[ANTIGENICITY OF SOY PROTEIN IN SOY-BASED INFANT FORMULA BONLACT® i].

BACKGROUND: The purpose of this study was to compare the antigenicity of Bonlact® i (BL) with that of defatted soy protein (SP) and soy protein isolate (SPI), which is the original source of BL, using sera from patients with soybean allergy. METHODS: Proteins were extracted from SP, SPI, and BL using PBS. Proteins in each sample were analyzed for antigenicity using inhibition ELISA with SP-specific IgE (sIgE), SDS-PAGE, and immunoblotting. Sere from patients with soybean allergy confirmed by an oral food challenge (OFC) (n=6, OFC+ Pt), and from patients who were positive for soy-sIgE without symptoms ( n = 7, sIgE+ Pt) were used for these assays. The cross-antigenicity of SP and BL with cow's milk (CM) proteins was also analyzed in the sera from patients with CM allergy using inhibition ELISA. RESULTS: SDS-PAGE showed that the proteins in BL produced a smear-like band in the low-molecular-weight region compared with that in SP and SPI. Inhibition ELISA against SP-sIgE showed that BL had a significantly lower inhibition rate than that of SP in both OFC+ Pt and sIgE+ Pt. Immunoblotting analysis showed that the bands of BL were thinner than those of SP and SPI. Additionally, SP and BL showed no cross-antigenicity with CM proteins. CONCLUSION: The proteins in BL was partially digested, and its antigenicity was lower than that of SP and SPI.

Use of Soy-Based Formulas and Cow's Milk Allergy: Lights and Shadows.

Soybean (Glycine max) is a species of legume native to East Asia and used in childhood diet for over 2,000 years in the East. Soy protein formulas have been available for almost a century. Nowadays, the increase in cow's milk allergy and vegetarian dietary preferences are driving consumers toward cow's milk alternatives. In this paper, we reviewed the nutritional composition of soy-based infant formula and discussed their possible use in pediatric age, mainly focusing on prevention and treatment of cow's milk allergy. Protein quality is determined by digestibility and amino acid content. Purified or concentrated vegetable proteins (e.g., soy protein and gluten) have high digestibility (>95%), similar to those of animal ones. For some intact vegetable products (e.g., whole cereals and pulses), protein digestibility is lower (80-90%). Food processing and heat treatment also influence protein digestibility. Considering these data, we tried to evaluate the possible use of soybean and derivatives in pediatric age, including the nutritional composition of soy formulas and the clinical indications for their use. Moreover, since plant-based beverages are being perceived as healthy by consumers and their use is growing on the market, we recommend that soy drink should not be used as a substitute for infant formulas or cow's milk in children younger than 24 months.

Zinc status and growth of Korean infants fed human milk, casein-based, or soy-based formula: three-year longitudinal study.

To evaluate the effect of feeding methods on growth and zinc nutritional status of infants early in life, we monitored from birth to 36 months in 51 infants who were exclusively fed human milk (HM, n = 20), casein-based formula (CBF, n = 12), or soy-based formula (SBF, n = 19) during the first five months of life. Zinc status was assessed by analyzing serum zinc concentrations and zinc intakes. Zinc contents in HM and formulas were measured. Zinc intake was estimated by weighing infants before and after feeding in the HM group and by collecting formula-intake records in the CBF and SBF groups. After solid foods were introduced, all foods consumed were also included to estimate zinc intake. The growth of infants in all groups was similar to that established for normal Korean infants. Human milk zinc concentrations declined as lactation progressed. Zinc concentrations in all formulas tested in this study were higher than HM and were also higher than those claimed by the manufacturers. During the first twelve months, mean serum zinc concentrations of infants were similar in all groups, although infants in the HM group consistently had the lowest zinc intake among the groups, and the overall zinc intake in infants fed SBF was highest. This finding could be explained by the different zinc bioavailability of HM and formulas. In conclusion, infants fed HM, CBF or SBF has normal growth up to three years of age, although HM contained the lowest zinc concentration followed by CBF, then SBF.

Zinc status and growth of Korean infants fed human milk, casein-based, or soy-based formula: three-year longitudinal study

To evaluate the effect of feeding methods on growth and zinc nutritional status of infants early in life, we monitored from birth to 36 months in 51 infants who were exclusively fed human milk (HM, n = 20), casein-based formula (CBF, n = 12), or soy-based formula (SBF, n = 19) during the first five months of life. Zinc status was assessed by analyzing serum zinc concentrations and zinc intakes. Zinc contents in HM and formulas were measured. Zinc intake was estimated by weighing infants before and after feeding in the HM group and by collecting formula-intake records in the CBF and SBF groups. After solid foods were introduced, all foods consumed were also included to estimate zinc intake. The growth of infants in all groups was similar to that established for normal Korean infants. Human milk zinc concentrations declined as lactation progressed. Zinc concentrations in all formulas tested in this study were higher than HM and were also higher than those claimed by the manufacturers. During the first twelve months, mean serum zinc concentrations of infants were similar in all groups, although infants in the HM group consistently had the lowest zinc intake among the groups, and the overall zinc intake in infants fed SBF was highest. This finding could be explained by the different zinc bioavailability of HM and formulas. In conclusion, infants fed HM, CBF or SBF has normal growth up to three years of age, although HM contained the lowest zinc concentration followed by CBF, then SBF.

The Effects of Soy-Based Infant Formula on Growth and Development, and the Isoflavone Concentration of Plasma and Urine in Full-Term Infants

Soy-based formula has been used for centuries in Korea. Soybeans contain phytochemicals with a biochemically active component, isoflavone. Isoflavone is a kind of phytoestrogens, structurally and functionally similar to estrogen. This study was conducted to investigate the effects of soy-based infant formula on growth, development, and isoflavone concentration in the plasma and urine. Thirty-nine healthy infants who were delivered at K university medical center were recruited. Experimental groups were the breast milk group (n = 15, BM) who were fed breast milk, soy-based formula group (n = 10, SBF) who were fed soy-based infant formula, and the casein-based formula group (n = 14, CBF) who were fed casein-based infant formula for 4 months. HPLC analysis was used to measure the concentration of isoflavones. The measurements of infant weight, length, head circumference and chest circumference were all in the normal growth range and were similar among the experimental groups. No significant differences were found in the scores of total mean of infant development test (Development Quotient, DQ) among the experimental groups. The isoflavone content of soy-based formula was significantly higher than. that of breast milk and casein-based formula. Plasma concentration of daidzein and genistein in the infants fed soy-based formula (daidzein : 264.1 ng/ml, genistein : 392.1 ng/ml) was significantly higher (p<.0001) than that in infants fed breast milk (daidzein : 3.4 ng/ml, genistein : 3.8 ng/ml) and casein-based formula (daidzein: 8.1 ng/ml, genistein: 9.3 ng/ml). Also, urinary daidzein and genistein concentrations in infants fed soy-based formula (daidzein: 19.82 microgram/ml, genistein : 17.89 microgram/ml) were significantly higher (p<.001) than those in infants fed breast milk (daidzein: 0.28 microgram/ml, genistein : 0.22 microgram/ml) and casein-based formula (daidzein : 0.45 microgram/ml, genistein : 0.33 microgram/ml).