Distal gut microbiome association with sleep duration and quality.

The relationship between sleep time and gut microbiota composition has revealed conflicting results. Previous research has focused on the acute effect of sleep deprivation on microbial composition, however, no research until now has analyzed the association between habitual sleep time and gut microbial composition. By using a cross-sectional design, we evaluated whether sleep duration and quality were associated with distal gut microbiota composition in a young, healthy population under normal living conditions. A total of 55 male (n=28) and female (n=27) participants, normal BMI within 18 to 35y were recruited. Sleep and physical activity time were analyzed by having the participants wearing a SenseWear® monitor for 7 days. Sleep quality was evaluated using the PSQI questionnaire. Body composition was examined through DXA. Alpha diversity was evaluated via 16S rRNA-V4 region. Metabolic syndrome risk was calculated according to the ATPIII criteria. Diet was analyzed through 24h food-records, and anxiety and depression were measured through Beck inventories. The main hypothesis of the present study was rejected, as we did not observe a significant relationship between habitual sleep duration and alpha diversity parameters in our young, healthy, normal BMI population; results that are consistent to previous studies with lower numbers of participants showing no effect of acute sleep deprivation on alpha diversity. It is possible that the high physical activity levels of our population and/or the lack of a secondary stressor prevented us from observing an effect of sleep on alpha diversity. Other key results observed either in female or male participants are: 1) the positive association between diet variety and gut microbial diversity, 2) the negative association between sleep quality and protein intake, 3) the stronger effect that diet has on alpha diversity in comparison to body composition, sleep, or physical activity, 4) the lower alpha diversity with higher BMI, 5) the lower alpha diversity with higher anxiety levels, 6) the relationship between poor sleep quality and depression/anxiety levels, 7) the potential mediator effect of physical activity and lean mass on the positive relationship between sleep time and fat mass, and lastly 8) the association between higher blood pressure and lower sleep time, as well as the potential mediator effect of gut diversity controlling this relationship. Overall, this work does not support a potential relationship between sleep parameters and gut alpha diversity in young, healthy participants performing high physical activity levels.