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Effect of Probiotics on Incident Ventilator-Associated Pneumonia in Critically Ill Patients: A Randomized Clinical
Jennie Johnstone1, Maureen Meade2, François Lauzier3
1University of Toronto, Toronto, Canada.
Importance:
Growing interest in microbial dysbiosis during critical illness has raised questions about the therapeutic potential of microbiome modification with probiotics. Prior randomized trials in this population suggest that probiotics reduce infection, particularly ventilator-associated pneumonia (VAP), although probiotic-associated infections have also been reported.
Objective:
To evaluate the effect of Lactobacillus rhamnosus GG on preventing VAP, additional infections, and other clinically important outcomes in the intensive care unit (ICU).
Design, Setting, And Participants:
Randomized placebo-controlled trial in 44 ICUs in Canada, the United States, and Saudi Arabia enrolling adults predicted to require mechanical ventilation for at least 72 hours. A total of 2653 patients were enrolled from October 2013 to March 2019 (final follow-up, October 2020).
Interventions:
Enteral L rhamnosus GG (1 × 1010 colony-forming units) (n = 1321) or placebo (n = 1332) twice daily in the ICU.
Main Outcomes And Measures:
The primary outcome was VAP determined by duplicate blinded central adjudication. Secondary outcomes were other ICU-acquired infections including Clostridioides difficile infection, diarrhea, antimicrobial use, ICU and hospital length of stay, and mortality.
Results:
Among 2653 randomized patients (mean age, 59.8 years [SD], 16.5 years), 2650 (99.9%) completed the trial (mean age, 59.8 years [SD], 16.5 years; 1063 women [40.1%.] with a mean Acute Physiology and Chronic Health Evaluation II score of 22.0 (SD, 7.8) and received the study product for a median of 9 days (IQR, 5-15 days). VAP developed among 289 of 1318 patients (21.9%) receiving probiotics vs 284 of 1332 controls (21.3%; hazard ratio [HR], 1.03 (95% CI, 0.87-1.22; P = .73, absolute difference, 0.6%, 95% CI, -2.5% to 3.7%). None of the 20 prespecified secondary outcomes, including other ICU-acquired infections, diarrhea, antimicrobial use, mortality, or length of stay showed a significant difference. Fifteen patients (1.1%) receiving probiotics vs 1 (0.1%) in the control group experienced the adverse event of L rhamnosus in a sterile site or the sole or predominant organism in a nonsterile site (odds ratio, 14.02; 95% CI, 1.79-109.58; P < .001).
Conclusions And Relevance:
Among critically ill patients requiring mechanical ventilation, administration of the probiotic L rhamnosus GG compared with placebo, resulted in no significant difference in the development of ventilator-associated pneumonia. These findings do not support the use of L rhamnosus GG in critically ill patients.
Trial Registration:
ClinicalTrials.gov Identifier: NCT02462590.
Insights
Probiotic Lactobacillus rhamnosus GG did not significantly reduce ventilator-associated pneumonia (VAP) in critically ill patients. The study found no benefit and a potential increased risk of adverse events, questioning its use in this population.
Area of Science:
- Critical Care Medicine
- Microbiome Research
- Infectious Diseases
Background:
- Microbial dysbiosis is a growing concern in critical illness.
- Probiotics are being investigated for microbiome modification and infection prevention.
- Previous studies suggest probiotics may reduce infections like ventilator-associated pneumonia (VAP), but probiotic-associated infections have also been noted.
Purpose of the Study:
- To assess the efficacy of Lactobacillus rhamnosus GG in preventing VAP.
- To evaluate the impact of L rhamnosus GG on other ICU-acquired infections.
- To determine the effect on additional clinical outcomes, including mortality and length of stay.
Main Methods:
- A randomized, placebo-controlled trial involving 2653 adult patients in 44 ICUs.
- Patients were predicted to require mechanical ventilation for at least 72 hours.
- Intervention involved twice-daily enteral administration of L rhamnosus GG or placebo.
Main Results:
- No significant difference in VAP incidence between the probiotic group (21.9%) and placebo group (21.3%).
- No significant differences observed in secondary outcomes, including other infections, antimicrobial use, or mortality.
- A statistically significant increase in adverse events related to L rhamnosus in sterile or non-sterile sites was noted in the probiotic group.
Conclusions:
- Lactobacillus rhamnosus GG administration did not reduce the incidence of VAP in critically ill, mechanically ventilated patients.
- The findings do not support the use of L rhamnosus GG for preventing VAP or other infections in this patient population.
- The observed increase in adverse events warrants caution regarding probiotic use in critically ill patients.
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