Comparison of oral collection methods for 16S rRNA gene and shotgun metagenomic sequencing

This study investigates the impact of different oral sample collection methods and storage conditions on the stability and composition of the oral microbiome. By comparing unpreserved saliva, saliva mixed with glycerol, and mouthwash samples, the research evaluates their microbial community profiles using 16S rRNA gene and shotgun metagenomic sequencing. The study also examines the room-temperature stability of these samples over a week and their intraindividual consistency over six months. Findings highlight that saliva in glycerol closely resembles unpreserved saliva, while mouthwash shows greater room-temperature stability. The results underscore the importance of consistent sample collection methods and suggest that mouthwash may be a viable option when immediate freezing is impractical. This work provides crucial insights for designing future studies on the oral microbiome and its relationship to health outcomes.