title: Oral microflora in betel-chewing adults of the Karen tribe in Thailand.
abstract: OBJECTIVE
  To study a possible influence of betel chewing on the composition of the oral microflora in plaque and saliva and on oral health parameters as well as a possible betel effect on oral bacteria in vitro.
  
  
  METHODS
  Thirty-two adults (16 betel chewers and 16 non-betel-chewing controls) of the Karen Hill tribe in Thailand were investigated. Saliva samples and 2 pooled supragingival plaque samples were taken from each individual for microbial analysis with culture and 4 subgingival samples for analysis with the DNA-DNA hybridization method against 12 periodontitis associated bacterial species. Caries (DMFS), plaque (PlI%) and bleeding on probing (% BoP) was registered as well as number of sites with >5mm probing pocket depth (PPD). Water extract of the betel (areca chatechu) nut was tested for its antimicrobial effect in vitro against 10 oral bacterial species with the agar diffusion method.
  
  
  RESULTS
  An antimicrobial effect of betel nut water extract was found on the oral microorganisms in vitro. The levels of mutans streptococci and lactobacilli in saliva were low or absent in both chewers and controls. The prevalence of the periodontitis associated bacteria was >90%. Betel chewers had significantly lower levels of some bacteria in subgingival plaque (Prevotella intermedia p<0.001) than non-chewers. This study population was low in missing teeth (mean 0.7 and 0.3), caries decay (DS 2.1 vs 1.6), and number of deep pockets (mean 1.9 vs 1.3). Great variation in oral hygiene (PlI and BoP) between the subjects was seen.
  
  
  CONCLUSIONS
  An antimicrobial effect of the betel nut was found in vitro and with a possible effect also in vivo; however it did not seem to influence clinical parameters such as plaque index, caries prevalence (DMFS), bleeding on probing and number of deep pockets.
authors.affiliation: Department of Oral Microbiology, Institute of Odontology, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Dahlén
authors.forename: Camilla
authors.initials: C
authors.lastname: Nauclér
authors.forename: Sofia
authors.initials: S
authors.lastname: Nordwall
authors.forename: Narong
authors.initials: N
authors.lastname: Suksu-art
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology; D001114:Areca / Q000737:chemistry*; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D003773:Dental Plaque / Q000382:microbiology*; D005260:Female; D006470:Hemorrhage / Q000473:pathology; D006801:Humans; D008297:Male; D008409:Mastication; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology / Q000502:physiology*; D009693:Nucleic Acid Hybridization; D010514:Periodontal Pocket / Q000473:pathology; D044382:Population Groups; D012463:Saliva / Q000382:microbiology*; D013785:Thailand
chemical_list: D000900:Anti-Bacterial Agents