Characterization of the oral microbiota of Kawasaki disease patients by metagenomic analysis: A pilot study

BACKGROUND: plasma cells within the respiratory tract, suggesting the upper airway may act as a potential portal of entry. However, evidence connecting respiratory infections to KD remains limited. This study aimed to explore the relationship between oral microbiota and KD development. METHODS: Oral swab samples were collected from 25 KD patients before and after intravenous immunoglobulin (IVIG) treatment, as well as from 25 healthy controls. Metagenomic sequencing was performed to characterize overall microbial composition and identify potential microbial markers associated with KD. RESULTS: Significant alterations in oral microbiota composition were observed between KD patients and healthy controls. The diversity of oral microbiota in KD patients was markedly lower than that in healthy controls, and exhibited an upward trend following IVIG treatment. Elevated levels of Streptococcus, Prevotella, and Veillonella, along with reduced levels of Haemophilus, Neisseria, and Rothia, were closely associated with KD development. Putative novel pathogen Abiotrophia defectiva was significantly enriched in patients with KD. Correlation analysis revealed that the relative abundances of several Haemophilus species were positively correlated with albumin levels in KD patients before IVIG treatment. Additionally, the anti-inflammatory bacterium Rothia mucilaginosa may play a protective role against the development of coronary artery lesions in KD. CONCLUSION: These findings provide new evidence that distinct alterations in the oral microbiome are associated with KD development. Oral microbiota-based biomarkers may represent a potential strategy for KD therapy.