Posted on Mar 20, 2017, 6 a.m.
Researchers find that dietary prebiotics may be effective against stress-induced insomnia.
Researchers recently published a study in the Frontiers in Behavioral Neuroscience journal that points to a link between prebiotics and more restful sleep.
The team, led by Robert Thompson of the Department of Integrative Physiology at the University of Colorado Boulder, conducted lab tests on rats. Results confirmed that use of prebiotics reduces stress-related insomnia.
The Effects of Stress on Intestinal Bacteria
Previous research shows that stress can alter gut microbiota. The modified bacteria affect the brain-gut axis, a system in the body that connects the endocrine and nervous systems. Disruptions to these systems can trigger episodes of hormone-induced insomnia.
When the body experiences stressful stimuli, it can trigger changes in secretions, motility, and mucosal function. This can create a hostile environment for beneficial bacteria.
Modified gut bacteria can also lead to gastrointestinal conditions like inflammatory bowel disease, irritable bowel syndrome, and gastroesophageal reflux disease (GERD).
Thompson’s team used two groups of male laboratory rats. The control group was fed standard food. The other group received a prebiotic supplement with their food. Fecal samples were collected and analyzed over a four-week period.
Final data shows an increase in beneficial gut bacteria for the prebiotic group. One of the bacteria found, Lactobacillus rhamnosus, is known to aid immune system function.
Researchers also collected information on the rats’ sleep-wake cycles using electroencephalography. Under normal conditions, rats in the control group were found to spend less time in NREM (non-rapid eye movement) sleep than those that received the prebiotics. During NREM sleep, brain activity drops dramatically. Some researchers believe the body uses this stage to process information and store memories. NREM sleep accounts for 20% to 50% of the average person’s night.
Stress Induced Insomnia and Prebiotics
The team introduced stress to both groups of rats via electrical shocks to their tails. When this happened, the prebiotic group showed a significant increase in REM sleep cycles when compared to the control group. More REM sleep is associated with better stress recovery.
From the data, researchers conclude that prebiotics encourage the growth of beneficial bacteria in the gastrointestinal tract. This strengthens the gut-brain axis, which allows the body to recover more efficiently from stress-related injury.
Further study is needed to understand exactly how prebiotics affect sleep. Researchers must now discover the chemical mechanisms that connect beneficial gut flora to the sleep cycle. Future trials may lead to more effective treatments for insomnia and other conditions related to the brain-gut axis.
Front. Behav. Neurosci., 10 January 2017 https://doi.org/10.3389/fnbeh.2016.00240 Dietary Prebiotics and Bioactive Milk Fractions Improve NREM Sleep, Enhance REM Sleep Rebound and Attenuate the Stress-Induced Decrease in Diurnal Temperature and Gut Microbial Alpha Diversity