Introduction to Gut Health and Sleep

Our gut health and sleep quality are far more connected than you may think. This is due to the gut-brain axis, the complex relationship between the two.

There is two-way communication between our central nervous system and our digestive tract, which links to the quality of our sleep.

It’s important to note that although the gut impacts sleep, sleep also impacts the gut, so you must be mindful of both to achieve optimum health. 

How Does Sleep Influence Gut Health?

Hormone Imbalance 

If you lack sleep, your hormones can become unbalanced, which can be seriously unpleasant. The stress hormone cortisol can rise, which can cause leaky gut. This means that food and toxins can pass through the intestines into the bloodstream, wreaking havoc on your body.1

Which Side You Sleep On

The concept of which side you sleep on affects your digestion is a relatively new idea, but studies show a massive link in this area. It is currently recommended that you sleep on your left side rather than your right. 

Your stomach’s natural position is on the left side of your body, and when you sleep on the left, gravity helps the waste travel from the small intestine to the large intestine. On your right side, gravity is working against you, making digestion harder throughout the night.2

Higher Risk of Disease

Not getting enough sleep can impact your digestive health by increasing the risk of obesity, type 2 diabetes and gastrointestinal diseases.

It can influence the foods you choose to eat3 as you will likely crave more carbohydrates and sugars for energy if you aren’t well-rested. The food you eat can significantly factor in your risk of developing gastrointestinal and metabolic diseases.

How To Heal The Gut To Benefit Sleep

Some foods may be impacting your sleep. Generally, a good rule of thumb is to not eat anything directly before bed, as your body then needs to spend time at night focusing on digesting that food rather than rejuvenating your body.

Don’t forget that looking after your gut can significantly benefit your overall health and sleep. We all get hungry at night sometimes, though, and it’s important to know what to avoid if you are going to eat.

Here are some simple steps to heal your gut microbiome that may help you drift off, have better quality sleep and have a more extended rest. 


Although alcohol can make us feel like we drift off easier, it may significantly reduce the quality of our sleep. Alcohol can interrupt the natural sleep cycle, decreasing the amount of REM sleep you get through the night.

REM is when your body is in restorative mode, so losing out on this reduces the benefits of a whole night's sleep. Alcohol can also cause acid reflux, as the oesophageal sphincter muscle is over-relaxed throughout the night.4

Spicy Foods

Spicy and acidic foods can also cause heartburn throughout the night, so these should be avoided before bed. Spicy foods not only cause heartburn but can also raise your body temperature. For most people, our body temperature should be lower to fall asleep, so having an increased body temperature can keep you awake longer than necessary.5

Heavy Foods

Eating heavy foods such as fried and fatty before bed can also impact the quality of our sleep. These foods take longer to digest, so your body works harder than it needs to throughout the night to digest what you’ve put in. 

High Water Content Foods 

Even what you consider a healthy choice of fruit can negatively affect your sleep throughout the night if you eat it too close to bedtime. Eating foods with a high water content before bed can disrupt sleep, as these foods fill your bladder as they digest.

This may cause you to empty your bladder during the night. Being well hydrated is essential to overall health, but eating these foods before bed can disrupt your rest. 


Caffeine can be hidden in foods you don’t expect; it’s not only present in drinks like tea and coffee. Chocolate food products often have high caffeine content, so snacking on chocolate before bed can reduce the amount of REM sleep you get and make it difficult to get a decent rest.

You will likely stay in the light stages of sleep if you have caffeine in your system before bed, which isn’t as restful for your body.6

Final Thoughts

Understanding how vital sleep is for gut health and gut health is for sleep has proven beneficial in terms of overall health. Now that you know that gut health is fundamental to your sleep cycle and the sleep cycle is essential to gut health, you can be more aware of your choices before bed.

Related content: An Introduction to Gut Health and Fat Loss


  4. Jiaqi Pan, Li Cen, Weixing Chen, Chaohui Yu, Youming Li, Zhe Shen, Alcohol Consumption and the Risk of Gastroesophageal Reflux Disease: A Systematic Review and Meta-analysis, Alcohol and Alcoholism, Volume 54, Issue 1, January 2019, Pages 62–69,
  5. Stephen J. Edwards, Iain M. Montgomery, Eric Q. Colquhoun, Jo E. Jordan, Michael G. Clark, Spicy meal disturbs sleep: an effect of thermoregulation?,International Journal of Psychophysiology, Volume 13, Issue 2, 1992, Pages 97-100,
  6. Jan Snel, Monicque M. Lorist, Chapter 6 - Effects of caffeine on sleep and cognition, Editor(s): Hans P.A. Van Dongen, Gerard A. Kerkhof, Progress in Brain Research, Elsevier, Volume 190, 2011, Pages 105-117,


Prev Article

What are 3 superfoods for your gut? - The Veggies Edition

Superfood isn’t actually a scientific term and is just a word commonly used to describe a particularly nutritious food. It was actually started in the early 20th century as a marketing strategy for bananas by the United Fruit Company.1  There are loads of superfoods, and many of them are readily...

Related Articles…