Synergistic effects of smoking and obesity on the subgingival microbiome

At the 47th Annual Meeting of the American Association for Dental Research (AADR), held in conjunction with the 42nd Annual Meeting of the Canadian Association for Dental Research (CADR), Najla Kasabreh, The Ohio State University, Columbus, presented an oral session titled "Synergistic Effects of Smoking and Obesity on the Subgingival Microbiome." The AADR/CADR Annual Meeting is in Fort Lauderdale, Fla., USA from March 21-24, 2018.

In the United States, over 35% of adults are obese, 20% of adults smoke and 4.7% of adults are obese smokers. While both smoking and obesity increase the risk for periodontitis, their individual and synergistic effects are not understood. This study compared the subgingival microbiomes of normal weight and obese nonsmokers as well as obese smokers.

Seventy-five periodontally and systemically healthy subjects with no recent history of antibiotics, pregnancy or oral prophylaxis were recruited and divided evenly between three groups based on body mass index and smoking status. Subgingival biofilm samples were collected, DNA was isolated and Illumina MiSeq sequencing was performed generating 599,652 classifiable sequences, which were compared to the Human Oral Microbiome Database.

The results showed that known periodontal pathogens Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) were present in the obese and smoker groups, but not in the controls. Streptococcus sobrinus was unique to the obese group. Diverging patterns of bacterial interactions were observed in obese smokers and non-smokers, indicating the role played by these factors in driving bacterial colonization.

"The data suggests that both smoking and increased body mass index alter the composition of the subgingival microbiome and that the collective effects of these two factors are not merely additive, but multiplicative. We also discovered that obesity affects the male and female oral microbiomes differently. This indicates a true need for precision dentistry that incorporates multiple metrics such as BMI, gender, smoking status and other variables in assessing risk and prognosticating treatment outcomes" said Najla Kasabreh.

Well-studied periodontal pathogens, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, are unique to obese individuals even when they are periodontally healthy, which might suggest why these populations are at increased risk for periodontal disease. Due to the ease of collection, low cost and unique position as the gateway to the body, the oral cavity warrants greater attention as a model to study the roles of environmental pertubations on the human microbiome.

Provided by International & American Associations for Dental Research