title: 16S community profiling identifies proton pump inhibitor related differences in gastric, lung, and oropharyngeal microflora.
abstract: OBJECTIVE
  To test the hypothesis that proton pump inhibitor (PPI) use results in changes in gastric microflora which, through full column reflux, results in lung and oropharyngeal microflora changes.
  
  
  METHODS
  We performed a prospective, cross-sectional cohort study of 116 children (57 off and 59 on PPIs) undergoing simultaneous bronchoscopy and upper endoscopy for the evaluation of chronic cough. We performed 16S sequencing on gastric, bronchoalveolar lavage, and oropharyngeal fluid. Fifty patients also underwent multichannel intraluminal impedance testing.
  
  
  RESULTS
  Streptococcus was more abundant in the gastric fluid of patients taking PPIs, and there was a significant correlation with PPI dose (mg/kg/d) and abundance of gastric Streptococcus (P = .01). There was also a significant difference in the abundance of oropharyngeal Streptococcus in patients treated with PPI. Eight unique bacterial genera were found in the gastric and lung fluid but not in the oropharyngeal suggesting exchange between the 2 sites and 2 of the 8 (Lactococcus, Acinetobacter) were more abundant in patients with more full column reflux, suggesting direct aspiration. Principal component analysis revealed greater overlap between gastric and lung than oropharyngeal microflora.
  
  
  CONCLUSIONS
  PPI use was associated with differences in gastric, lung, and oropharyngeal microflora. Although microflora exchange can occur between all 3 sites, gastric and lung microflora are more closely related, and the mechanism of exchange between sites may be aspiration of full column reflux.
authors: Aerodigestive Center, Division of Gastroenterology and Nutrition, Boston Children's Hospital, Boston, MA. Electronic address: rachel.rosen@childrens.harvard.edu.
authors: Rachel
authors: R
authors: Rosen
authors: Center for Computational Cancer Biology, Dana Farber Cancer Institute, Boston, MA.
authors: Lan
authors: L
authors: Hu
authors: Aerodigestive Center, Division of Gastroenterology and Nutrition, Boston Children's Hospital, Boston, MA.
authors: Janine
authors: J
authors: Amirault
authors: Aerodigestive Center, Division of Pulmonary Medicine, Boston Children's Hospital, Boston, MA.
authors: Umakanth
authors: U
authors: Khatwa
authors: The Broad Institute, Cambridge, MA.
authors: Doyle V
authors: DV
authors: Ward
authors: Department of Microbiology, Brigham and Women's Hospital, Boston, MA.
authors: Andrew
authors: A
authors: Onderdonk
mesh_terms: D000293:Adolescent; D001419:Bacteria / Q000187:drug effects* / Q000235:genetics; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D001999:Bronchoscopy; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004269:DNA, Bacterial / Q000032:analysis; D017097:Electric Impedance; D016099:Endoscopy, Gastrointestinal; D050782:Esophageal pH Monitoring; D005260:Female; D005500:Follow-Up Studies; D005764:Gastroesophageal Reflux / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D007828:Laryngoscopy; D008168:Lung / Q000382:microbiology*; D008297:Male; D009960:Oropharynx / Q000382:microbiology*; D011446:Prospective Studies; D054328:Proton Pump Inhibitors / Q000494:pharmacology*; D013270:Stomach / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D054328:Proton Pump Inhibitors