Gut health and sleep – what’s the connection?

Key Points

• Researchers are exploring the link between gut health and sleep 
• It’s early days, but research is pointing toward the gut microbiome playing a part in sleep quality
• Probiotics may have a role to play to support sleep in healthy people 
• Your health professional can help you decide what’s right for you and your gut health 

As we learn more about how our gut microbiome can play a role in our health, researchers are starting to look at the gut microbiome's effect on sleep quality and duration.

It’s a new area of research, with preliminary findings that show a lot of promise. And for those who suffer from sleep issues, there’s reason to be tentatively excited.  

It may surprise you that there’s a connection between gut health and anything other than digestion. But it turns out that gut health is related to a host of other things, like mood, immunity and – as we’re finding out – sleep. 

Unfortunately, this doesn’t mean that you can simply swap out a good bedtime routine for a spoonful of yogurt and then enjoy a peaceful slumber. It’s more complicated than that. (Isn’t it always?) 

We decided to ask Dietitian Kate Agnew to explain what it is that we do and don’t know about gut health and sleep.

Gut health and sleep – what do we know? 

“There’s growing evidence to suggest that sleep duration and quality are linked to gut health,” says Kate. 

“It’s early days, and there’s a lot more research that needs to happen, but a review has found some benefits of taking probiotic supplements in people without underlying medical conditions. It’s important to remember that everyone is individual, and you should always talk to a health professional for individual advice,” she says. 

Kate explains the reason behind this connection saying it still remains to be a bit of a ‘chicken or egg’ enigma.

“Sleep and your gut microbiome is a bidirectional relationship, so there's some research to say the state of your gut may affect your sleep. And then, of course, we know that the amount of sleep you get and the quality of that can impact your gut microbiome,” says Kate. 

Sleep and digestion are also related bidirectionally, with sleep affecting digestion and vice versa.

But why is this? Well, it has a little something to do with what we call the ‘gut-brain axis’. 

Wait, what’s the gut-brain axis? 

The gut-brain axis is the bidirectional relationship between your gut and your brain. 

As it turns out, your gut actually talks back to your brain; it’s not a one-way relationship as we originally thought. In fact, the gut influences your body’s functioning so much that some researchers refer to the gut-based nerve centre (the enteric nervous system) as the second brain in your stomach. 

This connection may be the reason you sometimes feel your emotions in your stomach, and why being hungry or full can affect your mood. 

Curious to know more? Keep reading with these recommended articles:

• The gut-brain axis 
• How to improve gut health 
• What is my gut microbiome
• The difference between prebiotics and probiotics
• How stress affects the gut 
• Understanding gut dysbiosis

Now, let’s get back to the topic. 

What the science is telling us about gut health and sleep 

A 2020 systematic review that looked at a total of 14 studies (out of 20 trials) suggested  that probiotics, or paraprobiotics, supplementation improved sleep quality. When the duration of the supplementation was longer than eight weeks and the subject was generally healthy, the magnitude of the effect was greater.

There are also many other factors that are at play here, but the outcome concluded: “Probiotics/paraprobiotics supplementation may have some efficacy in improving perceived sleep health, but more studies – using well-controlled, within-subject experimental designs – are still needed.”

A 2019 study found that “total microbiome diversity (AKA good gut health) was positively correlated with increased sleep efficiency and total sleep time, and it was negatively correlated with wake(ing) after sleep onset.”

The study concluded that growing evidence suggests the gut microbiome can influence sleep quality. It also mentioned that previous studies have yielded conflicting results and that the relationship between sleep physiology and the gut microbiome remains unclear.

So, can probiotics affect sleep?

As the above study suggests, there may be some benefit to taking probiotic supplements to aid in sleep duration and quality, but the findings only applied to relatively healthy people. 

It’s important to note that it’s early days, however. There are many different types of bacteria strains that are used in probiotic supplements, and not all of them serve the same health goals. 

And remember – a range of gut-health foods, like fibrous and fermented foods, can also be added to your diet to increase the diversity of your gut bacteria and improve your gut health.

So, do probiotics help you sleep? The answer is a definitive maybe. 

How can I find out if probiotic supplements will help me? 

The best way to find out what supplements you should take to support your individual health goals is to reach out to a health professional. A qualified dietitian or naturopath can help you understand how probiotics work and which ones are right for you. 

If you decide to look into supplements, you can have a free discovery call with a healthylife practitioner for guidance on what will work best for you.

Sleep better and eat better, and you can’t go wrong

So, ready to start your journey to feeling fabulous? Kate reminds us that while taking care of a single health component is always a great start, poor sleep impacts every system within your body, not just your gut, and vice versa.

And so whether you're looking to improve your sleep by improving your gut – or looking to improve your gut with better sleep – you’ll get the positive trickle-down effects of one or the other either way.

Kate is an Accredited Practising Dietitian who is passionate about innovation and problem-solving in health & nutrition. Her goal/aim is to ultimately create a healthier environment for all Australians.

Reviewed by the healthylife Advisory Board May 2022.