A probiotic containing L. plantarum and P. acidilactici strains for treating upper respiratory infections in children aged 6 months to 5 years: a randomized, double-blind trial

Abstract

Upper respiratory infections (URIs) are highly prevalent, especially among young children. We aimed to investigate the efficacy and safety of a specific probiotic formula in shortening the duration of pediatric URIs of viral origin. A randomized, double-blind clinical trial was conducted in children aged 6 months to 5 years, with URI with pharyngitis as diagnosed by a specialist. Participants were allocated to probiotic (strains L. plantarum KABP022, KABP023 and KABP033, and P. acidilactici KABP021) or placebo, twice daily for 15 days, and further followed up at 30 and 60 days from baseline. Antipyretic (ibuprofen) and antihistamine (cetirizine) were allowed as comedication and controlled. Co-primary outcomes were days of fever (axillary temperature >37.5ºC) and days of pain/discomfort (Face, Legs, Activity, Cry and Consolability [FLACC] score >3), as recorded in a diary. Causative viruses were identified by PCR in nasopharyngeal swabs. 75 children were randomized and included in the analysis. Most frequent causative agents were rhinoviruses, coronaviruses and respiratory syncytial virus. Compared to placebo, duration of fever and of pain/discomfort were reduced by 1.1 days (95%CI 0.5-1.7; p=0.001), and by 0.7 days (95%CI 0.2-1.2; p=0.006) in probiotic group, respectively. Sensitivity analyses by detected virus, age, sex and recent URI episodes produced similar results. Use of comedication and other symptoms did not differ between study groups. No significant differences were found in the number of adverse events between the groups. Conclusion: Intervention with this probiotic formula was associated with shorter duration of fever and pain/discomfort in pediatric URIs with pharyngitis. Trial Registration: Prospectively registered on Oct 5th, 2023, as ISRCTN-66122782.