Are probiotics and prebiotics effective in the prevention of travellers' diarrhea: A systematic review and meta-analysis

Travel Med Infect Dis. Jan-Feb 2019;27:11-19. doi: 10.1016/j.tmaid.2018.09.007. Epub 2018 Sep 29.


Background: Travellers' diarrhea (TD) impacts annually over 20 million tourists, business travellers and military troops on a worldwide basis. Reliance on antibiotic prophylaxis and educational programs has not lead to a significant reduction in TD rates. Previous reviews of probiotics for TD have not accounted for the strain-specificity of probiotic efficacy nor have investigated prebiotics for the prevention of TD.

Methods: Standard literature databases were searched from 1977 to June 2018 unrestricted by language. Inclusion criteria included: Probiotic, probiotic or symbiotic interventions, randomized, controlled clinical trials (RCTs) and ≥2 RCTs with the same probiotic strain or mixture.

Results: Of 158 screened articles, 12 RCT were included in the systematic review and 6 RCTs (with nine treatment different arms) were included in the meta-analysis. Saccharomyces boulardii CNCM I-745 showed a significant reduction in TD incidence (RR = 0.79, 95% C.I. 0.72-0.87, p < 0.001), while L. rhamnosus GG showed a trend (p = 0.08) and L. acidophilus showed no significant (p = 0.16) reduction of TD.

Conclusions: The number of trials using probiotics or prebiotics for the prevention of TD continues to be limited in number. Only one of three probiotics showed significant efficacy for the prevention of TD. More research is needed for other probiotics strains and prebiotics to determine if they could also prevent TD.

Keywords: E coli; Lactobacillus; Prebiotics; Saccharomyces; Travel.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Anti-Bacterial Agents
  • Databases, Factual
  • Diarrhea / microbiology
  • Diarrhea / prevention & control*
  • Humans
  • Incidence
  • Lactobacillus
  • Military Personnel
  • Prebiotics / administration & dosage*
  • Probiotics / administration & dosage*
  • Randomized Controlled Trials as Topic
  • Saccharomyces boulardii
  • Travel
  • Travel-Related Illness*


  • Anti-Bacterial Agents
  • Prebiotics