Single-session general anesthesia versus multiple-visit therapy for severe early childhood caries divergent short-term impacts on the oral–gut microbiome

Abstract Background The oral-gut microbial axis mediates bidirectional regulation between oral and gut microbiota. Single general anesthesia treatment and conventional multiple-visit therapy are two core strategies for severe early childhood caries (S-ECC), yet their concurrent impacts on oral and gut microbiota remain insufficiently compared. Objective To compare the short-term effects of the two regimens on the diversity and community structure of salivary and gut microbiota in children with S-ECC from the oral-gut axis perspective. Design: Fifty children aged 3–6 years with S-ECC were divided into single general anesthesia treatment group (C1, n = 25) and a conventional multiple-visit group (C2, n = 25) based on clinical indication, parental preference, and patient cooperation. 16S rRNA V3-V4 region high-throughput sequencing was applied to analyze microbial diversity and compositional changes before and after treatment. Results (1) Salivary microbiota: Group C1 exhibited significantly decreased observed features, shannon index and shifted community structure post-treatment (all P < 0.05), with marked reductions in core cariogens including Streptococcus mutans ( S. mutans ) and Prevotella denticola ( P. denticola )( P < 0.05). Group C2 showed no significant change in α-diversity but altered community structure ( P < 0.05); only Scardovia wiggsiae decreased significantly, while S. mutans presented a downward trend without statistical significance. (2) Gut microbiota: Neither group had significant α-diversity changes; only group C2 showed significantly altered gut community structure ( P < 0.05). Fecal S. mutans was downregulated in both groups, and the butyrate-producing genus Anaerobutyricum increased significantly in group C2 ( P < 0.05). Conclusion Single general anesthesia treatment effectively eliminates core cariogens and remodels oral microbiota with only transient diversity reduction and mild disturbance to gut microbial homeostasis. Conventional multiple-visit therapy has limited inhibitory effects on oral cariogens and causes more pronounced disruption to overall gut microbial stability. These findings highlight the differential short-term microbiological impacts of the two treatment strategies and warrant further investigation into their long-term implications.