Effect of gut microbiota modulation on sleep: a systematic review and meta-analysis of clinical trials

Context A bidirectional relationship between gut microbiota (GM) and circadian rhythms has been proposed. Objective The aim of this study was to analyze the efficacy of probiotic or prebiotic intervention on sleep quality and quantity. Data Sources A systematic review and meta-analysis were conducted using the databases PubMed (MEDLINE), Embase, CINAHL, and Web of Science. Only randomized clinical trials written in English or Spanish were considered. Data Extraction The initial search resulted in 219 articles. Following the removal of duplicates and consideration of the selection criteria, 25 articles were selected for the systematic review and 18 articles for the meta-analysis. Data Analysis Microbiota modulation was not demonstrated to be associated with significant improvement in sleep quality in the present meta-analysis (P = 0.31). In terms of sleep duration, the meta-analysis found no improvement due to GM modulation (P = 0.43). Conclusion The results of this meta-analysis indicate that there is still insufficient evidence to support the relationship between GM modulation and improved sleep quality. While several studies assume that including probiotics in the diet will undoubtedly improve sleep quality, more research is needed to fully understand this phenomenon. Systematic Review Registration PROSPERO registration no. CRD42021245118.