title: Smoking decreases structural and functional resilience in the subgingival ecosystem.
abstract: OBJECTIVE
  Dysbiotic microbial communities underlie the aetiology of several oral diseases, especially in smokers. The ability of an ecosystem to rebound from the dysbiotic state and re-establish a health-compatible community, a characteristic known as resilience, plays an important role in susceptibility to future disease. The present investigation was undertaken to examine the effects of smoking on colonization dynamics and resilience in marginal and subgingival biofilms.
  
  
  METHODS
  Marginal and subgingival plaque and gingival crevicular fluid samples were collected from 25 current and 25 never smokers with pre-existing gingivitis at baseline, following resolution, after 1, 2 4, 7, 14 and 21 days of undisturbed plaque formation and following resolution. 16S cloning and sequencing was used for bacterial identification and multiplexed bead-based flow cytometry was used to quantify the levels of 27 immune mediators.
  
  
  RESULTS
  Smokers demonstrated an early pathogenic colonization that led to sustained pathogen enrichment with periodontal and respiratory pathogens, eliciting a florid immune response. Smokers also demonstrated greater abundance of pathogenic species, poor compositional correlation between marginal and subgingival ecosystems, and significantly greater pro-inflammatory responses following resolution of the second episode of disease.
  
  
  CONCLUSIONS
  The ability of the subgingival microbiome to "reset" itself following episodes of disease is decreased in smokers, thereby lowering the resilience of the ecosystem and decreasing its resistance to future disease.
authors.affiliation: Division of Periodontology, College of Dentistry, The Ohio State University, Columbus, OH, USA.
authors.forename: Vinayak
authors.initials: V
authors.lastname: Joshi
authors.forename: Chad
authors.initials: C
authors.lastname: Matthews
authors.forename: Marcelo
authors.initials: M
authors.lastname: Aspiras
authors.forename: Marko
authors.initials: M
authors.lastname: de Jager
authors.forename: Marilyn
authors.initials: M
authors.lastname: Ward
authors.forename: Purnima
authors.initials: P
authors.lastname: Kumar
mesh_terms: D000328:Adult; D001419:Bacteria / Q000145:classification; D018407:Bacterial Physiological Phenomena; D018441:Biofilms; D016207:Cytokines / Q000032:analysis; D003773:Dental Plaque / Q000276:immunology / Q000382:microbiology* / Q000628:therapy; D004198:Disease Susceptibility / Q000382:microbiology; D017753:Ecosystem; D005260:Female; D005500:Follow-Up Studies; D005881:Gingiva / Q000276:immunology / Q000382:microbiology*; D005883:Gingival Crevicular Fluid / Q000276:immunology / Q000382:microbiology; D005891:Gingivitis / Q000276:immunology / Q000382:microbiology / Q000628:therapy; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D007378:Interleukins / Q000032:analysis; D008297:Male; D059013:Microbial Consortia / Q000502:physiology; D050296:Microbial Viability; D012907:Smoking / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D007378:Interleukins
keywords: 16S; DNA; bacteria; experimental; gingivitis; host-bacterial interactions