Tongue-Coating Microbial and Metabolic Characteristics in Halitosis

Area of Science:

• Oral Microbiology
• Metabolomics
• Halitosis Research

Background:

• Halitosis (bad breath) negatively impacts quality of life and social interactions.
• The tongue coating microbiome is implicated in halitosis development.
• Dynamic microbial and metabolic variations in halitosis are not fully understood.

Purpose of the Study:

• To investigate tongue coating microbial and metabolic profiles in individuals with halitosis but no other oral diseases.
• To utilize metagenomics and metabolomics for comprehensive analysis.
• To identify key microbial and metabolic features differentiating halitosis from healthy states.

Main Methods:

• Oral examination and halitosis assessment.
• Tongue coating sample collection for metagenomic and metabolomic analysis.
• Multiomics data analysis using machine learning classifiers (LASSO logistic regression, random forest).

Main Results:

• Elevated microbial richness and diversity in halitosis subjects.
• Increased abundance of Actinomyces, Prevotella, Veillonella, and Solobacterium; decreased Rothia and Streptococcus.
• Enriched pathways (e.g., cysteine and methionine metabolism) and elevated metabolites (indole-3-acetic acid, ornithine, L-tryptophan) in halitosis samples.
• Positive correlation between volatile sulfur compounds and indole-3-acetic acid levels.
• Identification of 19 species and 39 metabolites as diagnostic features for halitosis.

Conclusions:

• Significant shifts in tongue coating microbiome and metabolome characterize halitosis.
• These multiomic alterations suggest a potential etiological role in halitosis development.
• Findings provide novel insights into the mechanisms underlying halitosis.