Association between probiotic intervention and sleep quality in the general adult population: a systematic review and meta-analysis.

2026-03-25
Frontiers in nutrition 13

PubMed: 41958906
DOI: 10.3389/fnut.2026.1795450

Study Design

Type: Systematic Review
Sample size: n = 890
Population: adults, including both healthy individuals and those with poor sleep quality
Methods: Meta-analysis of randomized controlled trials (RCTs) published before December 2025; eight public databases were searched, data were extracted and risk of bias assessed, and meta-analysis was conducted using Review Manager 5.4.1

Background

The discovery of the microbiota-gut-brain axis provides a theoretical basis for using probiotic supplementation to improve sleep health. This meta-analysis systematically evaluated the efficacy of probiotics in adults, including both healthy individuals and those with poor sleep quality.

Methods

Eight public databases were searched to identify relevant randomized controlled trials (RCTs) published before December 2025 to be included in this review. Data from the included studies were extracted, and their risk of bias was assessed. Meta-analysis, sensitivity analysis, and publication bias assessment were conducted using Review Manager 5.4.1.

Results

A total of 13 studies involving 890 participants reported outcomes using the Pittsburgh Sleep Quality Index (PSQI). The meta-analysis revealed that probiotic supplementation significantly reduced PSQI scores compared to the control group (mean difference [MD] = -0.59, 95% confidence interval to -0.35, p < 0.001), indicating moderate heterogeneity (I² = 46%). For the Insomnia Severity Index (ISI), the probiotic group also showed significantly lower scores (MD = -0.86, 95% CI: -1.60 to -0.12, p = 0.02; I² = 26%). In contrast, no significant changes were observed in the Epworth Sleepiness Scale (ESS) scores or serum cortisol levels.

Conclusion

Probiotic supplementation was associated with a modest but statistically significant improvement in sleep quality among adults, regardless of their baseline sleep status (ranging from healthy to suboptimal), as measured by PSQI and ISI scores.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/view/CRD420251237016, PROSPERO (CRD420251237016).

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Bifidobacterium plantarum	—	Reduced Insomnia	Beneficial	Small	View source For the Insomnia Severity Index (ISI), the probiotic group also showed significantly lower scores (MD = -0.86, 95% CI: -1.60 to -0.12, p = 0.02)
Lactobacillus plantarum LP01	—	Improved Sleep Quality	Beneficial	Small	View source Probiotic supplementation significantly reduced PSQI scores compared to the control group (mean difference [MD] = -0.59, 95% confidence interval [CI]: -0.83 to -0.35, p < 0.001) ... For the Insomnia Severity Index (ISI), the probiotic group also showed significantly lower scores (MD = -0.86, 95% CI: -1.60 to -0.12, p = 0.02).
Lactobacillus rhamnosus LR06	—	Improved Sleep Quality	Beneficial	Small	View source Probiotic supplementation significantly reduced PSQI scores compared to the control group (mean difference [MD] = -0.59, 95% confidence interval [CI]: -0.83 to -0.35, p < 0.001) ... For the Insomnia Severity Index (ISI), the probiotic group also showed significantly lower scores (MD = -0.86, 95% CI: -1.60 to -0.12, p = 0.02).