Upper Airway Microbiota in Pediatric Obstructive Sleep Apnea: A Systematic Review

Pediatric obstructive sleep apnea (OSA) has been increasingly associated with alterations in upper airway microbial ecology, potentially contributing to airway inflammation and the disease's pathophysiology. This systematic review aimed to compile existing evidence on the differences in the oral and upper airway microbiome between children with OSA and those without. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 recommendations and was registered in PROSPERO (CRD420251030178). Electronic searches were conducted in MEDLINE, Scopus, Web of Science, and the Cochrane Library to find observational studies comparing the oral and/or oronasopharyngeal microbiota in children under 16 years old with and without OSA. Two reviewers independently performed study selection, data extraction, and risk of bias assessment using the AXIS tool, and the findings were narratively synthesized due to clinical and methodological diversity. Five cross-sectional or prospective observational studies, involving a total of 237 children, met the inclusion criteria. The studies focused on different oral and upper airway niches, with children with OSA more often showing an increase in genera such as Prevotella, Haemophilus, Fusobacterium, Veillonella, Porphyromonas, Treponema, Campylobacter, and Moraxella compared with controls. However, results regarding Neisseria abundance and α diversity metrics were inconsistent, and one study did not identify a distinct disease-specific microbial profile. Most studies were single-center with small sample sizes and a moderate risk of bias, and none sufficiently adjusted for key confounders, such as recent antibiotic use, diet, or socioeconomic factors. Overall, the evidence suggests niche-specific shifts in oral and oronasopharyngeal microbiota among children with OSA, but conclusions are limited by heterogeneity and study design. Larger, longitudinal, multicenter studies that integrate clinical phenotyping with high-resolution microbiome analyses are needed before specific microbial changes can be applied to diagnostic or therapeutic uses.