Bronchiolitis and recurrent respiratory infections: The role of oxidative stress from early life inflammation to long-term outcomes - A narrative review.

Bronchiolitis, primarily caused by respiratory syncytial virus (RSV), is a common respiratory infection in infants and a known precursor to recurrent wheezing and asthma. This review explores the role of oxidative stress and trace element deficiencies in the pathogenesis of bronchiolitis and its long-term sequelae. Infants with reduced lung function due to prematurity or congenital airway anomalies exhibit heightened susceptibility to RSV infection. Growing evidence implicates oxidative stress and deficiencies in zinc, selenium, and magnesium as significant contributors to disease progression. Impaired antioxidant defenses exacerbate viral inflammatory responses, leading to prolonged symptoms and recurrent wheezing with potential developmental delays. Studies consistently demonstrate that children with bronchiolitis exhibit elevated oxidative stress markers and reduced antioxidant capacity, with trace element deficiencies correlating with disease severity. Reduced defenses against oxidative stress may be associated with recurrent wheezing episodes, which are more frequent after rhinovirus bronchiolitis than after RSV bronchiolitis. Thus, RSV and rhinovirus (RV) bronchiolitis may unmask pre-existing vulnerabilities rather than directly causing long-term damage associated with later asthma. Micronutrient supplementation, particularly zinc and selenium, has shown potential in reducing respiratory infection duration and severity. COVID-19 pandemic evidence further supports nutritional status as a key modulator of respiratory disease outcomes, with nutraceuticals like curcumin and flavonoids demonstrating anti-inflammatory benefits. Given the safety and accessibility of micronutrient supplementation, early nutritional assessment and intervention in high-risk infants may offer a cost-effective strategy to improve long-term respiratory outcomes. Bronchiolitis should be viewed as a clinical signal warranting proactive, holistic pediatric care rather than merely an acute illness.