Probiotics before bed
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The Impact of Probiotics on Sleep Quality: A Comprehensive Review
Introduction to Probiotics and Sleep Quality
In recent years, the connection between gut health and sleep has garnered significant attention. Probiotics, which are live microorganisms that confer health benefits to the host, have been studied for their potential to improve sleep quality through the gut-brain axis. This article synthesizes findings from recent research to understand the effects of probiotics on sleep, particularly when taken before bed.
Probiotics and Subjective Sleep Metrics
Improvement in Sleep Quality
Several studies have indicated that probiotics can positively impact subjective sleep quality. A systematic review and meta-analysis found that supplementation with probiotics or paraprobiotics significantly reduced the Pittsburgh Sleep Quality Index (PSQI) score, indicating improved sleep quality1. This effect was more pronounced in healthy individuals and when a single strain of probiotic was used over a treatment duration of at least eight weeks1.
Variability in Study Outcomes
Despite these promising findings, not all studies have reported significant improvements in sleep quality. Variations in study designs, populations, and probiotic strains used contribute to these discrepancies. Some studies did not find significant changes in other subjective sleep scales or objective sleep parameters such as sleep efficiency and latency measured by polysomnography or actigraphy1 2.
Mechanisms of Action: Gut-Brain Axis
Neuroactive and Immunomodulatory Compounds
The gut microbiome produces various metabolites and compounds that can influence sleep. These include short-chain fatty acids, secondary bile acids, and neurotransmitters like serotonin, dopamine, and gamma-aminobutyric acid (GABA)2. Some of these compounds promote wakefulness, while others promote sleep, suggesting a complex interaction between gut health and sleep regulation2.
Stress and Anxiety Reduction
Probiotics may also help reduce stress and anxiety, which are closely linked to sleep problems. Some studies have shown that probiotic treatments can lower cortisol levels and improve sleep latency and duration, although results are mixed2. The bidirectional relationship between stress, anxiety, and sleep underscores the potential of probiotics to improve overall sleep health by modulating stress responses2.
Conclusion
While current evidence suggests that probiotics can improve subjective sleep quality, particularly as measured by the PSQI, the results are not universally consistent across all studies. The variability in outcomes highlights the need for more well-controlled, within-subject experimental designs to better understand the potential benefits of probiotics on sleep. Future research should focus on standardizing study designs and exploring the specific strains and dosages that are most effective for enhancing sleep quality.
In summary, taking probiotics before bed may offer some benefits for sleep quality, but further research is needed to establish stronger evidence and clearer guidelines for their use.
Sources and full results
Most relevant research papers on this topic
Effects of probiotics and paraprobiotics on subjective and objective sleep metrics: a systematic review and meta-analysis
Probiotics/paraprobiotics supplementation may improve perceived sleep health, but current evidence does not support benefits for other subjective sleep scales or objective measures of sleep.
Meta-AnalysisProbiotics, prebiotics and postbiotics for better sleep quality: a narrative review.
Prebiotics, postbiotics, and traditional probiotics show some evidence of improving sleep quality and stress, but stronger evidence may be found in future studies with methodological adjustments.
Systematic ReviewEffects of Probiotics on Cognitive Reactivity, Mood, and Sleep Quality
Probiotics administration improves psychological well-being by reducing depressive mood state, anger, and fatigue, and improving sleep quality in healthy individuals.
RCT
Highly CitedA review of probiotic supplementation in healthy adults: helpful or hype?
Probiotic supplementation in healthy adults can improve immune system responses, gut microbiota concentration, and gastrointestinal health, but does not consistently cause persistent changes or improve blood lipid profile.
Systematic Review
Rigorous JournalHighly CitedProbiotic Supplementation Improves Cognitive Function and Mood with Changes in Gut Microbiota in Community-Dwelling Older Adults: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial
Probiotics improve mental flexibility and reduce stress in healthy older adults, while also causing changes in gut microbiota.
RCTHighly CitedProbiotics to prevent necrotising enterocolitis in very preterm or very low birth weight infants.
Probiotic supplementation may reduce the risk of necrotising enterocolitis in very preterm or very low birth weight infants, but more research is needed.
Meta-Analysis
Very Rigorous JournalHighly CitedAGA Technical Review on the Role of Probiotics in the Management of Gastrointestinal Disorders.
Probiotics show potential in preventing and treating common gastrointestinal disorders, but their effectiveness remains unclear and their use in gastrointestinal disorders remains a matter of debate.
Systematic ReviewHighly CitedThe effects of probiotics in lactose intolerance: A systematic review
Probiotics show varying degrees of efficacy in alleviating lactose intolerance symptoms, with an overall positive relationship between probiotics and lactose intolerance.
Systematic ReviewHighly CitedEffect of prebiotics, probiotics, and synbiotics on gastrointestinal outcomes in healthy adults and active adults at rest and in response to exercise—A systematic literature review
Prebiotics can influence gut microbial composition and short chain fatty acid concentration, while probiotics have minimal effect on gastrointestinal status and do not significantly reduce gastrointestinal symptoms during exercise.
Systematic ReviewProbiotic supplementation elicits favourable changes in muscle soreness and sleep quality in rugby players.
Probiotic supplementation in elite rugby players may improve sleep quality and reduce muscle soreness, potentially benefiting their performance and motivation.
RCT