical to the sleep-wake cycle. This hormone is central to the body’s stress and inflammatory response, and exerts an effect on gut permeability and microbial diversity. Rising levels of cortisol very early in the day help to promote alertness, focus and energy. Changes to cortisol that occur within the gut-brain axis are likely to have an effect on sleep.
Put very simply: our gut affects how well we sleep, and sleep affects the health of our gut. When you improve one, you improve both, which makes for a much healthier – and better rested – you.
Sweet dreams!
Michael J. Breus, Ph.D., is a Clinical Psychologist and Diplomate of the American Board of Sleep Medicine as well as a Fellow of The American Academy of Sleep Medicine. He is one of only 168 psychologists in the world with his credentials and specialty in Sleep Disorders. Dr. Breus is the author of The Power of When, The Sleep Doctor’s Diet Plan, and Beauty Sleep. Dr. Breus is on uBiome’s scientific advisory board and on the clinical advisory board of The Dr. Oz Show and has appeared regularly on the show (39 times in 8 seasons). You can connect with Dr. Breus at www.thesleepdoctor.com or on Facebook: @thesleepdoctor, or Twitter @thesleepdoctor.
References
Akerstedt, T. (2006). Psychosocial stress and sleep. Scandinavian Journal of Work, Environment, & Health. 32(6): 493-501. http://www.jstor.org/stable/40967601.
Anderson, G. and Maes, M. (2015). The gut-brain axis: role of melatonin in linking psychiatric, inflammatory, and neurodegenerative conditions. Advances in Integrative Medicine. 2(1): 31-7. doi:10.1016/j.aimed.2014.12.007
Azvolinsky, A. (2015-4-16). Gut microbes influence circadian clock. The Scientist. http://www.the-scientist.com/?articles.view/articleNo/42715/title/Gut-Microbes-Influence-Circadian-Clock/
Bischoff, S.C. (2011). Gut health: a new objective in medicine? BMC Med, 9:24. doi: 10.1186/1741-7015-9-24
Brain Basics: Understanding Sleep. (2014-7-25). National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/brain_basics/understanding_sleep.htm
Bush, B. and Hudson, T. (2010). The role of cortisol in sleep. Natural Medicine Journal. 2:6. http://www.naturalmedicinejournal.com/journal/2010-06/role-cortisol-sleep
Carpenter, S. (2012-09). That gut feeling. Monitor on Psychology. 43:8. http://www.apa.org/monitor/2012/09/gut-feeling.aspx
Chichlowski, M. and Rudolph, C. (2015) Visceral pain and gastrointestinal microbiome. Journal of Neurogastroenterology and Motility. 21(2): 172-181. http://dx.doi.org/10.5056/jnm15025
Circadian Rhythm Fact Sheet. (2005-10-01). National Institute for General Medical Sciences. https://www.nigms.nih.gov/Education/Pages/Factsheet_CircadianRhythms.aspx
Forsythe, P. et al. (2010). Mood and gut feelings. Brain, Behavior, and Immunity. 24(1): 9-16. doi:10.1016/j.bbi.2009.05.058.
Foster, J.A. and McVey Neufeld, K A. (2013). Gut-brain axis: how the microbiome influences anxiety and depression. Trends in Neurosciences. 36(5): 305-312. doi:10.1016/j.tins.2013.01.005
Galland, L. (2014). The gut microbe and the brain. Journal of Medicinal Food. 17(12): 1261-72. doi: 10.1089/jmf.2014.7000.
Huang, W. et al. (2011). Circadian rhythms, sleep, and metabolism. Journal of Clinical Investigation. 121(6): 2133-41. doi: 10.1172/JCI46043.
The Human Microbiome. http://learn.genetics.utah.edu/content/microbiome/
Leone, V et al. (2015). Effects of diurnal variation of gut microbes and high-fat feeding on host circadian clock function and metabolism. Cell Host & Microbe, doi:10.1016/j.chom.2015.03.006.
Liang, X. et al. (2015). Rhythmicity of the intestinal microbiota is regulated by gender and the host circadian clock. Proceedings of the National Academy of Sciences. 201501305 DOI: 10.1073/pnas.1501305112
Moloney, R.D. and Desbonnet, L. et al. (2014) The microbiome: stress, health and disease. Mammalian Genome. 25(1): 49-74. doi: 10.1007/s00335-013-9488-5
Montel-Castro, A.J. et al. (2013). The microbiota-gut-brain axis: neurobehavioral correlates, health and sociality. Frontiers in Integrative Neuroscience. 7:70. doi: 10.3389/fnint.2013.00070
Moreno-Indias, I. et al (2015). Intermittent hypoxia alters gut microbiota diversity in a mouse model of sleep apnoea. European Respiratory Journal. 45(4): 1055-65. doi: 10.1183/09031936.00184314
Mukherjee, S. and Maitra, S.K. (2015). Gut melatonin in vertabrates: chronobiology and physiology. Frontiers in Endocrinology. 6:112 http://dx.doi.org/10.3389/fendo.2015.00112.
Pain and Sleep. National Sleep Foundation. https://sleepfoundation.org/sleep-disorders-problems/pain-and-sleep
Pollan, M. (2013, May). Some of my best friends are germs. New York Times Magazine. http://www.nytimes.com/2013/05/19/magazine/say-hello-to-the-100-trillion-bacteria-that-make-up-your-microbiome.html?_r=1
Schwartz, J.R.L. and Roth, T. (2008). Neurophysiology of sleep and wakefulness: basic science and clinical implications. Current Neuropharmacology. 6:4, pp. 367-378. doi: 10.2174/157015908787386050
Taylor, D. et al. (2005). Epidemiology of insomnia, depression and anxiety. SLEEP 28(11): 1457-1464. http://www.journalsleep.org/Articles/281117.pdf
Thaiss, C.A., et al. (2014) Transkingdom control of microbiota diurnal oscillation promotes metabolic homeostasis. Cell, 159:33, p514-529. doi: http://dx.doi.org/10.1016/j.cell.2014.09.048
Voight, R.M. et al. (2014) Circadian disorganization alters intestinal microbiota. PLoS ONE 9(5): e97500. doi: 10.1371/journal.pone.0097500
Wood, M. (2015-5-13). The microbiome and the midnight snack: how gut microbes influence the body’s clock. Science Life. http://sciencelife.uchospitals.edu/2015/05/13/the-microbiome-and-the-midnight-snack-how-gut-microbes-influence-the-bodys-clock/