Iron-binding proteins in milk and resistance to Escherichia coli infection in infants

The impact of heating-induced lactosylation on the digestibility of lactotransferrin

Lactosylation of lysines occurs during the heating of dairy products, yet how lactosylation impact the lysine release during digestion remains largely unknown. This study examines the effect of lactosylation on the digestibility of lactotransferrin using chemical analysis, proteomics, and peptidomics. Under the applied heating conditions, lactotransferrin primarily undergoes early-stage Maillard reactions, producing lactulose-lysine. Furosine content increases with heating time and temperature, with time being more influential. And 23 out of 54 lysines in lactotransferrin were lactosylated. Following in-vitro infant digestion, free lysine levels in samples heated at 130 °C for 30s decreased by 25 % compared to unheated ones, likely due to lactosylation hindering protease cleavage. Intriguingly, lactosylated lysine was absent in peptides ranging from 5 to 17 amino acids but remained in larger peptides. The formation of large lactosylated peptides from heating impeded free lysine release. Further investigation is needed to determine if the human body can utilize these lactosylated peptides.

The Iron Binding Ability Maps the Fate of Food-Derived Transferrins: A Review

As the demand for lactoferrin increases, the search for cost-effective alternative proteins becomes increasingly important. Attention naturally turns to other members of the transferrin family such as ovotransferrin. The iron-binding abilities of these proteins influence their characteristics, although the underlying mechanisms remain unclear. This overview systematically summarizes the effects of the iron-binding ability on the fate of food-derived transferrins (lactoferrin and ovotransferrin) and their potential applications. The findings indicate that iron-binding ability significantly influences the structure of food-derived transferrins, particularly their tertiary structure. Changes in structure influence their physicochemical properties, which, in turn, lead to different behaviors in response to environmental variations. Thus, these proteins exhibit distinct digestive characteristics by the time they reach the small intestine, ultimately performing varied physiological functions in vivo. Consequently, food-derived transferrins with different iron-binding states may find diverse applications. Understanding this capability is essential for developing food-derived transferrins and driving innovation in lactoferrin-related industries.

Antimicrobial Peptides (AMPs) and the Microbiome in Preterm Infants: Consequences and Opportunities for Future Therapeutics

Antimicrobial peptides (AMPs) are crucial components of the innate immune system in various organisms, including humans. Beyond their direct antimicrobial effects, AMPs play essential roles in various physiological processes. They induce angiogenesis, promote wound healing, modulate immune responses, and serve as chemoattractants for immune cells. AMPs regulate the microbiome and combat microbial infections on the skin, lungs, and gastrointestinal tract. Produced in response to microbial signals, AMPs help maintain a balanced microbial community and provide a first line of defense against infection. In preterm infants, alterations in microbiome composition have been linked to various health outcomes, including sepsis, necrotizing enterocolitis, atopic dermatitis, and respiratory infections. Dysbiosis, or an imbalance in the microbiome, can alter AMP profiles and potentially lead to inflammation-mediated diseases such as chronic lung disease and obesity. In the following review, we summarize what is known about the vital role of AMPs as multifunctional peptides in protecting newborn infants against infections and modulating the microbiome and immune response. Understanding their roles in preterm infants and high-risk populations offers the potential for innovative approaches to disease prevention and treatment.

To Boost or to Reset: The Role of Lactoferrin in Energy Metabolism

Many pathological conditions, including obesity, diabetes, hypertension, heart disease, and cancer, are associated with abnormal metabolic states. The progressive loss of metabolic control is commonly characterized by insulin resistance, atherogenic dyslipidemia, inflammation, central obesity, and hypertension, a cluster of metabolic dysregulations usually referred to as the "metabolic syndrome". Recently, nutraceuticals have gained attention for the generalized perception that natural substances may be synonymous with health and balance, thus becoming favorable candidates for the adjuvant treatment of metabolic dysregulations. Among nutraceutical proteins, lactoferrin (Lf), an iron-binding glycoprotein of the innate immune system, has been widely recognized for its multifaceted activities and high tolerance. As this review shows, Lf can exert a dual role in human metabolism, either boosting or resetting it under physiological and pathological conditions, respectively. Lf consumption is safe and is associated with several benefits for human health, including the promotion of oral and gastrointestinal homeostasis, control of glucose and lipid metabolism, reduction of systemic inflammation, and regulation of iron absorption and balance. Overall, Lf can be recommended as a promising natural, completely non-toxic adjuvant for application as a long-term prophylaxis in the therapy for metabolic disorders, such as insulin resistance/type II diabetes and the metabolic syndrome.

The Effect of Holder Pasteurization and Different Variants on Breast Milk Antioxidants

BACKGROUND

After birth, breast milk (BM) is a known essential source of antioxidants for infants. We analyzed the non-enzymatic total antioxidant capacity (TAC), oxygen radical absorbance capacity (ORAC), and glutathione, calcium, transferrin, and total protein levels of human breast milk before and after Holder pasteurization (HoP).

METHODS

The collected donor BM samples were pasteurized with HoP.

RESULTS

HoP decreased TAC (-12.6%), ORAC (-12.1%), transferrin (-98.3%), and total protein (-21.4%) levels; HoP did not influence the glutathione concentration, and it increased the total calcium (+25.5%) concentration. Mothers who gave birth via Cesarean section had significantly lower TAC in their BM. TAC and glutathione levels were elevated in the BM of mothers over the age of 30. BM produced in the summer had higher glutathione and calcium levels compared to BM produced in the winter. The glutathione concentration in term milk samples was significantly higher in the first two months of lactation compared to the period between the third and sixth months. The transferrin level of BM for female infants was significantly higher than the BM for boys, and mothers with a BMI above 30 had increased transferrin in their samples.

CONCLUSIONS

Antioxidant levels in human milk are influenced by numerous factors. Environmental and maternal factors, the postpartum age at breast milk collection, and Holder pasteurization of the milk influence the antioxidant intake of the infant.

High-Pressure Processing of Human Milk: A Balance between Microbial Inactivation and Bioactive Protein Preservation

BACKGROUND

Donor human milk banks use Holder pasteurization (HoP; 62.5°C, 30 min) to reduce pathogens in donor human milk, but this process damages some bioactive milk proteins.

OBJECTIVES

We aimed to determine minimal parameters for high-pressure processing (HPP) to achieve >5-log reductions of relevant bacteria in human milk and how these parameters affect an array of bioactive proteins.

METHODS

Pooled raw human milk inoculated with relevant pathogens (Enterococcus faecium, Staphylococcus aureus, Listeria monocytogenes, Cronobacter sakazakii) or microbial quality indicators (Bacillus subtilis and Paenibacillus spp. spores) at 7 log CFU/mL was processed at 300-500 MPa at 16-19°C (due to adiabatic heating) for 1-9 min. Surviving microbes were enumerated using standard plate counting methods. For raw milk, and HPP-treated and HoP-treated milk, the immunoreactivity of an array of bioactive proteins was assessed via ELISA and the activity of bile salt-stimulated lipase (BSSL) was determined via a colorimetric substrate assay.

RESULTS

Treatment at 500 MPa for 9 min resulted in >5-log reductions of all vegetative bacteria, but <1-log reduction in B. subtilis and Paenibacillus spores. HoP decreased immunoglobulin A (IgA), immunoglobulin M (IgM), immunoglobulin G, lactoferrin, elastase and polymeric immunoglobulin receptor (PIGR) concentrations, and BSSL activity. The treatment at 500 MPa for 9 min preserved more IgA, IgM, elastase, lactoferrin, PIGR, and BSSL than HoP. HoP and HPP treatments up to 500 MPa for 9 min caused no losses in osteopontin, lysozyme, α-lactalbumin and vascular endothelial growth factor.

CONCLUSION

Compared with HoP, HPP at 500 MPa for 9 min provides >5-log reduction of tested vegetative neonatal pathogens with improved retention of IgA, IgM, lactoferrin, elastase, PIGR, and BSSL in human milk.

Featured Prebiotic Agent: The Roles and Mechanisms of Direct and Indirect Prebiotic Activities of Lactoferrin and Its Application in Disease Control

Lactoferrin (LF) is a glycoprotein found in mammalian milk, and lactoferricin is a peptide derived from LF hydrolysate. Both LF and lactoferricin (LFcin) have diverse functions that could benefit mammals. Bovine LF (BLF) and BLFcin exhibit a wide range of antimicrobial activities, but most probiotic strains are relatively resistant to their antibacterial effects. BLF and BLF hydrolysate can promote the growth of specific probiotics depending on the culture conditions, the dose of BLF or BLF-related peptides, and the probiotic strains used. BLF supplementation has been shown to modulate several central molecular pathways or genes in Lacticaseibacillus rhamnosus GG under cold conditions, which may explain the prebiotic roles of BLF. LF alone or in combination with selected probiotics can help control bacterial infections or metabolic disorders, both in animal studies and in human clinical trials. Various LF-expressing probiotics, including those expressing BLF, human LF, or porcine LF, have been developed to facilitate the combination of LFs with specific probiotics. Supplementation with LF-expressing probiotics has positive effects in animal studies. Interestingly, inactivated LF-expressing probiotics significantly improved diet-induced nonalcoholic fatty liver disease (NAFLD) in a mouse model. This review highlights the accumulated evidence supporting the use of LF in combination with selected LF-resistant probiotics or LF-expressing probiotics in the field.

Lactoferrin: A glycoprotein that plays an active role in human health

Lactoferrin (Lf), existing widely in human and mammalian milk, is a multifunctional glycoprotein with many functions, such as immune regulation, anti-inflammation, antibacterial, antiviral, and antioxidant. These extensive functions largely attribute to its ability to chelate iron and interfere with the cellular receptors of pathogenic microorganisms and their hosts. Moreover, it is non-toxic and has good compatibility with other supplements. Thus, Lf has been widely used in food nutrition, drug carriers, biotechnology, and feed development. Although Lf has been continuously explored and studied, a more comprehensive and systematic compendium is still required. This review presents the recent advances in the structure and physicochemical properties of Lf as well as clinical studies on human diseases, with the aim of providing a reference for further research of Lf and the development of its related functional products.

H-ferritin in sows' colostrum- and milk-derived extracellular vesicles: a novel iron delivery concept

Iron deficiency anemia is a significant problem in piglets, as they are born with insufficient iron stores for supporting their rapid body growth. Further, sows' milk contains inadequate iron levels for meeting the demands of piglet rapid growth in the pre-wean stage. The forms of iron present in the milk are essential to understanding bioavailability and potential routes for supplementing iron to mitigate iron deficiency anemia in piglets. Recently, our studies showed that H-ferritin (FTH1) is involved in iron transport to different tissues and can be used as an oral iron supplement to correct iron deficiency in rats and monkeys. In this study, we investigate the FTH1 levels in colostrum and milk in Yorkshires-crossbred sows (n = 27) and collected samples at the 1st, 15th, and 28th days of lactation to measure FTH1. Colostrum and milk were found to have FTH1, but there is no significant difference between the different days of lactation. FTH1 has been observed to be enriched in extracellular vesicles (EVs) of other species, and therefore examined the EVs in the samples. Colostrum-derived EVs were enriched with L-ferritin compared to FTH1, while in milk-derived EVs, only FTH1 was detected (P = 0.04). In milk-derived EVs, FTH1 was significantly higher (P = 0.021; P = 006) than FTH1 in colostrum-derived EVs. Furthermore, FTH1 levels of milk-derived EVs were significantly higher (P = 0.0002; P = 0004) than whole milk and colostrum FTH1. These results indicate that FTH1 is enriched in the milk-derived EVs and suggest that EVs play a predominant role in the FTH1 delivery mechanism for the piglet. The extent to which FTH1 in EVs accounts for the overall iron delivery mechanism in piglets is yet to be determined.

Lactoferrin: An Effective Weapon in the Battle Against Bacterial Infections

The emergence of multidrug-resistant bacterial strains with respect to commercially available antimicrobial drugs has marked a watershed in treatment therapies to fight pathogens and has stimulated research on alternative remedies. Proteins of the innate immune system of mammals have been highlighted as potentially yielding possible treatment options for infections. Lactoferrin (Lf) is one of these proteins; interestingly, no resistance to it has been found. Lf is a conserved cationic nonheme glycoprotein that is abundant in milk and is also present in low quantities in mucosal secretions. Moreover, Lf is produced and secreted by the secondary granules of neutrophils at infection sites. Lf is a molecule of approximately 80 kDa that displays multiple functions, such as antimicrobial, anti-viral, anti-inflammatory, and anticancer actions. Lf can synergize with antibiotics, increasing its potency against bacteria. Lactoferricins (Lfcins) are peptides resulting from the N-terminal end of Lf by proteolytic cleavage with pepsin. They exhibit several anti-bacterial effects similar to those of the parental glycoprotein. Synthetic analog peptides exhibiting potent antimicrobial properties have been designed. The aim of this review is to update understanding of the structure and effects of Lf and Lfcins as anti-bacterial compounds, focusing on the mechanisms of action in bacteria and the use of Lf in treatment of infections in patients, including those studies where no significant differences were found. Lf could be an excellent option for prevention and treatment of bacterial diseases, mainly in combined therapies with antibiotics or other antimicrobials.

Full breastfeeding protection against common enteric bacteria and viruses: results from the MAL-ED cohort study

BACKGROUND

Breastfeeding is known to reduce the risk of enteropathogen infections, but protection from specific enteropathogens is not well characterized.

OBJECTIVE

The aim was to estimate the association between full breastfeeding (days fed breast milk exclusively or with nonnutritive liquids) and enteropathogen detection.

METHODS

A total of 2145 newborns were enrolled at 8 sites, of whom 1712 had breastfeeding and key enteropathogen data through 6 mo. We focused on 11 enteropathogens: adenovirus 40/41, norovirus, sapovirus, astrovirus, and rotavirus, enterotoxigenic Escherichia coli (ETEC), Campylobacter spp., and typical enteropathogenic E. coli as well as entero-aggregative E. coli, Shigella and Cryptosporidium. Logistic regression was used to estimate the risk of enteropathogen detection in stools and survival analysis was used to estimate the timing of first detection of an enteropathogen.

RESULTS

Infants with 10% more days of full breastfeeding within the preceding 30 d of a stool sample were less likely to have the 3 E. coli and Campylobacter spp. detected in their stool (mean odds: 0.92-0.99) but equally likely (0.99-1.02) to have the viral pathogens detected in their stool. A 10% longer period of full breastfeeding from birth was associated with later first detection of the 3 E. coli, Campylobacter, adenovirus, astrovirus, and rotavirus (mean HRs of 0.52-0.75). The hazards declined and point estimates were not statistically significant at 3 mo.

CONCLUSIONS

In this large multicenter cohort study, full breastfeeding was associated with lower likelihood of detecting 4 important enteric pathogens in the first 6 mo of life. These results also show that full breastfeeding is related to delays in the first detection of some bacterial and viral pathogens in the stool. As several of these pathogens are risk factors for poor growth during childhood, this work underscores the importance of exclusive or full breastfeeding during the first 6 mo of life to optimize early health.

Human milk microbes: Strategies to improve delivery to the infant

Mother's own milk provides personalized nutrition and immune protection to the developing infant. The presence of healthy microbes plays an important role in the infant's gut by programming the microbiota and excluding potential pathogens. This review describes the important components in mother's own milk that contribute to its superiority for infant nutrition and suggest potential strategies to replicate these factors in alternative feedings when sufficient milk is unavailable. Current strategies to supplement, substitute and replicate mother's own milk including microbial restoration, use of unpasteurized donor human milk, probiotics and fortification are discussed. Critical work remains to be done in understanding the human milk microbiome and metabolome and in improving lactation support for mothers of preterm infants. Increasing delivery of mother's own milk and milk components to infants would likely positively impact infant mortality and health worldwide.

The Immune System in Human Milk: A Historic Perspective

BACKGROUND

Human milk contains a remarkable array of immunological agents that evolved over millions of years to protect the recipient human infant. Furthermore, much of the protection persists long after weaning. However, the scientists who first discovered some components of this immune system have rarely been acknowledged.

SUMMARY

The scientists who made many fundamental immunological discoveries concerning the immune system in human milk include Alfred François Donné, Paul Ehrlich, Lars Å. Hanson, and Jules Bordet. Based upon their discoveries, a wealth of antimicrobial, anti-inflammatory, and immunomodulating agents, and living, activated leukocytes in human milk were later revealed during the last half of the 20th and the first part of the 21st century. Moreover, it was found that human milk enhances the colonization of commensal bacteria that aid to protect the human infant. Key Message: Their discoveries helped to revitalize breastfeeding in industrialized countries during the past several decades.

Variation in milk fat globule size and composition: A source of bioactives for human health

Milk fat globules (MFGs) are secreted from the mammalian gland and are composed of a triacylglycerol core surrounded by a triple membrane structure, the milk fat globule membrane (MFGM). The MFGM contains complex lipids and proteins reported to have nutritional, immunological, neurological and digestive functions. Human and ruminant milk are shown to share a similar MFG structure but with different size, profile and abundance of protein and polar lipids. This review summarizes the reported data on human, bovine, caprine and ovine MFG composition and concentration of bioactive components in different MFG-size fractions. A comprehensive understanding of compositional variations between milk from different species and MFG size fractions may help promote various milk sources as targeted supplements to improve human development and health. MFG size and MFGM composition are species-specific and affected by lactation, diet and breed (or maternal origin). Purification and enrichment methods for some bioactive proteins and lipids present in the MFGM have yet to be established or are not scaled sufficiently to be used to supplement human diets. To overcome this problem, MFG size selection through fractionation or herd selection may provide a convenient way to pre-enrich the MFG fraction with specific protein and lipid components to fulfill human dietary and health requirements.

Bovine Lactoferrin Protects Dextran Sulfate Sodium Salt Mice Against Inflammation and Impairment of Colonic Epithelial Barrier by Regulating Gut Microbial Structure and Metabolites

Background: Ulcerative colitis is characterized by relapsing and remitting mucosal inflammation. Bovine lactoferrin (BL) is a multifunctional protein that could regulate the intestinal flora and has anti-inflammatory effects. The aim of this study was to investigate the therapeutic effect of BL on colitis.

Methods: Dextran sulfate sodium salt (DSS) was utilized to establish a mouse model of colitis. BL was administered to treat DSS mice. The weight, the activity, and fecal status of the mice were recorded every day. Disease activity index was calculated. After the mice were euthanized, the colon length was measured. Hematoxylin and eosin staining was used to observe the pathological changes of the colon, and histological activity index was calculated. The myeloperoxidase (MPO) activity of colon tissue was measured. Western blot and immunohistochemistry were used to detect the expressions of Claudin-1, Occludin, and ZO-1. The expressions of IL-1β, IL-6, IL-10, TNF-α, and TGF-β in colon tissue were detected by ELISA. The protein expressions of MUC2, Reg3γ, β-defensin (HBD-2), and cAMP were detected by immunofluorescence (IF). 16S rDNA sequencing determined the type and structure of intestinal flora. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) measured the metabolites of the intestinal flora.

Results: Compared with the DSS group, the mice's weight in the BL group was higher and the length of the colon was longer. At the 14th day, MPO activity was higher in the BL group. The expressions of Claudin-1, Occludin, and ZO-1 in the colon were up-regulated in the BL group compared with the DSS group. The expressions of IL-1β, IL-6, and TNF-α were lower. The expressions of IL-10 and TGF-β were higher. IF showed that the expressions of MUC2 and β-defensin (HBD-2) were down-regulated, and the expressions of Reg3γ and cAMP were up-regulated. The 16S rDNA sequencing results showed that the alpha diversity and beta diversity were notably changed in the DSS mice treated with BL. Metabolomics results showed that BL changed purine metabolism in the DSS mice.

Conclusion: BL alleviated colitis in mice by improving the inflammatory response and the structure of the colon barrier in the colon. BL changed the composition and metabolites of the intestinal flora. Thus, BL might be an effective nutritional supplement for colitis treatment.

Estimation of numbers of mature and immature neutrophils in blood by a novel, rapid and simple technology

Counting numbers of blood neutrophils is one of the most common laboratory tests in modern clinical medicine. In this report, we have tested the idea that immunoassay of major constituents of mature neutrophils might serve as proxy of cell counting and allow the development of rapid and simple point-of-care tests. The procedure may also allow for the estimate of the state of maturity of the circulating blood cells. Immunoassays for myeloperoxidase (MPO) and lactoferrin (LF) were used to measure the respective protein in whole blood extracts of 275 unselected hospitalized patient and in 51 healthy controls and leukemia patients of which eight were followed before, during and after remission treatment. MPO was correlated to neutrophil counts in the unselected hospitalized population (r = 0.95, p <.0001). Huge variations were seen in whole blood extracts of patients with AML with very high MPO/LF ratios in half of the AML patients and in all three patients with APL. In extracts from patients with ALL no difference was found in the ratio as compared to healthy persons. The monitoring of AML patients during remission treatment showed intriguing patterns one of which suggested the possibility to monitor the myelopoietic activity in the bone marrow during the recovery phase. We show a novel and easy technology to count mature neutrophils in blood and also to monitor myeloid cell maturity in the blood as well as myelopoietic activity in the bone marrow. The technology lends itself to the development of a rapid and simple point-of-care test.

Can breastfeeding protect against antimicrobial resistance?

BACKGROUND

The proportion of infections among young children that are antimicrobial-resistant is increasing across the globe. Newborns may be colonized with enteric antimicrobial-resistant pathogens early in life, which is a risk factor for infection-related morbidity and mortality. Breastfeeding is actively promoted worldwide for its beneficial impacts on newborn health and gut health. However, the role of breastfeeding and human milk components in mitigating young children's carriage of antimicrobial-resistant pathogens and antibiotic resistance genes has not been comprehensively explored.

MAIN BODY

Here, we review how the act of breastfeeding, early breastfeeding, and/or human milk components, such as the milk microbiota, secretory IgA, human milk oligosaccharides, antimicrobial peptides, and microRNA -bearing extracellular vesicles, could play a role in preventing the establishment of antimicrobial-resistant pathogens in young children's developing gut microbiomes. We describe findings from recent human studies that support this concept.

CONCLUSION

Given the projected rise in global morbidity and mortality that will stem from antimicrobial-resistant infections, identifying behavioral or nutritional interventions that could decrease children's susceptibility to colonization with antimicrobial-resistant pathogens may be one strategy for protecting their health. We suggest that breastfeeding and human milk supplements deserve greater attention as potential preventive measures in the global effort to combat antimicrobial resistance, particularly in low- and middle-income settings.

Metabolomic Profile of Personalized Donor Human Milk

Human milk could be considered an active and complex mixture of beneficial bacteria and bioactive compounds. Since pasteurization drastically reduces the microbial content, we recently demonstrated that pasteurized donor human milk (DHM) could be inoculated with different percentages (10% and 30%) of mother's own milk (MOM) to restore the unique live microbiota, resulting in personalized milk (RM10 and RM30, respectively). Pasteurization affects not only the survival of the microbiota but also the concentration of proteins and metabolites, in this study, we performed a comparative metabolomic analysis of the RM10, RM30, MOM and DHM samples to evaluate the impact of microbial restoration on metabolite profiles, where metabolite profiles clustered into four well-defined groups. Comparative analyses of DHM and MOM metabolomes determined that over one thousand features were significantly different. In addition, significant changes in the metabolite concentrations were observed in MOM and RM30 samples after four hours of incubation, while the concentration of metabolites in DHM remained constant, indicating that these changes are related to the microbial expansion. In summary, our analyses indicate that the metabolite profiles of DHM are significantly different from that of MOM, and the profile of MOM may be partially restored in DHM through microbial expansion.

Microbial Safety of Milk Production and Fermented Dairy Products in Africa

In Africa, milk production, processing and consumption are integral part of traditional food supply, with dairy products being a staple component of recommended healthy diets. This review provides an overview of the microbial safety characteristics of milk production and fermented dairy products in Africa. The object is to highlight the main microbial food safety hazards in the dairy chain and to propose appropriate preventive and control measures. Pathogens of public health concern including Mycobacterium bovis, Brucella abortus and Coxiella burnettii, which have largely been eradicated in many developed nations, still persist in the dairy chain in Africa. Factors such as the natural antimicrobial systems in milk and traditional processing technologies, including fermentation, heating and use of antimicrobial additives, that can potentially contribute to microbial safety of milk and dairy products in Africa will be discussed. Practical approaches to controlling safety hazards in the dairy chain in Africa have been proposed. Governmental regulatory bodies need to set the necessary national and regional safety standards, perform inspections and put measures in place to ensure that the standards are met, including strong enforcement programs within smallholder dairy chains. Dairy chain actors would require upgraded knowledge and training in preventive approaches such as good agricultural practices (GAP), hazard analysis and critical control points (HACCP) design and implementation and good hygienic practices (GHPs). Food safety education programs should be incorporated into school curricula, beginning at the basic school levels, to improve food safety cognition among students and promote life-long safe food handling behaviour.

Understanding the Elements of Maternal Protection from Systemic Bacterial Infections during Early Life

Late-onset sepsis (LOS) and other systemic bloodstream infections are notable causes of neonatal mortality, particularly in prematurely born very low birth weight infants. Breastfeeding in early life has numerous health benefits, impacting the health of the newborn in both the short-term and in the long-term. Though the known benefits of an exclusive mother's own milk diet in early life have been well recognized and described, it is less understood how breastfed infants enjoy a potential reduction in risk of LOS and other systemic infections. Here we review how gut residing pathogens within the intestinal microbiota of infants can cause a subset of sepsis cases and the components of breastmilk that may prevent the dissemination of pathogens from the intestine.

Association between bovine leukemia virus proviral load and severity of clinical mastitis

The purpose of this study was to clarify the effect of Bovine leukemia virus (BLV) infection on natural immunity in the bovine mammary gland and on the severity of clinical mastitis. We classified milk samples from clinical mastitic cows into BLV-positive (n=76) and BLV-negative (n=12). BLV-positive cows were further divided into cows with High BLV proviral load (H-PVL) (n=23) and Low BLV proviral load (L-PVL) (n=53). Severity of clinical mastitis was classified as MILD, MODERATE, or SEVERE. Multiple logistic regression analysis was performed on the host factors and environmental factors with severity of clinical mastitis as the objective variable. BLV proviral load (PVL) and season at onset of mastitis showed significant correlation with the severity of clinical mastitis. Binary logistic regression analysis was performed on natural immunity factors lactoferrin and lingual antimicrobial peptide (LAP) concentration in milk, with PVL as the objective variable. Of these natural immunity factors, LAP concentration in milk showed significant correlation with PVL. The results of the present study suggested that PVL and season are associated with severity of clinical mastitis, and that the immune function in the mammary gland is decreased in cows with H-PVL compared to that in cows with L-PVL.

Investigation and comparison of the anti-tumor activities of lactoferrin, α-lactalbumin, and β-lactoglobulin in A549, HT29, HepG2, and MDA231-LM2 tumor models

To investigate the anti-tumor activities of lactoferrin, α-lactalbumin, and β-lactoglobulin, 4 types of human tumor cells (lung tumor cell A549, intestinal epithelial tumor cell HT29, hepatocellular cell HepG2, and breast cancer cell MDA231-LM2) were exposed to 3 proteins, respectively. The effects on cell proliferation, migration, and apoptosis were detected in vitro, and nude mice bearing tumors were administered the 3 proteins in vivo. Results showed that the 3 proteins (20 g/L) inhibited viability and migration, as well as induced apoptosis, in 4 tumor cells to different degrees (compared with the control). In vivo, tumor weights in the HT29 group (0.84 ± 0.22 g vs. control 2.05 ± 0.49 g) and MDA231-LM2 group (1.11 ± 0.25 g vs. control 2.49 ± 0.57 g) were significantly reduced by lactoferrin; tumor weights in the A549 group (1.07 ± 0.19 g vs. control 3.11 ± 0.73 g) and HepG2 group (2.32 ± 0.46 g vs. control 3.50 ± 0.74 g) were significantly reduced by α-lactalbumin. Moreover, the roles of lactoferrin, α-lactalbumin, and β-lactoglobulin in regulating apoptotic proteins were validated. In summary, lactoferrin, α-lactalbumin, and β-lactoglobulin were proven to inhibit growth and development of A549, HT29, HepG2, and MDA231-LM2 tumors to different degrees via induction of cell apoptosis.

Polysialic Acid Modulates the Binding of External Lactoferrin in Neutrophil Extracellular Traps

Neutrophil extracellular traps (NETs) are formed by neutrophils during inflammation. Among other things, these DNA constructs consist of antimicrobial proteins such as lactoferrin and histones. With these properties, NETs capture and destroy invading microorganisms. The carbohydrate polysialic acid (polySia) interacts with both lactoferrin and histones. Previous experiments demonstrated that, in humans, lactoferrin inhibits the release of NET and that this effect is supported by polySia. In this study, we examined the interplay of lactoferrin and polySia in already-formed NETs from bovine neutrophils. The binding of polySia was considered to occur at the lactoferricin (LFcin)-containing domain of lactoferrin. The interaction with the peptide LFcin was studied in more detail using groups of defined polySia chain lengths, which suggested a chain-length-dependent interaction mechanism with LFcin. The LFcin domain of lactoferrin was found to interact with DNA. Therefore, the possibility that polySia influences the integration of lactoferrin into the DNA-structures of NETs was tested by isolating bovine neutrophils and inducing NETosis. Experiments with NET fibers saturated with lactoferrin demonstrated that polySia initiates the incorporation of external lactoferrin in already-loaded NETs. Thus, polySia may modulate the constituents of NET.

Oropharyngeal Mother's Milk: State of the Science and Influence on Necrotizing Enterocolitis

Oropharyngeal administration of mother's own milk-placing drops of milk directly onto the neonate's oral mucosa-may serve to (ex utero) mimic the protective effects of amniotic fluid for the extremely low birth weight infant; providing protection against necrotizing enterocolitis. This article presents current evidence to support biological plausibility for the use of OroPharyngeal Therapy with Mother's Own Milk (OPT-MOM) as an immunomodulatory therapy; an adjunct to enteral feeds of mother's milk administered via a nasogastric or orogastric tube. Current methods and techniques are reviewed, published evidence to guide clinical practice will be presented, and controversies in practice will be addressed.

Lactoferrin: A Critical Player in Neonatal Host Defense

Newborn infants are at a high risk for infection due to an under-developed immune system, and human milk has been shown to exhibit substantial anti-infective properties that serve to bolster neonatal defenses against multiple infections. Lactoferrin is the dominant whey protein in human milk and has been demonstrated to perform a wide array of antimicrobial and immunomodulatory functions and play a critical role in protecting the newborn infant from infection. This review summarizes data describing the structure and important functions performed by lactoferrin in protecting the neonate from infection and contributing to the maturation of the newborn innate and adaptive immune systems. We also briefly discuss clinical trials examining the utility of lactoferrin supplementation in the prevention of sepsis and necrotizing enterocolitis in newborn infants. The data reviewed provide rationale for the continuation of studies to examine the effects of lactoferrin administration on the prevention of sepsis in the neonate.

Role of Lactobacilli and Lactoferrin in the Mucosal Cervicovaginal Defense

The innate defense system of the female mucosal genital tract involves a close and complex interaction among the healthy vaginal microbiota, different cells, and various proteins that protect the host from pathogens. Vaginal lactobacilli and lactoferrin represent two essential actors in the vaginal environment. Lactobacilli represent the dominant bacterial species able to prevent facultative and obligate anaerobes outnumber in vaginal microbiota maintaining healthy microbial homeostasis. Several mechanisms underlie the protection exerted by lactobacilli: competition for nutrients and tissue adherence, reduction of the vaginal pH, modulation of immunity, and production of bioactive compounds. Among bioactive factors of cervicovaginal mucosa, lactoferrin, an iron-binding cationic glycoprotein, is a multifunctional glycoprotein with antibacterial, antifungal, antiviral, and antiparasitic activities, recently emerging as an important modulator of inflammation. Lactobacilli and lactoferrin are largely under the influence of female hormones and of paracrine production of various cytokines. Lactoferrin is strongly increased in lower genital tract mucosal fluid of women affected by Neisseria gonorrheae, Chlamydia trachomatis, and Trichomonas vaginalis infections promoting both innate and adaptive immune responses. In vaginal dysbiosis characterized by low amounts of vaginal lactobacilli and increased levels of endogenous anaerobic bacteria, the increase in lactoferrin could act as an immune modulator assuming the role normally played by the healthy microbiota in vaginal mucosa. Then lactoferrin and lactobacilli may be considered as biomarkers of altered microbial homeostasis at vaginal level. Considering the shortage of effective treatments to counteract recurrent and/or antibiotic-resistant bacterial infections, the intravaginal administration of lactobacilli and lactoferrin could be a novel efficient therapeutic strategy and a valuable tool to restore mucosal immune homeostasis.

Excess iron intake as a factor in growth, infections, and development of infants and young children

The provision of iron via supplementation or the fortification of foods has been shown to be effective in preventing and treating iron deficiency and iron deficiency anemia in infants and young children. However, iron is a pro-oxidative element and can have negative effects on biological systems even at moderate amounts. An increasing number of studies have reported adverse effects of iron that was given to infants and young-children populations who initially were iron replete. These effects include decreased growth (both linear growth and weight), increased illness (usually diarrhea), interactions with other trace elements such as copper and zinc, altered gut microbiota to more pathogenic bacteria, increased inflammatory markers, and impaired cognitive and motor development. If these results can be confirmed by larger and well-controlled studies, it may have considerable programmatic implications (e.g., the necessity to screen for iron status before interventions to exclude iron-replete individuals). A lack of understanding of the mechanisms underlying these adverse outcomes limits our ability to modify present supplementation and fortification strategies. This review summarizes studies on the adverse effects of iron on various outcomes; suggests possible mechanisms that may explain these observations, which are usually made in clinical studies and intervention trials; and gives examples from animal models and in vitro studies. With a better understanding of these mechanisms, it may be possible to find novel ways of providing iron in a form that causes fewer or no adverse effects even when subjects are iron replete. However, it is apparent that our understanding is limited, and research in this area is urgently needed.

Effect of Daily Iron Supplementation in Healthy Exclusively Breastfed Infants: A Systematic Review with Meta-Analysis

BACKGROUND

The literature on the iron requirements of exclusively breastfed infants contains conflicting data and contrary views.

OBJECTIVE

The purpose of this study was to summarize the evidence for both benefits and risks of daily oral iron supplementation with regard to hematologic, growth, cognitive parameters, and adverse effects in exclusively breastfed infants.

MATERIALS AND METHODS

Structured electronic searches were conducted using PubMed, Cochrane Library databases, and Google Scholar for randomized controlled trials (RCTs) involving daily iron supplementation in full-term healthy exclusively breastfed infants. Random- and fixed-effects models were used for calculating the pooled estimates.

RESULTS

Four RCTs with 511 infants were included in the meta-analysis. Iron interventions had no significant effect on iron deficiency or iron deficiency anemia, serum ferritin level, or hemoglobin level. Iron interventions did result in a significant increase in Bayley psychomotor developmental indices in later life (mean difference [MD] = 7.00, confidence interval [95% CI] 0.99-13.01) and mean corpuscular volume (MD = 2.17 fL; 95% CI 0.99-3.35 fL). Iron supplementation was associated with slower growth during the exclusive breastfeeding period, but the long-term effect is unclear.

CONCLUSIONS

Limited available evidence suggests that daily iron supplementation has beneficial effects on hematologic parameters and cognitive development, but may delay physical growth in healthy exclusively breastfed infants. There was no evidence to suggest that iron supplementation could cause other adverse effects.

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.

Milk bioactive peptide database: A comprehensive database of milk protein-derived bioactive peptides and novel visualization

During processing and digestion, milk proteins are disassembled into peptides with an array of biological functions, including antimicrobial, angiotensin-converting enzyme inhibition, antioxidant, opioid, and immunomodulation. These functions are summarized in numerous reviews, yet information on which peptides have which functions remains scattered across hundreds of research articles. We systematically searched the literature for all instances of bioactive peptides derived from milk proteins from any mammalian source. The data were compiled into a comprehensive database, which can be used to search for specific functions, peptides, or proteins (http://mbpdb.nws.oregonstate.edu). To review this large dataset, the bioactive peptides reported in the literature were visually mapped on the parent protein sequences, providing information on sites with highest abundance of bioactive peptides.

Bioactive Proteins in Human Milk-Potential Benefits for Preterm Infants

Human milk contains many bioactive proteins that are likely to be involved in the better outcomes of breast-fed infants compared with those fed infant formula. Bovine milk proteins or protein fractions may be able to provide some of these benefits and may, therefore, be used for preterm infants. Recombinant human milk proteins are likely to exert bioactivities similar to those of the native human milk proteins, but considerable research is needed before they can be used in routine care of preterm infants.

Research and development on lactoferrin and its derivatives in China from 2011–2015

Lactoferrin (Lf), a multifunctional glycoprotein, is an important antimicrobial and immune regulatory protein present in neutrophils and most exocrine secretions of mammals. Lactoferricin (Lfcin) is located in the N-terminal region of this protein. In this review, the current state of research into Lf and Lfcin in China is described. Searching with HistCite software in Web Sci located 118 papers published by Chinese researchers from 2011–2015, making China one of the top 3 producers of Lf research and development in the world. The biological functions of Lf and Lfcin are discussed, including antibacterial, antiviral, antifungal, anticarcinogenic, and anti-inflammatory activities; targeted drug delivery, induction of neurocyte, osteoblast, and tenocyte growth, and possible mechanisms of action. The preparation and heterologous expression of Lf in animals, bacteria, and yeast are discussed in detail. Five Lf-related food additive factories and 9 Lf-related health food production companies are certified by the China Food and Drug Administration (CFDA). The latest progress in the generation of transgenic livestock in China, the safety of the use of transgenic animals, and future prospects for the uses of Lf and Lfcin are also covered.

Lactoferrin from Milk: Nutraceutical and Pharmacological Properties

Lactoferrin is an iron-binding protein present in large quantities in colostrum and in breast milk, in external secretions and in polymorphonuclear leukocytes. Lactoferrin's main function is non-immune protection. Among several protective activities shown by lactoferrin, those displayed by orally administered lactoferrin are: (i) antimicrobial activity, which has been presumed due to iron deprivation, but more recently attributed also to a specific interaction with the bacterial cell wall and extended to viruses and parasites; (ii) immunomodulatory activity, with a direct effect on the development of the immune system in the newborn, together with a specific antinflammatory effects; (iii) a more recently discovered anticancer activity. It is worth noting that most of the protective activities of lactoferrin have been found, sometimes to a greater extent, also in peptides derived from limited proteolysis of lactoferrin that could be generated after lactoferrin ingestion. Lactoferrin could therefore be considered an ideal nutraceutic product because of its relatively cheap production from bovine milk and of its widely recognized tolerance after ingestion, along with its well demonstrated protective activities. The most important protective activities shown by orally administered bovine lactoferrin are reviewed in this article.

Lactoferrin and Its Possible Role in Iron Enrichment of Infant Formulas

The properties and functions of lactoferrin in relation to its use in the supplementation of infant formulas are discussed. Special attention is paid to lactoferrin functions directly related to its ability to bind iron, that is, its effect on iron absorption and bacteriostatic and antioxidant activities. From the results obtained by different authors, it can be concluded that the addition of lactoferrin, usually bovine, to infant formulas, does not affect iron absorption. However, given its ability to bind iron, its use in infant formulas could be useful for protecting the gut of infants against infections from microbial-requiring iron, its ability to reduce interelemental interactions and especially to protect infant formulas supplemented with iron and ascorbic acid against free radical formation. Although bovine lactoferrin is at the moment the most easily available, today it is possible to have human recombinant lactoferrin. The possibility of adding it to infant formulas should be considered, if and when the toxicological evaluation proves favorable, because of the possible additional improvement of iron bioavailability.

Breastfed at Tiffany's

The importance of breast milk for the growing infant is undisputed; breastfeeding decreases infantile mortality by tenfold and decreases the incidence of infectious diseases. Despite its recognized benefits, the structural richness of breast milk has also impeded the characterization of the multiple effects of milk components on infant physiology. However, the important roles of some components of breast milk are beginning to be dissected. For instance, molecules such as immunoglobulin A (IgA) and milk oligosaccharides protect from gastrointestinal infections and influence the development of the gut microbiota. Deciphering the complex composition of breast milk brings to light multifaceted contributions that combine to make breast milk the ultimate personalized medicine.

Comparison of lactoferrin activity in fresh and stored human milk

OBJECTIVE

Lactoferrin (Lf), the dominant protein in human milk (HM), has been shown to have anti-inflammatory and anti-microbial activity in the neonatal gut. Previous studies indicate that freezing significantly decreases the concentration of Lf in HM. The objective of our study was to compare the activity of Lf in fresh and frozen HM over time.

STUDY DESIGN

HM samples were examined fresh and after storage at -20 °C for 3 and 6 months. Lf concentration was determined by enzyme-linked immunoassay, and the activity was measured by examination of nitric oxide (NO) production and tumor necrosis factor-α secretion from rat macrophages exposed to HM samples.

RESULT

After 3 and 6 months at -20 °C, the average decrease in Lf concentrations was 55% and 65%, respectively. The bioactivity of Lf also decreased significantly over 6 months.

CONCLUSION

Freezing HM for 3 or more months significantly decreases Lf levels and activity. Periodically providing fresh HM may benefit vulnerable preterm neonates.

In-Depth Characterization of Sheep (Ovis aries) Milk Whey Proteome and Comparison with Cow (Bos taurus)

An in-depth proteomic study of sheep milk whey is reported and compared to the data available in the literature for the cow whey proteome. A combinatorial peptide ligand library kit (ProteoMiner) was used to normalize protein abundance in the sheep whey proteome followed by an in-gel digest of a 1D-PAGE display and an in-solution digestion followed by OFFGEL isoelectric focusing fractionation. The peptide fractions obtained were then analyzed by LC-MS/MS. This enabled identification of 669 proteins in sheep whey that, to our knowledge, is the largest inventory of sheep whey proteins identified to date. A comprehensive list of cow whey proteins currently available in the literature (783 proteins from unique genes) was assembled and compared to the sheep whey proteome data obtained in this study (606 proteins from unique genes). This comparison revealed that while the 233 proteins shared by the two species were significantly enriched for immune and inflammatory responses in gene ontology analysis, proteins only found in sheep whey in this study were identified that take part in both cellular development and immune responses, whereas proteins only found in cow whey in this study were identified to be associated with metabolism and cellular growth.

Multifunctional iron bound lactoferrin and nanomedicinal approaches to enhance its bioactive functions

Lactoferrin (Lf), an iron-binding protein from the transferrin family has been reported to have numerous functions. Even though Lf was first isolated from milk, it is also found in most exocrine secretions and in the secondary granules of neutrophils. Antimicrobial and anti-inflammatory activity reports on lactoferrin identified its significance in host defense against infection and extreme inflammation. Anticarcinogenic reports on lactoferrin make this protein even more valuable. This review is focused on the structural configuration of iron-containing and iron-free forms of lactoferrin obtained from different sources such as goat, camel and bovine. Apart for emphasizing on the specific beneficial properties of lactoferrin from each of these sources, the general antimicrobial, immunomodulatory and anticancer activities of lactoferrin are discussed here. Implementation of nanomedicinial strategies that enhance the bioactive function of lactoferrin are also discussed, along with information on lactoferrin in clinical trials.

[Ca2+]i Oscillations and IL-6 Release Induced by α-Hemolysin from Escherichia coli Require P2 Receptor Activation in Renal Epithelia

Urinary tract infections are commonly caused by α-hemolysin (HlyA)-producing Escherichia coli. In erythrocytes, the cytotoxic effect of HlyA is strongly amplified by P2X receptors, which are activated by extracellular ATP released from the cytosol of the erythrocytes. In renal epithelia, HlyA causes reversible [Ca(2+)]i oscillations, which trigger interleukin-6 (IL-6) and IL-8 release. We speculate that this effect is caused by HlyA-induced ATP release from the epithelial cells and successive P2 receptor activation. Here, we demonstrate that HlyA-induced [Ca(2+)]i oscillations in renal epithelia were completely prevented by scavenging extracellular ATP. In accordance, HlyA was unable to inflict any [Ca(2+)]i oscillations in 132-1N1 cells, which lack P2R completely. After transfecting these cells with the hP2Y2 receptor, HlyA readily triggered [Ca(2+)]i oscillations, which were abolished by P2 receptor antagonists. Moreover, HlyA-induced [Ca(2+)]i oscillations were markedly reduced in medullary thick ascending limbs isolated from P2Y2 receptor-deficient mice compared with wild type. Interestingly, the following HlyA-induced IL-6 release was absent in P2Y2 receptor-deficient mice. This suggests that HlyA induces ATP release from renal epithelia, which via P2Y2 receptors is the main mediator of HlyA-induced [Ca(2+)]i oscillations and IL-6 release. This supports the notion that ATP signaling occurs early during bacterial infection and is a key player in the further inflammatory response.

Illness in breastfeeding infants relates to concentration of lactoferrin and secretory Immunoglobulin A in mother's milk

BACKGROUND AND OBJECTIVES

This study aims to better understand the relationship between immune compounds in human milk and infant health. We hypothesized that the concentration of immune compounds in milk would relate to infant illness symptoms according to two possible theoretical paradigms. In the 'protective' paradigm, high concentrations of immune compounds prevent infant illness. The converse, the 'responsive' framework, posits that concentrations of immune compounds are elevated in response to infection.

METHODOLOGY

Milk samples (n = 110) and illness data were collected among the Toba of Argentina from 30 mother-infant dyads. Samples were assayed for two immune proteins, lactoferrin and secretory immunoglobulin A (sIgA). Generalized estimating equations were used to assess the relationship between immune composition of milk and symptoms of illness in infants.

RESULTS

Lactoferrin was positively associated with symptoms of illness in infants (odds ratios >1), both in the month preceding the sample collection and the subsequent month. sIgA was negatively associated with symptoms (odds ratios <1) in the preceding and subsequent months, an association which was particularly strong for gastrointestinal symptoms.

CONCLUSIONS AND IMPLICATIONS

The two compounds investigated in our study had opposite relationships with symptoms of illness; the positive relationship between lactoferrin and illness lends support to our 'responsive' paradigm, and the negative relationship between sIgA and symptoms of illness was consistent with our 'protective' framework. That elevated lactoferrin is restricted to periods of illness suggests that there may be a cost to mother or infant associated with persistently elevated lactoferrin that is not incurred with elevated sIgA.