The Dentin Microbiome: A Metatranscriptomic Evaluation of Caries-Associated Bacteria

Area of Science:

• Microbiology
• Genomics
• Oral Health

Background:

• Dental caries is a global chronic disease influenced by host, diet, and microbial factors.
• Understanding the dentin microbiome's functional dynamics is crucial for caries research.

Purpose of the Study:

• To investigate the functional activity of the dentin microbiome in healthy versus carious teeth.
• To identify key microbial species and molecular functions associated with dental caries progression using metatranscriptomic analysis.

Main Methods:

• RNA sequencing (RNA-Seq) was performed on samples from healthy and decayed teeth.
• Illumina NovaSeq 2000 platform was used for sequencing.
• SAMSA2 pipeline facilitated taxonomic and functional annotation of the data.

Main Results:

• Upregulation of Streptococcus and Lactobacillus species (e.g., S. mutans, L. salivarius) in carious samples, linked to acid production and carbohydrate metabolism.
• Increased abundance of Mycobacterium species in decayed teeth, associated with biofilm formation and acid tolerance.
• Gene Ontology analysis revealed distinct functions in carious teeth (carbohydrate metabolism, oxidative stress) versus healthy teeth (homeostasis).

Conclusions:

• Dental caries is a polymicrobial disease with diverse bacterial species contributing to pathogenesis.
• Functional metatranscriptomic analysis provides critical insights into oral microbiome shifts during caries development.
• Findings highlight the importance of metabolic and stress-response mechanisms in microbial survival and disease progression.