Dietary Prebiotics May Improve Sleep and Reduce Stress

Feeling stressed? Can’t sleep at night?

You’re not alone.

According to the American Psychological Association, about 47% of adult Americans don’t sleep well because of stress.

Approximately 21% of them say that lack of sleep increases their stress level.

It’s a vicious cycle!

So, what should you do?

Dietary Prebiotics May Improve Sleep and Reduce Stress

New research suggests that dietary prebiotics could improve sleeping patterns and reduce the negative physiological effects of stress.

A study at the University of Colorado, found that dietary prebiotics may improve sleep and reduce stress. [1]

Specifically, they noted that diets rich in prebiotics improved time spent in NREM (Non Rapid Eye Movement) sleep - the stage in which brain waves are slowest, physical restoration and recovery occurs, and growth hormone is released - and may increase gut microbial species that reduce the impact of stress.

Wait, what are Prebiotics?

Prebiotics are carbohydrates that are not digested, but pass through the stomach and small intestine until they end up in the colon where they ‘feed’ gut microflora, or "good bacteria".

These Probiotic bacteria ferment prebiotics to use them as the food source.

Fermentation converts prebiotics into short-chain fatty acids, that nourish the microbiome in our digestive tracts and provide many health benefits. 

According to the World Health Organization, “In order for a food ingredient to be classified as a prebiotic, it has to be demonstrated, that it:

• is not broken down in the stomach or absorbed in the GI tract,
• is fermented by the gastrointestinal microflora; and
• most importantly, selectively stimulates the growth and/or activity of intestinal bacteria associated with health and wellbeing.” [2]

Where Do We Get Prebiotics?

Due to the fact that these special carbohydrates resist digestion in the stomach, they are also known as resistant starches.

The most common types of prebiotics, or resistant starches, are inulin, fructooligosaccharides (FOS), and other carbohydrates that resist digestion.

Top Prebiotic food sources include:

• Artichokes
• Garlic
• Onions
• Bananas
• Cooked and cooled potatoes, even rice, have higher resistant starch content than warm, freshly cooked counterparts. When cooling, the starches gel and form more highly branched structures that increase resistant starch content. 
• Natural Stacks Prebiotic +: Resistant Starch Complex combines organic green banana flour, raw potato starch, and inulin FOS to supply a full spectrum of Prebiotics

Benefits of Prebiotics

As noted in this study (albeit a rat study), dietary prebiotics may improve sleep quality by increasing the length of time we spend in the most restorative NREM stage of sleep. 

This study also supported the hypothesis that PREbiotics are food for PRObiotics. They literally feed good bacteria, helping it proliferate. More good bacteria is a good thing for digestive health and overall health as we discussed on this podcast, and this one (coming Thursday 3/23/17).

Aside from these suspected direct health benefits, this study also proved that dietary prebiotics can help reduce effects of stress exposure.

There are other benefits, from other studies as well:

Human Studies have found:

• Similar improvements in gut microbiome environment [3]
• Increased butyrate, a precursor to GABA, which may explain stress reduction [4]
• Improved body composition (reduction of body fat) when 5% of carbohydrate intake came from dietary prebiotics [5]
• Supports healthy metabolism and may improve insulin sensitivity [6]

More on The Link Between Prebiotics and Sleeping Patterns

Let's get back to the University of Colorado study that prompted this post.

Previous studies have suggested that stress can change our gut bacteria and this change interferes with the sleep/wake cycle (the circadian rhythm).

That’s why Robert S. Thompson and his team at the Department of Integrative Physiology at the University of Colorado, Boulder, wanted to examine how prebiotics influence sleep in the stressful conditions.

They supplemented one group of male rats with prebiotics. As the control group, scientists fed rats with a standard, calorically matched diet.

After 4 weeks, they discovered that rats supplemented with prebiotics had more beneficial probiotic bacteria in their guts, compared to rats from the control group.

One of the increased probiotic bacteria was Lactobacillus rhamnosus. Lactobacillus rhamnosus reduces anxiety- and depression-related behavior. Also, it calms down the exaggerated hypothalamic–pituitary–adrenal axis (HPA axis). [7]

This axis is responsible for activating the ‘flight or fight’ mode, that is triggered when you’re under stress.

Many factors influence the HPA axis:

• stress,
• physical activity,
• illness,
• blood levels of cortisol (stress hormone) and
• sleep/wake cycle.

So scientists used electroencephalography (EEG - discussed here) to measure the sleep/wake cycles, in both the prebiotics supplemented and control rats.

They discovered that rats on the prebiotic diet had longer non-rapid eye movement (NREM) sleep phases compared with rats on the control diet. Non-rapid eye movement (NREM) is the restorative sleep stage.

During the 5 stages of sleep, these NREM stages are associated with deeper, more restorative sleep. It is here that the body repairs, tissues regrow, bone and muscle grow, and the immune system strengthens.

How Prebiotics Lower Stress Levels

To test how rats respond to acute stress, researchers applied tail shocks. Rats that have consumed prebiotics had longer rapid eye movement sleep phase (REM) or REM rebound, then the controls. 

Intense exposure to stressors triggers the REM rebound, a known and well-researched defense mechanism. [8,9]

REM rebound is associated with a reduced risk for developing post-traumatic stress disorder. That’s why some scientists believe it’s beneficial coping mechanism.

But stress can decrease healthy diversity of the gut bacteria which leads to a temporary leveling out of natural fluctuations in body temperature.

Individual prebiotics can reduce these stress-evoked GI distress. [10]

Rats on the prebiotic diet, even under stress, maintained diverse probiotic bacteria and normal temperature fluctuations. 

Prebiotics Lower Stress Hormone Cortisol In Humans 

“Interestingly, people who ingested the prebiotic GOS had an attenuated waking cortisol response, suggesting that prebiotics may also impact diurnal rhythms in humans,” the authors wrote.

Robert S. Thompson, the lead author of the study continued:

"A next set of studies will be looking exactly at that question - can prebiotics help humans to protect and restore their gut microflora and recover normal sleep patterns after a traumatic event?"

It’s clear that prebiotics have protective influence on the diversity of gut microflora, stress, and sleep/wake cycle. 

Scientists concluded that:

“The results of the current study demonstrate that a (test) diet rich in prebiotics started in early life increases the growth of Lactobacillus rhamnosus and alleviates the stress-induced disruption of REM sleep, diurnal physiology and gut microbial alpha diversity.”

Prebiotics are present in many plants, like chicory root, garlic, Jerusalem artichokes, jicama, dandelion greens, and onions. They’re even present in breast milk.

And of course, you can easily incorporate more Prebiotics into your diet with our Prebiotic+ Resistant Starch Complex. 

How do you deal with stress and sleep deprivation in your life? What prebiotics do you consume? What’s your experience with our prebiotic supplement?

Let us know in the comments below.