In a cross-sectional study of 1,332 U.S. adolescents and young adults, investigators found that individuals with long sleep durations exhibited significantly higher oral microbiome diversity compared with those with healthy sleep durations, according to research scheduled for presentation at SLEEP 2025.
The study analyzed data from the 2011–2012 National Health and Nutrition Examination Survey (NHANES) for participants aged 16 to 26 years (mean age, 20.9 years; 50.4% female). Sleep duration was self-reported for weekdays or school/workdays and categorized as very short, short, healthy, or long based on American Academy of Sleep Medicine recommendations. Among participants aged 16 to 18 years, 50.6% reported the recommended 8 to 10 hours of sleep, while 61.2% of those aged 19 to 26 years reported sleeping 7 hours or more, as recommended.
Long sleepers (3% of the cohort) demonstrated significantly greater oral microbiome diversity across three alpha diversity measures: observed operational taxonomic units (OTU), 43 (95% CI, 22.3–63.72); Faith’s phylogenetic diversity (FPD), 2.96 (95% CI, 1.16–4.76); and Shannon-Weiner index (SWI), 0.64 (95% CI, 0.07–1.21). No statistically significant association was observed between sleep duration and the Inverse Simpson index (ISI).
Overall oral microbiome diversity across the sample was as follows: OTU, mean = 128.0 (95% CI, 122.35–133.64); FPD, 14.24 (95% CI, 13.87–14.62); SWI, 4.61 (95% CI, 4.54–4.67); ISI, 0.90 (95% CI, 0.89–0.90).
“For more than two decades, researchers have hypothesized that the microbiome is largely overlooked as a determinant of health and disease, and growing evidence has shown that disturbances in sleep health can alter the microbiome, particularly within the gut,” said lead author Marie-Rachelle Narcisse, PhD, of Brown University in Providence, RI. “I’m thrilled that our study highlights the potential relationship between sleep health and the oral microbiome and look forward to further exploring that connection.”
The research is among the first to explore the associations between sleep duration and oral microbiome composition in adolescents, a developmental stage marked by biological changes in circadian rhythms. The investigators used four generalized linear models to assess the associations between alpha diversity measures and sleep durations while controlling for covariates and accounting for NHANES complex survey design.
“The human mouth is one of the most densely colonized microbial habitats in the body and an entry point for pathogens that can contribute to gum inflammation and dental caries,” Dr. Narcisse said. “Our findings suggest the possibility that targeting the oral microbiome may offer more accessible, cost-effective intervention strategies than those focused solely on the gut. Further research is needed to understand the mechanisms underlying these associations."
The study was funded by the National Institute of General Medical Sciences.