Effects of bovine lactoferrin on the immature porcine intestine

Lactoferrin impairs pathogen virulence through its proteolytic activity

Antibiotics, often hailed as 'miracle drugs' in the 20th century, have revolutionised medicine by saving millions of lives in human and veterinary medicine, effectively combatting bacterial infections. However, the escalating global challenge of antimicrobial resistance and the appearance and spread of multidrug-resistant pathogens necessitates research into alternatives. One such alternative could be lactoferrin. Lactoferrin, an iron-binding multifunctional protein, is abundantly present in mammalian secretions and exhibits antimicrobial and immunomodulatory activities. An often overlooked aspect of lactoferrin is its proteolytic activity, which could contribute to its antibacterial activity. The proteolytic activity of lactoferrin has been linked to the degradation of virulence factors from several bacterial pathogens, impeding their colonisation and potentially limiting their pathogenicity. Despite numerous studies, the exact proteolytically active site of lactoferrin, the specific bacterial virulence factors it degrades and the underlying mechanism remain incompletely understood. This review gives an overview of the current knowledge concerning the proteolytic activity of lactoferrins and summarises the bacterial virulence factors degraded by lactoferrins. We further detail how a deeper understanding of the proteolytic activity of lactoferrin might position it as a viable alternative for antibiotics, being crucial to halt the spread of multi-drug resistant bacteria.

Science and Faith to Understand Milk Bioactivity for Infants

Milk bioactivity refers to the specific health effects of milk components beyond nutrition. The science of milk bioactivity involves the systematic study of these components and their health effects, as verified by empirical data, controlled experiments, and logical arguments. Conversely, 'faith in milk bioactivity' can be defined as personal opinion, meaning, value, trust, and hope for health effects that are beyond investigation by natural, social, or human sciences. Faith can be strictly secular, but also influenced by spirituality or religion. The aim of this paper is to show that scientific knowledge is frequently supplemented with faith convictions to establish personal and public understanding of milk bioactivity. Mammalian milk is an immensely complex fluid containing myriad proteins, carbohydrates, lipids, and micronutrients with multiple functions across species, genetics, ages, environments, and cultures. Human health includes not only physical health, but also social, mental, and spiritual health, requiring widely different fields of science to prove the relevance, safety, and efficacy of milk interventions. These complex relationships between milk feeding and health outcomes prevent firm conclusions based on science and logic alone. Current beliefs in and understanding of the value of breast milk, colostrum, infant formula, or isolated milk proteins (e.g., immunoglobulins, α-lactalbumin, lactoferrin, and growth factors) show that both science and faith contribute to understand, stimulate, or restrict the use of milk bioactivity. The benefits of breastfeeding for infants are beyond doubt, but the strong beliefs in its health effects rely not only on science, and mechanisms are unclear. Likewise, fear of, or trust in, infant formula may rely on both science and faith. Knowledge from science safeguards individuals and society against 'milk bioactivity superstition'. Conversely, wisdom from faith-based convictions may protect science from unrealistic 'milk bioactivity scientism'. Honesty and transparency about the potentials and limitations of both scientific knowledge and faith convictions are important when informing individuals and society about the nutritious and bioactive qualities of milk.

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.

A corn-fermented protein ingredient can be included in early nursey diets without compromising pig growth performance and health status

In nursery diets, ingredients with high protein content and highly digestible nutrients, such as corn-fermented protein product with added yeast mass (GDDY), can be included as an alternative to common protein sources. This study investigated the dietary inclusion of GDDY as an alternative protein source on growth performance and intestinal health of weaned pigs. A total of 594 weaned pigs (5.7 ± 0.9 kg; 18.5 days of age) were allotted to 36 pens in a randomized incomplete block design. Pens were assigned to one of 4 dietary treatments: CON: a common nursery feeding program; SBM75: CON diet replacing 75% of soybean meal (SBM) with GDDY; FM/ESBM: CON diet without fish meal (FM) and enzyme-treated SBM (ESBM) + GDDY; GDDY50: CON diet replacing 50% of SBM, FM, and ESBM with GDDY. Experimental diets were formulated to meet nutrient requirements of nursery pigs and provided in meal form through four phases during the nursery period. Pig growth performance was assessed on days 7, 14, 21, 28, 42, and 53. Pen fecal score was assessed daily from days 0 to 14, and 3 times per week from days 15 to 35. Intestinal health was assessed based on plasma immunoglobulin A (IgA) concentration and the differential sugar absorption test. The total tract digestibility of dry matter (DM), crude protein (CP), gross energy (GE), and phosphorus was also evaluated. From days 0 to 7 and days 7 to 14, dietary treatment had no effect (P > 0.05) on BW, ADG, and ADFI. For the rest of the experimental period, ADG and ADFI were greater (P < 0.05) in pigs fed CON in comparison with those fed SBM75 and GDDY50 and did not differ from pigs fed FM/ESBM. Pigs fed GDDY50 tended (P = 0.082) to have greater serum IgA concentration on day 20 when compared with SBM75 and FM/ESBM pigs. There were no differences among dietary treatments for DM, CP, and GE digestibility. Phosphorus digestibility was higher in FM/ESBM (P < 0.05) compared with SBM75 and GDDY50. These results supported the hypothesis that GDDY can be incorporated in nursery pig diets during the first couple weeks after weaning without affecting growth performance. However, in the late nursery period, inclusion levels starting at 14% can compromise performance.

Electrophoretically Co-Deposited Collagen-Lactoferrin Membranes with Enhanced Pro-Regenerative Properties for Oral Soft Tissue Regeneration

The quality of soft tissue defect regeneration after dental surgeries largely determines their final success. Collagen membranes have been proposed for the healing of such defects, but in some cases, they do not guarantee a sufficient volume of the regenerated tissue and vascularization. For this purpose, lactoferrin, a protein with natural pro-regenerative, anti-inflammatory, and pro-angiogenic activity, can be added to collagen. In this article, we used a semipermeable barrier-assisted electrophoretic deposition (SBA-EPD) method for the production of collagen-lactoferrin membranes. The membrane structure was studied by SEM, and its mechanical properties were shown. The lactoferrin release kinetics were shown by ELISA within 75 h. When tested in vitro, we demonstrated that the collagen-lactoferrin membranes significantly increased the proliferation of keratinocytes (HaCaT) and fibroblasts (977hTERT) compared to blank collagen membranes. In vivo, on the vestibuloplasty and free gingival graft harvesting models, we showed that collagen-lactoferrin membranes decreased the wound inflammation and increased the healing rates and regeneration quality. In some parameters, collagen-lactoferrin membranes outperformed not only blank collagen membranes, but also the commercial membrane Mucograft®. Thus, we proved that collagen-lactoferrin membranes produced by the SBA-EPD method may be a valuable alternative to commercially used membranes for soft tissue regeneration in the oral cavity.

Nutritional and health effects of bovine colostrum in neonates

High concentrations of immunoglobulins, bioactive peptides, and growth factors are found in bovine colostrum (BC), the milk produced by cows in the first few days after parturition. Various biological functions make it increasingly used to provide nutritional support and immune protection to the offspring of many species, including humans. These biological functions include cell growth stimulation, anti-infection, and immunomodulation. The primary components and biological functions of colostrum were reviewed in the literature, and the authors also looked at its latent effects on the growth and development of neonates as well as on conditions such as infections, necrotizing enterocolitis, short bowel syndrome, and feeding intolerance. The importance of BC in neonatal nutrition, immune support, growth and development, and gut health has been demonstrated in a number of experimental and animal studies. BC has also been shown to be safe at low doses without adverse effects in newborns. BC supplementation has been shown to be efficient in preventing several disorders, including rotavirus diarrhea, necrotizing enterocolitis, and sepsis in animal models of prematurity and some newborn studies. Therefore, BC supplementation should be considered in cases where maternal milk is insufficient or donor milk is unavailable. The optimal age, timing, dosage, and form of BC administration still require further investigation.

Therapeutic uses and applications of bovine lactoferrin in aquatic animal medicine: an overview

Aquaculture is an important food sector throughout the globe because of its importance in ensuring the availability of nutritious and safe food for human beings. In recent years, this sector has been challenged with several obstacles especially the emergence of infectious disease outbreaks. Various treatment and control aspects, including antibiotics, antiseptics, and other anti-microbial agents, have been used to treat farmed fish and shrimp against diseases. Nonetheless, these medications have been prohibited and banned in many countries because of the development of antimicrobial-resistant bacterial strains, the accumulation of residues in the flesh of farmed fish and shrimp, and their environmental threats to aquatic ecosystems. Therefore, scientists and researchers have concentrated their research on finding natural and safe products to control disease outbreaks. From these natural products, bovine lactoferrin can be utilized as a functional feed supplement. Bovine lactoferrin is a multi-functional glycoprotein applied in various industries, like food preservation, and numerous medications, due to its non-toxic and ecological features. Recent research has proposed multiple advantages and benefits of using bovine lactoferrin in aquaculture. Reports showed its potential ability to enhance growth, reduce mortalities, regulate iron metabolism, decrease disease outbreaks, stimulate the antioxidant defense system, and recuperate the overall health conditions of the treated fish and shrimp. Besides, bovine lactoferrin can be considered as a safe antibiotic alternative and a unique therapeutic agent to decrease the negative impacts of infectious diseases. These features can be attributed to its well-known antibacterial, anti-parasitic, anti-inflammatory, immunostimulatory, and antioxidant capabilities. This literature review will highlight the implications of bovine lactoferrin in aquaculture, particularly highlighting its therapeutic features and ability to promote immunological defensive pathways in fish. The information included in this article would be valuable for further research studies to improve aquaculture's sustainability and the functionality of aquafeeds.

Necrotizing enterocolitis: recent advances in treatment with translational potential

Necrotizing enterocolitis (NEC) is one of the most prevalent and devastating gastrointestinal disorders in neonates. Despite advances in neonatal care, the incidence and mortality due to NEC remain high, highlighting the need to devise novel treatments for this disease. There have been a number of recent advancements in therapeutic approaches for the treatment of NEC; these involve remote ischemic conditioning (RIC), stem cell therapy, breast milk components (human milk oligosaccharides, exosomes, lactoferrin), fecal microbiota transplantation, and immunotherapy. This review summarizes the most recent advances in NEC treatment currently underway as well as their applicability and associated challenges and limitations, with the aim to provide new insight into the paradigm of care for NEC worldwide.

The Role of Lactoferrin in Intestinal Health

The intestine represents one of the first barriers where microorganisms and environmental antigens come into tight contact with the host immune system. A healthy intestine is essential for the well-being of humans and animals. The period after birth is a very important phase of development, as the infant moves from a protected environment in the uterus to one with many of unknown antigens and pathogens. In that period, mother's milk plays an important role, as it contains an abundance of biologically active components. Among these components, the iron-binding glycoprotein, lactoferrin (LF), has demonstrated a variety of important benefits in infants and adults, including the promotion of intestinal health. This review article aims to provide a compilation of all the information related to LF and intestinal health, in infants and adults.

Effects of dietary supplementation of bovine lactoferrin on growth performance, immune function and intestinal health in weaning piglets

Weaning is a crucial period in the pig's life cycle, which is frequently followed by gastrointestinal (GI) infections, diarrhea and even death. This study focused on the impact of bovine lactoferrin (bLF) supplementation on the intestinal health of weaning piglets. Weaning piglets (Duroc × Landrace × Yorkshire, 23 days) were randomly allocated into four groups, which included negative control group (CON): basic diet; positive control group (ANT): basic diet + 20 mg/kg flavomycin + 100 mg/kg aureomycin; treatment group bLF-A: basic diet + 1 g/kg bLF; treatment group bLF-B: basic diet + 3 g/kg bLF. The result showed that dietary supplementation of bLF can improve growth performance and reduce diarrhea, which exhibits dose-dependency (P < 0.05). Compared with CON group, supplementation with bLF significantly improved immunity, and increased villus height and ratio of villus height/crypt depth at the small intestinal mucosa (P < 0.05). The mRNA expression of claudin-1, occludin and ZO-1 was greatly increased in the ileum of bLF group on days 7 and 14 (P < 0.05). Furthermore, the supplementation of bLF increased the abundance of Lactobacillus and Bifidobacterium and decreased the abundance of Escherichia coli in the cecum on day 7 (P < 0.05). The dietary supplementation of bLF enhanced the growth performance, reduced diarrhea rate in weaning piglets by improving intestinal immunity, morphology and barrier function, balancing intestinal microbiota. And bLF can be a promising feed additive in relieving stress situation of weaning piglets.

Effect of maternal lactoferrin supplementation on iron contents and anti-oxidant capacity in Dahe black Pig neonates

Iron levels are closely related to animals' growth performance and anti-oxidant function. Lactoferrin (LF) is an iron-binding glycoprotein, which can promote the absorption of iron and regulate immune function. This study aimed to clarify the effect of maternal LF supplementation on the iron metabolism of Dahe piglets. Sixty sows (Dahe black, parity 3-4, no significant differences in body weight) were randomly assigned to five groups: control (basal diet with no iron supplementation), supplemented 100 (LF1 group), 200 (LF2 group), or 300 (LF3 group) mg LF/kg in the basal diet, and the basal diet supplemented with 100 (Fe-Gly group) mg Fe/kg as ferrous glycine (Fe-Gly). The serum anti-oxidant parameters of the sows and neonatal piglets were determined. The iron contents, anti-oxidant gene expression levels, and Fe-acquisition genes were detected in the liver, heart, spleen, and other neonatal organs. The results indicated that (1) the LF3 group of sows had the highest serum and colostrum iron contents (P < 0.05). The maternal LF significantly promoted the iron stores in the heart, liver, spleen, and lung of piglets compared with Fe-Gly. (2) The maternal LF increased serum glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) activities of sows. Compared with other groups, the total anti-oxidant capacity (T-AOC) activity of LF2 groups increased significantly (P < 0.05). (3) LF significantly increased piglet serum GSH-Px, T-SOD, and T-AOC activities (P < 0.05). (4) Gene expression levels of GSH-Px, and SOD in the duodenum and jejunum of the LF2 group were significantly higher than in the Fe-Gly group (P < 0.05), while the expression levels in the liver and heart were lower (P < 0.05). (5) The expression levels of hepcidin and LF in the liver and duodenum of the LF2 group were significantly higher than in the Fe-Gly group (P < 0.05). In conclusion, maternal LF supplementation showed remarkable effects on iron storage in neonatal piglets, and exhibited strong antioxidant activities, it is helpful to prevent the occurrence of iron deficiency, and improves the immune function of animals.

Dietary Lactoferrin Supplementation Improves Growth Performance and Intestinal Health of Juvenile Orange-Spotted Groupers (Epinephelus coioides)

A 56-day feeding trial was conducted to investigate the effects of dietary lactoferrin (LF) supplementation on the growth performance and intestinal health of juvenile orange-spotted groupers fed high-soybean-meal (SBM) diets. The control diet (FM) and high-soybean-meal diet (SBM60) were prepared to contain 480 g/kg protein and 110 g/kg fat. Three inclusion levels of 2, 6, and 10 g/kg LF were added into the SBM60 to prepare three diets (recorded as LF2, LF6, and LF10, respectively). The results showed that the supplementation of LF in SBM60 increased the growth rate in a dose-dependent manner. However, the feed utilization, hepatosomatic index, whole-body proximate composition, and the abundance and diversity of intestinal microbiota did not vary across the dietary treatments (p > 0.05). After the dietary intervention with LF, the contents of the intestinal malondialdehyde, endotoxin, and d-lactic acid, as well as the plasma low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and total cholesterol were lower, and the intestinal activities of the glutathione peroxidase, lipase, trypsin, and protease were higher in the LF2-LF10 groups than that in the SBM60 group (p < 0.05). The supplementation of LF in SBM60 increased the muscle layer thickness of the middle and distal intestine and the mucosal fold length of the middle intestine vs. the SBM60 diet (p < 0.05). Furthermore, the supplementation of LF in SBM60 resulted in an up-regulation of the mRNA levels for the IL-10 and TGF-β1 genes and a down-regulation of the mRNA levels of the IL-1β, IL-12, IL-8, and TNF-α genes vs. the SBM60 diet (p < 0.05). The above results showed that a dietary LF intervention improves the growth and alleviates soybean meal-induced enteritis in juvenile orange-spotted groupers. The dietary appropriate level of LF was at 5.8 g/kg, through the regression analysis of the percent weight gain against the dietary LF inclusion levels.

The Lactoferrin Phenomenon-A Miracle Molecule

Numerous harmful factors that affect the human body from birth to old age cause many disturbances, e.g., in the structure of the genome, inducing cell apoptosis and their degeneration, which leads to the development of many diseases, including cancer. Among the factors leading to pathological processes, microbes, viruses, gene dysregulation and immune system disorders have been described. The function of a protective agent may be played by lactoferrin as a "miracle molecule", an endogenous protein with a number of favorable antimicrobial, antiviral, antioxidant, immunostimulatory and binding DNA properties. The purpose of this article is to present the broad spectrum of properties and the role that lactoferrin plays in protecting human cells at all stages of life.

Lactoferrin Induces Erythropoietin Synthesis and Rescues Cognitive Functions in the Offspring of Rats Subjected to Prenatal Hypoxia

The protective effects of recombinant human lactoferrin rhLF (branded “CAPRABEL™”) on the cognitive functions of rat offspring subjected to prenatal hypoxia (7% O₂, 3 h, 14th day of gestation) have been analyzed. About 90% of rhLF in CAPRABEL was iron-free (apo-LF). Rat dams received several injections of 10 mg of CAPRABEL during either gestation (before and after the hypoxic attack) or lactation. Western blotting revealed the appearance of erythropoietin (EPO) alongside the hypoxia-inducible factors (HIFs) in organ homogenates of apo-rhLF-treated pregnant females, their embryos (but not placentas), and in suckling pups from the dams treated with apo-rhLF during lactation. Apo-rhLF injected to rat dams either during pregnancy or nurturing the pups was able to rescue cognitive deficits caused by prenatal hypoxia and improve various types of memory both in young and adult offspring when tested in the radial maze and by the Novel Object Recognition (NOR) test. The data obtained suggested that the apo-form of human LF injected to female rats during gestation or lactation protects the cognitive functions of their offspring impaired by prenatal hypoxia.

Development of Visceral and Subcutaneous-Abdominal Adipose Tissue in Breastfed Infants during First Year of Lactation

This study aimed to investigate relationships between infant abdominal visceral and subcutaneous adiposity and human milk (HM) components and maternal body composition (BC) during first year of lactation. Subcutaneous-abdominal depth (SAD), subcutaneous-abdominal fat area (SFA), visceral depth (VD) and preperitoneal fat area of 20 breastfed infants were assessed at 2, 5, 9 and 12 months using ultrasound. Maternal BC was determined with bioimpedance spectroscopy. HM macronutrients and bioactive components concentrations and infant 24-h milk intake were measured and calculated daily intakes (CDI) determined. Maternal adiposity associated with infant SFA (negatively at 2, 5, 12, positively at 9 months, all overall p < 0.05). 24-h milk intake positively associated with infant SAD (p = 0.007) and VD (p = 0.013). CDI of total protein (p = 0.013), total carbohydrates (p = 0.004) and lactose (p = 0.013) positively associated with SFA. Lactoferrin concentration associated with infant VD (negatively at 2, 12, positively at 5, 9 months, overall p = 0.003). CDI of HM components and maternal adiposity have differential effects on development of infant visceral and subcutaneous abdominal adiposity. Maintaining healthy maternal BC and continuing breastfeeding to 12 months and beyond may facilitate favourable BC development reducing risk of obesity.

Potential Benefits of Bovine Colostrum in Pediatric Nutrition and Health

Bovine colostrum (BC), the first milk produced from cows after parturition, is increasingly used as a nutritional supplement to promote gut function and health in other species, including humans. The high levels of whey and casein proteins, immunoglobulins (Igs), and other milk bioactives in BC are adapted to meet the needs of newborn calves. However, BC supplementation may improve health outcomes across other species, especially when immune and gut functions are immature in early life. We provide a review of BC composition and its effects in infants and children in health and selected diseases (diarrhea, infection, growth-failure, preterm birth, necrotizing enterocolitis (NEC), short-bowel syndrome, and mucositis). Human trials and animal studies (mainly in piglets) are reviewed to assess the scientific evidence of whether BC is a safe and effective antimicrobial and immunomodulatory nutritional supplement that reduces clinical complications related to preterm birth, infections, and gut disorders. Studies in infants and animals suggest that BC should be supplemented at an optimal age, time, and level to be both safe and effective. Exclusive BC feeding is not recommended for infants because of nutritional imbalances relative to human milk. On the other hand, adverse effects, including allergies and intolerance, appear unlikely when BC is provided as a supplement within normal nutrition guidelines for infants and children. Larger clinical trials in infant populations are needed to provide more evidence of health benefits when patients are supplemented with BC in addition to human milk or formula. Igs and other bioactive factors in BC may work in synergy, making it critical to preserve bioactivity with gentle processing and pasteurization methods. BC has the potential to become a safe and effective nutritional supplement for several pediatric subpopulations.

Enteral Feeding Interventions in the Prevention of Necrotizing Enterocolitis: A Systematic Review of Experimental and Clinical Studies

Necrotizing enterocolitis (NEC), which is characterized by severe intestinal inflammation and in advanced stages necrosis, is a gastrointestinal emergency in the neonate with high mortality and morbidity. Despite advancing medical care, effective prevention strategies remain sparse. Factors contributing to the complex pathogenesis of NEC include immaturity of the intestinal immune defense, barrier function, motility and local circulatory regulation and abnormal microbial colonization. Interestingly, enteral feeding is regarded as an important modifiable factor influencing NEC pathogenesis. Moreover, breast milk, which forms the currently most effective prevention strategy, contains many bioactive components that are known to support neonatal immune development and promote healthy gut colonization. This systematic review describes the effect of different enteral feeding interventions on the prevention of NEC incidence and severity and the effect on pathophysiological mechanisms of NEC, in both experimental NEC models and clinical NEC. Besides, pathophysiological mechanisms involved in human NEC development are briefly described to give context for the findings of altered pathophysiological mechanisms of NEC by enteral feeding interventions.

Supplementation of protease to low amino acid diets containing superdose level of phytase for wean-to-finish pigs: effects on performance, postweaning intestinal health and carcass characteristics

This experiment investigated the effects of protease supplementation to low amino acid (AA) diets containing phytase on pig growth performance, postweaning intestinal health and carcass characteristics. A total of 936 weaned pigs (21 d of age, initial BW 5.87 ± 0.31 kg) were used in a 2 × 2 factorial design comparing the main effects of AA supply [standard feeding program: balanced for all nutrients with adjustment of Ca and P due to inclusion of phytase (2,500 FTU/kg in Phase 1 to 4; 500 FTU/kg in Phase 5 to 9) vs. low AA feeding program: 15% lower standardized ileal digestible lysine with relative reduction of all other essential AA] and protease level (0 vs. 0.0125%). Pens were assigned to dietary treatment according to a randomized complete block design with 26 pigs per pen and nine replicates per dietary treatment. Feed and water were provided on an ad libitum basis for all phases throughout the wean-to-finish period. Feed intake and body weight were determined every 2 wk during nursery period and monthly in the grow-finish period. Intestinal health in the first 17 d was assessed based on lactulose:mannitol ratio (L:M), serum IgA, and pen diarrhea assessment. Overall, pigs fed standard wean-to-finish diets had greater (P < 0.05) ADG and G:F than pigs fed low AA diets. Pig growth performance was not different throughout the wean-to-finish period with or without protease supplementation and with no interaction between AA supply and protease supplementation. There were no differences among dietary treatments for carcass characteristics. No difference was observed for urinary L:M and serum IgA; however, the L:M ratio was approximately 32% lower in pigs fed low AA diets + protease compared with pigs fed standard and low AA diets at d 5 and d 17 postweaning. Pigs fed protease supplemented diets had lower incidence of diarrhea (χ² < 0.05) compared with pigs fed diets without protease. Results of the experiment indicate that dietary protease supplementation benefits intestinal health of nursery pigs.

Lactoferrin as a regenerative agent: The old-new panacea?

Lactoferrin (Lf) possesses various biological properties and therapeutic potentials being a perspective anti-inflammatory, antibacterial, antiviral, antioxidant, antitumor, and immunomodulatory agent. A significant body of literature has also demonstrated that Lf modulates regenerative processes in different anatomical structures, such as bone, cartilage, skin, mucosa, cornea, tendon, vasculature, and adipose tissue. Hence, this review collected and analyzed the data on the regenerative effects of Lf, as well as paid specific attention to their molecular basis. Furthermore, tissue and condition-specific activities of different Lf types as well as problems of their delivery to the targeted organs were discussed. The authors strongly hope that this review will stimulate researchers to focus on the highlighted topics thus accelerating the progress of Lf's wider clinical application.

Human milk immunomodulatory proteins are related to development of infant body composition during the first year of lactation

BACKGROUND

To investigate relationships between infant body composition (BC) and human milk (HM) immunomodulatory proteins (IMPs) during the first 12 months of lactation.

METHODS

BC of breastfeeding dyads (n = 20) was measured with ultrasound skinfolds (infants) and bioimpedance spectroscopy (infants/mothers) at 2, 5, 9, and/or 12 months post partum. Breastfeeding frequency, 24-h milk intake, and IMP concentrations (lactoferrin, lysozyme, secretory immunoglobulin A (sIgA)) were measured, and calculated daily intakes (CDIs) were determined. We used linear regression/mixed-effects models and adjusted results for multiple comparisons.

RESULTS

No associations were seen between maternal characteristics and IMP concentrations/CDIs or between IMP concentrations and infant BC. Lactoferrin CDI was negatively associated with infant fat-free mass index (P = 0.002); lysozyme CDI was positively associated with infant fat mass (P = 0.004) and fat mass index (P = 0.004) measured with ultrasound skinfolds.

CONCLUSION

In this small cohort of infants breastfed on demand during first year of life, we report differential associations of HM IMPs with infant BC, showing that in addition to their critical role in shaping infant immunity, lactoferrin, and lysozyme also influence development of infant BC, highlighting the importance of breastfeeding for 12 months and beyond.

IMPACT

HM IMPs (concentrations and, most importantly, daily intakes) time-dependently and differentially associate with development of infant lean mass and adiposity during first 12 months of lactation. There is no information on how intakes and concentrations of these components affect development of infant BC. HM contains IMPs-lactoferrin, lysozyme, and sIgA, which not only play a critical role in shaping infant's immunity, but also influence infant growth and development of BC, highlighting the importance of breastfeeding for 12 months and beyond and warranting careful consideration of the dose effects of supplemented formula.

A prospective on multiple biological activities of lactoferrin contributing to piglet welfare

Piglets, especially weaning piglets, show a lower level of immunity and higher morbidity and mortality, owing to their rapid growth, physiological immaturity, and gradual reduction of maternal antibodies, which seriously affects their growth and thus, value. It is important that piglets adapt to nutrient digestion and absorption and develop sound intestinal function and colonization with gut microbiota as soon as possible during their early life stage. Lactoferrin is a natural glycoprotein polypeptide that is part of the transferrin family. It is widely found in mucosal secretions such as saliva and tears, and most highly in milk and colostrum. As a multifunctional bioactive protein and a recommended food additive, lactoferrin is a potential alternative therapy to antibiotics and health promoting additive for piglet nutrition and development. It is expected that lactoferrin, as a natural food additive, could play an important role in maintaining pig health and development. This review examines the following known beneficial effects of lactoferrin: improves the digestion and capacity for absorption in the intestinal tract; promotes the absorption of iron and reduces the incidence of iron deficiency anemia; regulates intestinal function and helps to balance the microbial biota; and enhances the resistance to disease of the piglets via modulating and enhancing the immune system.

Bioactive proteins in bovine colostrum and effects of heating, drying and irradiation

Bovine colostrum (BC) contains bioactive proteins, such as immunoglobulin G (IgG), lactoferrin (LF) and lactoperoxidase (LP). BC was subjected to low-temperature, long-time pasteurization (LTLT, 63 °C, 30 min) or high-temperature, short-time pasteurization (HTST, 72 °C, 15 s) and spray-drying (SD), with or without γ-irradiation (GI, ∼14 kGy) to remove microbial contamination. Relative to unpasteurized liquid BC, SD plus GI increased protein denaturation by 6 and 11%, respectively, increasing to 19 and 27% after LTLT and to 48% after HTST, with no further effects after GI (all P < 0.05). LTLT, without or with GI, resulted in 15 or 29% denaturation of IgG, compared with non-pasteurized BC, and 34 or 58% for HTST treatment (all P < 0.05, except LTLT without GI). For IgG, only GI, not SD or LTLT, increased denaturation (30-38%, P < 0.05) but HTST increased denaturation to 40%, with further increases after GI (60%, P < 0.05). LTLT and HTST reduced LP levels (56 and 81% respectively) and LTLT reduced LF levels (21%), especially together with GI (47%, P < 0.05). Denaturation of BSA, β-LgA, β-LgB and α-La were similar to IgG. Methionine, a protective amino acid against free oxygen radicals, was oxidised by LTLT + GI (P < 0.05) while LTLT and HTST had no effect. Many anti-inflammatory proteins, including serpin anti-proteinases were highly sensitive to HTST and GI but preserved after LTLT pasteurization. LTLT, followed by SD is an optimal processing technique preserving bioactive proteins when powdered BC is used as a diet supplement for sensitive patients.

Translational Advances in Pediatric Nutrition and Gastroenterology: New Insights from Pig Models

Pigs are increasingly important animals for modeling human pediatric nutrition and gastroenterology and complementing mechanistic studies in rodents. The comparative advantages in size and physiology of the neonatal pig have led to new translational and clinically relevant models of important diseases of the gastrointestinal tract and liver in premature infants. Studies in pigs have established the essential roles of prematurity, microbial colonization, and enteral nutrition in the pathogenesis of necrotizing enterocolitis. Studies in neonatal pigs have demonstrated the intestinal trophic effects of akey gut hormone, glucagon-like peptide 2 (GLP-2), and its role in the intestinal adaptation process and efficacy in the treatment of short bowel syndrome. Further, pigs have been instrumental in elucidating the physiology of parenteral nutrition-associated liver disease and the means by which phytosterols, fibroblast growth factor 19, and a new generation of lipid emulsions may modify disease. The premature pig will continue to be a valuable model in the development of optimal infant diets (donor human milk, colostrum), specific milk bioactives (arginine, growth factors), gut microbiota modifiers (pre-, pro-, and antibiotics), pharmaceutical drugs (GLP-2 analogs, FXR agonists), and novel diagnostic tools (near-infrared spectroscopy) to prevent and treat these pediatric diseases.

Milk lactoferrin concentration of primiparous and multiparous sows during lactation

Lactoferrin (LF), a sialylated iron-binding glycoprotein, has numerous vital physiological functions including immunomodulation and protection against a large group of microorganisms, improving neurodevelopment, health, growth performance, and milk production. Lactoferrin occurs in human milk at a higher concentration compared with bovine milk, but little information is available on LF concentrations in porcine milk and the effects of sow parity on milk LF concentration. The objective of this study was to quantify the LF concentration in porcine milk and to compare that concentration between gilts and sows during lactation. We also investigated the effect of genetic background and litter size of the female pig on the LF concentration of porcine milk. The milk from 30 gilts and 35 sows was collected at 3 stages of lactation, namely colostrum, transition, and mature milk. Standard and experimental samples were analyzed by ultra-high performance liquid chromatography using a diode array UV detector. The following findings were reported: (1) porcine milk contained significant levels of LF with the highest concentration in colostrum, which decreased by ∼62% and ∼67% in transitional and mature milk, respectively; (2) mature gilt milk contained a 22% higher concentration of LF compared with sow milk, which was statistically significant; (3) breed line had an overall significant effect on the LF content of porcine milk; however, when the breed was considered, no significant difference was observed; and (4) LF concentration of porcine milk was not significantly influenced by the litter size. The presence of LF in a higher concentration in porcine milk suggests that LF is an important constituent of pig milk that might contribute to the optimum growth and development of piglets.

Effects of Bovine Lactoferrin on Rat Intestinal Epithelial Cells

OBJECTIVE

To determine the effects of bovine lactoferrin (bLF) on cell viability, proliferation, and the protective roles in intestinal epithelial cells-6 (IEC-6) treated by lipopolysaccharide (LPS).

METHODS

Cell viability and proliferation of IEC-6 were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Brdu assay separately. Cell cycle distribution was analyzed by flow cytometry. Inflammatory cytokines were analysed by real-time PCR and ELISA. Western blot was utilized to measure the level of MAPK and NF-κβ nuclear translocation.

RESULTS

Dose-dependent effects of bLF on cell viability and proliferation were observed in IEC-6 cells (both P < 0.05), especially at a dose of 100 μg/ml. The percentage of cells in the G2 and S phase was significantly higher than those of the control group (8.17 ± 0.49% vs 4.72 ± 0.55%, P < 0.01 and 12.75 ± 0.33% vs 9.48 ± 0.33%, P < 0.01, respectively). The mRNA level of IL-1β, IL-6 and TNF-α was decreased by co-stimulation of bLF and LPS compared with the LPS treatments alone in IEC-6 cells (all P < 0.001). The secretion of IL-6 and TNF-α were also decreased by co-stimulation of bLF and LPS (both P < 0.01). Bovine lactoferrin treatment at dose of 100 μg/ml could inhibit the activation of MAPK/NF-κβ signal pathway induced by LPS (both P < 0.001).

CONCLUSIONS

Bovine lactoferrin could promote the cell viability and proliferation, and have anti-inflammatory effects via inhibition of the activation of MAPK and NF-κβ nuclear translocation. Supplementation of formula with bLF may be beneficial in preventing NEC in preterm infants.

Effects of Single and Combined Supplementation of Dietary Probiotic with Bovine Lactoferrin and Xylooligosaccharide on Hemato-Immunological and Digestive Enzymes of Silvery-Black Porgy (Sparidentex hasta) Fingerlings

The aim of this study was to evaluate the effects of different levels of dietary Lactobacillus plantarum as probiotic (Pro) with bovine lactoferrin (LF) and xylooligosacharide (XOS) on growth performance, hemato-immune response, body composition, digestive enzymes activity and expression of immune-related and growth-related genes of sobaity (Sparidentex hasta) for 8 weeks. Fish were fed with feed including: control diet (no LF, XOS and pro inclusion), diet 1 (400 mg kg−1 LF + 5000 mg kg−1 XOS), diet 2 (400 mg kg−1 LF + 10000 mg kg −1 XOS), diet 3 (400 mg kg−1 LF + 1 × 106 gr−1 Pro (L. plantarum)), diet 4 (800 mg kg−1 LF + 5000 mg kg −1 XOS), diet 5 (800 mg kg−1 LF + 10000 mg kg−1 XOS), diet 6 (800 mg kg−1 LF + 1 × 106 gr−1 Pro (L. plantarum)). Growth performance, hematological parameters (except for white blood cell counts), body composition and immune-related gene expression were not affected by different experimental groups (p>0.05). Nonetheless, non-specific immune response (except for total immunoglobulin) and growth-related gene expression of treatments and control group significantly varied (P<0.05). Digestive enzymes activity including total protease and amylase increased by supplementing diets with different combinations of immunostimulants (P<0.05). Our results suggest that diets supplemented with selected levels of LF, XOS and L. plantarum could not improve growth performance, body composition and hemato-immune response, but improved digestive enzyme activities in S. hasta fingerlings.

Protective effects of lactoferrin on injured intestinal epithelial cells

PURPOSE

Lactoferrin has been used as a milk supplement to prevent disease progression in necrotizing enterocolitis. However, the underlying mechanism is still unclear. We hypothesize that lactoferrin administration can modulate intestinal epithelial cell injury.

METHODS

We established an in vitro model of epithelial cell injury by treating rat intestinal epithelial cells IEC-18 and human Caco-2 cells with hydrogen peroxide (H₂O₂), while lactoferrin was added as treatment at the same time. Live/dead cells were detected by immunofluorescence. Gene expression of inflammatory markers interleukin-6 (IL-6), intestinal stem cells (Lgr5), and proliferation marker (Wnt/β-catenin) were measured. Data was presented as mean ± SEM and compared using one-way ANOVA. A p-value <0.05 was considered significant.

RESULTS

Compared to control cells, H₂O₂ induced cell death in both IEC-18 and Caco-2 cells, whereas treatment with lactoferrin maintained cell viability. In addition, lactoferrin reduced gene expression of IL-6, while it increased gene expression of Lgr5 and Wnt/β-catenin.

CONCLUSIONS

Intestinal cell injury can be induced by exposure to H₂O₂, mimicking epithelial damage during intestinal injury. This damage can be reversed by lactoferrin administration by reducing inflammation and inducing cell proliferation. Lactoferrin can be a potential pharmacological intervention for the prevention and recovery of intestinal epithelial injury.

The Impact of Lactoferrin on the Growth of Intestinal Inhabitant Bacteria

Lactoferrin (Lf) is an iron-binding milk glycoprotein that promotes the growth of selected probiotic strains. The effect of Lf on the growth and diversification of intestinal microbiota may have an impact on several issues, including (i) strengthening the permeability of the epithelial cell monolayer, (ii) favoring the microbial antagonism that discourages the colonization and proliferation of enteric pathogens, (iii) enhancing the growth and maturation of cell-monolayer components and gut nerve fibers, and (iv) providing signals to balance the anti- and pro-inflammatory responses resulting in gut homeostasis. Given the beneficial role of probiotics, this contribution aims to review the current properties of bovine and human Lf and their derivatives in in vitro probiotic growth and Lf interplay with microbiota described in the piglet model. By using Lf as a component in pharmacological products, we may enable novel strategies that promote probiotic growth while conferring antimicrobial activity against multidrug-resistant microorganisms that cause life-threatening diseases, especially in neonates.

The Risk of Necrotizing Enterocolitis Differs Among Preterm Pigs Fed Formulas With Either Lactose or Maltodextrin

OBJECTIVES

When breast milk is unavailable for preterm infants, formulas are needed that won't increase the risk of necrotizing enterocolitis (NEC). Adding novel ingredients to formula to reduce NEC has not been effective clinically. Instead, we tested the prediction that NEC can be reduced by removing the maltodextrin now included in preterm formulas.

METHODS

The preterm pig model of spontaneous NEC was used to evaluate growth, health, and intestinal responses to 6 to 7 days of feeding formulas that were identical except for the source of carbohydrate; either 100% lactose or maltodextrin; colostrum was used as the control.

RESULTS

Formula with maltodextrin resulted in a 50% incidence of NEC with 30% mortality. The lactose formula and colostrum resulted in a 0% incidence of NEC. Growth was highest for pigs fed the formula with lactose, intermediate with maltodextrin, and minimal when bovine colostrum was fed (P < 0.05). Although the small intestine was larger when colostrum was fed (P < 0.05), because rates of glucose uptake were lower (P < 0.05), total small intestine capacities to transport glucose were similar for healthy pigs in all 3 groups.

CONCLUSIONS

If lactose-based formulas reduce NEC clinically, the transition of preterm infants to enteral feeding can be accelerated, improving growth and development, and shortening reliance on parenteral nutrition. Although colostrum protects against NEC, chronic feeding does not promote body weight gain after preterm birth. The preterm pig can be used for preclinical studies that evaluate the mechanisms by which carbohydrates and other ingredients influence growth, development, health, and risk of NEC.

Preterm Life in Sterile Conditions: A Study on Preterm, Germ-Free Piglets

Preterm infants born with immature organ systems, which can impede normal development, can also be highly sensitive to different biological and/or environmental factors. Animal models could aid in investigating and understanding the effects of different conditions on the health of these immunocompromised infants. The epitheliochorial placentation of the pig prevents the prenatal transfer of protective colostral immunoglobulins. Surgical colostrum-deprived piglets are free of maternal immunoglobulins, and the cells that are normally provided via colostrum. We bred preterm germ-free piglets in sterile conditions and compared them with their term counterparts. Enterocyte development and intestinal morphology, tight junction proteins claudin-1 and occludin, pattern-recognizing receptors, adaptor molecules and coreceptors (RAGE, TLR2, TLR4, TLR9, MyD88, TRIF, MD2, and CD14), and inflammasome NLRP3 transcription were all evaluated. The production of inflammatory mediators IFN-α, IL-4, IL-6, IL-8, IL-10, IL-12/23 p40, TNF-α, IFN-γ, and high mobility group box 1 (HMGB1) in the intestine of germ-free piglets was also assessed. In the preterm germ-free piglets, the ileum showed decreased lamina propria cellularity, reduced villous height, and thinner and less distinct stratification - especially muscle layer, in comparison with their term counterparts. Claudin-1 transcription increased in the intestine of the preterm piglets. The transcription levels of pattern-recognizing receptors and adaptor molecules showed ambiguous trends between the groups. The levels of IL-6, IL-8, IL-10, and TNF-α were increased in the preterm ileum numerically (though not significantly), with statistically significant increases in the colon. Additionally, IL-12/23 p40 and IFN-γ were statistically significantly higher in the preterm colon. Both blood plasma and intestinal HMGB1 levels were nonsignificantly higher in the preterm group. We propose that the intestine of the preterm germ-free piglets showed "mild inflammation in sterile conditions." This model, which establishes preterm, hysterectomy-derived germ-free piglets, without protective maternal immunoglobulins, can be used to study influences of microbiota, nutrition, and therapeutic interventions on the development and health of vulnerable immunocompromised preterm infants.

Effect of cow colostrum on the performance and survival rate of local newborn piglets in Benin Republic

The effect of bovine colostrum, including its thermally labile compounds, on the survival and growth performance of local breed piglets reared by their mother, in Benin, was evaluated over a 49-day trial. Three groups of 16 piglets, stemming from two primiparous sows belonging to a unique traditional farm, were respectively fed for the first 48 h of life with either bovine colostrum heated to 85 °C for 30 min, or thawed bovine colostrum, or colostrum from the mother. Thereafter, the animals that received bovine colostrum turned back to their mother. At day 21, almost all piglets from the group that received heated colostrum died. The highest total weight gain was obtained in the group that received thawed bovine colostrum (P ˂ 0.01), followed by the group left with the mother. Corresponding average daily gains (ADGs) were 56, 34 and 2 g/day, respectively (P ˂ 0.05). At the end of the trial, the treatment effect was highly significant on the survival of piglets (100% in the thawed colostrum group vs. 00 and 50%, respectively, in the heated colostrum group and in the group left with the mother). At day 49, numerically higher weight and ADGs were obtained in the group that received thawed cow colostrum. Thawed bovine colostrum improved the growth performance and piglet survival in the local pig breed in Benin, probably owing to thermally labile components. Bovine colostrum may be used in our farms in order to reduce pre-weaning mortality, improve the profitability of livestock farmers, and ensure survival of traditional farms. The use of bovine colostrum on farms could be facilitated by collaboration between pig farmers and bovine farmers. It could also be facilitated by the creation of a colostrum bank.

Bovine lactoferrin free of lipopolysaccharide can induce a proinflammatory response of macrophages

Background

Lactoferrin (LF) is an 80 kDa glycoprotein which is known for its effects against bacteria, viruses and other pathogens. It also has a high potential in nutrition therapy and welfare of people and a variety of animals, including piglets. The ability to bind lipopolysaccharide (LPS) is one of the described anti-inflammatory mechanisms of LF. Previous studies suggested that cells can be stimulated even by LPS-free LF. Therefore, the aim of our study was to bring additional information about this possibility. Porcine monocyte derived macrophages (MDMF) and human embryonic kidney (HEK) cells were stimulated with unpurified LF in complex with LPS and with purified LF without bound LPS.

Results

Both cell types were stimulated with unpurified as well as purified LF. On the other hand, neither HEK0 cells not expressing any TLR nor HEK4a cells transfected with TLR4 produced any pro-inflammatory cytokine transcripts after stimulation with purified LF. This suggests that purified LF without LPS stimulates cells via another receptor than TLR4. An alternative, TLR4-independent, pathway was further confirmed by analyses of the NF-kappa-B-inducing kinase (NIK) activation. Western blot analyses showed NIK which activates different NFκB subunits compared to LF-LPS signaling via TLR4. Though, this confirmed an alternative pathway which is used by the purified LF free of LPS. This stimulation of MDMF led to low, but significant amounts of pro-inflammatory cytokines, which can be considered as a positive stimulation of the immune system.

Conclusion

Our results suggest that LF’s ability is not only to bind LPS, but LF itself may be a stimulant of pro-inflammatory pathways.

Lactoferrin and prematurity: a promising milk protein?

Lactoferrin (Lf) is the major whey protein in milk, with multiple beneficial health effects including direct antimicrobial activities, anti-inflammatory effects, and iron homeostasis. Oral Lf supplementation in human preterm infants has been shown to reduce the incidence of sepsis and necrotizing enterocolitis. In preclinical models of antenatal stress and perinatal brain injury, bovine Lf protected the developing brain from neuronal loss, improved connectivity, increased neurotrophic factors, and decreased inflammation. It also supported brain development and cognition. Further, Lf can prevent preterm delivery by reducing proinflammatory factors and inhibiting premature cervix maturation. We review here the latest research on Lf in the field of neonatology.

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.

Bovine lactoferrin regulates cell survival, apoptosis and inflammation in intestinal epithelial cells and preterm pig intestine

Bovine lactoferrin (bLF) may modulate neonatal intestinal inflammation. Previous studies in intestinal epithelial cells (IECs) indicated that moderate bLF doses enhance proliferation whereas high doses trigger inflammation. To further elucidate cellular mechanisms, we profiled the porcine IEC proteome after stimulation with bLF at 0, 0.1, 1 and 10g/L by LC-MS-based proteomics. Key pathways were analyzed in the intestine of formula-fed preterm pigs with and without supplementation of 10g/L bLF. Levels of 123 IEC proteins were altered by bLF. Low bLF doses (0.1-1g/L) up-regulated 11 proteins associated with glycolysis, energy metabolism and protein synthesis, indicating support of cell survival. In contrast, a high bLF dose (10g/L) up-regulated three apoptosis-inducing proteins, down-regulated five anti-apoptotic and proliferation-inducing proteins and 15 proteins related to energy and amino acid metabolism, and altered three proteins enhancing the hypoxia inducible factor-1 (HIF-1) pathway. In the preterm pig intestine, bLF at 10g/L decreased villus height/crypt depth ratio and up-regulated the Bax/Bcl-2 ratio and HIF-1α, indicating elevated intestinal apoptosis and inflammation. In conclusion, bLF dose-dependently affects IECs via metabolic, apoptotic and inflammatory pathways. It is important to select an appropriate dose when feeding neonates with bLF to avoid detrimental effects exerted by excessive doses.

BIOLOGICAL SIGNIFICANCE

The present work elucidates dose-dependent effects of bLF on the proteomic changes of IECs in vitro supplemented with data from a preterm pig study confirming detrimental effects of enteral feeding with the highest dose of bLF (10g/L). The study contributes to further understanding on mechanisms that bLF, as an important milk protein, can regulate the homeostasis of the immature intestine. Results from this study urge neonatologists to carefully consider the dose of bLF to supplement into infant formula used for preterm neonates.

Antimicrobial protein and Peptide concentrations and activity in human breast milk consumed by preterm infants at risk of late-onset neonatal sepsis

Objective

We investigated the levels and antimicrobial activity of antimicrobial proteins and peptides (AMPs) in breast milk consumed by preterm infants, and whether deficiencies of these factors were associated with late-onset neonatal sepsis (LOS), a bacterial infection that frequently occurs in preterm infants in the neonatal period.

Study design

Breast milk from mothers of preterm infants (≤32 weeks gestation) was collected on days 7 (n = 88) and 21 (n = 77) postpartum. Concentrations of lactoferrin, LL-37, beta-defensins 1 and 2, and alpha-defensin 5 were measured by enzyme-linked immunosorbent assay. The antimicrobial activity of breast milk samples against Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, and Streptococcus agalactiae was compared to the activity of infant formula, alone or supplemented with physiological levels of AMPs. Samples of breast milk fed to infants with and without subsequent LOS were compared for levels of AMPs and inhibition of bacterial growth.

Results

Levels of most AMPs and antibacterial activity in preterm breast milk were higher at day 7 than at day 21. Lactoferrin was the only AMP that limited pathogen growth >50% when added to formula at a concentration equivalent to that present in breast milk. Levels of AMPs were similar in the breast milk fed to infants with and without LOS, however, infants who developed LOS consumed significantly less breast milk and lower doses of milk AMPs than those who were free from LOS.

Conclusions

The concentrations of lactoferrin and defensins in preterm breast milk have antimicrobial activity against common neonatal pathogens.

Dietary bovine lactoferrin increases intestinal cell proliferation in neonatal piglets

Lactoferrin is a bioactive milk protein that stimulates cell proliferation in vitro; however, limited in vivo evidence exists to allow lactoferrin to be incorporated into infant formula. Herein, the effect of dietary bovine lactoferrin (bLF) on neonatal intestinal growth and maturation was investigated guided by the hypothesis that bLF would increase cellular proliferation leading to functional differences in neonatal piglets. Colostrum-deprived piglets were fed formula containing 0.4 [control (Ctrl)], 1.0 (LF1), or 3.6 (LF3) g bLF/L for the first 7 or 14 d of life. To provide passive immunity, sow serum was provided orally during the first 36 h of life. Intestinal cell proliferation, histomorphology, mucosal DNA concentration, enzyme activity, gene expression, and fecal bLF content were measured. Intestinal enzyme activity, DNA concentration, and villus length were unaffected by bLF. However, crypt proliferation was 60% greater in LF1- and LF3-fed piglets than in Ctrl piglets, and crypt depth and area were 20% greater in LF3-fed piglets than in Ctrl piglets. Crypt cells from LF3-fed piglets had 3-fold higher β-catenin mRNA expression than did crypt cells from Ctrl piglets. Last, feces of piglets fed bLF contained intact bLF, suggesting that some bLF was resistant to digestion and could potentially affect intestinal proliferation through direct interaction with intestinal epithelial cells. This study is the first to our knowledge to show that dietary bLF stimulates crypt cell proliferation in vivo. The increased β-catenin expression indicates that Wnt signaling may in part mediate the stimulatory effect of bLF on intestinal cell proliferation.

Intestinal proteomics in pig models of necrotising enterocolitis, short bowel syndrome and intrauterine growth restriction

Necrotising enterocolitis (NEC), short bowel syndrome (SBS) and intrauterine growth restriction (IUGR) are three conditions associated with intestinal dysfunction in newborn infants, particularly those born preterm. Piglet (Sus scrofa) models have recently been developed for NEC, SBS and IUGR, and tissue proteomic analyses have identified unknown pathways and new prognostic disease markers. Intestinal HSPs, iron metabolism proteins and proteins related to amino acid (e.g. arginine) and glucose metabolism are consistently affected by NEC progression and some of these proteins are also affected by SBS and IUGR. Parallel changes in some plasma and urinary proteins (e.g. haptoglobin, globulins, complement proteins, fatty acid binding proteins) may mirror the intestinal responses and pave the way to biomarker discovery. Explorative non-targeted proteomics provides ideas about the cellular pathways involved in intestinal adaptation during the critical neonatal period. Proteomics, combined with other -omic techniques, helps to get a more holistic picture of intestinal adaptation during NEC, SBS and IUGR. Explorative -omic research methods also have limitations and cannot replace, but only supplement, classical hypothesis-driven research that investigate disease mechanisms using a single or few endpoints.

Lactoferrin from bovine colostrum regulates prolyl hydroxylase 2 activity and prevents prion protein-mediated neuronal cell damage via cellular prion protein

Prion disorders are associated with the conversion of normal cellular prion protein (PrPc) to the abnormal scrapie isoform of prion protein (PrPsc). Recent studies have shown that expression of normal PrPc is regulated by hypoxia-inducible factor-1 alpha (HIF-1α), and that lactoferrin increases full-length PrPc on the cell surface. Lactoferrin is an 80-kDa iron-binding glycoprotein with various biological activities, including iron-chelating ability. HIF-1α and the associated ubiquitin-proteasome pathway are regulated by HIF prolyl-hydroxylases 2 (PHD2). We hypothesized that lactoferrin regulates PHD2 expression and enzymatic activity, and the PHD2 regulation promotes HIF-1α stability and prevention of neuronal cell death mediated by prion protein (PrP) residues (106-126). Lactoferrin prevented PrP (106-126)-induced neurotoxicity by the induction of PrPc expression via promoting HIF-1α stability in neuronal cells. Our results demonstrated that lactoferrin prevented PrP (106-126)-induced neurotoxicity via the up-regulation of HIF-1α stability determined by PHD2 expression and enzymatic activity. These findings suggest that possible therapies such as PHD2 inhibition, or promotion of lactoferrin secretion, may have clinical benefits in neurodegenerative diseases, including prion disease.

Transcriptomic profiling of intestinal epithelial cells in response to human, bovine and commercial bovine lactoferrins

Lactoferrin (Lf) is an iron-binding glycoprotein present in high concentration in human milk. It is a pleiotropic protein and involved in diverse bioactivities, such as stimulation of cell proliferation and immunomodulatory activities. Lf is partly resistant to proteolysis in the gastrointestinal tract. Thus, Lf may play important roles in intestinal development. Due to differences in amino acid sequences and isolation methods, Lfs from human and bovine milk as well as commercially available bovine Lf (CbLf) may differ functionally or exert their functions via various mechanisms. To provide a potential basis for further applications of CbLf, we compared effects of Lfs on intestinal transcriptomic profiling using an intestinal epithelial cell model, human intestinal epithelial crypt-like cells (HIEC). All Lfs significantly stimulated proliferation of HIEC and no significant differences were found among these three proteins. Microarray assays were used to investigate transcriptomic profiling of intestinal epithelial cells in response to Lfs. Selected genes were verified by RT-PCR with a high validation rate. Genes significantly regulated by hLf, bLf, and CbLf were 150, 395 and 453, respectively. Fifty-four genes were significantly regulated by both hLf and CbLf, whereas 129 genes were significantly modulated by bLf and CbLf. Although only a limited number of genes were regulated by all Lfs, the three Lfs positively influenced cellular development and immune functions based on pathway analysis using IPA (Ingenuity). Lfs stimulate cellular and intestinal development and immune functions via various signaling pathways, such as Wnt/β-catenin signaling, interferon signaling and IL-8 signaling.