Cord Obstruction and Delayed Cord Clamping Do Not Affect Gut Function in Neonatal Piglets.

INTRODUCTION: Birth-related obstruction of umbilical blood flow may induce hypoxic insults that affect postnatal organ adaptation. Using newborn cesarean-delivered pigs, we hypothesized that cord obstruction during delivery negatively affects physiological transition and gut maturation. Further, we investigated if delayed cord clamping (DCC) improves gut outcomes, including sensitivity to formula-induced necrotizing enterocolitis (NEC)-like lesions. METHODS: In experiment 1, preterm (n = 24) and near-term (n = 29) piglets were subjected to umbilical cord obstruction (UCO, 5-7 min in utero), with corresponding pigs delivered without obstruction (CON, n = 17-22). Experiment 2 assessed preterm pigs subjected to delayed cord clamping (n = 30, 60 s) or immediate cord transection with umbilical cord milking (UCM, n = 34). Postnatal vital parameters were recorded, together with a series of gut parameters after 3 days of formula feeding. RESULTS: UCO induced respiratory-metabolic acidosis in near-term pigs at birth (pH 7.16 vs. 7.32, pCO2 12.5 vs. 9.2 kPa, lactate 5.2 vs. 2.5 mmol/L, p < 0.05). In preterm pigs, UCO increased failure of resuscitation and mortality shortly after birth (88 vs. 47%, p < 0.05). UCO did not affect gut permeability, transit time, macromolecule absorption, six digestive enzymes, or sensitivity to NEC-like lesions. In experiment 2, DCC improved neonatal hemodynamics (pH 7.28 vs. 7.20, pCO2 8.9 vs. 9.9 at 2 h, p < 0.05), with no effects on gut parameters. CONCLUSION: UCO and DCC affect neonatal transition and hemodynamics, but not neonatal gut adaptation or sensitivity to NEC-like lesions. Our findings suggest that the immature newborn gut is highly resilient to transient birth-related changes in cord blood flow.

Enteral plasma feeding improves gut function and immunity in piglets after birth asphyxia.

INTRODUCTION: Birth asphyxia may negatively affect gut function and immunity in newborns. Conversely, immunomodulatory milk diets may protect the gut and immune system against damage caused by asphyxia. Using caesarean-derived pigs as models, we hypothesised that enteral feeding with plasma improves gut and immune functions in asphyxiated newborns. METHODS: Near-term pig fetuses (98% gestation,) were delivered by caesarean section after 8 min umbilical cord occlusion, leading to transient birth asphyxia (ASP, n = 75) and compared with non-occluded controls (CON, n = 69). Piglets were further randomised to supplementation with/without porcine plasma (plasma, PLA/vehicle, VEH), into bovine colostrum (first 24 h) or formula (until 72 h). RESULTS: Compared with CON, ASP piglets took longer to achieve stable respiration and showed reduced blood pH, weight gain and survival. Independent of asphyxia, plasma supplementation reduced gut haemorrhagic lesions, permeability and inflammatory cytokines together with improved villous morphology and brush-border enzyme activities. Asphyxia reduced blood cytokine responses to ex vivo bacterial stimulation, whereas plasma supplementation ameliorated this effect. CONCLUSION: Dietary plasma supplementation improves survival, gut functions and immunity in both normal and asphyxiated newborns. The components in plasma that mediate gut-protective effects in piglets remain to be identified, but may benefit also birth-compromised newborn infants. IMPACT: Complicated deliveries leading to birth asphyxia, may negatively affect gut, liver and immune adaptation in the first days after birth. Using a model of birth asphyxia in caesarean-derived piglets, we show that enteral feeding with maternal plasma exerts gut maturational and immunomodulatory effects in both control and asphyxiated animals in the first days of life. The mechanisms behind the gut-protective effects of plasma are unknown, but plasma components hold potential for new oral therapies for compromised newborn infants as well as piglets.

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.

Skeletal consequences of preterm birth in pigs as a model for preterm infants.

Preterm birth affects about 10% of all live births with many resultant health challenges, including metabolic bone disease of prematurity (MBDP), which is characterized by elevated alkaline phosphatase, suppressed phosphate, and deficient skeletal development. Because of the lack of an animal model, very little is known about bone structure, strength, and quality after preterm birth. This study investigated the utility of a pig model to replicate clinical features of preterm birth, including MBDP, and sought to determine if early postnatal administration of IGF-1 was an effective treatment. Preterm pigs, born by caesarean section at 90% gestation, were reared in intensive care facilities (respiratory, thermoregulatory, and nutritional support) and compared with sow-reared term pigs born vaginally. Preterm pigs were systemically treated with vehicle or IGF-1 (recombinant human IGF-1/BP-3, 2.25 mg/kg/d). Tissues were collected at postnatal days 1, 5, and 19 (the normal weaning period in pigs). Most bone-related outcomes were affected by preterm birth throughout the study period, whereas IGF-1 supplementation had almost no effect. By day 19, alkaline phosphatase was elevated, phosphate and calcium were reduced, and the bone resorption marker C-terminal crosslinks of type I collagen was elevated in preterm pigs compared to term pigs. Preterm pigs also had decrements in femoral cortical cross-sectional properties, consistent with reduced whole-bone strength. Thus, the preterm pig model replicates many features of preterm bone development in infants, including features of MBDP, and allows for direct interrogation of skeletal tissues, enhancing the field's ability to examine underlying mechanisms.

Premature birth interrupts a critical period of skeletal development as the majority of fetal bone mineral accumulation occurs during the last gestational trimester, leaving preterm infants at increased risk for low bone mineral density and fractures. Although there are some data on growth in bone mass in preterm infants, very little is known about bone structural properties, quality, and strength during development after preterm birth. In this study, we sought to evaluate the pig as a model for postnatal skeletal development after premature birth. Preterm pigs born after approximately 90% of the full gestation period were compared to full-term control pigs through day 19 of life. Levels of 2 blood markers used to diagnose osteoporosis of prematurity were replicated in the pig model. Bone properties related to strength were reduced even when accounting for their smaller body size, possibly suggesting elevated fracture risk in preterm infants. Based on the similarities between the preterm pig model and preterm human infants, the pig model may prove to be useful to study factors and interventions affecting postnatal bone development after preterm birth.

Adverse Metabolic Phenotypes in Parenterally Fed Neonatal Pigs Do Not Persist into Adolescence.

BACKGROUND: Nutrition during fetal and neonatal life is an important determinant for the risk of adult-onset diseases, especially type 2 diabetes and obesity. OBJECTIVES: We aimed to determine whether total parenteral nutrition (TPN) compared with enteral formula feeding [enteral nutrition (EN)] in term piglets during the first 2 wk after birth would increase the long-term (5-mo) development of metabolic syndrome phenotypes with adverse glucose homeostasis, fatty liver disease, and obesity. METHODS: Neonatal female pigs were administered TPN (n = 12) or fed enterally with a liquid enteral milk-replacer formula (EN, n = 12) for 14 d. After transitioning TPN pigs to enteral feeding of liquid formula (days 15-26), both groups were adapted to a solid high-fat diet (30% of the total diet) and sucrose (20% of the total diet) diet (days 27-33), which was fed until the end of the study (140 d). Body composition was measured by dual-energy X-ray absorptiometry at 14, 45, and 140 d. Serum biochemistry and glucose-insulin values (after a fasting intravenous glucose tolerance test) were obtained at 140 d. Liver and muscle were analyzed for insulin receptor signaling and triglycerides. RESULTS: Body weight was similar, but percent fat was higher, whereas percent lean and bone mineral density were lower in TPN than in EN pigs (P < 0.01) at 45 d of age but not at 140 d. At 140 d, there were no differences in serum markers of liver injury or lipidemia. Intravenous glucose tolerance test at 140 d showed a lower (P < 0.05) AUC for both glucose and insulin in TPN than in EN pigs, but the ratio of AUCs of insulin and glucose was not different between groups. CONCLUSIONS: Administration of TPN during the neonatal period increased adipose deposition that transiently persisted in early adolescence when challenged with a high-fat diet but was not sustained or manifested as glucose intolerance.