Abstract
BACKGROUND: The homeostasis of the subgingival microbiome is crucial for periodontal health, although the dynamics governing its community variation remain insufficiently studied. This study aims to investigate the dynamics of subgingival microbiota reassembly after disruption, focusing on core taxa, functions, and driving forces. METHODS: 339 subgingival plaques in periodontally healthy states were collected before and after ultrasonic cleaning across 12 timepoints for 1 year. All samples underwent full-length 16S rRNA sequencing; 30 were selected for metagenomic sequencing. RESULTS: Our findings revealed that disturbed subgingival microbiota underwent short-term disruptions but subsequently reverted to baseline, maintaining stability within a year. Homogeneous selection dominated assembly, driving convergent structure under consistent pressure. Such a recovery process was accompanied by key taxa increased sequentially: Pseudomonas fluorescens early, Haemophilus parainfluenzae mid-stage, and Capnocytophaga spp. late. Functionally, reconstruction began with energy metabolism, expanded via biofilm formation and LPS biosynthesis mid-stage, and involved late apoptosis and complex amino acid metabolism. Microbial interactions, including positive regulation from Veillonella HMT 780 to Fusobacterium HMT 248, internally drove community assembly. CONCLUSION: Our study clarifies species and functional dynamics during subgingival microbiota reconstruction and maps time-directed networks among stage-specific bacteria, offering a theoretical basis for targeted microbiome regulation.