By Dr Sammie Gill, Gastroenterology Dietitian and Scientific Research and Development Manager, Symprove.
Sleep is inseparably linked to the health of the immune system, and 70% of the immune system sits along the gut – so it’s no wonder there is now focus on how the gut influences sleep and vice versa, and how this translates to health.
Yet despite the emphasis on the importance of sleep for health, one third of adults report less than seven hours of sleep per night, and an estimated 20% of the working population are employed in shift work. Simultaneously, sleep disorders (such as insomnia) are increasingly common. Additionally, our lifestyles are often not conducive to a good nights’ sleep. For example, going on holidays and crossing time zones.
Concerningly, the research to date has consistently highlighted that poor quality and/or quantity of sleep can drive short-term ill health (e.g., somatic pain, emotional distress, mood changes, increased stress) and long-term ill-health (high blood pressure, weight-related issues, type 2 diabetes, high cholesterol).
The rotation of Earth leads to the oscillation of light-dark cycles over a 24-hour period and humans have synchronised to this by developing sleep-wake cycles (or circadian rhythms); a mechanism that dictates things such as feeding, temperature and hormonal changes in a coordinated manner. While our sleep-wake cycle is orchestrated by the brain’s central ‘master clock’, it is well established that this in turn synchronises all the little peripheral clocks, which exist in virtually every individual cell in the human body!
Sleep-Wake Cycles and the Gut Microbiome
In recent years, there has been growing interest into the effects of our sleep-wake cycles on the gut microbiome. Current research has shown that our sleep-wake cycles drive rhythmic compositional and functionality changes in gut microbial communities, which alters the shape of the microbial landscape over the course of a 24-hour period. And while diversity of the gut microbiome appears to be linked to healthier sleep, a lack of quality and/or quantity of sleep could lead to ‘misalignment’ or ‘dysregulation’ of our normal sleep-wake cycle, leading to unfavourable shifts in the gut microbiome, potentially increasing the risk of chronic health conditions.
As our understanding of the links between sleep and the gut microbiome expands, the focus on encouraging a good night’s sleep for health will continue to be at the forefront.
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