Effect of khat chewing on 14 selected periodontal bacteria in sub- and supragingival plaque of a young male population

Background/aims: The habit of chewing khat (Catha edulis) for its amphetamine-like effects is highly prevalent in Yemen and east Africa, and has expanded to Western countries. The purpose of this study was to estimate and compare the prevalence and levels of 14 periodontal bacteria in gingival plaque of khat chewers and khat nonchewers, as well as of khat chewing sides and khat nonchewing sides. Methods: A total of 408 sub- and supragingival plaque samples were collected from 51 young males (29 khat chewers and 22 khat nonchewers; age range 19-28 years) and analyzed using whole genomic DNA probes and checkerboard DNA-DNA hybridization. Clinical parameters were recorded for all teeth at six sites per tooth. Results: Streptococcus intermedius and Veillonella parvula were significantly more prevalent in the subgingival plaque of chewers, which also showed significantly higher levels of V. parvula and Eikenella corrodens. Similar results were found for the subgingival plaque of the chewing sides compared to the nonchewing sides. However, there was a significantly higher prevalence and higher levels of Tannerella forsythia in the subgingival plaque of the nonchewing sides. No significant differences were observed for the supragingival plaque between the two study groups. There was a significantly lower prevalence of Capnocytophaga gingivalis and Fusobacterium nucleatum in the khat chewing sides, and higher levels of V. parvula and Actinomyces israelii. Conclusion: The data suggest that khat chewing induces a microbial profile that is not incompatible with gingival health.