Dynamic changes in oral microbiome composition during early childhood caries management

Early childhood caries (ECC) is a prevalent dental disease with significant public health burdens. Oral microbiota plays a key role in caries development. Although several studies have compared the oral microbiota before and after caries treatment, few have investigated the dynamic changes in oral microbial communities beyond 3 months. This 6-month prospective study monitored dynamic changes in the dental plaque microbiome, salivary pH, and oral hygiene status among children with ECC undergoing caries management. The outcomes were assessed at baseline (T0), immediately post-treatment (T1), and at 1-month, 3-month, and 6-month follow-ups (T2-T4). Children's oral hygiene status improved significantly after ECC management (p < 0.001). Their salivary pH levels increased at T1 but returned to the initial level during follow-up visits. Higher Chao1 scores were observed at T2, T3, and T4 when compared to T0 and T1 (p < 0.001). The principal coordinate analysis revealed distinct clustering patterns between baseline and post-treatment visits. Significant differences were observed in the relative abundance of Corynebacterium (p < 0.01), Corynebacterium matruchotii (p < 0.01), and Selenomonas noxia (p < 0.05) during the study period. The relative abundance of Corynebacterium and Corynebacterium matruchotii was significantly higher at T3 and T4 when compared to T1 (p < 0.01). Additionally, Saccharibacteria was positively correlated with children's dmfs scores and negatively correlated with children's salivary pH values. The above findings possibly indicated that comprehensive ECC management might be associated with dynamic changes in the oral microbiome. Further well-designed randomized controlled trials are warranted to determine the impact of dental treatment on oral microbiota dynamics. KEY POINTS: • Dynamic changes observed in the oral microbiome following dental treatment • Abundance of Saccharibacteria associated with children's caries status and salivary pH values • Children's oral health-related behaviors improved after comprehensive dental management.