Supragingival dental biofilm microbiomes of tobacco heating system smokers, cigarette smokers and non-smokers.

OBJECTIVES

The study compared the bacterial composition of supragingival dental biofilm (SDB) among smokers and non-smokers (NS).

MATERIALS AND

METHODS

This cross-sectional study included 60 subjects allocated into three groups: tobacco heating system smokers (THSS), cigarette smokers (CS) and NS. SDB samples were collected, and bacterial DNA was extracted and prepared for next generation sequencing of the 16s rRNA gene hypervariable regions. Bioinformatic pipelines were applied to assess microbial diversity and taxonomic composition.

RESULTS

No significant differences were observed in alpha diversity (Observed taxa and Shannon index) or beta diversity (Bray-Curtis index) among groups. In contrast, significant differences in microbiome bacterial composition were identified across multiple taxonomic levels. At the genus level, Alysiella (p = 0.016) and Propionibacterium (p = 0.025) were most abundant in THSS, whereas Actinobaculum (p = 0.004), Avibacterium (p = 0.015) and Haemophilus (p = 0.030) predominated in NS. At the species level: Alysiella filiformis (p = 0.006) and Streptococcus thermophilus (p = 0.025) were most abundant in THSS, Streptococcus lactarius (p = 0.05) in CS, and Prevotella multiformis (p = 0.016) and Lactobacillus salivarius (p = 0.018) in NS group.

CONCLUSIONS

Distinct differences in bacterial composition of SDB were observed among THSS, CS and NS. The increased abundance of anaerobic bacteria with cariogenic potential in THSS and CS suggests a more dysbiotic profile and increased pathogenic potential compared to NS.

CLINICAL RELEVANCE: Variations in SDB bacterial composition may influence the pathological potential of dental biofilms in smokers and non-smokers.