Prediction and validation of microbial community function from normal pulp to pulpitis caused by deep dentinal caries

Area of Science:

• Dental microbiology
• Oral microbiome research
• Pulpitis pathogenesis

Background:

• Microbial dysbiosis is implicated in dental pulp disease progression.
• Limited research exists on microbial community function in deep dentinal caries-induced pulpitis.

Purpose of the Study:

• To predict and verify the functional roles of microbial communities in deep dentinal caries affecting pulp status.
• To differentiate microbial functions in normal pulp (NP), reversible pulpitis (RP), and irreversible pulpitis (IRP).

Main Methods:

• 16S ribosomal DNA sequencing and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) for microbial composition and function prediction in 111 samples.
• Quantitative PCR (qPCR) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for functional verification in 60 samples.
• Comparison of microbial communities and functions across NP, RP, and IRP groups.

Main Results:

• Microbial abundance significantly differed in the irreversible pulpitis (IRP) group.
• Predicted functional differences between reversible pulpitis (RP) and normal pulp (NP) involved membrane transport.
• Predicted functional differences between IRP and NP involved amino acid, co-factor, and vitamin metabolism. LC-MS/MS confirmed amino acid metabolism alterations in IRP vs. NP.

Conclusions:

• The near-pulp microbiome in RP and NP with deep dentinal caries exhibits similar functional profiles.
• Amino acid metabolism is a key distinguishing functional pathway in the near-pulp microbial community between IRP and NP groups.
• These findings highlight specific microbial metabolic shifts associated with pulpitis severity.