The Surprising Connection Between Your Gut and Your Sleep: Here's What You Need to Know

Unravel the fascinating links between your gut health and sleep quality, and discover simple lifestyle tweaks that can revolutionise your nights.

Microbial armies in your gut

Your gut houses both benevolent and malevolent types of bacteria. The adult intestinal tract is a bustling metropolis of approximately 1,000 types of microbiota (Li et al., 2018), which silently ward off viruses and harmful bacteria. At the same time, 70% of your immune system resides in your gut (National Institute of Allergy and Infectious Diseases, 2013), making sure the bacteria and germs in the gut don't cross their boundaries.

The intricate dance between gut and brain

What if I told you that your gut and sleep patterns are in a complex tango? The human gut, often referred to as the "second brain", has a direct connection to your grey matter, and here's the kicker - it plays a significant role in how well you sleep (Li et al., 2018).

• The vagus nerve, a veritable information superhighway, bridges your gut and brain. This allows substances produced by your gut microbiome to influence brain functions, including sleep.
• The gut regulates the production of neurotransmitters like serotonin, which is instrumental in managing sleep, digestion, and mood. Researchers in Japan found that depleting microbes in the gut led to diminished serotonin levels, which, in turn, influence the sleep-wake cycle (Ogawa et al., 2020).

Sleep: the guardian of your immune system

But why does this even matter? Here's the scoop: sleep is intimately linked to your immune system. Emerging studies have begun to shed light on how the gut and sleep can impact each other (Smith et al., 2019). High-quality sleep nurtures a robust immune defence, ensuring your gut flora remains in tip-top shape.

Here's where it gets even more intriguing: during sleep, parts of your immune system kick into high gear (Ganz, 2012). When white blood cells detect an invader, they release cytokines, which act as messengers for the immune system, orchestrating its responses to diseases and pathogens.

However, there's a catch. This activity is influenced by sleep and your body's internal 24-hour clock, known as the circadian rhythm, which is in turn affected by your diet, meal timings, and sleep patterns.

The slippery slope of sleep deprivation

Research has shown that even mild sleep deprivation can negatively impact gut health (Benedict et al., 2016). This manifests as reduced insulin sensitivity, a decrease in beneficial gut bacteria, and changes in the microbiome linked to type II diabetes.

Sleep deprivation can cause inflammation by releasing the pro-inflammatory cytokines, which in turn can change the composition and abundance of intestinal microbes (Zhang et al., 2023).

Sleep deprivation isn't just about feeling groggy. Poor sleep quality can wreak havoc on cognitive and neuro-behavioural performance and has been linked to cancer and Alzheimer's (Smith et al., 2019).

Want better sleep? Take charge of your gut!

You can bolster your sleep by encouraging the growth of good bacteria in your gut.

What's more, you don't have to wait until your first cup of coffee to feel invigorated.

So, how can you wield the power of your gut to seize the night? Here are actionable steps:

• Adopt a Balanced Diet: Feast on whole foods rich in fibre. Variety is key, so include a diverse range of these nutritious gems.
• Cut Back on the Nasties: Reign in your consumption of processed sugars, saturated fats, and salt.
• Get Your Beauty Sleep: Aim for 7-8 hours of sleep. This gives your microbial guardians ample time to battle inflammation.
• Consume Fermented Foods: Fermented foods such as kvass, kimchi, sauerkraut and yoghurt are some of the most potent natural sources of probiotic bacteria.

Remove these products from your diet to help your gut:

• White bread/white rice
• Fried food
• Red meat
• Foods with high refined sugars
• Ultra-processed foods

Add these products to your diet to help your gut:

• Whole-meal bread/brown rice
• Leafy greens (kale, spinach)
• Lean white meats (chicken, fish)
• Legumes (lentils, beans, peas)
• Fruits
• Fermented foods (kvass, kefir, sauerkraut, kimchi)

Takeaway

Sleep, gut health and immune system are inextricably intertwined. Skimping on sleep throws your gut microbiome off-kilter, making you susceptible to a host of issues such as leaky gut, inflammation, and serotonin deficiencies. This vicious cycle continues as your compromised gut makes it even harder to catch those precious Z's.

By valuing and nurturing your gut through a healthy diet and sufficient sleep, you can break the cycle. The payoff? Improved sleep quality and an enhanced zest for life!