Gut Microbiota Composition and Sleep in Preschoolers: The ELFE Birth Cohort Study.

Background/objectives: Sleep is essential for children's well-being, yet insufficient sleep duration and quality are common among preschoolers. The brain-gut microbiota axis, a bidirectional communication network connecting the brain, the gastrointestinal tract, and the microorganisms living there, known as the gut microbiota, influences sleep regulation, but its role in children remains largely unexplored. Here, we examined the association between gut microbiota and sleep in preschoolers from Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort study.

Methods: This study included 597 children (51.2% boys) with available stool samples and sleep data at 3.5 years. The gut microbiota data was analyzed using bacterial 16S rRNA sequencing. Data on day and night sleep durations and frequencies of sleep onset difficulties and night waking were collected through telephone questionnaires and grouped into 'optimal' and 'suboptimal' clusters using Latent Class Analysis. Statistical analyses involved multivariate logistic regressions or multivariate permutation analysis of variance, controlling for confounders.

Results: In total, 25% of the included children were in the suboptimal sleep cluster. No significant associations were found between gut microbiota diversity and composition and sleep clusters at age 3.5 years. Similarly, no differences were found in the abundance of specific microbiota genera between the two sleep clusters.

Conclusions: While emerging evidence suggests correlations between gut microbiota and sleep in preschool children, our results do not confirm such correlations. The data used in this study were obtained from a homogeneous, high socioeconomic population, which must be considered when interpreting the findings. Further research is needed to validate the results of this study.