Methods: Subgingival bacterial communities were sampled from 82 patients: 22 non-smoker healthy controls (NS-Controls), 28 non-smoker periodontal patients (NS-Perio) and 32 smoker periodontal patients (S-Perio). These samples were studied by pyrosequencing PCR products of the 16S ribosomal RNA gene.
Results: In all the analyzed subgingival samples, 116 bacterial genera were identified. The most abundant genus in all patients was Fusobacterium (48%-32%). In comparison to the NS-Controls, the NS-Perio and the S-Perio showed a significantly higher prevalence of patients with presence for Anaeglobus, Bulleidia, Desulfobulbus, Eubacterium, Filifactor, Mogibacterium, Mycoplasma, Phocaeicola, Schwartzia, Tannerella and Treponema (Fisher’s exact test, p<0.05). With respect to the influence of smoking habit, Anaeroglobus, Bulleidia, Corynebacterium and Granulicatella were more prevalent in the S-Perio than in the NS-Perio (Fisher’s exact test, p<0.05).
In comparison to the NS-Controls, the periodontal patient groups had significantly higher percentages of abundance of Filifactor, Porphyromonas, Tannerella, Treponema, Atopobium, Eubacterium, Peptostreptococcus and TM7 (Kruskal-Wallis test, p<0.05). With respect to the influence of smoking habit, TM7 and Veillonella were more abundant in the S-Perio than in the NS-Perio (3% and 2% versus 1% and 0.5% respectively), while Porphyromonas presented a significantly lower value in the S-Perio (16% versus 26%) (U Mann-Whitney test, p<0.05).
Rarefaction curves and diversity indices showed a greater number of bacterial species in samples from periodontal patients (mainly non-smokers), appearing species undetected in the NS-Controls.
Conclusion: 16S pyrosequencing allowed to demonstrate the different composition and greater diversity of subgingival microbiome in chronic periodontitis, confirming the association of putative periodontal pathogens and implicating a number of other taxa that will be targets for future research. The microbial profile of smoking-associated periodontitis is less diverse and distinct from that of non-smokers.