Anne Staudt Kvistgaard

Whey Protein Processing Influences Formula-Induced Gut Maturation in Preterm Pigs

Immaturity of the gut predisposes preterm infants to nutritional challenges potentially leading to clinical complications such as necrotizing enterocolitis. Feeding milk formulas is associated with greater risk than fresh colostrum or milk, probably due to loss of bioactive proteins (e.g., immunoglobulins, lactoferrin, insulin-like growth factor, transforming growth factor-β) during industrial processing (e.g., pasteurization, filtration, spray-drying). We hypothesized that the processing method for whey protein concentrate (WPC) would affect gut maturation in formula-fed preterm pigs used as a model for preterm infants. Fifty-five caesarean-delivered preterm pigs were distributed into 4 groups given 1 of 4 isoenergetic diets: formula containing conventional WPC (filtration, multi-pasteurization, standard spray-drying) (CF); formula containing gently treated WPC (reduced filtration and pasteurization, gentle spray-drying) (GF); formula containing minimally treated WPC (rennet precipitation, reduced filtration, heat treatment <40°C, freeze-drying) (MF); and bovine colostrum (used as a positive reference group) (BC). Relative to CF, GF, and MF pigs, BC pigs had greater villus heights, lactose digestion, and absorption and lower gut permeability (P < 0.05). MF and BC pigs had greater plasma citrulline concentrations than CF and GF pigs and intestinal interleukin-8 was lower in BC pigs than in the other groups (P < 0.05). MF pigs had lower concentrations of intestinal claudin-4, cleaved caspase-3, and phosphorylated c-Jun than CF pigs (P < 0.05). The conventional and gently treated WPCs had similar efficacy in stimulating proliferation of porcine intestinal epithelial cells. We conclude that processing of WPC affects intestinal structure, function, and integrity when included in formulas for preterm pigs. Optimization of WPC processing technology may be important to preserve the bioactivity and nutritional value of formulas for sensitive newborns.

Raw bovine milk improves gut responses to feeding relative to infant formula in preterm piglets

For preterm neonates, the quality of the first milk is crucial for intestinal maturation and resistance to necrotizing enterocolitis (NEC). Among other factors, milk quality is determined by the stage of lactation and processing. We hypothesized that unprocessed mature bovine milk (BM; raw bovine milk) would have less bioactivity than corresponding bovine colostrum (BC) in a preterm pig model, but have improved bioactivity relative to its homogenized, pasteurized, spray-dried equivalent, whole milk powder (WMP), or a bovine milk protein-based infant formula (IF). For 5 days, newborn preterm pigs received parenteral and enteral nutrition consisting of IF (n = 13), BM (n = 13), or BC (n = 14). In a second study, WMP (n = 15) was compared with IF (n = 10) and BM (n = 9). Compared with pigs fed IF, pigs that were fed BM had significantly improved intestinal structure (mucosal weight, villus height) and function (increased nutrient absorption and enzyme activities, decreased gut permeability, nutrient fermentation, and NEC severity). BC further improved these effects relative to BM (lactase activity, lactose absorption, plasma citrulline, and tissue interleukin-8). WMP induced similar effects as BM, except for lactase activity and lactose absorption. In conclusion, the maturational and protective effects on the immature intestine decreased in the order BC>BM>WMP, but all three intact bovine milk diets were markedly better than IF. The stage of lactation (colostrum vs. mature milk) and milk processing (e.g., homogenization, fractionation, pasteurization, spray-drying) are important factors in determining milk quality during the early postnatal period of preterm neonates.

Growth, Nutrition, and Cytokine Response of Breast-fed Infants and Infants Fed Formula With Added Bovine Osteopontin.

Objectives: Breast milk contains a high concentration of osteopontin (OPN), a protein having multiple functions. In contrast, infant formula is low in OPN. A randomized clinical trial was performed to evaluate effects of adding a highly enriched bovine OPN fraction to formula, and infants whose mothers had already decided not to breast-feed were recruited. They were fed regular formula (F0) or the same formula with bovine OPN at 65 (F65) or 130 (F130) mg/L (50% and 100% of human milk level, respectively) from 1 to 6 months of age and were compared with a reference group of breast-fed (BF) infants. Methods: Morbidity was recorded daily and 3-day dietary records collected monthly. Anthropometry was assessed monthly, and blood samples were taken at 1, 4, and 6 months of age. Hematology and iron status, serum cytokines, plasma amino acids, and blood urea nitrogen were analyzed. Results: Formulas were well tolerated and there were no significant differences in formula intake or growth among the formula-fed groups. The F130 group had significantly lower plasma threonine than the F0 and F65 groups, and significantly lower plasma branched-chain amino acids (BCAAs) than the F0 group and, thus, was closer to BF infants. Plasma TNF-&agr; was higher in formula-fed infants than in BF infants. Among the formula-fed groups, the proinflammatory cytokine TNF-&agr; was significantly lower in the F65 and F130 groups than in the F0 group, suggesting that OPN downregulates inflammatory cytokines and thus affects immune function. Conclusions: Addition of OPN to infant formula changes amino acid metabolism and cytokine responses of FF infants and makes them more similar to BF infants. The lower prevalence of pyrexia in the F130 infants than in F0 infants suggests that adding OPN may confer health benefits.

α-Lactalbumin and Casein-Glycomacropeptide Do Not Affect Iron Absorption from Formula in Healthy Term Infants

Iron absorption from infant formula is relatively low. α-Lactalbumin and casein-glycomacropeptide have been suggested to enhance mineral absorption. We therefore assessed the effect of α-lactalbumin and casein-glycomacropeptide on iron absorption from infant formula in healthy term infants. Thirty-one infants were randomly assigned to receive 1 of 3 formulas (4 mg iron/L, 13.1 g protein/L) from 4-8 wk to 6 mo of age: commercially available whey-predominant standard infant formula (standard formula), α-lactalbumin-enriched infant formula (α-LAC), or α-lactalbumin-enriched/casein-glycomacropeptide-reduced infant formula (α-LAC/RGMP). Nine breast-fed infants served as a reference. At 5.5 mo of age, (58)Fe was administered to all infants in a meal. Blood samples were collected 14 d later for iron absorption and iron status indices. Iron deficiency was defined as depleted iron stores, iron-deficient erythropoiesis, or iron deficiency anemia. Iron absorption (mean ± SD) was 10.3 ± 7.0% from standard formula, 8.6 ± 3.8% from α-LAC, 9.2 ± 6.5% from α-LAC/RGMP, and 12.9 ± 6.5% from breast milk, with no difference between the formula groups (P = 0.79) or all groups (P = 0.44). In the formula-fed infants only, iron absorption was negatively correlated with serum ferritin (r = -0.49; P = 0.005) and was higher (P = 0.023) in iron-deficient infants (16.4 ± 12.4%) compared with those with adequate iron status (8.6 ± 4.4%). Our findings indicate that α-lactalbumin and casein-glycomacropeptide do not affect iron absorption from infant formula in infants. Low serum ferritin concentrations are correlated with increased iron absorption from infant formula.

Bovine Osteopontin Modifies the Intestinal Transcriptome of Formula-Fed Infant Rhesus Monkeys to Be More Similar to Those That Were Breastfed

BACKGROUND Osteopontin (OPN) is a multifunctional protein found in human milk at high concentration. OBJECTIVE The impact of supplemental bovine OPN on growth, body composition, and the jejunal transcriptome was assessed. METHODS Newborn rhesus monkeys were randomly assigned to be breastfed (n = 4) or to receive formula [formula fed (FF), n = 6] or formula supplemented with 125 mg/L of bovine OPN (bOPN, n = 6) for 3 mo. Jejunal mRNA was extracted and subjected to microarray analysis. RESULTS Growth was similar among all the treatment groups, but breastfed monkeys were ∼25% leaner at 3 mo. Pairwise comparisons demonstrated that 1017 genes were differentially expressed between breastfed and FF groups, 217 between breastfed and bOPN groups, and 119 between FF and bOPN groups. The data were also analyzed with the use of weighted gene coexpression network analysis, which revealed 6 modules of coexpressed genes that differed among the 3 treatments. Nearly 50% of genes were assigned to one module in which breastfed differed from FF and bOPN expression was intermediate. This module was enriched for genes related to cell adhesion and motility, cytoskeletal remodeling, wingless and integration site signaling, and neuronal development. Most of these canonical pathways centered on integrins, which are receptors for OPN. CONCLUSIONS The intestinal transcriptome of breastfed and FF monkeys differs, but bovine OPN at levels similar to human milk shifts gene expression profiles to be more similar to breastfed monkeys.

Pre-clinical in vitro and in vivo safety evaluation of bovine whey derived osteopontin, Lacprodan® OPN-10.

Lacprodan® OPN-10 is a proprietary whey-based protein product that contains bovine-derived osteopontin (OPN), found in human milk and other bodily tissues. In vitro genotoxicity tests conducted according to accepted guidelines at up to 5000μg/plate OPN failed to induce genetic mutations in Salmonella typhimurium strains and Escherichia coli strain and did not induce chromosomal aberrations or cytotoxicity in human lymphocytes. Administration of an acute dose of Lacprodan® OPN-10 (2300mg/kg body weight) to male and female mice did not induce chromosomal damage or mitotic apparatus damage to erythroblasts from bone marrow. Lacprodan® OPN-10 was evaluated in a 13-week oral toxicity study in which rats were fed diets containing 0.5%, 1.0% and 2.0% Lacprodan® OPN-10. No test-article-related clinical observations or toxicological effects on body or organ weights, food consumption, ophthalmic effects, locomotor activity, hematology, clinical chemistry, urinalysis, or pathology were identified. In a teratogenicity study, administration of Lacprodan® OPN-10 up to 2500mg/kgbw/day via gavage to pregnant rats had no effect on dams or pups. The No Observed Adverse Effect Level (NOAEL) for Lacprodan® OPN-10 in the 13-week toxicity study was 2.0% of the diet (equivalent to 1208mg/kgbw/day in male rats and 1272mg/kgbw/day in female rats).

Effects of osteopontin-enriched formula on lymphocyte subsets in the first 6 months of life: a randomized controlled trial

BackgroundHuman milk is rich in osteopontin (OPN), which has immunomodulatory functions.MethodsIn a randomized controlled trial, standard formula (SF) and the same formula with 65 mg of OPN/L (F65) or 130 mg of OPN/L (F130), representing ~50 and 100% of the OPN concentration in human milk, were compared. We examined frequencies and composition of peripheral blood immune cells by four-color immunoflow cytometry of formula-fed infants at ages 1, 4, and 6 months, and compared them with a breastfed (BF) reference group.ResultsThe F130 group had increased T-cell proportions compared with the SF (P=0.036, average effect size 0.51) and F65 groups (P=0.008, average effect size 0.65). Compared with the BF group, the monocyte proportions were increased in the F65 (P=0.001, average effect size 0.59) and F130 (P=0.006, average effect size 0.50) groups, but were comparable among the formula groups.ConclusionOPN in an infant formula at a concentration close to that of human milk increased the proportion of circulating T cells compared with both SF and formula with added OPN at ~50% of the concentration in human milk. This suggests that OPN may favorably influence immune ontogeny in infancy and that the effects appear to be dose-dependent.