Prevention of Atopic Diseases with the Use of Hypoallergenic Infant Formula: A Systematic Review and Meta-Analysis

BackgroundAtopic diseases are estimated to affect 30-40% of the global population. However, the potential protective effect of hypoallergenic infant formula against conditions such as atopic dermatitis (AD), cows milk protein allergy (CMPA), and asthma remains uncertain. ObjectiveTo conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating hypoallergenic formula for atopic disease prevention in high-risk infants. The primary outcome was AD and secondary outcomes were CMPA and asthma. MethodsA systematic review and meta-analysis was conducted according to PRISMA 2020. RCTs involving high-risk infants were identified through PubMed, Cochrane Library, and Web of Science. Exclusion criteria included interventions not initiated at birth, enrolment of sick infants, and non-RCTs. Pooled Relative Risks (RR) with 95% confidence intervals (CI) were calculated using a random-effects model. ResultsWe included 9 RCTs that enrolled high-risk infants. The meta-analysis found a borderline significant protective effects of AD (RR=0.78 [0.59-1.03], p=0.059; I2=46.5%), a significant protective effect of hypoallergenic formula in prevention of CMPA (RR=0.51 [0.27-0.97], p=0.0228; I2=37.3%), and no significant risk reduction for asthma (RR=0.78 [0.51-1.20], p=0.059; I2=37.5%). ConclusionThis systematic review and meta-analysis found no statistically significant protective effect of hypoallergenic formula for AD or asthma, though a non-significant trend toward risk reduction was observed. A significant risk reduction was seen for CMPA (RR{approx}0.5), although not all diagnoses were confirmed by oral food challenge. These findings suggest potential patient-specific benefits, but larger, well-designed RCTs are needed to confirm them.