Oral ingestion of colostrum alters intestinal transforming growth factor-beta receptor intensity in newborn pigs

Dietary lysozyme supplementation contributes to enhanced intestinal functions and gut microflora of piglets

Lysozyme plays a significant role in defense against bacterial pathogens and in regulating the interactions between gut microbiota and host immune systems. Here, the effects of dietary lysozyme on the intestinal development, immunity, and colonic microbiota of piglets were comprehensively evaluated. Twenty-four seven-day-old piglets from Landrace × Yorkshire sows (n = 8 per group) received no supplementation (group A, the control), 0.5 g kg-1 lysozyme (group B), or 1.0 g kg-1 lysozyme (group C). After the 14-day treatment, piglets supplemented with 1.0 g kg-1 lysozyme had higher average weaning weight, jejunal villus height (VH), and ileal lymphocyte counts than those in the control groups (P < 0.005). Serum total protein and albumin were significantly up-regulated (P < 0.005) and immunoglobulin G tended to increase in the 0.5 g kg-1 lysozyme group (P = 0.065). Bacteroidetes, Proteobacteria, and Fibrobacteres all showed a significant increase in relative abundance after lysozyme treatment at the highest dosage (P < 0.005). At the genus level, the relative abundance of Lactobacillus, Treponema_2, and Prevotellaceae_NK3B31_group was significantly increased in the lysozyme-treated groups. Furthermore, microbial genes related to glycerolipid, propanoate, and pyruvate metabolism showed much more abundance in the 1.0 g kg-1 lysozyme group. Interleukin-4 in the colonic mucosa was significantly up-regulated, while transforming growth factor-β1 showed significant reduction in the lysozyme-treated group. Moreover, mucosal catalase and malondialdehyde in colon samples increased significantly. These results demonstrate that dietary lysozyme efficaciously improves the development of intestinal structure and functions and promotes the enrichment of beneficial microbes in the gut microbiota in terms of both composition and metabolic functions.

Recent progress of porcine milk components and mammary gland function

As the only nutritional source for newborn piglets, porcine colostrum and milk contain critical nutritional and immunological components including carbohydrates, lipids, and proteins (immunoglobulins). However, porcine milk composition is more complex than these three components. Recently, scientists identified additional and novel components of sow colostrum and milk, including exosomes, oligosaccharides, and bacteria, which possibly act as biological signals and modulate the intestinal environment and immune status in piglets and later in life. Evaluation of these nutritional and non-nutritional components in porcine milk will help better understand the nutritional and biological function of porcine colostrum and milk. Furthermore, some important functions of the porcine mammary gland have been reported in recent published literature. These preliminary studies hypothesized how glucose, amino acids, and fatty acids are transported from maternal blood to the porcine mammary gland for milk synthesis. Therefore, we summarized recent reports on sow milk composition and porcine mammary gland function in this review, with particular emphasis on macronutrient transfer and synthesis mechanisms, which might offer a possible approach for regulation of milk synthesis in the future.

Facilitating Colostrum Collection by Hospitalized Women in the Early Postpartum Period for Infant Trophic Feeding and Oral Immune Therapy

Administration of colostrum for early trophic feedings and colostrum oral immune therapy for neonates in the NICU is essential to enhance gut maturation and lower risk of infections. However, it is often difficult for women to collect early colostrum because of its thick viscosity and low volume. Women may be unable to sit upright during pumping sessions because of postsurgical pain, acute or chronic illness, or birth complications and may need assistance. In this article, we describe specific techniques that providers can use to help women to collect colostrum when they are unable to accomplish collection on their own. Helping women collect and administer colostrum to their neonates in the NICU may engage and motivate them to continue to pump and provide breast milk for their hospitalized neonates.

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.

Whey protein concentrate enhances intestinal integrity and influences transforming growth factor-β1 and mitogen-activated protein kinase signalling pathways in piglets after lipopolysaccharide challenge

Whey protein concentrate (WPC) has been reported to have protective effects on the intestinal barrier. However, the molecular mechanisms involved are not fully elucidated. Transforming growth factor-β1 (TGF-β1) is an important component in the WPC, but whether TGF-β1 plays a role in these processes is not clear. The aim of this study was to investigate the protective effects of WPC on the intestinal epithelial barrier as well as whether TGF-β1 is involved in these protection processes in a piglet model after lipopolysaccharide (LPS) challenge. In total, eighteen weanling pigs were randomly allocated to one of the following three treatment groups: (1) non-challenged control and control diet; (2) LPS-challenged control and control diet; (3) LPS+5 %WPC diet. After 19 d of feeding with control or 5 %WPC diets, pigs were injected with LPS or saline. At 4 h after injection, pigs were killed to harvest jejunal samples. The results showed that WPC improved (P<0·05) intestinal morphology, as indicated by greater villus height and villus height:crypt depth ratio, and intestinal barrier function, which was reflected by increased transepithelial electrical resistance and decreased mucosal-to-serosal paracellular flux of dextran (4 kDa), compared with the LPS group. Moreover, WPC prevented the LPS-induced decrease (P<0·05) in claudin-1, occludin and zonula occludens-1 expressions in the jejunal mucosae. WPC also attenuated intestinal inflammation, indicated by decreased (P<0·05) mRNA expressions of TNF-α, IL-6, IL-8 and IL-1β. Supplementation with WPC also increased (P<0·05) TGF-β1 protein, phosphorylated-Smad2 expression and Smad4 and Smad7 mRNA expressions and decreased (P<0·05) the ratios of the phosphorylated to total c-jun N-terminal kinase (JNK) and p38 (phospho-JNK:JNK and p-p38:p38), whereas it increased (P<0·05) the ratio of extracellular signal-regulated kinase (ERK) (phospho-ERK:ERK). Collectively, these results suggest that dietary inclusion of WPC attenuates the LPS-induced intestinal injury by improving mucosal barrier function, alleviating intestinal inflammation and influencing TGF-β1 canonical Smad and mitogen-activated protein kinase signalling pathways.

Transforming growth factor-β2 and endotoxin interact to regulate homeostasis via interleukin-8 levels in the immature intestine

A balance between pro- and anti-inflammatory signals from milk and microbiota controls intestinal homeostasis just after birth, and an optimal balance is particularly important for preterm neonates that are sensitive to necrotizing enterocolitis (NEC). We suggest that the intestinal cytokine IL-8 plays an important role and hypothesize that transforming growth factor-β2 (TGF-β2) acts in synergy with bacterial lipopolysaccharide (LPS) to control IL-8 levels, thereby supporting intestinal homeostasis. Preterm pigs were fed colostrum (containing TGF-β2) or infant formula (IF) with or without antibiotics (COLOS, n = 27; ANTI, n = 11; IF, n = 40). Intestinal IL-8 levels and NEC incidence were much higher in IF than in COLOS and ANTI pigs (P < 0.001), but IL-8 levels did not correlate with NEC severity. Intestinal TGF-β2 levels were high in COLOS but low in IF and ANTI pigs. Based on these observations, the interplay among IL-8, TGF-β2, and LPS was investigated in a porcine intestinal epithelial cell line. TGF-β2 attenuated LPS-induced IL-6, IL-1β, and TNF-α release by reducing early ERK activation, whereas IL-8 secretion was synergistically induced by LPS and TGF-β2 via NF-κB. The TGF-β2/LPS-induced IL-8 levels stimulated cell proliferation and migration following epithelial injury, without continuous NF-κB activation and cyclooxygenase-2 expression. We suggest that a combined TGF-β2-LPS induction of IL-8 stimulates epithelial repair just after birth when the intestine is first exposed to colonizing bacteria and TGF-β2-containing milk. Moderate IL-8 levels may act to control intestinal inflammation, whereas excessive IL-8 production may enhance the damaging proinflammatory cascade leading to NEC.

Developmental changes of TGF-β1 and Smads signaling pathway in intestinal adaption of weaned pigs

Weaning stress caused marked changes in intestinal structure and function. Transforming growth factor-β1 (TGF-β1) and canonical Smads signaling pathway are suspected to play an important regulatory role in post-weaning adaptation of the small intestine. In the present study, the intestinal morphology and permeability, developmental expressions of tight junction proteins and TGF-β1 in the intestine of piglets during the 2 weeks after weaning were assessed. The expressions of TGF-β receptor I/II (TβRI, TβRII), smad2/3, smad4 and smad7 were determined to investigate whether canonical smads signaling pathways were involved in early weaning adaption process. The results showed that a shorter villus and deeper crypt were observed on d 3 and d 7 postweaning and intestinal morphology recovered to preweaning values on d 14 postweaning. Early weaning increased (P<0.05) plasma level of diamine oxidase (DAO) and decreased DAO activities (P<0.05) in intestinal mucosa on d 3 and d 7 post-weaning. Compared with the pre-weaning stage (d 0), tight junction proteins level of occludin and claudin-1 were reduced (P<0.05) on d 3, 7 and 14 post-weaning, and ZO-1 protein was reduced (P<0.05) on d 3 and d 7 post-weaning. An increase (P<0.05) of TGF-β1 in intestinal mucosa was observed on d 3 and d 7 and then level down on d 14 post-weaning. Although there was an increase (P<0.05) of TβR II protein expression in the intestinal mucosa on d3 and d 7, no significant increase of mRNA of TβRI, TβRII, smad2/3, smad4 and smad7 was observed during postweaning. The results indicated that TGF-β1 was associated with the restoration of intestinal morphology and barrier function following weaning stress. The increased intestinal endogenous TGF-β1 didn't activate the canonical Smads signaling pathway.

Neonatal piglet survival: impact of sow nutrition around parturition on fetal glycogen deposition and production and composition of colostrum and transient milk

Piglet survival is a major problem, especially during the first 3 days after birth. Piglets are born deficient of energy, but at the same time they have a very high energy requirement because of high physical activity, high need for thermoregulation (because of their lean body with low insulation) and high heat production in muscle tissues. To be able to survive, newborn piglets may rely upon three different sources of energy, namely, glycogen, colostrum and transient milk, which orchestrate to cover their energy requirements. Piglets are born with limited amounts of energy in glycogen depots in the liver and muscle tissues and these depots are sufficient for normal activity for ∼16 h. Intake and oxidation of fat and lactose from colostrum must supply sufficient amount of energy to cover at least another 18 h until transient milk becomes available in the sow udder ∼34 h after the first piglet is born. Selection for large litters during the last two decades has challenged piglets even further during the critical neonatal phase because the selection programs indirectly decreased birth weight of piglets and because increased litter size has increased the competition between littermates. Different attempts have been made to increase the short-term survival of piglets, that is, survival until day 3 of lactation, by focusing on improving transfer of vital maternal energy to the offspring, either in utero or via mammary secretions. Thus, the present review addresses how sow nutrition in late gestation may favor survival of newborn piglets by increasing glycogen depots, improving colostrum yield or colostrum composition, or by increasing production of transient milk.

Quality indicators for human milk use in very low-birthweight infants: are we measuring what we should be measuring?

OBJECTIVE

The objective of this study was to compare the currently used human milk (HM) quality indicators that measure whether very low-birthweight (VLBW; <1500 g birthweight) infants 'ever' received HM and whether they were still receiving HM at discharge from the neonatal intensive care unit (NICU) to the actual amount and timing of HM received.

STUDY DESIGN

This study used data from a large NIH-funded cohort study and calculated whether VLBW infants ever received HM (HM-Ever) and of these infants, the percentage who were still receiving HM at NICU discharge (HM-DC). Then, the HM-DC indicator (exclusive, partial and none) was compared with the amount and timing of HM feedings received by these same infants.

RESULT

Of the 291 VLBW infants who met inclusion criteria, 285 received some HM (HM-Ever=98%). At NICU discharge (HM-DC), 24.2, 15.1 and 60.7% were receiving exclusive, partial and no HM, respectively. Of the 60.7% infants with no HM-DC, some had received higher amounts of HM during the NICU hospitalization than infants categorized as exclusive and partial for HM-DC. Of the infants with no HM-DC, 76.8 and 59.7% had received exclusive HM during the days 1-14 and days 1-28 exposure periods, respectively.

CONCLUSION

The average daily dose (HM-DD; in ml kg(-1) d(-1)) and cumulative percentage (HM-PCT; as % of cumulative enteral intake) of HM feedings were sufficient to significantly reduce the risk of multiple morbidities, including late-onset sepsis, necrotizing enterocolitis, neurocognitive delay and rehospitalization, in the majority of the VLBW infants who were discharged with no HM-DC. Quality indicators that focus on the amount and timing of HM feedings in the NICU should be added to the HM-Ever and HM-DC measures.

Supporting breastfeeding in the neonatal intensive care unit: Rush Mother's Milk Club as a case study of evidence-based care

The translation of the evidence for the use of human milk (HM) in the neonatal intensive care unit (NICU) into best practices, toolkits, policies and procedures, talking points, and parent information packets is limited, and requires use of evidence-based quality indicators to benchmark the use of HM, consistent messaging by the entire NICU team about the importance of HM for infants in the NICU, establishing procedures that protect maternal milk supply, and incorporating lactation technologies that take the guesswork out of HM feedings and facilitate milk transfer during breastfeeding.

Improving the use of human milk during and after the NICU stay

The feeding of human milk (milk from the infant's own mother; excluding donor milk) during the newborn intensive care unit (NICU) stay reduces the risk of costly and handicapping morbidities in premature infants. The mechanisms by which human milk provides this protection are varied and synergistic, and appear to change over the course of the NICU stay. The fact that these mechanisms include specific human milk components that are not present in the milk of other mammals means that human milk from the infant's mother cannot be replaced by commercial infant or donor human milk, and the feeding of human milk should be a NICU priority. Recent evidence suggests that the impact of human milk on improving infant health outcomes and reducing the risk of prematurity-specific morbidities is linked to specific critical exposure periods in the post-birth period during which the exclusive use of human milk and the avoidance of commercial formula may be most important. Similarly, there are other periods when high doses, but not necessarily exclusive use of human milk, may be important. This article reviews the concept of "dose and exposure period" for human milk feeding in the NICU to precisely measure and benchmark the amount and timing of human milk use in the NICU. The critical exposure periods when exclusive or high doses of human milk appear to have the greatest impact on specific morbidities are reviewed. Finally, the current best practices for the use of human milk during and after the NICU stay for premature infants are summarized.

The prenatal porcine intestine has low transforming growth factor-beta ligand and receptor density and shows reduced trophic response to enteral diets

Transforming growth factor-beta (TGF-β) plays a role in enterocyte proliferation control, cell differentiation, and immune regulation via binding to specific TGF-β receptors (TGF-β R) in the intestinal epithelium. Endogenous TGF-β production is low in the intestine during the perinatal period, but some exogenous TGF-β ligands are supplied by amniotic fluid intake in the fetus and by colostrum ingestion in the neonate. It is not clear, however, whether luminal TGF-β receptors are present and functional at this critical time. We studied intestinal TGF-β receptors by immunohistochemistry during the last 20% of gestation in pigs and in chronically catheterized fetuses following exposure to colostrum, milk, and amniotic fluid (control). In fetal pigs, the TGF-β Rs were predominantly localized to the crypt epithelium, but staining intensity increased markedly just before term and shifted to the villous epithelium in newborn pigs, concurrently with marked increases in villous heights and crypt depths (+100–200%, P < 0.05). In contrast to previous observations in term newborn pigs, fetal pigs did not show any milk-induced change in TGF-β receptor densities or localization, although a moderate increase in villous height was observed, relative to control (+25–50%, P < 0.05). We conclude that intestinal TGF-β receptor density and localization are immature and unresponsive to TGF-β containing milk diets in prenatal pigs. Immaturity of TGF-β-mediated immune regulation may play a role in the increased sensitivity of preterm neonates to diet-induced intestinal inflammatory disorders.

Gut responses to enteral nutrition in preterm infants and animals

Preterm birth is associated with immature digestive function that may require the use of total parenteral nutrition and special oral feeding regimens. Little is known about the responses to oral food in the preterm neonate and how enteral nutrients affect the immature gastrointestinal tract (GIT). In vivo studies are difficult to perform in laboratory rodents because of their small body size and that of immature organs at birth, and this makes the large farm animals (e.g., pigs, cattle, sheep) more attractive models in this field. In these species, preterm delivery at 88%-95% gestation is associated clinical complications and degrees of GIT immaturity similar to those in infants born at 70%-90% gestation. Studies in both animals and infants indicate that the immature GIT responds to the first enteral food with rapid increases in gut mass and surface area, blood flow, motility, digestive capacity, and nutrient absorption. To a large extent, the enteral food responses are birth independent, and can be elicited also in utero, at least during late gestation. Nevertheless, preterm neonates show compromised GIT structure, function, and immunology, particularly when delivered by caesarean section and fed diets other than mother's milk. Formula-fed preterm infants are thus at increased risk of developing diseases such as necrotizing enterocolitis, unless special care is taken to avoid excessive nutrient fermentation and bacterial overgrowth. The extent to which results obtained in preterm animals (most notably the pig) can be used to reflect similar conditions in preterm infants is discussed.