A pilot randomized controlled trial evaluating a resveratrol/β-glucan nasal spray for preventing respiratory symptoms in preschool children with recurrent wheezing

Background Respiratory tract infections (RTIs) are a leading cause of morbidity in preschool children, particularly in those with recurrent wheezing. Natural compounds such as resveratrol and carboxymethyl-beta-glucan have shown immunomodulatory, antiviral, and anti-inflammatory activity, supporting their potential role in preventing pediatric airway infections.Objective To evaluate the efficacy, safety, and tolerability of Linfovir (R), a nasal spray containing resveratrol and carboxymethyl-beta-glucan, in reducing respiratory infectious symptoms in preschool children with recurrent respiratory infections and wheezing.Methods This multicenter, randomized, double-blind, placebo-controlled trial enrolled children aged 2-6 years with a history of recurrent respiratory infections. Participants were randomized 1:1 to receive Linfovir (R) or placebo once daily for 12 weeks, with follow-up at 16 weeks. Primary and secondary outcomes including days with respiratory symptoms, number of infections, antibiotic courses, and medical visits were recorded via the VIRAPP (R) electronic diary.Results Eighty-two children were included in the Full Analysis Set. The primary endpoint was not statistically significant. However, a numerical reduction in days with respiratory symptoms was observed in the resveratrol/beta-glucan nasal spray group compared with placebo (15.0 vs. 20.4 days in the FAS population), corresponding to an approximate 26% relative difference. Similar non-significant patterns favoring the intervention were observed for infectious episodes, antibiotic courses, and medical visits. Treatment adherence was high in both groups, and no serious adverse events occurred.Conclusions In this pilot randomized controlled trial, the resveratrol/beta-glucan nasal spray was safe and well tolerated. Although the study did not show a statistically significant effect on the primary endpoint, the observed numerical differences consistently favored the intervention. These findings should be interpreted as exploratory and hypothesis-generating and require confirmation in larger adequately powered studies.