The connection between sleep and gut health

Inadequate sleep has become a public health concern, and therefore awareness of the negative impact of a lack of sleep has increased. Of course, people don’t need a public health campaign to tell them how lack of sleep negatively impacts daily functioning—unfortunately, everyone has personal experience. However, it may be the less noticeable negative side effects that people need to be most aware of.

Inadequate sleep increases obesity and inflammation, impairs immune and antioxidant defenses, and negatively impacts mood.^1,2 Inadequate sleep is associated with heightened emotional reactivity, reduced attention, memory and executive cognitive function.³

It has been suggested that the circadian disruption associated with shorter sleep duration alters the gut microbiome. This in turn increases systemic inflammation associated with metabolic syndrome and may explain the connection between metabolic syndrome and inadequate sleep.⁴

Short-term sleep deprivation has been shown to alter the human gut microbiome with just two nights of decreased sleep (4.25 hours),⁵ but may not do so over longer periods of sleep deprivation.⁶ A recent study reported that self-reported sleep quality was positively associated with microbial diversity in young healthy adults.⁷ Conclusions are challenging because of small subject numbers, differences in fecal testing protocols, and the multiple factors that impact both sleep and the microbiome. Regardless, the connection between sleep and the microbiome is bidirectional, undoubtedly complex and most likely mitigated by the gut brain axis.⁸

The cytokines, especially interleukin (IL)-1 beta and IL-6, may explain part of the communication between sleep physiology and the gut microbiome.⁹ A recent study found a link between gut microbiome composition, sleep physiology, IL-6, the immune system and cognition—suggesting that manipulating any one of these factors may improve the others.¹⁰

While probiotics are best known for modifying the gut microbiome, they may also benefit sleep quality.¹¹ However, as a single-ingredient supplement, they alone may not benefit all aspects of sleep. Therefore, it may be wise to consider probiotics as part of a multi-ingredient dietary supplement that targets these related factors. For example, melatonin,¹² valerian,¹³ magnesium,¹⁴ lavender,¹⁵ and tryptophan¹⁶ have all been shown to benefit sleep. And zinc has been shown to play a role in sleep,¹⁴ gut health,¹⁷ and immunity and inflammation.¹⁸

Nobody can go wrong with the foundation of a healthy diet and exercise to address gut health, inflammation and sleep.¹⁹ Sleep is a key component of good health, but all aspects of health start with a healthy lifestyle. After all, every aspect of health is interconnected.

Susan Hewlings, Ph.D., RD, is director of scientific affairs at GRAS Associates/Nutrasource.

References

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4 Reynolds AC et al. "The shift work and health research agenda: Considering changes in gut microbiota as a pathway linking shift work, sleep loss and circadian misalignment, and metabolic disease." Sleep Med Rev. 2017;34:3-9.

5 Benedict C et al. "Gut microbiota and glucometabolic alterations in response to recurrent partial sleep deprivation in normal-weight young individuals." Mol Metab. 2016;5(12):1175-1186.

6 Zhang SL et al. "Human and rat gut microbiome composition is maintained following sleep restriction." Proc Natl Acad Sci U S A. 2017;114(8):E1564-e1571.

7 Grosicki GJ et al. "Self-reported sleep quality is associated with gut microbiome composition in young, healthy individuals: a pilot study." Sleep Med. 2020;73:76-81.

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16 Markus CR et al. "Evening intake of alpha-lactalbumin increases plasma tryptophan availability and improves morning alertness and brain measures of attention." Am J Clin Nutr. 2005;81(5):1026-1033.

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