Shotgun metagenomic analysis of the oral microbiome in gingivitis: a nested case-control study

Background Gingivitis, i.e. inflammation of the gums, is often induced by dental plaque. However, its exact link to the oral microbiota remains unclear.Methods In a case-control study involving 120 participants, comprising 60 cases and 60 controls (mean age (SD) 36.6 (7.6) years; 50% males), nested within a prospective multicentre cohort study, we examined the oral microbiome composition of gingivitis patients and their controls using shotgun metagenomic sequencing of saliva samples. Participants underwent clinical and radiographic oral health examinations, including bleeding on probing (BOP), at six tooth sites. BOP ≥33% was considered ‘generalized gingivitis/initial periodontitis’(GG/IP), and BOP