title: The effect of fiber supplementation on irritable bowel syndrome: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Fiber has been used for many years to treat irritable bowel syndrome (IBS). This approach had fallen out of favor until a recent resurgence, which was based on new randomized controlled trial (RCT) data that suggested it might be effective. We have previously conducted a systematic review of fiber in IBS, but new RCT data for fiber therapy necessitate a new analysis; thus, we have conducted a systematic review of this intervention.
  
  
  METHODS
  MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched up to December 2013. Trials recruiting adults with IBS, which compared fiber supplements with placebo, control therapy, or "usual management", were eligible. Dichotomous symptom data were pooled to obtain a relative risk (RR) of remaining symptomatic after therapy as well as number needed to treat (NNT) with a 95% confidence interval (CI).
  
  
  RESULTS
  We identified 14 RCTs involving 906 patients that had evaluated fiber in IBS. There was a significant benefit of fiber in IBS (RR=0.86; 95% CI 0.80-0.94 with an NNT=10; 95% CI=6-33). There was no significant heterogeneity between results (I(2)=0%, Cochran Q=13.85 (d.f.=14), P=0.46). The benefit was only seen in RCTs on soluble fiber (RR=0.83; 95% CI 0.73-0.94 with an NNT=7; 95% CI 4-25) with no effect seen with bran (RR=0.90; 95% CI 0.79-1.03).
  
  
  CONCLUSIONS
  Soluble fiber is effective in treating IBS. Bran did not appear to be of benefit, although we did not uncover any evidence of harm from this intervention, as others have speculated from uncontrolled data.
authors: Health Sciences Center, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada.
authors: Paul
authors: P
authors: Moayyedi
authors: Division of Gastroenterology and Hepatology, Department of Medicine, Houston Methodist Hospital, Houston, Texas, USA.
authors: Eamonn M M
authors: EM
authors: Quigley
authors: Dartmouth-Hitchcock Medical Center, Division of Gastroenterology and Hepatology, One Medical Center Drive, Lebanon, New Hampshire, USA.
authors: Brian E
authors: BE
authors: Lacy
authors: The Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
authors: Anthony J
authors: AJ
authors: Lembo
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Yuri A
authors: YA
authors: Saito
authors: Digestive Health Associates of Texas, Baylor University Medical Center, Dallas, Texas, USA.
authors: Lawrence R
authors: LR
authors: Schiller
authors: Division of Gastroenterology at Cedars-Sinai, University of Southern California, Los Angeles, California, USA.
authors: Edy E
authors: EE
authors: Soffer
authors: Department of Gastroenterology, VA Greater Los Angeles Healthcare System, Los Angeles, California, USA.
authors: Brennan M R
authors: BM
authors: Spiegel
authors: 1] Leeds Gastroenterology Institute, St. James's University Hospital, Leeds, UK [2] Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK.
authors: Alexander C
authors: AC
authors: Ford
mesh_terms: D004043:Dietary Fiber / Q000627:therapeutic use*; D019587:Dietary Supplements; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000178:diet therapy*; D016032:Randomized Controlled Trials as Topic