Are probiotics and prebiotics the key to a good night’s sleep?

Studies have shown that a healthy gut can lead to a happier mind  and healthier body  - but can it lead to a better night’s sleep too? According to recent studies, yes - supporting your gut microbiome and boosting your overall count of ‘good’ bacteria has the potential to make your sleep count for more.

“Research is showing that, like we have a circadian rhythm that governs our sleep-wake cycles, so does our microbiome (aka the trillions of micro-organisms that reside in the gut),” says nutritional therapist Eve Kalinik . “By virtue of that relationship, our gut can be negatively affected by poor sleep and a lack of decent shut eye can be in part driven by imbalances in the microbiome. It’s a two-way relationship: our microbiome needs the rest and rejuvenation and likewise it helps support better slumber.”

"Our gut bacteria, often referred to as our ‘gut microbiome’, play a huge role in our health, supporting our immune system, metabolism and digestion," adds Marta Anhelush, supplement specialist  BioCare 's resident nutritionist. "Not surprisingly perhaps, they also regulate our nervous system and are partially responsible for the regulation of our mood, stress response, and sleep. This is because gut bacteria produce different neurotransmitters, such as our sleep hormone - melatonin."

“Melatonin, the main hormone for healthy sleep, is created in the gut as well as the brain and can operate on its own rhythm, independent of its pineal counterpart,” says Eve. “Gut bacteria also produce and manage around 90 to 95 per cent of our serotonin,” she adds. “Studies show that low levels of serotonin production can play a role in sleep conditions like insomnia and overall levels of anxiety and depression that may also be a reason for poor sleep.”

Keeping our gut health in peak condition has also been shown to have positive effects on our immunity, making us less susceptible to getting sick. “A weak immune system not only leads to more colds and flus, but can also mean inflammatory conditions are more likely, which can lead to pain,” says nutritional therapist Joanna Lutyens. “Any illness or discomfort can have an impact on our quality of sleep.”

There are two main ways to boost your gut health and therefore improve your sleeping habits - taking probiotic  supplements (live beneficial bacteria) and through diet. “Different types of fibre provide ‘food’ for different strains of bacteria and it has been suggested that it is the diversity of the microbiome that makes it a healthier one,” says Eve. “This means plenty of vegetables, moderate fruit, nuts and seeds for example.” Upping your intake of prebiotic-rich foods is key.

What are prebiotics - and how do they help?

Prebiotics act as the ‘fertiliser’ for the beneficial bacteria in order for them to thrive and increase in number. They have more potent feeding effects on the gut microbiome. Eve recommends garlic, onions, leeks, chicory, under-ripe bananas and oats. Other examples include lentils, chickpeas and butter beans. They’re best eaten spread out throughout the day.

Prebiotics can also help boost various parts of the sleep cycle too to help improve brain function. In a recent study conducted by the University of Colorado at Boulder, scientists found that when 3-week old rats were fed a diet high in prebiotic foods, they spent more time in non-rapid-eye-movement sleep (non-REM), the more restful and restorative type of sleep.

They also found that they spent more time in REM sleep after being exposed to a stressful event. REM is important as it’s believed to help promote recovery from stress. Stress can also cause diversity of gut microbiome to dwindle and body temperature to fluctuate. However, the rats who ate a more prebiotic-rich diet were found to be able to counteract these effects more successfully.

Kiwis are one fruit that is high in prebiotic fibre; "A study in New Zealand  found that eating green kiwis resulted in a positive effect on two of our clock genes that affect sleep," says Lisa Borg, lead nutritionist at Pulse Light Clinic .

As well as particular foods, supplements can also be useful as demonstrated by medical journalist Dr Michael Mosley  in the BBC’s The Truth About Sleep. He took a prebiotic called Bimuno  for 5 days and monitored the effect it had on his sleep patterns. At the start of the trial, Mosley spent 21 per cent of his time in bed awake. However by the end of it, it had reduced to 8 per cent. Out of all the strategies that he tried to improve his sleep, he found the use of prebiotics the most effective.

Professor Philip Burnet from the Department of Psychiatry at the University of Oxford who oversaw the experiment noted that the beneficial by-products produced could be the reason for the positive effects. “Your good bacteria break down this fibre to produce molecules called short-chain fatty acids,” he explained . “These are the things that might be having an effect on your sleep. Of course, when this prebiotic grows good bacteria, the bacteria themselves have beneficial effects, like synthesising vitamins and beneficial effects to the bowel and the immune system.”

Encouraging findings, but as noted by the authors of the study in Colorado and Professor Burnet in subsequent interviews, further investigation is needed.

What are probiotics - and how do they help?

Probiotics are the actual strains of beneficial bacteria themselves, levels of which can be increased through diet and supplementation. “Fermented foods provide natural sources of beneficial bacteria that include cheese (ideally unpasteurised), kefir, kombucha , unpasteurised sauerkraut and kimchi,” explains Eve.

The effects of probiotics on mood found a reduction in depressive mood states, anger, and fatigue which can all have an impact on the quality of our sleep, according to a 2019 Frontiers in Psychiatry study . "The researchers speculated that probiotics, by interacting with intestinal microbiota, facilitated the production of precursors of neuroactive substances involved in modulating sleep," said Lisa. "They also found the higher the quality of sleep, the better the mood. This demonstrates the gut-brain connection and is vitally important to our general well-being."

A probiotic called Symprove , from £79, is Eve's supplement of choice which she advises taking first thing in the morning on an empty stomach. This allows the bacteria to reach your gut more quickly and begin colonising. “It not only boosts numbers of beneficial strains but crucially it also changes the pH environment of the gut to make it more conducive for these bacteria to thrive and survive.” It contains four species of naturally occurring bacteria: L. rhamnosus, E. faecium, L. acidophilus, and L. plantarum.

Taking a probiotic with multiple strains in it is key. “We need to always remember that not all bacteria are born the same,” notes Joanna. “Identifying specific strains of bacteria is important, as research shows that each strain is good at doing different things in our gut.

“Two particular strains, Lactobacillus acidophilus Rosell-52 & Bifidobacterium longum Rosell-175 have been clinically researched in trials and have been found to help with a reduction of anxiety, low mood, sleep disturbance and improved ability to deal with stress in participants.” These can be found her probiotic of choice - OptiBac Probiotics ‘For Every Day,’  from £12.95.

We also recommend Biocare's Mindlinx , £34.10, which also includes strains Lactobacillus and Bifidobacterium.

MORE GLOSS: How to boost your gut health on a budget

Any final takeaways?

While upping your prebiotics and probiotics can be helpful in terms of boosting your microbiome and therefore improving your sleep, Eve cautions that they only form part of the puzzle. Revising your eating patterns is also important. “I would suggest avoiding late-night snacking, particularly anything high in sugar, as that could have an effect on how well you sleep. It’s asking your gut to work later into the evening too,” cautions Eve.

She recommends having a try of fasting . “Fasting overnight for 12 hours, so having nothing later than 8pm and no earlier than 8am for example, seems to have positive effects on the microbiome and ergo sleep too.”

Lifestyle modifications are paramount too. “One of THE most important things to help manage your gut bacteria AND improve sleep is to manage stress, so some kind of meditation is crucial,” advises Eve. “This doesn’t have to be sitting on a cushion and humming - although it has been said that sound vibrations might better tune and tone your vagus nerve (that connects the brain and the gut) - and that has a positive effect on stress.

“That aside, your meditation can be simply taking a gentle walk, listening to soothing music or even cooking. Anything that essentially puts your body, and your gut, into a state of ‘rest + digest’ is the aim if you want to maximise your pillow time too.”

For more advice on gut health, check out  Be Good to Your Gut: The Ultimate Guide to Gut Health  by Eve Kalinik, £9.99.

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