title: Exhaled breath and fecal volatile organic biomarkers of chronic kidney disease.
abstract: BACKGROUND
  While much is known about the effect of chronic kidney disease (CKD) on composition of body fluids little is known regarding its impact on the gases found in exhaled breath or produced by intestinal microbiome. We have recently shown significant changes in the composition of intestinal microbiome in humans and animals with CKD. This study tested the hypothesis that uremia-induced changes in cellular metabolism and intestinal microbiome may modify the volatile organic metabolites found in the exhaled breath or generated by intestinal flora.
  
  
  METHODS
  SD rats were randomized to CKD (5/6 nephrectomy) or control (sham operation) groups. Exhaled breath was collected by enclosing each animal in a glass chamber flushed with clean air, then sealed for 45 min and the trapped air collected. Feces were collected, dissolved in pure water, incubated at 37 degrees C in glass reactors for 24 h and the trapped air collected. Collected gases were analyzed by gas chromatography.
  
  
  RESULTS
  Over 50 gases were detected in the exhaled breath and 36 in cultured feces. Four gases in exhaled breath and 4 generated by cultured feces were significantly different in the two groups. The exhaled breath in CKD rats showed an early rise in isoprene and a late fall in linear aldehydes. The CKD animals' cultured feces released larger amounts of dimethyldisulfide, dimethyltrisulfide, and two thioesters.
  
  
  CONCLUSIONS
  CKD significantly changes the composition of exhaled breath and gaseous products of intestinal flora.
  
  
  CONCLUSIONS
  Analysis of breath and bowel gases may provide useful biomarkers for detection and progression of CKD and its complications.
authors.affiliation: Department of Chemistry, University of California Irvine, Irvine, CA, USA.
authors.forename: Simone
authors.initials: S
authors.lastname: Meinardi
authors.forename: Kyu-Bok
authors.initials: KB
authors.lastname: Jin
authors.forename: Barbara
authors.initials: B
authors.lastname: Barletta
authors.forename: Donald R
authors.initials: DR
authors.lastname: Blake
authors.forename: Nosratola D
authors.initials: ND
authors.lastname: Vaziri
mesh_terms: D000447:Aldehydes / Q000032:analysis / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001944:Breath Tests; D002070:Butadienes / Q000032:analysis / Q000378:metabolism; D002849:Chromatography, Gas; D004195:Disease Models, Animal; D018450:Disease Progression; D004220:Disulfides / Q000032:analysis / Q000378:metabolism; D045853:Exhalation; D005243:Feces / Q000737:chemistry; D005740:Gases / Q000032:analysis* / Q000378:metabolism; D045782:Hemiterpenes / Q000032:analysis / Q000378:metabolism; D006801:Humans; D008297:Male; D054892:Metagenome; D009392:Nephrectomy; D010420:Pentanes / Q000032:analysis / Q000378:metabolism; D051381:Rats; D051436:Renal Insufficiency, Chronic / Q000378:metabolism* / Q000473:pathology; D013440:Sulfides / Q000032:analysis / Q000378:metabolism; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000378:metabolism
chemical_list: D000447:Aldehydes; D015415:Biomarkers; D002070:Butadienes; D004220:Disulfides; D005740:Gases; D045782:Hemiterpenes; D010420:Pentanes; D013440:Sulfides; D055549:Volatile Organic Compounds; C005059:isoprene; C054170:dimethyl trisulfide; C021181:dimethyl disulfide