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

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 likely 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 > 37.5 °C) 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. Seventy-five children were randomized and included in the analysis. The most frequent causative agents were rhinoviruses, coronaviruses, and respiratory syncytial virus. Compared to placebo, the durations 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 the probiotic group, respectively. Sensitivity analyses by detected virus, age, sex, and recent URI episodes produced similar results. The 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.

conclusionIntervention with this probiotic formula was associated with a shorter duration of fever and pain/discomfort in pediatric URIs with pharyngitis.

trial registrationProspectively registered on Oct 5 WHAT IS KNOWN: • Acute upper respiratory tract infections (URIs) are highly prevalent in children, but due to their frequent viral etiology, treatment is often symptomatic only. Some probiotics have shown promising results against URIs, but evidence mostly relies on untrained, subjective diagnosis by participants or their parents. Recently, a probiotic formula containing strains L. plantarum KABP022, KABP023, and KABP033 and P. acidilactici KABP021 reduced viral load and duration of symptoms in a randomized trial in 300 adults with laboratory-confirmed Covid19, against placebo. WHAT IS NEW: • In children with URI with pharyngitis, as diagnosed by a specialist, intervention with said probiotic formula reduced the duration both of fever and of pain/discomfort, compared to placebo. Results were robust to sensitivity analyses by age, sex, number of recent URIs, and by most prevalent causative viruses in the study population.