Hydrolyzed infant formulas for allergy prevention-Scientific evidence and recommendations for the practice

Background According to the S3 guideline on Allergy Prevention (update 2021), infants who are not (fully) breastfed and at increased risk of allergies should be considered for feeding with infant formula with clinically proven efficacy for reducing allergies. Some manufacturers claim that their products offer such benefits. Objective The following article provides an overview of the scientific evidence and current international guidelines for the use of hydrolyzed infant formulas (so-called hypoallergenic or HA formula) for the prevention of atopic diseases. Material and methods A literature search was conducted in medical databases (time period 2016-2021) on the benefits of hydrolyzed infant formulas for allergy prevention in at-risk infants and on associated international guidelines. Accordingly, the current recommendations of the German S3 guidelines are discussed. Results There is insufficient evidence to support a general allergy preventive effect of hydrolyzed infant formulas in infants at increased risk of allergies. The largest globally recognized German infant nutrition intervention study (GINI) suggests that one of the hydrolyzed study products may have been effective in reducing the risk of atopic dermatitis in at-risk infants; however, in view of methodological weaknesses, these results cannot be used as the sole basis for general recommendations for hydrolyzed infant formulas. In recent years, international professional societies have also tended to no longer recommend these products for otherwise healthy infants with the goal of preventing allergies. Conclusion There is no evidence for allergy prevention effects in any of the infant formulas based on partially hydrolyzed protein that are currently on the market in Germany. Caution should be exercised when recommending products that are marketed and labelled as hypoallergenic, without scientific evidence.