Sleep is a big part of our health, and affects even our gut health and digestion.

Our body systems are all connected, we can’t isolate one symptom. As a nutritional therapist I look for the root cause of your symptoms to understand how I can help you.

In this blog I look at the impact of sleep on our digestion and gut health.

1. Loss Of Sleep Affects Your Gut Microbiome

Did you know sleep loss can affect your gut bacteria? In one study with just two night of less sleep (around 4 hours rather than 8 hours) there were changes in the gut microbiome.

The study used normal healthy men and after just two nights they had more microbes that are associated with metabolic disruption (think blood sugar balances, weight gain).

They also had worse insulin response, meaning they were less able to pack away glucose from their food.

We also know that sleep loss can cause microbial imbalances in the gut that interact with how we manage energy from our food.

Experiments on mice have shown that bacteria from sleep deprived mice when given to germ free mice, negatively affected their insulin responses.

2. Gut Microbes Affect Our Body Clock

Our circadian rhythm is our own internal body clock. This is maintained by every cell in the body,  and affects our hormones and metabolism. Recent studies have discovered that gut bacteria moves around during the day and the night, and this affects our internal body clock, so gut bacteria may impact on how much we sleep, or the quality of sleep.

Researchers have also demonstrated in mice that when they induced jet-lag there were changes in the gut bacteria that increased glucose intolerance and obesity. These changes were also visible when they transferred jet lagged mice bacteria to germ-free mice.  

3. When We’re Tired We Eat More

We know that when we’re tired we tend to go for energy dense food (3pm chocolate cravings anyone?) to give our brain a boost. It’s been shown the people who are sleep deprived will make poor food choices compared to well rested people.

In fact we actually get more enjoyment from food when we’re tired. One study found sleep restriction boosts a signal that may increase the pleasure and satisfaction gained from eating. 

The same study found that for each extra hour of being awake participants used up about 17 extra calories, amounting to around 70 calories for 4 hours of lost sleep. But they ate an extra 300 calories when they were sleep deprived. If you’re consistently tired, then you could be eating more than you need which will lead to weight gain over time.  

4. Sleep Apnea may lead to high blood pressure

In a study on rats there are indications having disrupted sleep can lead to hypertension. Researchers experimented on rats mimicking the interruptions in sleep from sleep apnea and those rats who also ate a high fat diet went on to get high blood pressure.

Rats which only had sleep apnea, or only had a high fat diet didn’t get a rise in blood pressure. This is interesting because sleep apnea often comes with other conditions such as obesity, diabetes or ageing, and whilst we are not rats, this study showed the link between gut bacteria and a rise in blood pressure, when accompanied by loss of sleep.

Another research project showed a positive association between sleep apnea and Irritable Bowel Syndrome. This happens because sleep apnea leads to increased sympathetic nervous system activity which induces or escalates IBS symptoms. 

5. Your IBS or colitis and sleep

If you have to get up in the night to go to the bathroom, or wake with abdominal pains you may struggle to get back to sleep, or have more disrupted sleep. This means when you’re more tired the next day you can feel the pain more acutely. IBS clients often complain of poor sleep, and feeling exhausted.

Sleep can also play a part in Inflammatory Bowel Disease (IBD) as well. A recent study showed that less than 6 hours sleep/day and more than 9 hours sleep/day are each associated with an increased risk of ulcerative colitis.  We know sleep changes lead to increased inflammation, which has been linked to higher rates of depression, and mood changes, as well as other conditions like obesity, and metabolic changes like diabetes. 

What you can do to improve your sleep

Each one of us is different, and I work with people in a tailored way to find a diet that suits each client. I also coach people over 4 weeks or 3 months to get results,

  • Eat a wide variety of gut-friendly foods. This means including lots of real foods, like vegetables and fruits, whole grains, pulses, nuts and seeds. Reduce meat consumption to see how this affects you.
  • Increase your fibre intake until you’re getting around 30g a day (most people  only get up to 19g)
  • Eat fermented foods every day, such as full-fat yoghurt or make sauerkraut (fermented cabbage).
  • Increase the range of foods in your diet – aim for 30 different foods a week.
  • Eat antioxidant rich foods like berries, green tea, 70% dark chocolate, green leafy veg, nuts and seeds.
  • Intermittent fasting – aim for at least 12 hours overnight to allow your body time off from digesting. Don’t eat just before you go to bed. Avoid snacking before bedtime.

I can help you navigate the range of diet advice to find a solution that helps you, your body and lifestyle. Contact me to book a free 15 min discovery call where we can talk about how to work together.  


Hi I'm Anna Mapson, registered Nutritional Therapist.

I help people with IBS and SIBO get control of unpredictable gut symptoms to find long term relief from painful and embarrassing IBS without restrictive dieting.

I can help you to:

  • understand your digestion better, so you recognise your triggers
  • eat a well balanced diet, with tasty meals that are simple to prepare
  • develop better digestion and more energy

Find more about my 3 month 1:1 Gut Reset programme

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