Abstract
BACKGROUND: Tonsillar hypertrophy (TH) and adenotonsillar hypertrophy (ATH) are primary risk factors for paediatric obstructive sleep apnoea (OSA), but their salivary microbiota differ. OBJECTIVE: This study aimed to investigate whether the tonsillar surface and core microbiota resemble the salivary microbiota, and whether these microbial profiles are influenced by adenoid hypertrophy and related clinical factors. DESIGN: Forty-nine children undergoing tonsillectomy were enrolled, including 21 children with TH and 28 with ATH. Saliva and tonsillar surface swabs were collected preoperatively, and core tissues were obtained intraoperatively. Microbiota were profiled via 16S rRNA sequencing, compared across sites and groups, and correlated with preoperative clinical indicators. RESULTS: The tonsillar core microbiota was relatively stable across all children, whereas the surface and salivary microbiota shifted with adenoid hypertrophy. Prevotella, Neisseria, Veillonella, Alloprevotella, Lancefieldella and Haemophilus were consistently more abundant on the tonsillar surface compared to the core. Gemella was uniquely enriched on the surface and positively correlated with the obstructive apnoea-hypopnoea index and red cell distribution width in the TH group. CONCLUSIONS: This study reveals distinct microbial profiles between the tonsillar surface and core. In TH, surface microbiota was associated with OSA severity and haematological indicators, suggesting potential relevance that warrants further investigation.