Background Fusobacterium nucleatum ( F. n ) is an important opportunistic pathogen causing oral and gastrointestinal disease. Faecalibacterium prausnitzii ( F. p ) is a next-generation probiotic and could serve as a biomarker of gut eubiosis/dysbiosis to some extent. Alterations in the human oral and gut microbiomes are associated with viral respiratory infection. The aim of this study was to characterise the oral and fecal bacterial biomarker (i.e., F. n and F. p ) in COVID-19 patients by qPCR and investigate the pharyngeal microbiome of COVID-19 patients through metagenomic next-generation sequencing (mNGS). Results Pharyngeal F. n was significantly increased in COVID-19 patients, and it was higher in male than female patients. Increased abundance of pharyngeal F. n was associated with a higher risk of a positive SARS-CoV-2 test (adjusted OR = 1.32, 95% CI = 1.06 ~ 1.65, P < 0.05). A classifier to distinguish COVID-19 patients from the healthy controls based on the pharyngeal F. n was constructed and achieved an area under the curve (AUC) of 0.843 (95% CI = 0.688 ~ 0.940, P < 0.001). However, the level of fecal F. n and fecal F. p remained unaltered between groups. Besides, mNGS showed that the pharyngeal swabs of COVID-19 patients were dominated by opportunistic pathogens. Conclusions Pharyngeal but not fecal F. n was significantly increased in COVID-19 patients, clinicians should pay careful attention to potential coinfection. Pharyngeal F. n may serve as a promising candidate indicator for COVID-19. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02336-6.
【저자키워드】 COVID-19, SARS-CoV-2, Metagenomic next-generation sequencing, Fusobacterium nucleatum, Faecalibacterium prausnitzii, 【초록키워드】 Biomarker, Coinfection, respiratory infection, Viral, pathogen, qPCR, Next-generation sequencing, male, Microbiome, Control, Pathogens, respiratory, gastrointestinal disease, Dysbiosis, COVID-19 patients, Bacterial, COVID-19 patient, fecal, Gut, AUC, opportunistic pathogen, an area, Opportunistic Pathogens, Pharyngeal swab, Classifier, supplementary material, higher risk, clinician, alteration, Female patients, healthy controls, pharyngeal, positive, SARS-CoV-2 test, viral respiratory infection, Fusobacterium, significantly increased, Faecalibacterium, Result, remained, adjusted, groups, Increased, metagenomic, the healthy, 【제목키워드】 Fusobacterium,