Impact of the administration of probiotics on mortality in critically ill adult patients: a meta-analysis of randomized controlled trials

Chest. 2013 Mar;143(3):646-655. doi: 10.1378/chest.12-1745.


Background: The objective of this study was to systematically review and quantitatively synthesize all randomized controlled trials (RCTs) that have compared important outcomes in critically ill patients who received an administration of probiotics.

Methods: A systematic literature search of PubMed, Scopus, and the Cochrane Central Register of Controlled Trials was conducted using specific search terms. Eligible studies were RCTs that compared the effect of prebiotics, probiotics, or synbiotics administration with control on ICU and hospital mortality rates in critically ill adult patients. Weighted mean differences (WMDs), pooled ORs, and 95% CIs were calculated using the Mantel-Haenszel fixed- and random-effects models.

Results: Thirteen trials with 1,439 patients were analyzed. Probiotics did not significantly reduce ICU (OR, 0.85; 95% CI, 0.63-1.15) or hospital (OR, 0.90; 95% CI, 0.65-1.23) mortality. By contrast, probiotics administration reduced the incidence of ICU-acquired pneumonia (OR, 0.58; 95% CI, 0.42-0.79) and was associated with a shorter stay in the ICU (WMD, -1.49 days; 95% CI, -2.12 to -0.87 days). Finally, probiotics use was not associated with a shorter duration of mechanical ventilation (WMD, -0.18 days; 95% CI, -1.72-1.36 days) or a shorter hospital length of stay (WMD, -0.45 days; 95% CI, -1.41-0.52 days).

Conclusions: The present meta-analysis suggests that the administration of probiotics did not significantly reduce ICU or hospital mortality rates but did reduce the incidence of ICU-acquired pneumonia and ICU length of stay.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • Adult
  • Critical Illness / mortality*
  • Cross Infection / prevention & control
  • Hospital Mortality
  • Humans
  • Length of Stay / statistics & numerical data
  • Pneumonia / prevention & control
  • Probiotics / therapeutic use*
  • Randomized Controlled Trials as Topic