The interplay of sleep characteristics with health factors and gut microbiome.

Lower alpha diversity was associated with poorer sleep quality, later chronotype, and greater social jet lag.

• Study population consisted of 6941 participants from the Lifelines Dutch Microbiome Project.
• Alpha diversity measures were linked to multiple sleep characteristics including sleep quality, chronotype, and social jet lag.
• Beta diversity was linked to both sleep quality and social jet lag.

137 bacterial species were associated with sleep characteristics, of which 35.6% were validated in an independent cohort.

• A total of 137 bacterial species showed associations with sleep-related variables.
• 35.6% of these species associations were validated in an independent replication cohort.
• Associations spanned multiple sleep characteristics including sleep quality, chronotype, and social jet lag.

Mediation analyses indicated that changes in species abundance are largely a consequence of sleep behavior rather than a cause.

• Mediation analyses were used to assess the directionality of relationships between sleep behavior and gut microbiome composition.
• The predominant direction of effect was from sleep behavior to microbial species abundance.
• This suggests that sleep patterns shape the gut microbiome rather than the reverse in most cases.

Certain bacterial species may mediate the influence of diet on sleep, specifically Clostridia species UC5_1_1E11 and SGB14844 mediated the effect of coffee intake on social jet lag.

• Mediation analyses identified specific microbial species as intermediaries between dietary exposures and sleep outcomes.
• Clostridia species UC5_1_1E11 and SGB14844 were identified as mediators of the relationship between coffee intake and social jet lag.
• These findings suggest a diet–microbiome–sleep axis where dietary components influence sleep through gut microbial changes.

Beta diversity of the gut microbiome was linked to both sleep quality and social jet lag.

• Beta diversity, reflecting overall community composition differences between individuals, was associated with sleep quality.
• Beta diversity was also associated with social jet lag, a measure of discrepancy between social and biological clock timing.
• These findings complement the alpha diversity results and indicate that overall microbiome community structure differs according to sleep characteristics.