The Effect of Fiber Supplementation on Irritable Bowel... : Official journal of the American College of Gastroenterology | ACG (original) (raw)

CLINICAL AND SYSTEMATIC REVIEWS

The Effect of Fiber Supplementation on Irritable Bowel Syndrome: A Systematic Review and Meta-analysis

Moayyedi, Paul BSc, MB, ChB, PhD, MPH, FRCP, FRCPC, AGAF, FACG1; Quigley, Eamonn M M MD, FRCP, FACP, FACG, FRCPI2; Lacy, Brian E MD, PhD, FACG3; Lembo, Anthony J MD, FACG4; Saito, Yuri A MD, MPH, FACG5; Schiller, Lawrence R MD, FACP, FACG6; Soffer, Edy E MD, FACG7; Spiegel, Brennan M R MD, MSHS, FACG8; Ford, Alexander C MB, ChB, MD9,10

1Health Sciences Center, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada

2Division of Gastroenterology and Hepatology, Department of Medicine, Houston Methodist Hospital, Houston, Texas, USA

3Dartmouth-Hitchcock Medical Center, Division of Gastroenterology and Hepatology, One Medical Center Drive, Lebanon, New Hampshire, USA

4The Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA

5Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA

6Digestive Health Associates of Texas, Baylor University Medical Center, Dallas, Texas, USA

7Division of Gastroenterology at Cedars-Sinai, University of Southern California, Los Angeles, California, USA

8Department of Gastroenterology, VA Greater Los Angeles Healthcare System, Los Angeles, California, USA

9Leeds Gastroenterology Institute, St. James's University Hospital, Leeds, UK

10Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK

Correspondence: Paul Moayyedi, Health Sciences Center, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada L8N 3Z5. E-mail: [email protected]

Received 28 February 2014; accepted 03 June 2014

Guarantor of the article: Paul Moayyedi, BSc, MB, ChB, PhD, MPH, FRCP, FRCPC, AGAF, FACG.

Specific author contributions: P.M., E.M.M.Q., B.E.L., A.J.L., Y.A.S., L.R.S., E.E.S., B.M.R.S., and A.C.F. conceived the study. P.M. and A.C.F. collected all data. P.M. and A.C.F. analyzed and interpreted the data. P.M. drafted the manuscript. All authors commented on drafts of the paper. All authors have approved the final draft of the manuscript.

Financial support: This study was supported by the American College of Gastroenterology.

Potential competing interests: None.

Abstract

OBJECTIVES:

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.