Natural killer cell populations and cytotoxic activity in pigs fed mother's milk, formula, or formula supplemented with bovine lactoferrin

Lingering Effects of Early Institutional Rearing and Cytomegalovirus Infection on the Natural Killer Cell Repertoire of Adopted Adolescents

Adversity during infancy can affect neurobehavioral development and perturb the maturation of physiological systems. Dysregulated immune and inflammatory responses contribute to many of the later effects on health. Whether normalization can occur following a transition to more nurturing, benevolent conditions is unclear. To assess the potential for recovery, blood samples were obtained from 45 adolescents adopted by supportive families after impoverished infancies in institutional settings (post-institutionalized, PI). Their immune profiles were compared to 39 age-matched controls raised by their biological parents (non-adopted, NA). Leukocytes were immunophenotyped, and this analysis focuses on natural killer (NK) cell populations in circulation. Cytomegalovirus (CMV) seropositivity was evaluated to determine if early infection contributed to the impact of an atypical rearing. Associations with tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ), two cytokines released by activated NK cells, were examined. Compared to the NA controls, PI adolescents had a lower percent of CD56bright NK cells in circulation, higher TNF-α levels, and were more likely to be infected with CMV. PI adolescents who were latent carriers of CMV expressed NKG2C and CD57 surface markers on more NK cells, including CD56dim lineages. The NK cell repertoire revealed lingering immune effects of early rearing while still maintaining an overall integrity and resilience.

Immunoregulatory actions of calf thymus extract (TFX®) in vitro in relation to its effect on expression of mitogen activated protein kinases

The in vitro immunotropic actions of a calf thymus extract - thymus factor X (TFX®) preparation were investigated. The preparation did not lower the viability of the A549 epithelial cell line and mouse bone marrow cells in the investigated concentration range. TFX® exhibited a co-stimulatory action of concanavalin A (Con A)-induced mouse thymocyte proliferation and partially restored the mitogen-induced proliferation capability of mouse thymocytes exposed to hydrocortisone (HC). The preparation also inhibited Herpes virus-1 (HSV-1) replication in A549 cells when preincubated with the virus and when added to the infected cells. In addition, it weakly inhibited lipopolysaccharide (LPS)-induced TNF α, IL-1β and IL-6 by the THP-1 monocyte cell line. The determination of mitogen activated protein kinase (MAPK) expression in Jurkat T cells revealed strong increases in ERK-2 kinase and p38α subunits. In WEHI 231 immature B cells, TFX® elevated p38α, and had a particularly strong elevating effect on p38γ. In HL-60 myeloblastic cells, the expression of p38α, β and γ was not detectable, almost blocked for p38δ and JNK, but accompanied by an increase in ERK-1. In turn, the effects of TFX® in J744E macrophages resulted in a strong increase in p38γ expression, moderate elevations of ERK and a drop in p38δ. Significant increases in MAPK expression were also found in cells from the lymphoid organs. In the bone marrow cell population, p38α, β and γ, in thymocytes p38α, γ and δ, and in splenocytes p38β and γ, subunit expression was elevated. We conclude that the changes in MAPK expression may be attributed to cell maturation and differentiation, and explain the beneficial therapeutic effects of TFX®.

Effects of oral probiotic and lactoferrin interventions on iron-zinc homeostasis, oxidant/antioxidant equilibrium and diarrhoea incidence of neonatal piglets

The objective of this study was to examine the effects of early-life host specific probiotic and lactoferrin (LF) supplementations on diarrhoea incidence, iron (Fe)-zinc (Zn) balance and antioxidant capabilities in serum of neonatal piglets. A total of eight sow litters obtained from parity matched sows were randomly divided into four groups and assigned to one of the four interventions: control (2.0 ml normal saline), bovine lactoferrin (bLF) (100 mg bLF in normal saline), probiotic (Pb) (1×109 cfu of swine origin Pediococcus acidilactici FT28 strain) and bLF+Pb (both 100 mg bLF and 1×109 cfu of P. acidilactici FT28). All the piglets received supplementations once daily orally for first 7 days of life. The incidence of diarrhoea markedly decreased in bLF group compared to control group. Notably, no incidences of diarrhoea were recorded in Pb and bLF+Pb groups. The Zn and Fe concentrations were significantly increased from day 7 to 21 in bLF and on day 21 in bLF+Pb group. No such changes were noted in Pb group. Total antioxidant capacity (TAC) in serum was significantly increased on days 7 and 15 in bLF group and on days 7 and 21 in bLF+Pb group. Malonaldehyde concentration was markedly reduced from day 7 to 21 in bLF and bLF+Pb groups. The concentrations of nitrate on days 15 and 21 and malonaldehyde on day 7 were significantly higher in Pb group, but mean TAC was unaltered from day 0 to 21. Although no correlation between the incidence of diarrhoea and Zn/Fe and oxidant/antioxidant homeostasis was noted in the Pb group, the supplementation of P. acidilactici FT28 alone was sufficient to prevent the incidence of diarrhoea in neonatal piglets. Taken together, it is concluded that strategic supplementation of P. acidilactici FT28 in early life could help in preventing diarrhoea until weaning of piglets.

The application of lactoferrin in infant formula: The past, present and future

Human milk is universally regarded as the gold standard to fulfill nutrition needs of infants. Lactoferrin (LF) is a major multiple bioactive glycoprotein in human milk but little is presented in infant formula. LF can resist digestion in the infant gastrointestinal tract and is absorbed into the bloodstream in an intact form to perform physiological functions. Evidence suggest that LF prevents pathogen infection, promotes immune system development, intestinal development, brain development and bone health, as well as ameliorates iron deficiency anemia. However, more clinical studies of LF need to be further elucidated to determine an appropriate dosage for application in infant formula. LF is sensitive to denaturation induced by processing of infant formula such as heat treatments and spay drying. Thus, further studies should be focus on maximizing the retention of LF activity in the infant formula process. This review summarizes the structural features of LF. Then the digestion, absorption and metabolism of LF in infants are discussed, followed by the function of LF for infants. Further, we summarize LF in infant formula and effects of processing of infant formula on bioactivities of LF, as well as future perspectives of LF research.

Human Breast Milk: The Key Role in the Maturation of Immune, Gastrointestinal and Central Nervous Systems: A Narrative Review

Premature birth is a major cause of mortality and morbidity in the pediatric population. Because their immune, gastrointestinal and nervous systems are not fully developed, preterm infants (<37 weeks of gestation) and especially very preterm infants (VPIs, <32 weeks of gestation) are more prone to infectious diseases, tissue damage and future neurodevelopmental impairment. The aim of this narrative review is to report the immaturity of VPI systems and examine the role of Human Breast Milk (HBM) in their development and protection against infectious diseases, inflammation and tissue damage. For this purpose, we searched and synthesized the data from the existing literature published in the English language. Studies revealed the significance of HBM and indicate HBM as the best dietary choice for VPIs.

Breast Milk: A Meal Worth Having

A mother is gifted with breast milk, the natural source of nutrition for her infant. In addition to the wealth of macro and micro-nutrients, human milk also contains many microorganisms, few of which originate from the mother, while others are acquired from the mouth of the infant and the surroundings. Among these microbes, the most commonly residing bacteria are Staphylococci, Streptococci, Lactobacilli and Bifidobacteria. These microorganisms initiate and help the development of the milk microbiota as well as the microbiota of the gastrointestinal tract in infants, and contribute to developing immune regulatory factors such as cytokines, growth factors, lactoferrin among others. These factors play an important role in reducing the risk of developing chronic diseases like type 2 diabetes, asthma and others later in life. In this review, we will summarize the known benefits of breastfeeding and highlight the role of the breast milk microbiota and its cross-talk with the immune system in breastfed babies during the early years of life.

Role of Human Milk Bioactives on Infants' Gut and Immune Health

Exclusive human milk feeding of the newborn is recommended during the first 6 months of life to promote optimal health outcomes during early life and beyond. Human milk contains a variety of bioactive factors such as hormones, cytokines, leukocytes, immunoglobulins, lactoferrin, lysozyme, stem cells, human milk oligosaccharides (HMOs), microbiota, and microRNAs. Recent findings highlighted the potential importance of adding HMOs into infant formula for their roles in enhancing host defense mechanisms in neonates. Therefore, understanding the roles of human milk bioactive factors on immune function is critical to build the scientific evidence base around breastfeeding recommendations, and to enhance positive health outcomes in formula fed infants through modifications to formulas. However, there are still knowledge gaps concerning the roles of different milk components, the interactions between the different components, and the mechanisms behind health outcomes are poorly understood. This review aims to show the current knowledge about HMOs, milk microbiota, immunoglobulins, lactoferrin, and milk microRNAs (miRNAs) and how these could have similar mechanisms of regulating gut and microbiota function. It will also highlight the knowledge gaps for future research.

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.

Lactoferrin for the treatment of COVID-19 (Review)

The coronavirus disease 2019 (COVID-19) outbreak was caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The clinical outcomes of elderly individuals and those with underlying diseases affected by COVID-19 are serious, and may result in acute respiratory distress syndrome (ARDS) and even mortality. Currently, the clinical treatments for COVID-19 mostly involve symptom alleviation measures and non-specific broad spectrum antiviral drugs, as highly effective antiviral drugs and vaccines are not yet available. Lactoferrin (LF) is a safe iron-binding glycoprotein that is present in the milk of the majority of mammals and exhibits broad-spectrum antiviral activity, including against coronaviruses. In addition, LF also exhibits anti-inflammatory, anti-infective and immune-regulating properties, which are in line with the treatment requirements for SARS-CoV-2 infection. Therefore, the use of LF may be of value in the prevention and/or management of COVID-19. The aim of the present review was to summarize the previous reports on the antiviral properties of LF and compare these with the characteristics of SARS-CoV-2 infection, in order to determine whether LF could be used to assist in the prevention of COVID-19 and to investigate the possible underlying mechanisms governing its mode of action.

Cyberlindnera jadinii Yeast as a Protein Source for Weaned Piglets-Impact on Immune Response and Gut Microbiota

Supplying novel feed ingredients for pig production is crucial to enhance food security and decrease the environmental impact of meat production. Several studies have focused on evaluating the beneficial health effects of yeast in pigs. However, its use as a protein source has been partially addressed. Previously, we have shown that yeast at high inclusion levels maintains growth performance and digestibility, while nutrient digestibility, intestinal villi height and fecal consistency were improved. The present study combined microbiome, short-chain fatty acid, and immune parameter analysis to investigate the effect of high inclusion of yeast in diets for post-weaning piglets. Our results showed that yeast did not have a significant impact on the hematological or biochemical parameters in blood. The different immune cell subpopulations isolated from blood and distal jejunal lymph nodes (DJLN) were analyzed by flow cytometry and showed that yeast diet induced an increased number of the subtype of leukocytes CD45+/CD3-/CD8+, a special type of Natural Killer (NK) cells. Also, a very mild to moderate infiltration of neutrophilic granulocytes and lower IgA level were observed in the colon of yeast fed piglets. The microbiome profiling in different compartments of the gastrointestinal tract of piglets was performed using 16S rRNA metabarcoding. The results showed that 40% replacement of dietary protein had a statistically significant effect on the microbial communities in cecum and colon, while the microbial population in ileum and jejunum were not affected. Analysis of predicted microbial metabolic pathways analysis revealed significant upregulation of short-chain fatty acids, ether lipid metabolisms, secondary bile acids, and several other important biosynthesis pathways in cecum and colon of pigs fed yeast. In conclusion, the results showed that diet containing 40% of yeast protein positively shaped microbial community in the large intestine and increased the number of a specific subpopulation of NK cells in the DJLN. These results showed that yeast modulates the microbiome and decreases the secretion of IgA in the colon of post-weaning pigs.

Human Breast-Milk Feeding Enhances the Humoral and Cell-Mediated Immune Response in Neonatal Piglets

Background

The benefits of breastfeeding infants are well characterized, including those on the immune system. However, determining the mechanism by which human breast milk (HBM) elicits effects on immune response requires investigation in an appropriate animal model.

Objective

The primary aim of this study was to develop a novel porcine model and to determine the differential effects of feeding HBM and a commercial milk formula (MF) on immune response and gastrointestinal microbial colonization in a controlled environment.

Methods

Male piglets were fed HBM (n = 26) or MF (n = 26) from day 2 through day 21. Piglets were vaccinated (n = 9/diet group) with cholera toxin and cholera toxin subunit B (CTB) and tetanus toxoid at 21 d or were fed placebo (n = 6/diet group) and then weaned to a standard solid diet at the age of 21 d. Humoral and cell-mediated immune responses were assessed from blood on days 35 and 48. Immune response was further examined from tissues, including mesenteric lymph nodes (MLNs), Peyer's patches (PPs), and spleen. The colonization of gut microbiota was characterized from feces on days 16 and 49.

Results

Serum antibody titers in piglets fed HBM were 4-fold higher (P < 0.05) to CTB and 3-fold higher (P < 0.05) to tetanus toxoid compared with piglets fed MF on day 48. Compared with MF, the numbers of immunoglobulin A antibody-producing cells to CTB were 13-fold higher (P < 0.05) in MLNs and 11-fold higher (P < 0.05) in PPs in the HBM diet group on day 51. In addition, significantly increased T cell proliferation was observed in the HBM group relative to the MF group. Furthermore, microbial diversity in the HBM group was lower (P < 0.05) than in the MF group.

Conclusions

This porcine model appears to be valid for studying the effects of early postnatal diet on immune responses and the gastrointestinal microbiome. Our results lay the groundwork for future studies defining the role of infant diet on microbiota and immune function.

Bioavailability of a Novel Form of Microencapsulated Bovine Lactoferrin and Its Effect on Inflammatory Markers and the Gut Microbiome: A Pilot Study

Bovine lactoferrin, extracted from milk or whey, is used in a range of products to enhance immunity and support digestive health, iron absorption, and homeostasis. This study examined the absorption and effect of Progel (Brisbane, Queensland, Australia) microencapsulated bovine lactoferrin (Inferrin^TM, Bega Bionutrients, Victoria, Australia) on immune markers and the microbiome. A double-blind randomised, cross-over trial was conducted with 12 healthy males randomised to one of two doses, equivalent to 200 mg or 600 mg lactoferrin, for two four-week supplementation arms, with a two-week washout period. Subjects received either standard bovine lactoferrin or Inferrin^TM for each arm. Baseline and post each trial arm, CD69+ activation on CD4+ and CD8+ cells was analysed, bovine and human lactoferrin contents of faecal and serum samples were reported, and the gut microbiome was analysed using 16S sequencing and metagenomic sequencing. The mean level of CD69+ activation on the CD4+ cells was lower after supplementation regardless of the form or dose of lactoferrin. This was statistically significant for the 200 mg dose. A higher level of bovine lactoferrin was found post-supplementation in those taking Inferrin^TM, although this was not statistically significant. Changes in phylum-level microbial community profiling were detected post-supplementation in the second trial arm, particularly in those receiving Inferrin^TM. Metagenomic sequencing showed changes in the volumes of the top 100 species of bacteria present before and after all treatment arms. Results suggest that lactoferrin supplementation may have beneficial effects on the microbiome and immune system, and that the use of Inferrin^TM improves absorption. Larger detailed studies are needed to ascertain the potential positive effects of bovine lactoferrin supplementation.

Correlation analyses of CpG island methylation of cluster of differentiation 4 protein with gene expression and T lymphocyte subpopulation traits

Objective

Cluster of differentiation 4 protein (CD4) gene is an important immune related gene which plays a significant role in T cell development and host resistance during viral infection.

Methods

In order to unravel the relationship of CpG island methylation level of CD4 gene with its gene expression and T lymphocyte subpopulation traits, we used one typical Chinese indigenous breed (Dapulian, DP) and one commercial breed (Landrace), then predicted the CpG island of CD4 gene, determined the methylation status of CpG sites by bisulfite sequencing polymerase chain reaction (BSP), and carried out the correlation analyses of methylation frequencies of CpG sites with mRNA expression and T lymphocyte subpopulation traits.

Results

There was one CpG island predicted in the upstream −2 kb region and exon one of porcine CD4 gene, which located 333 bp upstream from the start site of gene and contained nine CpG sites. The correlation analysis results indicated that the methylation frequency of CpG_2 significantly correlated with CD4 mRNA expression in the DP and Landrace combined population, though it did not reach significance level in DP and Landrace separately. Additionally, 15 potential binding transcription factors (TFs) were predicted within the CpG island, and one of them (Jumonji) contained CpG_2 site, suggesting that it may influence the CD4 gene expression through the potential binding TFs. We also found methylation frequency of CpG_2 negatively correlated with T lymphocyte subpopulation traits CD4+CD8−CD3−, CD4−CD8+CD3− and CD4+/CD8+, and positively correlated with CD4−CD8+CD3+ and CD4+CD8+CD3+ (for all correlation, p<0.01) in DP and Landrace combined population. Thus, the CpG_2 was a critical methylation site for porcine CD4 gene expression and T lymphocyte subpopulation traits.

Conclusion

We speculated that increased methylation frequency of CpG_2 may lead to the decreased expression of CD4, which may have some kind of influence on T lymphocyte subpopulation traits and the immunity of DP population.

Effects of Recombinant Human Lactoferrin on Osteoblast Growth and Bone Status in Piglets

Lactoferrin (LF), an ~80 kDa iron-binding glycoprotein, modulates many biological effects, including antimicrobial and immunomodulatory activities. Recently, it was shown that LF also regulates bone cell activity, suggesting its therapeutic effect on postmenopausal bone loss. However, a minimal amount is known regarding the effects of recombinant human LF (rhLF) supplementation on bone status in young healthy infants. We found osteoblast cell differentiation was significantly promoted in vitro. Furthermore, treatment of human osteoblast cells with rhLF rapidly induced phosphorylation of p44/p42 mitogen-activated protein kinase (p44/p42 MAPK, ERK1/2). In order to investigate the effects of rhLF on bone status in vivo, we used a piglet model, which is a useful model for human infants. Piglets were supplemented with rhLF milk for 30 days. Bone formation markers, Serum calcium concentration, bone mineral density (BMD), bone mineral content (BMC), tibia bone strength, and the overall metabolite profile analysis showed that rhLF was advantageous to the bone growth in piglets. These findings suggest that rhLF supplementation benefits neonate bone health by modulating bone formation.

Prebiotics and Bioactive Milk Fractions Affect Gut Development, Microbiota, and Neurotransmitter Expression in Piglets

OBJECTIVE

This study tested the hypothesis that the addition of prebiotics and 2 functional milk ingredients to infant formula would maintain normal growth and gut development, and modify microbiota composition and neurotransmitter gene expression in neonatal piglets.

METHODS

Two-day-old male piglets (n = 24) were fed formula (CONT) or formula with polydextrose (1.2 g/100 g diet), galactooligosaccharides (3.5 g/100 g diet), bovine lactoferrin (0.3 g/100 g diet), and milk fat globule membrane-10 (2.5 g/100 g diet) (TEST) for 30 days. On study day 31, intestinal samples, ileal and colonic contents, and feces were collected. Intestinal histomorphology, disaccharidase activity, serotonin (5'HT), vasoactive intestinal peptide (VIP), and tyrosine hydroxylase (TH) were measured. Gut microbiota composition was assessed by pyrosequencing of the V3-V5 regions of 16S rRNA and quantitative polymerase chain reaction.

RESULTS

Body weight of piglets on TEST was greater (P ≤ 0.05) than CONT on days 17 to 30. Both groups displayed growth patterns within the range observed for sow-reared pigs. TEST piglets had greater jejunal lactase (P = 0.03) and higher (P = 0.003) ileal VIP expression. TEST piglets tended to have greater (P = 0.09) sucrase activity, longer (P = 0.08) ileal villi, and greater (P = 0.06) duodenal TH expression. Microbial communities of TEST piglets differed from CONT in ascending colon (AC, P = 0.001) and feces (P ≤ 0.05). CONT piglets had greater relative abundances of Mogibacterium, Collinsella, Klebsiella, Escherichia/Shigella, Eubacterium, and Roseburia compared with TEST piglets in AC. In feces, CONT piglets harbored lower (P ≤ 0.05) proportions of Parabacteroides, Clostridium IV, Lutispora, and Sutterella than TEST piglets.

CONCLUSIONS

A mixture of bioactive ingredients improved weight gain and gut maturation, modulated colonic and fecal microbial composition, and reduced the proportions of opportunistic pathogens.

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.

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.

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.

Dietary bovine lactoferrin alters mucosal and systemic immune cell responses in neonatal piglets

Lactoferrin (LF) is a multifunctional immune protein found at high concentrations in human milk. Herein, the effect of dietary bovine LF (bLF) on mucosal and systemic immune development was investigated. Colostrum-deprived piglets were fed formula containing 130 [control (Ctrl)], 367 (LF1), or 1300 (LF3) mg of bLF/(kg body weight · d). To provide passive immunity, sow serum was provided orally during the first 36 h of life. Blood, spleen, mesenteric lymph node (MLN), and ascending colon (Asc) contents were collected on day 7 (n = 10-14/group) and day 14 (n = 10-12/group). Immune cell populations were quantified by flow cytometry and immunoglobulins (Igs) were measured by ELISA. Additionally, immune cells were isolated from spleen and MLNs (n = 7/group) on day 7 and stimulated ex vivo with phytohemagglutinin or lipopolysaccharide (LPS) ± LF for 72 h. Secreted cytokine concentrations were quantified by multiplex assay. Lymphocyte populations [cluster determinant (CD)4, CD8, and natural killer cells] developed normally and were unaffected by dietary bLF. LF3 piglets tended to have 1.4 to 2 times more serum IgG than Ctrl piglets (P = 0.07) or LF1 piglets (P = 0.03), but IgA in Asc contents was unaffected by bLF. Asc IgA was 4 times higher on day 14 than day 7. Spleen cells from LF3 piglets produced 2 times more interleukin (IL)-10 and tumor necrosis factor (TNF)-α ex vivo than those from Ctrl or LF1 piglets. MLN cells from LF1 and LF3 piglets produced 40% more IL-10 and tended to produce 40% more IL-6 (P = 0.05) than those from Ctrl piglets. However, ex vivo bLF did not affect the cytokine response of spleen or MLN cells to LPS. In summary, dietary bLF alters the capacity of MLN and spleen immune cells to respond to stimulation, supporting a role for LF in the initiation of protective immune responses in these immunologically challenged neonates.

Gut-targeted immunonutrition boosting natural killer cell activity using Saccharomyces boulardii lysates in immuno-compromised healthy elderly subjects

The aim of this study was to assess the immunomodulatory effect of KC-1317 (a symbiotic mixture containing Saccharomyces boulardii lysate in a cranberry, colostrum-derived lactoferrin, fragaria, and lactose mixture) supplementation in immune-compromised but otherwise healthy elderly subjects. A liquid formulation of KC-1317 was administered in a randomized controlled trial (RCT) fashion to healthy volunteers (65-79 years) previously selected for low natural killer (NK) cell activity, and this parameter was checked at the completion of the study. A significant improvement in NK cell activity of KC-1317 consumers was observed as compared to placebo at the end of 2 months. Although preliminary, these beneficial immune-modulatory effects of KC-1317 in aged individuals might indicate its employment within a wider age-management strategy.