Comparable tongue coating microbiota profiles from a simplified single-swab versus different sampling approaches: A...

Area of Science:

• Microbiome research
• Oral health
• Systemic disease biomarkers

Background:

• Tongue coating microbiota is a potential biomarker for systemic diseases.
• Lack of standardized sampling protocols hinders clinical application and cross-study comparisons.
• Pilot study to evaluate the reliability of different tongue coating sampling methods.

Purpose of the Study:

• To assess the reliability of different tongue coating microbiota sampling methods.
• To determine if a single scrape yields comparable results to multiple scrapes.
• To identify a practical and reproducible sampling protocol.

Main Methods:

• Collected tongue coating samples from healthy adults using four methods (single/multiple scrapes, swabs/scraper).
• Performed metagenomic sequencing to analyze microbial diversity, taxonomic composition, and functional profiles.
• Analyzed DNA quality, alpha/beta diversity, genus/species abundance, and KEGG functional predictions.

Main Results:

• Single-scrape method showed comparable microbial profiles, alpha-diversity, and beta-diversity to multi-scrape methods.
• Consistent taxonomic compositions (dominant genera: Streptococcus, Prevotella, Rothia) and minimal variation in functional pathways.
• Findings suggest spatial stability and representative sampling potential of tongue coating microbiota.

Conclusions:

• A single scrape using a sterile flocked swab is a practical, reproducible, and cost-effective sampling method.
• This simplified approach yields representative tongue coating microbiome data in healthy adults.
• Further validation in larger, diverse cohorts is needed for clinical application and standardization.