Bovine osteopontin modifies the intestinal transcriptome of formula-fed infant rhesus monkeys to be more similar to those that were breastfed

Advancements in emulsion systems for specialized infant formulas: Research process and formulation proposals for optimizing bioavailability of nutraceuticals

With the rapid advancements in nutrition and dietary management, infant formulas for special medical purposes (IFSMPs) have been developed to cater to the unique nutraceutical requirements of infants with specific medical conditions or physiological features. However, there are various challenges in effectively preserving and maximizing the health benefits of the specific nutraceuticals incorporated in IFSMPs. This review provides an overview of the nutritional compositions of various IFSMPs and highlights the challenges associated with the effective supplementation of specific nutraceuticals for infants. In addition, it emphasizes the promising potential of emulsion delivery systems, which possess both encapsulation and delivery features, to significantly improve the solubility, stability, oral acceptance, and bioavailability (BA) of nutraceutical bioactives. Based on this information, this work proposes detailed strategies for designing and developing model IFSMP emulsions to enhance the BA of specially required nutraceuticals. Key areas covered include emulsion stabilization, selective release mechanisms, and effective absorption of nutraceuticals. By following these proposals, researchers and industry professionals can design and optimize emulsion-based IFSMPs with enhanced health benefits. This review not only outlines the developmental states of IFSMP formulations but also identifies future research directions aimed at improving the physiological health benefits of IFSMPs. This effort lays the theoretical groundwork for the further development of emulsion-type IFSMP in infant formula (IF) industry, positioning the IF industry to better meet the complex needs of infants requiring specialized nutrition.

Supplementing infant milk formula with a multi-strain synbiotic and osteopontin enhances colonic microbial colonization and modifies jejunal gene expression in lactating piglets

A total of ninety-six weaned piglets were assigned to four dietary treatments in a 2 × 2 design. The treatments included: a standard milk formula (CTR); CTR + probiotics (6.4 × 108 cfu L-1Bifidobacterium longum subsp. infantis CECT 7210 and 1.1 × 108 cfu L-1Lactobacillus rhamnosus NH001) + prebiotics (galacto-oligosaccharides 4.36 g L-1 and human-milk-oligosaccharide 0.54 g L-1) (SYN); CTR + osteopontin (0.43 g L-1) (OPN); and CTR + SYN + OPN (CON). Daily records including feed intake, body weight, and clinical signs, were maintained throughout the 15-day trial. At the end of the study samples from blood, digestive content, and gut tissues were collected to determine serum TNF-α, intestinal fermentative activity (SCFA and ammonia), colonic microbiota (16S rRNA Illumina-MiSeq), histomorphology, and jejunal gene expression (Open-Array). No statistical differences were found in weight gain; however, the animals supplemented with osteopontin exhibited higher feed intake. In terms of clinical signs, synbiotic supplementation led to a shorter duration of diarrhoea episodes. Regarding gut health, the sequenced faecal microbiota revealed better control of potentially dysbiotic bacteria with the CON diet at day 15. In the colon compartment, a significant increase in SCFA concentration, a decrease in ammonia concentration, and a significant decrease in intraepithelial lymphocyte counts were particularly observed in CON animals. The supplemented diets were also associated with modified jejunal gene expression. The synbiotic combination was characterized by the upregulation of genes related to intestinal maturation (ALPI, SI) and nutrient transport (SLC13A1, SLC15A1, SLC5A1, SLC7A8), and the downregulation of genes related to the response to pathogens (GBP1, IDO, TLR4) or the inflammatory response (IDO, IL-1β, TGF-β1). Osteopontin promoted the upregulation of a digestive function gene (GCG). Correlational analysis between the microbiota population and various intestinal environmental factors (SCFA concentration, histology, and gene expression) proposes mechanisms of communication between the gut microbiota and the host. In summary, these results suggest an improvement in the colonic colonization process and a better modulation of the immune response when milk formula is supplemented with the tested synbiotic combined with osteopontin, benefiting from a synergistic effect.

An expert panel on the adequacy of safety data and physiological roles of dietary bovine osteopontin in infancy

Human milk, due to its unique composition, is the optimal standard for infant nutrition. Osteopontin (OPN) is abundant in human milk but not bovine milk. The addition of bovine milk osteopontin (bmOPN) to formula may replicate OPN's concentration and function in human milk. To address safety concerns, we convened an expert panel to assess the adequacy of safety data and physiological roles of dietary bmOPN in infancy. The exposure of breastfed infants to human milk OPN (hmOPN) has been well-characterized and decreases markedly over the first 6 months of lactation. Dietary bmOPN is resistant to gastric and intestinal digestion, absorbed and cleared from circulation within 8-24 h, and represents a small portion (<5%) of total plasma OPN. Label studies on hmOPN suggest that after 3 h, intact or digested OPN is absorbed into carcass (62%), small intestine (23%), stomach (5%), and small intestinal perfusate (4%), with <2% each found in the cecum, liver, brain, heart, and spleen. Although the results are heterogenous with respect to bmOPN's physiologic impact, no adverse impacts have been reported across growth, gastrointestinal, immune, or brain-related outcomes. Recombinant bovine and human forms demonstrate similar absorption in plasma as bmOPN, as well as effects on cognition and immunity. The panel recommended prioritization of trials measuring a comprehensive set of clinically relevant outcomes on immunity and cognition to confirm the safety of bmOPN over that of further research on its absorption, distribution, metabolism, and excretion. This review offers expert consensus on the adequacy of data available to assess the safety of bmOPN for use in infant formula, aiding evidence-based decisions on the formulation of infant formula.

Effects of pasteurization on osteopontin concentrations in human breastmilk

BACKGROUND

Osteopontin (OPN) is an important breastmilk protein involved in infant intestinal, immunological, and brain development. However, little is known about how common milk pasteurization and storage techniques affect this important bioactive protein.

METHODS

Human milk osteopontin concentration was measured in single-donor fresh (n = 1) or frozen (n = 20) breastmilk, pooled Holder-pasteurized donor breastmilk (n = 11), and a shelf-stable (retort pasteurized) breastmilk product (n = 2) by ELISA. Single-donor breastmilk samples were subjected to pasteurization and/or freezing before measuring osteopontin concentrations.

RESULTS

Holder pasteurization of breastmilk resulted in an ∼50% decrease in osteopontin concentration within single-donor samples. Breastmilk from mothers of preterm infants trended toward higher osteopontin concentration than mothers of term infants; however, samples from preterm mothers experienced greater osteopontin degradation upon pasteurization. A commercial breastmilk product that underwent retort pasteurization had lower osteopontin concentration than a Holder-pasteurized pooled breastmilk product. Finally, freezing breastmilk prior to Holder pasteurization resulted in less osteopontin degradation than Holder pasteurization prior to freezing.

CONCLUSIONS

Commonly used breastmilk pasteurization and storage techniques, including freezing and Holder pasteurization, decrease the concentration of the bioactive protein osteopontin in human breastmilk. Holder pasteurization reduced osteopontin concentration by an average of 63%, while freezing resulted in an 8-12% decrease.

IMPACT

Pasteurization of human breastmilk significantly decreases the concentration of the bioactive protein osteopontin. Use of both pasteurization and freezing techniques for breastmilk preservation results in greater loss of osteopontin. This study presents for the first time an analysis of osteopontin concentrations in single-donor pasteurized milk samples.

Gastro-Intestinal Digested Bovine Milk Osteopontin Modulates Gut Barrier Biomarkers In Vitro

SCOPE

Osteopontin (OPN) is a multifunctional protein naturally present in mammals' milk, associated with immune homeostasis and intestinal maturation. This study aims to investigate the protein digestion pattern and the cellular bioactivity of bovine milk OPN digesta in vitro.

METHODS AND RESULTS

A modified INFOGEST static in vitro infant digestion protocol and a Caco-2/HT-29 co-culture cell model are employed to evaluate the digestion properties and the anti-inflammatory effects of OPN. OPN is resistant to gastric hydrolysis but degraded into large peptides during intestinal digestion. Its 10 kDa digesta permeate with predicted extensive bioactivities protects the co-culture cell model from the inflammation-induced dysfunction by dose-dependently recovering the expression of occludin, claudin-3, and ZO-1. Low dosage of OPN significantly decreases the production of IL-8 and IL-6, and downregulates the mRNA and protein expression of MyD88, NF-κB p65, and IκB-α, whereas a high dose evokes a mild pro-inflammatory response. Interestingly, anti-inflammatory effect of OPN digesta is stronger than lactoferrin and whey protein concentrate counterparts.

CONCLUSION

The findings demonstrate that the bioactive peptides released from in vitro infant gastrointestinal digestion of bovine milk OPN alleviates intestinal epithelial cell inflammation by inhibiting NF-κB pathway activation and potentiates the barrier function of the intestinal epithelium.

Bovine milk osteopontin improved intestinal health of pregnant rats fed a high-fat diet through improving bile acid metabolism

The main purpose of the current study was to investigate the ameliorative effects of bovine milk osteopontin (bmOPN) on the gut dysfunction of pregnant rats fed a high-fat diet (HFD). Bovine milk osteopontin was supplemented at a dose of 6 mg/kg body weight. Bovine milk osteopontin supplementation during pregnancy reduced colonic inflammation of HFD dams, and it also increased the colonic expression of ZO-1 and claudin-4 of HFD dams. Bovine milk osteopontin significantly enriched the relative abundance of Bacteroidetes, whereas it decreased Proteobacteria, Helicobacteraceae, and Desulfovibrionaceae in feces of HFD dams. The levels of isobutyric acid and pentanoic acid in the HFD + bmOPN group were higher than that of the HFD group. Functional predication analysis of microbial genomes revealed that bmOPN supplementation to HFD pregnancies changed 4 Kyoto Encyclopedia of Genes and Genomes pathways including bile acid biosynthesis. Further, bmOPN enriched hepatic taurochenodeoxycholic acid and tauroursodeoxycholic acid plus taurohyodeoxycholic acid in the gut of HFD maternal rats. Our findings suggested that bmOPN improved the gut health of HFD pregnant rats partially through modulating bile acid biosynthesis.

Specific Milk Composition of miR-30b Transgenic Mice Associated with Early Duodenum Maturation in Offspring with Lasting Consequences for Growth

BACKGROUND

Milk composition is complex and includes numerous components essential for offspring growth and development. In addition to the high abundance of miR-30b microRNA, milk produced by the transgenic mouse model of miR-30b-mammary deregulation displays a significantly altered fatty acid profile. Moreover, wild-type adopted pups fed miR-30b milk present an early growth defect.

OBJECTIVE

This study aimed to investigate the consequences of miR-30b milk feeding on the duodenal development of wild-type neonates, a prime target of suckled milk, along with comprehensive milk phenotyping.

METHODS

The duodenums of wild-type pups fed miR-30b milk were extensively characterized at postnatal day (PND)-5, PND-6, and PND-15 using histological, transcriptomic, proteomic, and duodenal permeability analyses and compared with those of pups fed wild-type milk. Milk of miR-30b foster dams collected at mid-lactation was extensively analyzed using proteomic, metabolomic, and lipidomic approaches and hormonal immunoassays.

RESULTS

At PND-5, wild-type pups fed miR-30b milk showed maturation of their duodenum with 1.5-fold (P < 0.05) and 1.3-fold (P < 0.10) increased expression of Claudin-3 and Claudin-4, respectively, and changes in 8 duodenal proteins (P < 0.10), with an earlier reduction in paracellular and transcellular permeability (183 ng/mL fluorescein sulfonic acid [FSA] and 12 ng/mL horseradish peroxidase [HRP], respectively, compared with 5700 ng/mL FSA and 90 ng/mL HRP in wild-type; P < 0.001). Compared with wild-type milk, miR-30b milk displayed an increase in total lipid (219 g/L compared with 151 g/L; P < 0.05), ceramide (17.6 μM compared with 6.9 μM; P < 0.05), and sphingomyelin concentrations (163.7 μM compared with 76.3 μM; P < 0.05); overexpression of 9 proteins involved in the gut barrier (P < 0.1); and higher insulin and leptin concentrations (1.88 ng/mL and 2.04 ng/mL, respectively, compared with 0.79 ng/mL and 1.06 ng/mL; P < 0.01).

CONCLUSIONS

miR-30b milk displays significant changes in bioactive components associated with neonatal duodenal integrity and maturation, which could be involved in the earlier intestinal closure phenotype of the wild-type pups associated with a lower growth rate.

A comprehensive review on infant formula: nutritional and functional constituents, recent trends in processing and its impact on infants' gut microbiota

Human milk is considered the most valuable form of nutrition for infants for their growth, development and function. So far, there are still some cases where feeding human milk is not feasible. As a result, the market for infant formula is widely increasing, and formula feeding become an alternative or substitute for breastfeeding. The nutritional value of the formula can be improved by adding functional bioactive compounds like probiotics, prebiotics, human milk oligosaccharides, vitamins, minerals, taurine, inositol, osteopontin, lactoferrin, gangliosides, carnitine etc. For processing of infant formula, diverse thermal and non-thermal technologies have been employed. Infant formula can be either in powdered form, which requires reconstitution with water or in ready-to-feed liquid form, among which powder form is readily available, shelf-stable and vastly marketed. Infants' gut microbiota is a complex ecosystem and the nutrient composition of infant formula is recognized to have a lasting effect on it. Likewise, the gut microbiota establishment closely parallels with host immune development and growth. Therefore, it must be contemplated as an important factor for consideration while developing formulas. In this review, we have focused on the formulation and manufacturing of safe and nutritious infant formula equivalent to human milk or aligning with the infant's needs and its ultimate impact on infants' gut microbiota.

Milk Osteopontin and Human Health

Osteopontin (OPN) is a multifunctional protein found in all vertebrates. OPN is expressed in many different cell types, and is consequently found in most tissues and physiological secretions. OPN is involved in a multitude of biological processes, such as activation and regulation of the immune system; biomineralization; tissue-transformative processes, including growth and development of the gut and brain; interaction with bacteria; and many more. OPN is found in the highest concentrations in milk, where it is believed to initiate and regulate developmental, immunological and physiological processes in infants who consume milk. Processes for the isolation of bovine OPN for use in infant formula have been developed, and in recent years, many studies have investigated the effects of the intake of milk OPN. The purpose of this article is to review and compare existing knowledge about the structure and function of milk OPN, with a particular focus on the effects of milk OPN on human health and disease.

Comparison of 30 Cytokines in Human Breast Milk between 1989 and 2013 in Japan

Milk cytokines play a vital role in mucosal immunity during infancy by supporting immune development and functions. Although the maternal background characteristics influence milk cytokines, changes in cytokine levels across generations remain unclear. Colostrum (C, n = 48) and mature milk (MM, n = 49) samples were collected from lactating Japanese women in 1989 (2727 samples) and 2013 (1408 samples). Milk cytokines were comprehensively measured using a suspension array and immunosorbent assays. The positive rates and cytokine concentrations were compared between the two generations using logistic and multiple regression analyses. Twenty-eight cytokines tested positive in all sample groups (1989-C, 1989-MM, 2013-C, and 2013-MM). The median osteopontin (OPN) level was significantly higher in the 1989-C group than in the 2013-C group (318.1 vs. 137.5 μg/mL; p = 0.0016) but did not differ between the MM groups. The median TGF-β1 level was significantly lower in the 1989-MM group than in the 2013-MM group (1056.2 vs. 1330.8 pg/mL; p = 0.008) but did not differ between the C groups. Most cytokines were comparable between generations, except for potential variation in the C-OPN and TGF-β1 levels. Milk cytokine secretion may reflect temporal changes in maternal background characteristics; however, the results from the analysis of 30-year-old samples may have influenced the milk cytokine levels. Further studies are needed with a larger number of milk samples collected from the same individuals at multiple time points over a wide lactation period, with detailed data on the maternal and infant background characteristics and diets.

Naturally Occurring N-Terminal Fragments of Bovine Milk Osteopontin Are Transported across Models of the Intestinal Barrier

Osteopontin (OPN) is a bioactive integrin-binding protein found in high concentrations in milk, where it is present both as a full-length protein and as several N-terminally derived fragments. OPN resists gastric digestion, and via interaction with receptors in the gut or by crossing the intestinal barrier into circulation, ingested milk OPN may influence physiological processes. The aim of this study was to investigate OPN interaction with intestinal cells and its transport across models of the intestinal barrier. Immunodetection of OPN incubated with Caco-2 cells at 4 °C and 37 °C showed that OPN binds to the intestinal cells, but it is not internalised. Transepithelial transport was studied using mono- and co-cultures of Caco-2 cells and mucus-producing HT29-MTX cells in transwell membranes. OPN was shown to cross the barrier models in a time-, temperature-, and energy-dependent process inhibited by wortmannin, indicating that the transport takes place via the transcytosis pathway. Analyses of the naturally occurring milk mixture of full-length and N-terminal fragments showed that the N-terminal fragments of OPN bound intestinal cells most effectively and that the fragments were transported across the intestinal membrane models. This suggests that proteolytic processing of OPN increases its biological activity after ingestion.

The Effect of Human and Bovine Milk Osteopontin on Intestinal Caco-2 Cells: A Transcriptome Comparison

Osteopontin (OPN) is a multifunctional protein abundantly present in human milk, whereas the concentration is significantly lower in bovine milk. Human and bovine milk OPN are structurally similar and both proteins resist gastric digestion and reach the intestines in a bioactive form. Intervention studies have indicated the beneficial effects of supplementing infant formula with bovine milk OPN and several in vivo and in vitro studies have shown that bovine milk OPN positively influences intestinal development. To investigate the functional relationship, we compared the effect of simulated gastrointestinal digested human and bovine milk OPN on gene expression in Caco-2 cells. After incubation, total RNA was extracted and sequenced and transcripts were mapped to the human genome. Human and bovine milk OPN regulated the expression of 239 and 322 genes, respectively. A total of 131 genes were similarly regulated by the OPNs. As a control, a whey protein fraction with a high content of alpha-lactalbumin had a very limited transcriptional impact on the cells. Enrichment data analysis showed that biological processes related to the ubiquitin system, DNA binding, and genes associated with transcription and transcription control pathways were affected by the OPNs. Collectively, this study shows that human and bovine milk OPN have a significant and highly comparable effect on the intestinal transcriptome.

Studies and Application of Sialylated Milk Components on Regulating Neonatal Gut Microbiota and Health

Breast milk is rich in sialic acids (SA), which are commonly combined with milk oligosaccharides and glycoconjugates. As a functional nutrient component, SA-containing milk components have received increasing attention in recent years. Sialylated human milk oligosaccharides (HMOs) have been demonstrated to promote the growth and metabolism of beneficial gut microbiota in infants, bringing positive outcomes to intestinal health and immune function. They also exhibit antiviral and bacteriostatic activities in the intestinal mucosa of new-borns, thereby inhibiting the adhesion of pathogens to host cells. These properties play a pivotal role in regulating the intestinal microbial ecosystem and preventing the occurrence of neonatal inflammatory diseases. In addition, some recent studies also support the promoting effects of sialylated HMOs on neonatal bone and brain development. In addition to HMOs, sialylated glycoproteins and glycolipids are abundant in milk, and are also critical to neonatal health. This article reviews the current research progress in the regulation of sialylated milk oligosaccharides and glycoconjugates on neonatal gut microbiota and health.

Milk Osteopontin for Gut, Immunity and Brain Development in Preterm Pigs

Deficient levels of milk osteopontin (OPN) in infant formula may partly account for developmental differences between infants fed formula or maternal milk. We hypothesized that a milk diet supplemented with bovine milk OPN improves gut, immunity and brain development and tested this in a preterm pig model. Preterm pigs delivered by cesarean section (90% gestation) were fed raw bovine milk (CON, n = 19) or the same diet supplemented with a physiologically relevant dose of OPN (46 mg/(kg·d), n = 16). Endpoints related to clinical outcomes, systemic immunity and neurocognitive development were assessed during the study and gut tissues were collected at Day 19. Growth pattern, early motor development and most systemic immune parameters were similar between OPN and CON pigs. The OPN pigs had higher villus-to-crypt ratios than CON pigs and higher monocyte and lymphocyte counts on Day 8. Gut digestive and absorptive functions and cognitive performance (T-maze test) were similar between OPN and CON pigs. In conclusion, dietary supplementation with OPN above basal bovine milk levels induced minor improvements in gut structure and systemic immunity without any effects on cognitive performance. The minimal levels of OPN in infant formula to secure optimal adaptation in the immediate neonatal period remain to be determined.

Osteopontin Levels in Human Milk Are Related to Maternal Nutrition and Infant Health and Growth

Background: Osteopontin (OPN) is a glycosylated phosphoprotein found in human tissues and body fluids. OPN in breast milk is thought to play a major role in growth and immune system development in early infancy. Here, we investigated maternal factors that may affect concentrations of OPN in breast milk, and the possible associated consequences for the health of neonates. Methods: General characteristics, health status, dietary patterns, and anthropometric measurements of 85 mothers and their babies were recorded antenatally and during postnatal follow-up. Results: The mean concentration of OPN in breast milk was 137.1 ± 56.8 mg/L. Maternal factors including smoking, BMI, birth route, pregnancy weight gain, and energy intake during lactation were associated with OPN levels (p < 0.05). Significant correlations were determined between body weight, length, and head circumference, respectively, and OPN levels after one (r = 0.442, p = < 0.001; r = −0.284, p = < 0.001; r = −0.392, p = < 0.001) and three months (r = 0.501, p = < 0.001; r = −0.450, p = < 0.001; r = −0.498, p = < 0.001) of lactation. A negative relation between fever-related infant hospitalizations from 0–3 months and breast milk OPN levels (r = −0.599, p < 0.001) was identified. Conclusions: OPN concentrations in breast milk differ depending on maternal factors, and these differences can affect the growth and immune system functions of infants. OPN supplementation in infant formula feed may have benefits and should be further investigated.

A literature review on lactopontin and its roles in early life

OBJECTIVE

Our study aims to review the functions and possible mechanisms of lactopontin (LPN) in early life.

BACKGROUND

Human milk proteins provide a variety of protection and health benefits in early life. One of these multifunctional proteins is LPN, which is osteopontin (OPN) derived from milk.

METHODS

Information used to write this paper was collected from Uniprot, PubMed, and Google Scholar, including in vitro, in vivo, and clinical studies.

CONCLUSIONS

LPN is a highly phosphorylated, O-glycosylated acidic protein and a unique type of OPN, as it presents at the highest concentration and a higher degree of posttranslational modifications (PTMs) in human milk than other tissues and excretions. LPN is present in milk and the intestinal tracts of infants after consumption as a mixture of intact protein and peptides, which can bind diverse integrin and receptors in the target cell and drive downstream signaling pathways. LPN is found to play important roles in developing the immune, intestinal and nervous systems in early life. Moreover, LPN has also shown to support preterm infants' health when they are especially vulnerable after delivery via animal studies. Additionally, LPN can form protein complex with another milk bioactive protein, lactoferrin (LF), to withstand proteolysis and perform more efficient biological activity. Therefore, LPN showed great potential for early life while more clinical trials and evidence are still emergying.

Recombinant Bovine and Human Osteopontin Generated by Chlamydomonas reinhardtii Exhibit Bioactivities Similar to Bovine Milk Osteopontin When Assessed in Mouse Pups Fed Osteopontin-Deficient Milk

SCOPE

Osteopontin (OPN), a highly phosphorylated and glycosylated protein, is present in most body fluids, including milk. OPN appears at a high concentration in human milk (130-180 mg L^-1 ), but not bovine milk (≈18 mg mL^-1 ). It is previously shown that milk OPN is involved in various biological processes and therefore may be a valuable infant formula additive.

METHODS AND RESULTS

In the present study, recombinant bovine OPN (rbOPN) and recombinant human OPN (rhOPN) are generated in a Chlamydomonas reinhardtii (C. reinhardtii) algal expression system. The rbOPN and rhOPN are phosphorylated but not glycosylated. To assess the bioactivities of rbOPN and rhOPN and compare their bioactivities to those of bovine milk OPN (bmOPN), wild-type (WT) mouse pups nursed by OPN knock-out (KO) dams are orally fed bmOPN, rbOPN, and rhOPN daily from postnatal days 1-21 (P1-21). Effects of these OPNs on development of the brain, intestine, and immune function are evaluated. The results show that rbOPN and rhOPN exhibit effects similar to those of bmOPN as well as mouse milk OPN on stimulating proliferation of the small intestine, increasing brain myelination and cognitive development, and enhancing development of immune function.

CONCLUSION

rbOPN and rhOPN are likely to provide beneficial bioactivities when added to infant diets.

Associations of Human Milk Oligosaccharides and Bioactive Proteins with Infant Morbidity and Inflammation in Malawian Mother-Infant Dyads

BACKGROUND

Human milk oligosaccharides (HMOs) and bioactive proteins likely benefit infant health, but information on these relations is sparse.

OBJECTIVES

We aimed to examine associations of milk content of HMOs and bioactive proteins with incidence and longitudinal prevalence of infant morbidity (any illness, fever, diarrhea, acute respiratory infection, and loss of appetite) and markers of inflammation [C-reactive protein (CRP) and α-1-acid glycoprotein (AGP)]. These are secondary analyses of a randomized controlled trial.

METHODS

Breast milk samples at 6 mo postpartum (n  = 659) were analyzed to quantify absolute abundance of HMOs, relative abundance of fucosylated HMOs, sialylated HMOs, and 51 individual HMOs, and concentrations of 6 bioactive proteins (lactalbumin, lactoferrin, lysozyme, antitrypsin, IgA, and osteopontin). We examined associations of these constituents with infant morbidity from 6 to 7 and 6 to 12 mo, and CRP and AGP at 6 and 18 mo, considering maternal secretor status [presence or absence of the functional enzyme encoded by the fucosyltransferase 2 gene (FUT2) ] and adjusting for covariates and multiple hypothesis testing.

RESULTS

In secretors there were positive associations between total HMOs and longitudinal prevalence of fever (P = 0.032), between fucosylated HMOs and incidence of diarrhea (P = 0.026), and between lactoferrin and elevated CRP at 18 mo (P = 0.011). In nonsecretors, there were inverse associations between lactoferrin and incidence of fever (P  = 0.007), between osteopontin and longitudinal prevalence of lost appetite (P  = 0.038), and between fucosylated HMOs and incidence of diarrhea (P = 0.025), lost appetite (P = 0.019), and concentrations of AGP and CRP at 6 mo (P = 0.001 and 0.010); and positive associations between total HMOs and incidence of lost appetite (P = 0.024) and elevated CRP at 18 mo (P  = 0.026), between lactalbumin and incidence of diarrhea (P = 0.006), and between lactoferrin and elevated CRP at 18 mo (P = 0.015).

CONCLUSIONS

Certain HMOs and bioactive proteins were associated with infant morbidity and inflammation, particularly in nonsecretors. Further research is needed to elucidate the causality of these relations.This trial was registered at clinicaltrials.gov as NCT01239693.

Longitudinal Changes in the Concentration of Major Human Milk Proteins in the First Six Months of Lactation and Their Effects on Infant Growth

Our knowledge related to human milk proteins is still limited. The present study determined the changes in multiple human milk proteins during the first six months of lactation, investigated the influencing factors of milk proteins, and explored the impact of milk proteins on infant growth. A total of 105 lactating women and their full-term infants from China were prospectively surveyed in this research. Milk samples were collected at 1–5 days, 8–14 days, 1 month, and 6 months postpartum. Concentrations of total protein and α-lactalbumin were measured in all milk samples, and concentrations of lactoferrin, osteopontin, total casein, β-casein, α_s−1 casein, and κ-casein were measured in milk from 51 individuals using ultra performance liquid chromatography coupled with mass spectrometry. The concentration of measured proteins in the milk decreased during the first six months of postpartum (p-trend < 0.001). Maternal age, mode of delivery, maternal education, and income impacted the longitudinal changes in milk proteins (p-interaction < 0.05). Concentrations of α_s−1 casein in milk were inversely associated with the weight-for-age Z-scores of the infants (1 m: r −0.29, p 0.038; 6 m: r −0.33, p 0.020). In conclusion, the concentration of proteins in milk decreased over the first six months postpartum, potentially influenced by maternal demographic and delivery factors. Milk protein composition may influence infant weights.

Factors influencing milk osteopontin concentration based on measurements from Danish Holstein cows

Our objective was to determine the content of the bioactive protein osteopontin (OPN) in bovine milk and identify factors influencing its concentration. OPN is expressed in many tissues and body fluids, with by far the highest concentrations in milk. OPN plays a role in immunological and developmental processes and it has been associated with several milk production traits and lactation persistency in cows. In the present study, we report the development of an enzyme linked immunosorbent assay (ELISA) for measurement of OPN in bovine milk. The method was used to determine the concentration of OPN in milk from 661 individual Danish Holstein cows. The median OPN level was determined to 21.9 mg/l with a pronounced level of individual variation ranging from 0.4 mg/l to 67.8 mg/l. Breeding for increased OPN in cow's milk is of significant interest, however, the heritability of OPN in milk was found to be relatively low, with an estimated value of 0.19 in the current dataset. The variation explained by the herd was also found to be low suggesting that OPN levels are not affected by farm management or feeding. Interestingly, the concentration of OPN was found to increase with days in milk and to decrease with parity.

Associations of human milk oligosaccharides and bioactive proteins with infant growth and development among Malawian mother-infant dyads

BACKGROUND

Human milk oligosaccharides (HMOs) and bioactive breast milk proteins have many beneficial properties. Information is sparse regarding associations between these milk constituents and infant growth and development in lower-income countries.

OBJECTIVES

We aimed to examine associations of milk content of HMOs and bioactive proteins at 6 mo postpartum with infant growth and motor and cognitive development. These are secondary analyses of a randomized controlled trial in rural Malawi.

METHODS

Breast milk samples were analyzed at 6 mo (n = 659) for general categories of HMOs (total HMOs, fucosylated HMOs, and sialylated HMOs), 51 individual HMOs, and 6 bioactive proteins (lactalbumin, lactoferrin, lysozyme, antitrypsin, IgA, and osteopontin). We examined associations of the relative abundances of HMOs and concentrations of bioactive proteins with infant growth from 6 to 12 mo [change in length-for-age (ΔLAZ), weight-for-age, weight-for-length, and head circumference z-scores] as well as ability to stand or walk alone at 12 mo, and motor and language skills, socioemotional development, executive function, and working memory at 18 mo. Analyses were adjusted for covariates and multiple hypothesis testing.

RESULTS

Among all participants, there were inverse associations of IgA and lactoferrin concentrations with motor skills (P = 0.018 and P = 0.044), and a positive association of lactalbumin concentration with motor skills (P = 0.038). Among secretors only [fucosyltransferase 2 gene (FUT2) positive], there were positive associations of absolute abundance of HMOs with ΔLAZ (P = 0.035), and relative abundance of fucosylated and sialylated HMOs with language at 18 mo (P < 0.001 and P = 0.033, respectively), and inverse associations of osteopontin with standing and walking at 12 mo (P = 0.007 and 0.002, respectively). Relative abundances of several individual HMOs were associated with growth and development, mostly among secretors.

CONCLUSIONS

Certain bioactive breast milk proteins and HMOs are associated with infant growth and motor and cognitive development. Further studies are needed to determine if a causal relation exists.This trial was registered at clinicaltrials.gov as NCT01239693.

Early-Life Supplementation of Bovine Milk Osteopontin Supports Neurodevelopment and Influences Exploratory Behavior

INTRODUCTION

Osteopontin (OPN) is a whey protein found at high concentration in human milk and is involved in processes such as bone cell proliferation and differentiation. Milk OPN has shown to be involved in various aspects of development, including the immune system and gut health. However, the influence of dietary bovine milk OPN inclusion on brain and cognitive development has not been studied extensively until recently. This research examines whether dietary supplementation of bovine milk OPN supports brain and cognitive development in the translational pig model.

METHODS

From postnatal day (PND) 2 to 34, twenty-one intact male pigs were provided ad libitum access to one of two dietary treatments, a standard soy protein isolate-based milk replacer to serve as a control diet (n = 11) and the same base diet supplemented with bovine milk OPN to serve as a test diet (n = 10). In addition to growth and health outcomes, recognition memory was tested using the novel object recognition (NOR) task from PND 28 to 32, and magnetic resonance imaging was conducted at PND 34 to evaluate brain development.

RESULTS

No dietary effects were observed for growth performance or health indices. For the behavioral analysis, pigs that received the test diet exhibited shorter (p < 0.05) latency to the first object visited compared with pigs fed the control diet. Although the control group exhibited novelty preference, there was no difference in recognition index between dietary groups. Neuroimaging outcomes revealed increased (p < 0.05) relative brain volumes of the corpus callosum, lateral ventricle, left and right internal capsule, left and right putamen-globus pallidus, and right hippocampus, and right cortex in the test group. Diffusion tensor imaging revealed higher (p < 0.05) radial diffusivity in the corpus callosum and lower (p < 0.05) fractional anisotropy in pigs provided the test diet.

CONCLUSION

Dietary supplementation of bovine milk OPN increased the relative volume of several brain regions and altered behaviors in the NOR task. Underlying mechanisms of bovine milk OPN influencing the development of brain structures and additional behaviors warrant further investigation.

Evaluation of Bioactivities of Bovine Milk Osteopontin Using a Knockout Mouse Model

OBJECTIVES

Osteopontin (OPN) is a multifunctional protein present abundantly in human milk, but at low levels in bovine milk and infant formula. Bovine milk OPN (bmOPN) is commercially available, and may therefore, be added to formula. OPN exerts its multiple functions by binding to its receptors to activate cell signaling pathways. The OPN receptor (integrin)-binding site is conserved across species; therefore, bmOPN may exert bioactivities in humans and mice. The objective of the present study was to evaluate bioactivities of bmOPN using an established OPN knock-out (KO) mouse model.

METHODS

We evaluated bioactivities of bmOPN, including effects on intestinal growth, immune response, and brain development. In the present study, wild-type (WT) pups were nursed by WT dams, KO dams, or KO dams with bmOPN supplementation from postnatal days 1 to 21 (P1--P21).

RESULTS

Our results show that orally ingested bmOPN is partly resistant to in vivo gastrointestinal digestion, and supplemental bmOPN exhibited similar effects as mouse milk OPN (mmOPN) on promoting growth of the small intestine revealed by histological analysis of duodenum villus height and crypt depth at P10, on modifying TNF-α response against a LPS challenge at P30, as well as promoting brain myelination by increasing expression of myelin-associated glycoprotein (MAG) and myelin basic protein (MBP) and improving cognitive development.

CONCLUSIONS

Our finding that bmOPN with an amino acid sequence different from mmOPN but with a conserved integrin binding site exerts bioactivities similar to mmOPN suggests that bmOPN may provide bioactivities to human infants when added to formula.

Clinical and Immunological Metrics During Pediatric Rhesus Macaque Development

Background: Clinical measurements commonly used to evaluate overall health of laboratory animals including complete blood count, serum chemistry, weight, and immunophenotyping, differ with respect to age, development, and environment. This report provides comprehensive clinical and immunological reference ranges for pediatric rhesus macaques over the first year of life. Methods: We collected and analyzed blood samples from 151 healthy rhesus macaques, aged 0-55 weeks, and compared mother-reared infants to two categories of nursery-reared infants; those on an active research protocol and those under derivation for the expanded specific-pathogen-free breeding colony. Hematology was performed on EDTA-anticoagulated blood using a Sysmex XT2000i, and serum clinical chemistry was performed using the Beckman AU480 chemistry analyzer. Immunophenotyping of whole blood was performed with immunofluorescence staining and subsequent flow cytometric analysis on a BD LSRFortessa. Plasma cytokine analysis was performed using a Millipore multiplex Luminex assay. Results: For hematological and chemistry measurements, pediatric reference ranges deviate largely from adults. Comparison of mother-reared and nursery-reared animals revealed that large differences depend on rearing conditions and diet. Significant differences found between two nursery-reared cohorts (research and colony animals) indicate large influences of experimental factors and anesthetic events on these parameters. Immune cells and cytokine responses presented with distinct patterns for infants depending on age, birth location, and rearing conditions. Conclusions: Our results illustrate how the immune system changed over time and that there was variability among pediatric age groups. Reference ranges of results reported here will support interpretations for how infection and treatment may skew common immune correlates used for assessment of pathology or protection in research studies as well as help veterinarians in the clinical care of infant non-human primates. We highlighted the importance of using age-specific reference comparisons for pediatric studies and reiterated the utility of rhesus macaques as a model for human studies. Given the rapid transformation that occurs in multiple tissue compartments after birth and cumulative exposures to antigens as individuals grow, a better understanding of immunological development and how this relates to timing of infection or vaccination will support optimal experimental designs for developing vaccines and treatment interventions.

Milk osteopontin retains integrin-binding activity after in vitro gastrointestinal transit

Osteopontin (OPN) is a multifunctional protein highly expressed in milk, where it is hypothesized to be involved in immunological signaling via the conserved Arg-Gly-Asp (RGD) integrin-binding sequence. Intervention studies have indicated beneficial effects of orally administered OPN in animal and human infants, but the mechanisms underlying these effects are not well described. To induce physiological effects, OPN must resist gastrointestinal transit in a bioactive form. In this study, we subjected bovine milk OPN to in vitro gastrointestinal transit, and characterized the generated fragments using monoclonal antibody and mass spectrometric analyses. We found that the fragment Trp²⁷-Phe¹⁵¹ containing the integrin-binding RGD sequence resisted in vitro gastric digestion. This resistance was dependent on glycosylation of threonine residues near the integrin-binding sequence in both human and bovine milk OPN. Furthermore, the fragment Trp²⁷-Phe¹⁵¹ retained the ability to interact with integrins in an RGD-dependent process. These results suggest a mechanism for how ingested milk OPN can induce physiological effects via integrin signaling in the intestine.

Advances in Infant Formula Science

Human milk contains a plethora of nutrients and bioactive components to help nourish the developing neonate and is considered the “gold standard” for early life nutrition—as befits the only food “designed” by evolution to feed human infants. Over the past decade, there is considerable evidence that highlights the “intelligence” contained in milk components that contribute to infant health beyond basic nutrition—in areas such as programming the developing microbiome and immune system and protecting against infection. Such discoveries have led to new opportunities for infant milk formula (IMF) manufacturers to refine nutritional content in order to simulate the functionality of breast milk. These include the addition of specialized protein fractions as well as fatty acid and complex carbohydrate components—all of which have mechanistic supporting evidence in terms of improving the health and nutrition of the infant. Moreover, IMF is the single most important dietary intervention whereby the human microbiome can be influenced at a crucial early stage of development. In this respect, it is expected that the complexity of IMF will continue to increase as we get a greater understanding of how it can modulate microbiota development (including the development of probiotics, prebiotics, and synbiotics) and influence long-term health. This review provides a scientific evaluation of key features of importance to infant nutrition, including differences in milk composition and emerging “humanized” ingredients.

Osteopontin in human milk and infant formula affects infant plasma osteopontin concentrations

BACKGROUND

Osteopontin (OPN), a multifunctional protein, is present abundantly in human milk, but not in bovine milk and infant formulas. A recent randomized clinical trial showed that supplementing infant formula with bovine milk OPN (bOPN) resulted in better immune outcomes.

METHODS

Human milk OPN (hOPN) concentrations were analyzed by ELISA. Plasma samples were obtained from infants receiving one of four treatments: breast milk (BF), unsupplemented formula (F0), formula supplemented with 65 mg/L bOPN (F65), or with 130 mg/L bOPN (F130). Plasma samples were analyzed for hOPN and bOPN by ELISA.

RESULTS

The hOPN concentration was high in early lactation (D1 to D8), decreased gradually after D9, and deceased significantly after 1 month. At 4 and 6 months, higher levels of hOPN were found in plasma samples from the BF, F65, and F130 groups than in samples from the F0 group; the plasma bOPN concentration in the F130 group was greater than that in the F65 group.

CONCLUSION

Dynamic changes in the concentration of milk OPN may reflect infant needs for different amounts of milk OPN for various functions at different developmental stages. Supplemental bOPN in infant formula may exert its beneficial effects by increasing endogenous OPN in plasma.

Early life nutrition

Nutritionally, the first 1,000 days of an infant's life - from conception to two years - has been identified as a highly influential period, during which lasting health can be achieved. Significant evidence links patterns of infant feeding to both short and long-term health outcomes, many of which can be prevented through nutritional modifications. Recommended globally, breastfeeding is recognised as the gold standard of infant nutrition; providing key nutrients to achieve optimal health, growth and development, and conferring immunologic protective effects against disease. Nevertheless, infant formulas are often the sole source of nutrition for many infants during the first stage of life. Producers of infant formula strive to supply high quality, healthy, safe alternatives to breast milk with a comparable balance of nutrients to human milk imitating its composition and functional performance measures. The concept of 'nutritional programming', and the theory that exposure to specific conditions, can predispose an individual's health status in later life has become an accepted dictum, and has sparked important nutritional research prospects. This review explores the impact of early life nutrition, specifically, how different feeding methods affect health outcomes.

Milk osteopontin promotes brain development by up-regulating osteopontin in the brain in early life

Osteopontin (OPN) is a pleiotropic protein and is abundantly present in milk. Its functions include immune modulation and cellular proliferation and differentiation. OPN is highly expressed in the brain. We investigated the effects of milk-derived OPN on brain development of mouse pups. Wild-type (WT) dams producing OPN⁺ milk and OPN knockout (KO) dams producing OPN^- milk nursed WT pups (OPN^+/+), yielding 2 pup treatment groups, OPN⁺ OPN^+/+ and OPN^- OPN^+/+, for comparison. Preliminary studies supported use of this model by showing high concentrations of OPN in milk of WT dams and no OPN in milk of OPN KO dams, and production of similar amounts of milk by WT and KO dams. The ability of ingested milk OPN to enter the brain was revealed by appearance of orally gavaged [¹²⁵I]-labeled and antibody-probed milk OPN in brains of pups. Brain OPN mRNA levels were similar in both nursed groups, but the brain OPN protein level was significantly lower in the OPN^- OPN^+/+ group at postnatal days 6 and 8. Behavior tests showed impaired memory and learning ability in OPN^- OPN^+/+ pups. In addition, our study revealed increased expression of myelination-related proteins and elevated proliferation and differentiation of NG-2 glia into oligodendrocytes in the brain of OPN⁺ OPN^+/+ pups, accompanied by increased activation of ERK-1/2 and PI3K/Akt signaling. We concluded that milk OPN can play an important role in brain development and behavior in infancy by promoting myelination.-Jiang, R., Prell, C., Lönnerdal, B. Milk osteopontin promotes brain development by up-regulating osteopontin in the brain in early life.

Osteopontin Levels in Human Milk Vary Across Countries and Within Lactation Period: Data From a Multicenter Study

OBJECTIVES

Osteopontin (OPN) is a multifunctional protein expressed in many cell types, tissues and body fluids with the highest concentrations found in milk; significantly higher in human than in bovine milk. Intervention studies have indicated beneficial effects of supplementing infant formula with bovine OPN. In this multicenter study, we determined the OPN content in human milk samples from 629 Chinese, Danish, Japanese and Korean mothers.

METHODS

At each study site, milk samples were collected and analyzed for OPN and protein concentration using ELISA and infrared spectroscopy, respectively.

RESULTS

A total of 829 milk samples from 629 women were included. When delivering the first sample, mean maternal age was 31.4 years (SD 4.0), and median infant age was 13.4 weeks (interquartile range 4.6-17.9). The median OPN concentration varied across sites; from 99.7 mg/L in Danish, 185.0 mg/L in Japanese, 216.2 mg/L in Korean to 266.2 mg/L in Chinese mothers (P < 0.001), corresponding to 1.3%, 2.4%, 1.8% and 2.7% of the total protein content (OPN/protein%) (P < 0.05), respectively. Based on 75 Chinese and 33 Japanese mothers delivering more than 1 sample, multilevel (mixed model) linear regression analysis showed a decrease in OPN concentration with infant age (β = (-11.3), 95% confidence interval (CI) = (-13.9) to (-8.8) and β = (-2.1), 95% CI = (-3.2) to (-0.9), respectively).

CONCLUSIONS

In this large multicenter study, we observed statistically significant differences in the OPN concentration and the OPN/protein% in human milk samples between countries. Based on mothers delivering more than 1 sample, a significant decrease within the lactation period was observed.

Osteopontin adsorption to Gram-positive cells reduces adhesion forces and attachment to surfaces under flow

The bovine milk protein osteopontin (OPN) may be an efficient means to prevent bacterial adhesion to dental tissues and control biofilm formation. This study sought to determine to what extent OPN impacts adhesion forces and surface attachment of different bacterial strains involved in dental caries or medical device–related infections. It further investigated if OPN’s effect on adhesion is caused by blocking the accessibility of glycoconjugates on bacterial surfaces. Bacterial adhesion was determined in a shear-controlled flow cell system in the presence of different concentrations of OPN, and interaction forces of single bacteria were quantified using single-cell force spectroscopy before and after OPN exposure. Moreover, the study investigated OPN’s effect on the accessibility of cell surface glycoconjugates through fluorescence lectin-binding analysis. OPN strongly affected bacterial adhesion in a dose-dependent manner for all investigated species (Actinomyces naeslundii, Actinomyces viscosus, Lactobacillus paracasei subsp. paracasei, Staphylococcus epidermidis, Streptococcus mitis, and Streptococcus oralis). Likewise, adhesion forces decreased after OPN treatment. No effect of OPN on the lectin-accessibility to glycoconjugates was found. OPN reduces the adhesion and adhesion force/energy of a variety of bacteria and has a potential therapeutic use for biofilm control. OPN acts upon bacterial adhesion without blocking cell surface glycoconjugates.

Lipid-Based Nutrient Supplements During Pregnancy and Lactation Did Not Affect Human Milk Oligosaccharides and Bioactive Proteins in a Randomized Trial

BACKGROUND

Human milk oligosaccharides (HMOs) and bioactive proteins are beneficial to infant health. Recent evidence suggests that maternal nutrition may affect the amount of HMOs and proteins in breast milk; however, the effect of nutrient supplementation on HMOs and bioactive proteins has not yet been well studied.

OBJECTIVE

We aimed to determine whether lipid-based nutrient supplements (LNSs) affect milk bioactive protein and HMO concentrations at 6 mo postpartum in women in rural Malawi. These are secondary outcomes of a previously published randomized controlled trial.

METHODS

Women were randomly assigned to consume either an iron and folic acid capsule (IFA) daily from ≤20 wk gestation until delivery, followed by placebo daily from delivery to 6 mo postpartum, or a multiple micronutrient (MMN) capsule or LNS daily from ≤20 wk gestation to 6 mo postpartum. Breast milk concentrations of total HMOs, sialylated HMOs, fucosylated HMOs, lactoferrin, lactalbumin, lysozymes, antitrypsin, immunoglobulin A, and osteopontin were analyzed at 6 mo postpartum (n = 647). Between-group differences in concentrations and in proportions of women classified as having low concentrations were tested.

RESULTS

HMO and bioactive protein concentrations did not differ between groups (P > 0.10 for all comparisons). At 6 mo postpartum, the proportions of women with low HMOs or bioactive proteins were not different between groups except for osteopontin. A lower proportion of women in the IFA group had low osteopontin compared with the LNS group after adjusting for covariates (OR: 0.5; 95% CI: 0.3, 0.9; P = 0.016).

CONCLUSION

The study findings do not support the hypothesis that supplementation with an LNS or MMN capsule during pregnancy and postpartum would increase HMO or bioactive milk proteins at 6 mo postpartum among Malawian women. This trial was registered at clinicaltrials.gov as NCT01239693.

Benefits of Lactoferrin, Osteopontin and Milk Fat Globule Membranes for Infants

The provision of essential and non-essential amino acids for breast-fed infants is the major function of milk proteins. In addition, breast-fed infants might benefit from bioactivities of milk proteins, which are exhibited in the intestine during the digestive phase and by absorption of intact proteins or derived peptides. For lactoferrin, osteopontin and milk fat globule membrane proteins/lipids, which have not until recently been included in substantial amounts in infant formulas, in vitro experiments and animal models provide a convincing base of evidence for bioactivities, which contribute to the protection of the infant from pathogens, improve nutrient absorption, support the development of the immune system and provide components for optimal neurodevelopment. Technologies have become available to obtain these compounds from cow´s milk and the bovine compounds also exhibit bioactivities in humans. Randomized clinical trials with experimental infant formulas incorporating lactoferrin, osteopontin, or milk fat globule membranes have already provided some evidence for clinical benefits. This review aims to compare findings from laboratory and animal experiments with outcomes of clinical studies. There is good justification from basic science and there are promising results from clinical studies for beneficial effects of lactoferrin, osteopontin and the milk fat globule membrane complex of proteins and lipids. Further studies should ideally be adequately powered to investigate effects on clinically relevant endpoints in healthy term infants.

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.

The Role of Lactoferrin in Gastrointestinal and Immune Development and Function: A Preclinical Perspective

The early postnatal period is a critical time for gastrointestinal (GI) and immune development. Neonates fed mother's milk have more rapid GI and immune development than fed-formula infants. In addition, clinical and epidemiologic data provide strong evidence that breastfeeding reduces the incidence and/or severity of infectious diseases. Lactoferrin is a 77 kDa, iron-binding glycoprotein that is present at high concentration in human milk compared with bovine milk and infant formula. It is a multifunctional protein that mediates many of the physiological processes in which breastfed infants have advantages over their formula-fed peers, including promoting GI and immune development, protection from infections, and improved cognitive development. Feeding bovine lactoferrin or recombinant human lactoferrin was well tolerated and stimulated intestinal cell proliferation and increased villus length and crypt depth in piglets. Lactoferrin also influenced both systemic and GI immune development by stimulating a balanced T-helper-1/T-helper-2 cytokine immune response. Further, there was a tendency for immune cells to secrete more anti-inflammatory cytokines in an unstimulated state, while being primed for a robust pro-inflammatory response when presented with a bacterial trigger in piglets fed lactoferrin. These findings support clinical studies demonstrating benefits of dietary lactoferrin in the prevention of infections, late onset sepsis, and necrotizing enterocolitis.

An Opinion on "Staging" of Infant Formula: A Developmental Perspective on Infant Feeding

Breast milk is a dynamic fluid with compositional changes occurring throughout the period of lactation. Some of these changes in nutrient concentrations reflect the successively slowing growth rate and developmental changes in metabolic requirements that infants undergo during the first year of life. Infant formula, in contrast, has a static composition, intended to meet the nutritional requirements of infants from birth to 6 or 12 months of age. To better fit the metabolic needs of infants and to avoid nutrient limitations or excesses, we suggest that infant formulas should change in composition with the age of the infant, that is, different formulas are created/used for different ages during the first year of life. We propose that specific formulas for 0 to 3 months (stage 1), 3 to 6 months (stage 2), and 6 to 12 months (stage 3) of age may be nutritionally and physiologically advantageous to infants. Although this initially may impose some difficult practical/conceptual issues, we believe that this staging concept would improve nutrition of formula-fed infants and, ultimately, improve outcomes and make their performance more similar to that of breast-fed infants.