Comment on comment on "Antigen-reduced infant formulae"

Hydrolysed formula and risk of allergic or autoimmune disease: systematic review and meta-analysis

OBJECTIVE

To determine whether feeding infants with hydrolysed formula reduces their risk of allergic or autoimmune disease.

DESIGN

Systematic review and meta-analysis, as part of a series of systematic reviews commissioned by the UK Food Standards Agency to inform guidelines on infant feeding. Two authors selected studies by consensus, independently extracted data, and assessed the quality of included studies using the Cochrane risk of bias tool.

DATA SOURCES

Medline, Embase, Web of Science, CENTRAL, and LILACS searched between January 1946 and April 2015.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective intervention trials of hydrolysed cows' milk formula compared with another hydrolysed formula, human breast milk, or a standard cows' milk formula, which reported on allergic or autoimmune disease or allergic sensitisation.

RESULTS

37 eligible intervention trials of hydrolysed formula were identified, including over 19,000 participants. There was evidence of conflict of interest and high or unclear risk of bias in most studies of allergic outcomes and evidence of publication bias for studies of eczema and wheeze. Overall there was no consistent evidence that partially or extensively hydrolysed formulas reduce risk of allergic or autoimmune outcomes in infants at high pre-existing risk of these outcomes. Odds ratios for eczema at age 0-4, compared with standard cows' milk formula, were 0.84 (95% confidence interval 0.67 to 1.07; I(2)=30%) for partially hydrolysed formula; 0.55 (0.28 to 1.09; I(2)=74%) for extensively hydrolysed casein based formula; and 1.12 (0.88 to 1.42; I(2)=0%) for extensively hydrolysed whey based formula. There was no evidence to support the health claim approved by the US Food and Drug Administration that a partially hydrolysed formula could reduce the risk of eczema nor the conclusion of the Cochrane review that hydrolysed formula could allergy to cows' milk.

CONCLUSION

These findings do not support current guidelines that recommend the use of hydrolysed formula to prevent allergic disease in high risk infants.

REVIEW REGISTRATION

PROSPERO CRD42013004252.

Immunogenicity and antigenicity of a partially hydrolyzed cow's milk infant formula

We evaluated the immunogenicity and antigenicity of a formula based on partially hydrolyzed cow's milk whey protein in infants at risk of atopy and in controls. Total IgE and specific IgE, IgG, and IgG4 subclass antibodies against egg albumin and cow's milk alpha-lactalbumin, casein, and beta-lactoglobulin were measured by radioimmunoassay of cord blood and of peripheral blood at 5 days and 6 months of life in five groups of infants: 16 breast-fed infants at risk of atopy (group 1), 21 partially hydrolyzed whey formula-fed infants at risk of atopy (group 2), 14 formula-fed infants at risk of atopy (group 3), 10 breast-fed control infants (group 4), and 13 formula-fed control infants (group 5). Total IgE concentration was significantly lower in group 2 at 6 months than in groups 3 and 5 infants and similar to that observed in groups 1 and 4 infants. The concentration of specific antiegg and anti-cow's milk protein IgG and of specific anti-cow's milk alpha-lactalbumin and beta-lactoglobulin IgG4 subclass antibodies was significantly reduced in group 2 as compared to group 3 infants and similar to that found in breast-fed infants. In conclusion, the partially hydrolyzed formula was less immunogenic and antigenic than a traditional formula and was as immunogenic and antigenic as breast milk.

Plasma amino acid concentrations in healthy, full-term infants fed hydrolysate infant formula

The effect of feeding hydrolysate infant formula (HF) on protein and amino acid metabolism was investigated in healthy, full-term infants who were either breast-fed (BF, n = 10) or received conventional formula (CF, n = 10) or HF based on soy and beef collagen (n = 10) with equal total protein equivalent contents. There were no differences between groups for gain in weight, length, and head and chest circumferences throughout the study. Plasma concentrations of total proteins, albumin, urea nitrogen, uric acid, and creatinine as well as total amino acid and total essential amino acid concentrations did not differ at the ages of 2, 4, and 8 weeks. In contrast, significant differences were seen in concentrations of five free amino acids. Arginine concentrations were significantly higher at the age of 4 weeks in the infants fed HF than in the other groups (71 +/- 12 versus 27 +/- 6 and 30 +/- 4, mumol/L, mean +/- SEM, HF versus BF and CF, p < 0.01). Plasma histidine concentrations were also higher in infants receiving HF (4 weeks: 217 +/- 33 versus 91 +/- 18, HF versus BF, p < 0.01; 8 weeks: 218 +/- 33 versus 105 +/- 20, HF versus CF, p < 0.01). The most pronounced feeding-related differences were seen in plasma glycine concentrations (2 weeks: 653 +/- 89 versus 345 +/- 55, HF versus BF, p < 0.01; 8 weeks: 613 +/- 74 versus 385 +/- 56 and 312 +/- 46, HF versus BF and CF, p < 0.01), with the mean value exceeding the upper limit of the normal range in infants fed HF. Although the biological importance of the differences observed remains to be clarified, further investigations on amino acid metabolism are needed to establish the final nutritional safety of feeding hydrolysate infant formulae.