Comparative study of oral bacterial composition and neutrophil count between smokers and non-smokers

Abstract

Exposure to tobacco smoke has significantly impacted on the gingival and oral flora, therefore, this study was conducted to investigate the bacterial flora in the oral cavity of smokers and compare it with that of normal non-smokers. The study included 20 male smokers (mean age: 30 ± 7.2) and 20 male non-smokers (mean age: 31 ± 8.6). Bacterial isolates were identified after isolation by biochemical tests. The number of neutrophils in saliva was also estimated for all study individuals. The results revealed 171 bacterial isolate from smokers and non-smokers. The predominant isolate was Streptococcus sp. in both groups but with higher percentage in non-smokers (42.6%) compared to smokers (31.6%). Anaerobic bacteria showed a higher percentage (36.2%) in smokers compared to non-smokers (22.8%) at P < 0.05. Gram-negative bacilli showed higher significant percentage in smokers (32.7%) compared to non-smokers (12.9%) (P < 0.05). The mean number of neutrophils in smokers was significantly lower (30 cell/ml) than non-smokers (48 cell/ml). Well-known pathogenic isolates presented only in oral samples of smokers. In conclusion, smoking may have a negative effect on neutrophils presence in the oral cavity and this may encourage the growth of opportunistic pathogenic bacteria to cause oral infections such as periodontitis as well as other infections.