Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 7, 2016; 22(21): 5122-5131
Published online Jun 7, 2016. doi: 10.3748/wjg.v22.i21.5122
Contemporary meta-analysis of short-term probiotic consumption on gastrointestinal transit
Larry E Miller, Angela K Zimmermann, Arthur C Ouwehand
Larry E Miller, Angela K Zimmermann, Miller Scientific Consulting, Inc., Asheville, NC 28803, United States
Arthur C Ouwehand, DuPont Nutrition and Health, FIN-02460 Kantvik, Finland
Author contributions: Miller LE and Ouwehand AC designed the research; Miller LE and Zimmermann AK performed the research; Miller LE analyzed the data; Miller LE, Zimmermann AK, and Ouwehand AC wrote the paper; and Miller LE, Zimmermann AK, and Ouwehand AC approved the final draft of the paper.
Supported by Danisco Sweeteners.
Conflict-of-interest statement: Miller LE is a consultant to Bio-K Plus, DuPont, Fonterra, Natren, and UAS Laboratories. Ouwehand AC is an employee of DuPont Nutrition and Health. Zimmermann AC denies any conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Larry E Miller, PhD, Miller Scientific Consulting, Inc., 1854 Hendersonville Road, 231, Asheville, NC 28803, United States.
Telephone: +1-828-4501895 Fax: +1-828-6496907
Received: December 4, 2015
Peer-review started: December 7, 2015
First decision: January 28, 2016
Revised: February 9, 2016
Accepted: March 1, 2016
Article in press: March 2, 2016
Published online: June 7, 2016

AIM: To determine the efficacy of probiotic supplementation on intestinal transit time (ITT) in adults and to identify factors that influence these outcomes.

METHODS: We conducted a systematic review of randomized controlled trials of probiotic supplementation that measured ITT in adults. Study quality was assessed using the Jadad scale. A random effects meta-analysis was performed with standardized mean difference (SMD) of ITT between probiotic and control groups as the primary outcome. Meta-regression and subgroup analyses examined the impact of moderator variables on SMD of ITT.

RESULTS: A total of 15 clinical trials with 17 treatment effects representing 675 subjects were included in this analysis. Probiotic supplementation was moderately efficacious in decreasing ITT compared to control, with an SMD of 0.38 (95%CI: 0.23-0.53, P < 0.001). Subgroup analyses demonstrated statistically greater reductions in ITT with probiotics in subjects with vs without constipation (SMD: 0.57 vs 0.22, P < 0.01) and in studies with high vs low study quality (SMD: 0.45 vs 0.00, P = 0.01). Constipation (R2 = 38%, P < 0.01), higher study quality (R2 = 31%, P = 0.01), older age (R2 = 27%, P = 0.02), higher percentage of female subjects (R2 = 26%, P = 0.02), and fewer probiotic strains (R2 = 20%, P < 0.05) were predictive of decreased ITT with probiotics in meta-regression. Medium to large treatment effects were identified with B. lactis HN019 (SMD: 0.67, P < 0.001) and B. lactis DN-173 010 (SMD: 0.54, P < 0.01) while other probiotic strains yielded negligible reductions in ITT relative to control.

CONCLUSION: Probiotic supplementation is moderately efficacious for reducing ITT in adults. Probiotics were most efficacious in constipated subjects, when evaluated in high-quality studies, and with certain probiotic strains.

Keywords: Constipation, Gastrointestinal, Intestinal transit time, Meta-analysis, Probiotics

Core tip: We performed a contemporary systematic review and meta-analysis of randomized controlled trials to determine the effects of short-term probiotic supplementation on transit time in adults. Probiotic supplementation is moderately efficacious for reducing intestinal transit time in adults. Probiotics were most efficacious in constipated subjects, when evaluated in high-quality studies, and with certain probiotic strains.