A new study to be presented at the SLEEP 2025 annual meeting found that oral microbiome diversity is positively associated with long sleep duration among teenagers and young adults.

Results show that compared to those with a healthy sleep duration, teenagers and young adults with a long sleep duration (3% of participants) had significantly higher oral microbiome diversity. The study is among the first to demonstrate this connection in adolescents, opening a new avenue of research into how the oral microbiome may be related to sleep health during this crucial developmental period.

“For more than two decades, researchers have hypothesised 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, who is an assistant professor of psychiatry and human behavior at the Warren Alpert Medical School of Brown University, and a research scientist at the E.P. Bradley Hospital COBRE Center for Sleep and Circadian Rhythms in Child and Adolescent Mental Health in Providence, Rhode Island. “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 study examined a representative sample of 1,332 American adolescents and young adults aged 16-26, using cross-sectional data from the National Health and Nutrition Examination Survey. The mean age was 20.9 years, and 50.4% were female. The sleep variables were self-reported sleep hours on weekdays or school/work days, categorised as very short, short, healthy, and long sleep according to American Academy of Sleep Medicine recommendations. Five in 10 teenagers (50.6%) reported the recommended hours of sleep (8-10 hours), while six in 10 young adults (61.2%) reported a healthy sleep duration (7-9 hours).

The AASM recommends that teens sleep 8 to 10 hours on a regular basis, and adults should sleep seven or more hours per night on a regular basis, to promote optimal health. Sufficient, high-quality sleep is associated with better health outcomes, including improved attention, behaviour, learning, memory, emotional regulation, quality of life, and mental and physical health. Notably, poor sleep can weaken immune function and increase inflammation, which may affect oral health.

Narcisse noted that the human mouth is one of the most densely colonised microbial habitats in the body, and the oral cavity is an entry point for pathogens that can lead to chronic conditions such as gum inflammation and dental caries. Further research is needed to understand the relationship between sleep health and the oral microbiome.

“Adolescence is a pivotal period marked by biological changes in sleep-wake cycles, yet studies exploring the link between sleep health and the oral microbiome during this stage of life are scarce,” Narcisse said. “Our findings suggest that targeting the oral microbiome to improve adolescent sleep health, or conversely, improving sleep to influence the oral microbiome, holds the promise to offer more accessible, cost-effective intervention strategies than approaches focused solely on the gut.”

This study was supported by a grant from the National Institute of General Medical Sciences. The research abstract was published recently in an online supplement of the journal Sleep and will be presented on Tuesday, June 10, during SLEEP 2025 in Seattle. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.