Probiotics for the prevention of ventilator-associated pneumonia and other outcomes in critically ill children: a systematic review and meta-analysis of randomized controlled trials.

Critically ill children face high risks of mortality and healthcare-associated infections. Probiotics may improve outcomes by modulating gut microbiota and enhancing immune function. To evaluate the efficacy and safety of probiotics in critically ill children in pediatric intensive care units (PICUs). We systematically reviewed randomized controlled trials (RCTs) from PubMed, EMBASE, SCOPUS, and Web of Science until 10 June 2024. The primary outcome was all-cause mortality; secondary outcomes were ventilator-associated pneumonia (VAP), length of hospital stay (LOS), and duration of mechanical ventilation (MV). Risk ratios (RR) and mean differences (MD) were pooled using random-effects models (DerSimonian-Laird), with Hartung-Knapp adjustment as a sensitivity analysis. Evidence certainty was assessed using GRADE. Eight RCTs involving 744 children were included. Probiotics did not significantly reduce all-cause mortality (RR 0.85, 95% CI 0.66-1.11; P = .24; I² = 0%; low certainty); estimates were similar under Hartung-Knapp adjustment (RR 0.85, 0.69-1.06; P = .14) and in a sensitivity analysis restricted to low-risk-of-bias trials (RR 0.89, 0.60-1.34; P = .58). Probiotics significantly reduced VAP (RR 0.47, 95% CI 0.35-0.64; P < .0001; I² = 0%; high certainty), halving pneumonia risk (absolute risk reduction 21.9%; number needed to treat approximately 5). Reductions in LOS (MD -2.57 days, 95% CI -7.26 to 2.11; P = .20) and MV (MD -1.61 days, -4.43 to 1.20; P = .17) were nonsignificant (low certainty). No serious probiotic-associated adverse events occurred. High-certainty evidence indicates probiotics reduce VAP in critically ill children; the mortality effect was inconclusive. Probiotics may be considered an adjunctive strategy for VAP prevention in the PICU, pending larger multicenter trials. CRD42024546238.