Association of prophylactic synbiotics with reduction in diarrhea and pneumonia in mechanically ventilated critically ill patients: A propensity score analysis

Introduction: The preventive association of synbiotics therapy has not been thoroughly clarified in mechanically ventilated patients. The purpose of this study was to evaluate whether synbiotics therapy has preventive association against septic complications in ventilated critically ill patients. Methods: Critically ill patients who were mechanically ventilated were included in this retrospective observational study. Patients who received synbiotics (Bifidobacterium breve, Lactobacillus casei, and galactooligosaccharides) within 3 days after admission (denoted as synbiotics group) were compared with patients who did not receive synbiotics. The incidences of enteritis, pneumonia, and bacteremia were evaluated as clinical outcome. Enteritis was defined as an acute onset of diarrhea consisting of continuous liquid watery stools for more than 12 h. The confounding factors include APACHE II on admission, gender, the cause of admission and antibiotics. Results: We included 179 patients in this study: 57 patients received synbiotics and 122 patients did not receive synbiotics. The incidences of enteritis were significantly lower in the synbiotics group compared with the control group (3.5% vs. 15.6%; p < 0.05). The odds ratios for diarrhea-free days during the first 28 days for the synbiotics group as compared with the controls were 4.354 (95% confidence interval (CI), 2.407 to 7.877; p < 0.001) in an ordinal logistic regression model with propensity scores. The odds ratios for pneumonia-free days during the first 28 days for the synbiotics group were 2.529 (95% CI, 1.715 to 3.731; p < 0.001). The incidences of bacteremia did not have significant differences. Conclusion: Prophylactic synbiotics appeared to have preventive association on enteritis and pneumonia in mechanically ventilated critically ill patients. (C) 2018 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.