title: Poor predictive value of breath hydrogen response for probiotic effects in IBS.
abstract: OBJECTIVE
  Previous observations suggested that an early rise in breath hydrogen after lactulose (ERBHAL) may identify patients with irritable bowel syndrome (IBS) likely to respond to probiotics. Therefore, we aimed to (i) investigate whether treatment with a probiotic changes breath hydrogen response in patients with ERBHAL and (ii) whether these changes identify patients who may benefit symptomatically from probiotics.
  
  
  METHODS
  In a randomized, double-blind, placebo-controlled trial, patients with IBS (Rome III) were randomized to either 65 mL/day fermented milk product containing probiotic (FMPP) or placebo for 6 weeks, followed by 6 weeks' open-label treatment and 6 weeks' withdrawal. Breath hydrogen responses to lactulose (15 g) and liquid-gastric emptying time were evaluated before and at the end of each treatment period. Symptoms were measured using a 100-mm visual analog scale.
  
  
  RESULTS
  Loss of ERBHAL occurred in 36% of 23 patients receiving FMPP and 41% of 22 receiving placebo (P = 1.00). Amongst 40 patients who completed open-label FMPP treatment, ERBHAL was lost in a further 38%, continued in 25%, and regained in 10%. Similar variability occurred in the withdrawal phase. Variability was unrelated to changes in gastric emptying. No differences in symptom response were seen between treatment groups nor in relation to the loss or retention of ERBHAL.
  
  
  CONCLUSIONS
  Breath hydrogen patterns after lactulose are poorly reproducible. No FMPP-specific effects on fermentation patterns or symptoms were observed. The presence of ERBHAL is not useful to predict symptomatic response to probiotic therapy in patients with IBS.
authors.affiliation: Department of Gastroenterology, Central Clinical School, Monash University, Alfred Health, Melbourne, Victoria, Australia.
authors.forename: Chu K
authors.initials: CK
authors.lastname: Yao
authors.affiliation: Department of Gastroenterology, Central Clinical School, Monash University, Alfred Health, Melbourne, Victoria, Australia.
authors.forename: Jacqueline S
authors.initials: JS
authors.lastname: Barrett
authors.affiliation: Department of Gastroenterology, Box Hill Hospital, Melbourne, Victoria, Australia.
authors.forename: Hamish
authors.initials: H
authors.lastname: Philpott
authors.affiliation: Department of Gastroenterology, Box Hill Hospital, Melbourne, Victoria, Australia.
authors.forename: Alvin R T
authors.initials: AR
authors.lastname: Chung
authors.affiliation: Department of Gastroenterology, Box Hill Hospital, Melbourne, Victoria, Australia.
authors.forename: Daniel
authors.identifier: http://orcid.org/0000-0003-3662-6307
authors.initials: D
authors.lastname: van Langenberg
authors.affiliation: Department of Gastroenterology, Box Hill Hospital, Melbourne, Victoria, Australia.
authors.forename: Mayur
authors.initials: M
authors.lastname: Garg
authors.affiliation: Department of Gastroenterology, Central Clinical School, Monash University, Alfred Health, Melbourne, Victoria, Australia.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Gibson
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005746:Gastric Emptying; D006801:Humans; D006859:Hydrogen / Q000032:analysis*; D043183:Irritable Bowel Syndrome / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D007792:Lactulose; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D019936:Probiotics / Q000008:administration & dosage / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007792:Lactulose; D006859:Hydrogen
keywords: SIBO; irritable bowel syndrome; lactulose breath test; probiotic