Abstract ID: 3422

Primary Topic: Natural products/botanicals/supplements
Secondary Topic: Research Methodology
Tertiary Topic: State of the science/evidence base for integrative modalities

Probiotics and Gastrointestinal Conditions: An Overview of Evidence from the Cochrane Collaboration
Elizabeth A Parker, PhD, RD, University of Maryland School of Medicine, Baltimore, MD, United States; Tina Roy, BS, Geisinger Commonwealth School of Medicine, Scranton, PA, United States; Christopher R D'Adamo, PhD, University of Maryland School of Medicine, Baltimore, MD, United States; L. Susan Wieland, PhD, , Baltimore, MD, United States

Late Breaker: No


Alterations in the gut microbiota are associated with numerous gastrointestinal (GI) conditions. Probiotics, live microorganisms that may confer a health benefit to the host when consumed, are increasingly used to treat GI conditions. Our objective was to summarize the evidence on probiotics and GI conditions available from Cochrane, a non-profit organization that produces rigorous systematic reviews of health interventions.

Methods/Session Format

The Cochrane Library was searched to identify Cochrane reviews with a primary focus on the efficacy of probiotics for GI conditions. We extracted data from each review on the number (N) of included trials and participants, N probiotic combinations, and N trials specifying probiotic strain and dosage, length of intervention and follow-up, and occurrence of adverse events (AE). We also extracted the review conclusions on probiotic efficacy.


Fourteen Cochrane reviews published between 2006 and 2015 focused on probiotics and GI conditions (diarrhea, N=5; colitis, N=4; Crohn’s disease, N=3; liver conditions, N=2). One review on liver conditions identified no trials; the remaining 13 reviews included 1-63 trials with 11-8014 participants. The exclusive N of probiotic combinations included in each review ranged from 1 to 21; Lactobacillus rhamnosus GG was the most commonly studied. In total, 63% of included trials specified probiotic strain, 94% reported dosage, 79% specified intervention length, 29% indicated follow-up duration, and 73% reported AEs. Four reviews on diarrheal conditions reported that probiotics were beneficial; all other reviews were inconclusive. 


There is good evidence for the efficacy of probiotics for diarrheal conditions; however, reviews on probiotics for other conditions require further updating to establish efficacy. Future clinical trials and systematic reviews of probiotics should specify important and often unreported information about the species, strain, manufacturing processes and storage conditions of the tested probiotics and the duration of follow-up. Findings from this review will help improve future probiotics research and the development of clinical guidance on their use.