Comparative Analysis of Respiratory Disorders and Oral Microbial Flora in Smokers and Nonsmokers from District Swabi, Pakistan

Abstract

Tobacco smoking is a pervasive public health concern known to negatively affect both oral and systemic health. This study aimed to investigate the impact of cigarette smoking on the composition of oral microbial flora and associated respiratory symptoms among male residents of District Swabi, Pakistan. A total of 44 participants—22 smokers and 22 non-smokers—were included in the research. Oral samples were collected using sterile cotton swabs and subjected to microbiological analysis, including culturing on nutrient agar, Gram staining, and biochemical tests such as catalase and oxidase assays. Eight predominant bacterial species were identified in the oral cavities of smokers: Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Serratia marcescens, Acinetobacter baumannii, Haemophilus influenzae, Clostridium difficile, and Streptococcus pneumoniae. These bacteria included several opportunistic and pathogenic strains, indicating a significant shift in the oral microbiome due to tobacco exposure. Most bacterial isolates from smokers tested positive for catalase, suggesting increased oxidative stress adaptation. Demographic and behavioral data revealed that smoking was most prevalent among individuals aged 18–30 years, and low to moderate smoking intensity was common. Additionally, a high prevalence of respiratory symptoms—such as morning cough, phlegm production, wheezing, and dyspnea—was reported among smokers, despite the absence of family history for respiratory illness. These findings highlight the detrimental effects of smoking on both microbial ecology and respiratory health, emphasizing the need for targeted tobacco cessation programs and early public health interventions.

Keywords: Tobacco smoking, Oral microbiota, Gram staining, Respiratory symptoms, Pathogenic bacteria