With Research becoming increasingly focused on our gut health (microbiome), it is now showing that poor sleep can directly impact the diversity and health our our microbiome that resides in our gut —the trillions of bacteria that supports our mental health (hello gut brain connection), immunity and digestion (hello weight loss). In fact, our gut and our sleep rhythms are surprisingly more connected than we might think.
Our Gut-Sleep Connection
Our body runs on a natural 24-hour internal rhythm called our circadian rhythm. Our circadian rhythm regulates everything in our bodies from our sleep-wake cycles, to our hormone production—and yes, even your digestion.
Our gut microbiome also follows a circadian rhythm. Certain strains of bacteria become more active during the day, while others work their magic whilst we sleep (at night). When our sleep routine is disrupted (shift work, late nights, parenting or insomnia), it can throw out our rhythm of our microbiome.
Studies have shown that even just two nights of poor sleep can significantly reduce microbial diversity and increase levels of pro-inflammatory bacteria. Over time, this has a play on affect within our body on things like nutrient absorption and utilization, immune balance, to even things such as our mood and metabolism.
What Happens to the Gut When We Don’t Sleep Well?
Poor sleep over a long period of time, can impact our gut in many different ways:
- Increased inflammation: A lack of sleep can activate our immune system and increase our levels of inflammation, which in turn, disrupts the gut lining and microbial balance.
- Impaired digestion and detoxification: Sleep is a time when our body repairs and detoxifies. Disrupted sleep has been shown to slow down our digestion and affect how well the liver and gut process our waste products.
- Hormonal chaos: Poor sleep affects your hunger hormones—ghrelin (which increases appetite) goes up (ever has a late night and wonder why we crave sugar and carbs the next day), while leptin (signals our fullness) goes down. This can all lead to cravings for sugary, processed foods that can cause an imbalance within our gut bacteria even more.
- Increased gut permeability: Just like with chronic stress, poor sleep can also contribute to “leaky gut,” (intestinal permeability) where the gut lining becomes more permeable and less protective which can lead to food sensitivities and chronic health conditions if left for long periods of time.
Common Signs Our Sleep Can Be Impacting Our Gut
- Waking up bloated or discomfort
- Brain fog or low energy during the day
- Craving for sugar, caffeine, carbs, or processed foods
- Disrupted bowel movements (constipation or diarrhea)
- Mood swing, anxiety or depression
How to Support Your Gut Through Better Sleep
Improving your sleep doesn’t have to be complicated—small, consistent shifts can make a big difference:
Create a wind-down routine
Give your nervous system the signal that it’s time to rest. This might look like herbal tea, journaling, stretching, or reading instead of scrolling. Your gut microbes thrive on routine!
Prioritise natural light first thing in the morning
Morning sunlight helps regulate melatonin production (your sleep hormone), which supports the quality of our sleep.
Limit stimulants and heavy meals before bed
Caffeine after 2pm and big meals late at night can overstimulate our hormones, making it harder for our bodies to rest and repair.
Use relaxation tools
Try breathwork, meditation, or even vibroacoustic sound therapy to calm the nervous system before bed. A relaxed body = a better sleep = more energy and a happier gut.
Stick to a consistent bedtime
Going to bed and waking up at the same time each day supports your circadian rhythm and helps your gut microbiome stay balanced.
The Bottom Line
Sleep is not a luxury—it’s a foundational part of our health and gut health. Just like a varied, fibre-rich diet or nervous system support, quality sleep helps our gut repair, restore, and rebalance.
If you’re waking up tired, bloated, or craving sugar, the gut might be trying to tell you something. Start by nourishing your body with rest. The microbiome will thank you.