# Sleep and Circadian Rhythm Phenotypes in Adolescent Depression: Exploring the Role of the Oral Microbiome

> **NIH NIH P20** · EMMA PENDLETON BRADLEY HOSPITAL · 2024 · $130,527

## Abstract

The human mouth is a gateway for harmful pathogens that can lead to chronic conditions like gum 
inflammation and caries. The oral cavity is the second most populated microbial habitat in the body. It is 
densely colonized by over 700 microbe species and harbors an even more diverse bacterial population 
than the gut. Recent observational studies involving adults have indicated differences in oral microbiome 
diversity and abundance based on depression. Emerging evidence suggests the role of internal circadian 
rhythms in the oral microbiome, indicating circadian misalignment could significantly influence its 
composition and abundance, a phenomenon also affected by sleep loss. These findings hold particular 
significance for adolescents experiencing depression and undergoing developmental changes in 
sleep/wake patterns. Most of the work on the taxonomic composition of microbial communities has been 
descriptive and based on small-scale clinical studies. Research on the associations between the oral 
microbiome and depression has mainly involved adults. These associations need replication on 
adolescent and young adult population data. The National Health and Nutrition Examination Survey 
provides a unique opportunity to replicate these associations as ii contains data on oral microbiome 
diversity and abundance, sleep and rest-activity rhythms patterns, and depression from a representative 
sample of adolescents and young adults in the United States (U.S.). Our ultimate goal is to lay the 
foundation for informing new mechanistic models for adolescent depression through in-depth oral 
microbiome research. To that end, we have developed the following specific aims: Aim 1. Describe the 
oral microbiome composition and structure among adolescents (ages 14-17) and young adults (ages 
18-24); Aim 2. Compare sleep and circadian rhythm phenotypes on oral microbiome composition and 
structure; Aim 3. Explore associations between oral microbiome composition and structure and 
depression; and Aim 4. Explore associations between sleep and circadian rhythm phenotypes, oral 
microbiome, and depressive symptoms. This proposal addresses the COBRE's goals of examining sleep, 
circadian rhythms, and adolescent mental health. In the long term, this study will make a meaningful 
contribution to public health, especially adolescent mental health in the U.S.

## Key facts

- **NIH application ID:** 11177213
- **Project number:** 5P20GM139743-04
- **Recipient organization:** EMMA PENDLETON BRADLEY HOSPITAL
- **Principal Investigator:** Marie-Rachelle Narcisse
- **Activity code:** P20 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $130,527
- **Award type:** 5
- **Project period:** 2024-03-01 → 2026-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11177213

## Citation

> US National Institutes of Health, RePORTER application 11177213, Sleep and Circadian Rhythm Phenotypes in Adolescent Depression: Exploring the Role of the Oral Microbiome (5P20GM139743-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/11177213. Licensed CC0.

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