This study is a prospective, multicenter, randomized controlled trial designed to evaluate the clinical efficacy, tolerance, and safety of a partially hydrolyzed whey protein formula in infants with mild allergic symptoms. Partially hydrolyzed formulas contain low-molecular weight peptides and have been shown to improve protein tolerance and digestibility and to reduce allergenicity compared with intact cow's milk protein formulas. However, evidence regarding their therapeutic effects in infants who have already developed allergic symptoms remains limited.
Eligible infants with mild allergic manifestations who are predominantly formula-fed will be randomly assigned in a 1:1 ratio to receive either a partially hydrolyzed whey protein formula or an intact cow's milk protein formula. Infants in the intervention group will receive a 100% partially hydrolyzed whey protein formula during the initial intervention period and will transition to a 60% partially hydrolyzed whey protein formula after reaching 6 months of age, while infants in the control group will continue feeding with an intact protein formula.
The primary outcome is the overall improvement rate of allergic symptoms after 2 weeks of intervention. Secondary outcomes include tolerance after transition to the follow-on formula at 6 months of age, changes in skin, gastrointestinal, and respiratory symptoms, growth parameters, and safety outcomes. The results of this study are expected to provide evidence to support nutritional management strategies for infants with mild allergic symptoms.