The Surprising Link Between Sleep and Digestion
Today, we’re talking about the hottest area in nutritional science: colon bacteria.
Wait, wait, don’t click away just yet. This is cutting-edge information that’s completely changing the way we understand health…and it’s only a little bit icky. In fact, the gut microbiome, which comprises the trillions of microorganisms that are flourishing in your stomach and intestines, could be the single most critical and undervalued aspect of your overall health.
Don’t believe us? In and on your body, for every cell that belongs to you, there are ten microbial cells (a collective term for bacteria, fungi, and viruses), which means only a tenth of your cells are actually “yours.” Plus, to the extent that we are bearers of genetic information, more than 99 percent of it is microbial. In fact, after the Human Genome Project, we’re starting to see enormous support for the American Gut Project, since we are now beginning to understand that the genetic information in our microbiome may exert a stronger influence on our health than the genes we inherit from our parents.
The Sleep-Stomach Connection
The first thing you need to know is that your sleep quality exerts a profound influence on your gut health. Low-quality sleep means the body doesn’t sufficiently suppress the production of cortisol, the much-feared “stress hormone,” and that can mess with the balance of your gut bacteria. This is huge, because the most crucial measure of your gut health is how diverse it is. The more kinds of beneficial bacteria you have, the more benefits you’re going to get, because, a little like the X-Men, each member of the group has different advantages. Lactobacillus acidophilus Bar13, for example, may improve fat loss, while Bifidobacterium infantis has been linked to some mental benefits.[1][2] Diverse gut flora can help us better absorb the nutrients in our food, as well as improve unpleasant digestive problems like bloating, pain, and diarrhea.[3][4][5][6]
But on top of the cortisol factor, a healthy sleep cycle helps the body produce the hormones melatonin and prolactin, which have been found to improve the good bacteria in the intestines and help digestion.[7][8][9] In short: If you have poor sleep patterns, your hormones aren’t able to optimize digestion, and the gut bacteria are negatively altered.
Beyond the quality and efficiency of your digestion, gut diversity has profound implications for overall health. In fact, multiple human studies have shown that not only does crummy gut diversity lead to increased fat storage and insulin resistance (which is the decisive factor in your diabetes risk), it’s also a cause of inflammation, which is linked to autoimmune diseases, heart disease, and arthritis.[10][11][12][13]
Brain vs. Belly: Who’s in Charge Here?
What’s truly game-changing about new research into the gut microbiome is the fact that researchers are beginning to uncover a link between mental health and gut health. Now, the idea that the mind can affect the gut may not sound so surprising (after all, indigestion is a relatively well-known side effect of stress), but what is still being explored is how the gut can affect the mind.
At first, it was just with animal studies, with high gut diversity linked to, among other things, less anxiety and higher levels of brain-derived neurotrophic factor (BDNF), a protein that supports the growth of new brain cells.[14][15][16][17][18][19]
But human studies have also shown surprising links between a healthy gut and a healthy mind. A 2011 study in the British Journal of Medicine administered probiotics to both rats and human subjects and noted a significant decrease in psychological distress in both species [20]. Findings like these remind us of the fact that the mind does not go unaffected by changes in the body, and many more studies have proposed links between gut diversity, inflammation, and mental conditions like Parkinson’s disease and dementia—suggesting that the gut may be one of the best places to start if we want to protect the brain.[21][22][23][24][25]
The Easy-to-Digest Upshot
All of this is to say that almost every facet of your health is affected by an alien ecosystem in your guts that you’ve probably never given much thought to. Now, we’d be remiss if we didn’t recommend eating plenty of fermented foods, like sauerkraut, yogurt, and kimchi, to get a lot of healthy bacteria flourishing in your colon. Their slightly sour taste comes from the billions of live bacteria belonging to the Lactobacillus and Bifidobacterium families, the most commonly observed (and lauded) in the studies cited here.
But as always, you should never underestimate the impact that a good night’s sleep can have on your health, and that’s especially true with your gut. It’s a lot to take in, but all you need to remember is this: Eat plenty of probiotics, keep your body fat low, and get a dang good night’s sleep.
Interested in how sleep affects weight loss? Check out this blog post.
Footnotes/resources:
Sudo N, et al. [1] Postnatal microbial colonization programs the hypothalamic-pituitary-adrenal system for stress response in mice. J Physiol. 2004 Jul 1;558(Pt 1):263-75.
Candela, M, et al. [2] Interaction of probiotic Lactobacillus and Bifidobacterium strains with human intestinal epithelial cells: adhesion properties, competition against enteropathogens and modulation of IL-8 production. Int J Food Microbiol. 2008 Jul 31;125(3):286-92.
Logan AC et al. [3] Chronic fatigue syndrome: lactic acid bacteria may be of therapeutic value. Med Hypotheses. 2003 Jun;60(6):915-23.
Marteau P, et al. [4] A randomized, double-blind, controlled study and pooled analysis of two identical trials of fermented milk containing probiotic Bifidobacterium lactis CNCM I-2494 in healthy women reporting minor digestive symptoms. Neurogastroenterol Motil. 2013 Apr;25(4):331-e252.
Guyonnet D, et al. [5] Fermented milk containing Bifidobacterium lactis DN-173 010 improves gastrointestinal well-being and digestive symptoms in women reporting minor digestive symptoms: a randomised, double-blind, parallel, controlled study. Br J Nutr. 2009 Dec;102(11):1654-62.
Reid G, et al. [6] Potential uses of probiotics in clinical practice. Potential uses of probiotics in clinical practice. Clin Microbiol Rev. 2003 Oct;16(4):658-72.
Mei, Q et al. [7] A protective effect of melatonin on intestinal permeability is induced by diclofenac via regulation of mitochondrial function in mice. Acta Pharmacol Sin. 2011 Apr;32(4):495-502.
Lu, WZ et al. [8] Melatonin improves bowel symptoms in female patients with irritable bowel syndrome: a double-blind placebo-controlled study. Aliment Pharmacol Ther. 2005 Nov 15;22(10):927-34.
Prolactin is an important regulator of intestinal calcium transportCharoenphandhu N, et al. [9] Can J Physiol Pharmacol. 2007 Jun;85(6):569-81.
Le Chatelier E, et al. [10] Richness of human gut microbiome correlates with metabolic markers. Nature. 2013 Aug 29;500(7464):541-6.
Andreasen AS, et al. [11] Effects of Lactobacillus acidophilus NCFM on insulin sensitivity and the systemic inflammatory response in human subjects. Br J Nutr. 2010 Dec;104(12):1831-8.
Carvalho BM, Saad MJ [12] Influence of gut microbiota on subclinical inflammation and insulin resistance. Mediators Inflamm. 2013;2013:986734.
Kadooka Y, et al. [13] Regulation of abdominal adiposity by probiotics (Lactobacillus gasseri SBT2055) in adults with obese tendencies in a randomized controlled trial. Eur J Clin Nutr. 2010 Jun;64(6):636-43.
Messaoudi M, et al. [14] Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects. Br J Nutr. 2011 Mar;105(5):755-64.
Ohland CL et al. [15] Effects of Lactobacillus helveticus on murine behavior are dependent on diet and genotype and correlate with alterations in the gut microbiome. Psychoneuroendocrinology. 2013 Sep;38(9):1738-47.
Tillisch, K. [16] The effects of gut microbiota on CNS function in humans. Gut Microbes. 2014 May-Jun;5(3):404-10.
Davari, S et al. [17] Probiotics treatment improves diabetes-induced impairment of synaptic activity and cognitive function: behavioral and electrophysiological proofs for microbiome-gut-brain axis. Neuroscience. 2013 Jun 14;240:287-96.
Lee, YK et al. [18] Proinflammatory T-cell responses to gut microbiota promote experimental autoimmune encephalomyelitis. Proc Natl Acad Sci U S A. 2011 Mar 15;108 Suppl 1:4615-22.
Wang, Y et al. [19] The role of microbiome in central nervous system disorders. Brain Behav Immun. 2014 May;38:1-12.
Messaoudi M, et al. [20] Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects. Br J Nutr. 2011 Mar;105(5):755-64.
Ohland CL et al. [21] Effects of Lactobacillus helveticus on murine behavior are dependent on diet and genotype and correlate with alterations in the gut microbiome. Psychoneuroendocrinology. 2013 Sep;38(9):1738-47.
Tillisch, K. [22] The effects of gut microbiota on CNS function in humans. Gut Microbes. 2014 May-Jun;5(3):404-10.
Davari, S et al. [23] Probiotics treatment improves diabetes-induced impairment of synaptic activity and cognitive function: behavioral and electrophysiological proofs for microbiome-gut-brain axis. Neuroscience. 2013 Jun 14;240:287-96.
Lee, YK et al. [24] Proinflammatory T-cell responses to gut microbiota promote experimental autoimmune encephalomyelitis. Proc Natl Acad Sci U S A. 2011 Mar 15;108 Suppl 1:4615-22.
Wang, Y et al. [25] The role of microbiome in central nervous system disorders. Brain Behav Immun. 2014 May;38:1-12.