Enteritis and gut microbiome dysbiosis cause morbidity and mortality in suckling and weanling pigs. We hypothesized that oral faecal filtrate transplantation (FFT) from healthy sow donors to neonatal piglets would modulate gut colonization, prevent diarrhoea, and improve survival and growth. Piglets were randomised to receive oral FFT (n = 150) or placebo (CON, n = 150) daily for six days. Colon microbiota composition was analysed by 16 S rRNA gene amplicon and metagenomic sequencing on days 27 and 41, alongside resistome, blood lactate and immunoglobulin (Ig) G, and gut enzymatic activity analysis. Growth, diarrhoea, and survival were monitored throughout. Baseline characteristics, including birth weight, blood lactate, and IgG, were similar between groups. The FFT reduced post-weaning diarrhoea and mortality pre- and post-weaning (p < 0.05). This reduction was associated with distinct changes in the faecal microbiota composition, including the enrichment of metagenome-assembled genomes assigned to beneficial bacterial families such as Oscillospiraceae and Lachnospiraceae. The FFT also influenced β-diversity and gut enzymatic activity, suggesting a broader intestinal health impact. Importantly, FFT did not increase antimicrobial resistance genes of public health concern. The FFT recipients exhibited higher body weights during suckling, though no significant weight differences post-weaning. Mucosal disaccharidase and aminopeptidase activities were lower in FFT piglets on day 41 (p < 0.05), while plasma intestinal fatty-acid binding protein levels remained similar. In conclusion, FFT reduced post-weaning diarrhoea and mortality, influenced gut microbiota and enzymatic activity, and tended to promote suckling growth. If approved, FFT could support weaning and reduce antimicrobial use in pig production.

AbstractFecal virome transfer (FVT) shows promise in reducing necrotizing enterocolitis (NEC), likely due to donor bacteriophages preventing the gut dysbiosis preceding disease. However, concurrent transfer of eukaryotic viruses may carry a risk of infection for the recipient. To increase safety, we investigated chemostat propagation as a method to eliminate eukaryotic viruses from donor feces while maintaining a diverse and reproducible bacteriophage community. Donor feces was collected from healthy suckling piglets and inoculated into a fermenter containing growth media supplemented with lactose and milk oligosaccharides (MOs). During continuous medium exchange (20% volume/h), dilution significantly reduced eukaryotic viruses. Viral richness was concurrently reduced although still preserving a stable community of 200-250 bacteriophages. Inclusion of MOs in the medium ensured higher bacterial richness and a bacterial community closer resembling donor feces. FecalLactobacillaceaebacteria were lost during cultivation but partially replaced by members of theBacteroidotaphylum in MO-supplemented cultures, accompanied by phages predicted to haveParabacteroidesas host. After cultivation, virus-like particles (VLPs) were isolated, and their ability to reduce NEC incidence testedin vivo. Preterm piglets were delivered by cesarean section and received either the lactose- or MO-propagated viromes by oral route (n= 14-15/group). These were compared with groups receiving the same dose of donor fecal virome (1010VLPs/kg) or vehicle control. The piglets were subsequently fed infant formula for 96 hours followed by euthanasia and tissue sampling. Both chemostat-propagated viromes effectively mitigated diarrhea compared to the donor virome. The donor virome partially engrafted in recipients and led to higher levels ofLactobacillaceaebacteria andLactobacillaceaetargeting phages. However, these signatures were lost in recipients of chemostat-propagated viromes, and only minor microbiome effects and no NEC prevention were observed. To conclude, we providein vivoproof-of-concept for chemostat propagation of fecal viruses as a means to deplete eukaryotic viruses and in turn reduce side effects in newborn virome recipients. However, chemostat culture conditions need further optimization to preserve the donor phageome.

We present an integrated acoustofluidic plasmapheresis system designed for ultralow blood volume applications, such as neonatal care, enabling in-line sampling and plasma separation from whole blood. The system combines a two-stage acoustophoresis chip with microperistaltic pumps and PDMS-based flow pulsation dampeners to ensure continuous, stable operation. The input whole blood is acoustically separated into a cell-free plasma fraction and a returnable cell fraction, enabling closed-loop operation for neonates who have a circulating blood volume as low as 50 mL. The system achieves a plasma generation rate of 27.5 μL/min with ∼100% cell removal, outperforming previous microfluidic plasma separation approaches in terms of purity, throughput, and minimal sample volume. Plasma quality was validated by quantifying hemolysis and residual cellular content, while system robustness was demonstrated across hematocrit levels up to 50%, which is close to the average upper hematocrit value in neonates. Compared to previous microfluidic techniques, our system achieves the fastest generation of clinical quality undiluted plasma with the lowest required blood volume, making it highly suitable for point-of-care integration in neonatal intensive care units.

Birth asphyxia can result in kidney dysfunction, disturbances in systemic electrolytes and fluid balance in newborns. Currently, there is no proven dietary approach to support asphyxiated newborns. This study investigates whether oral plasma supplementation improves kidney function and overall health in asphyxiated newborns. Cesarean-delivered near-term pigs with or without an 8 min intrauterine clamping of the umbilical cord were fed a milk replacer dissolved in water for 24 h in Experiment 1. Pigs were fed 72 h with milk replacers dissolved in either maternal plasma or water in Experiment 2. Blood, urine, and kidney tissue were collected for further analyses. Asphyxia disrupted blood electrolyte balance. And plasma feeding led to higher fluid retention for both asphyxiated and control pigs. Additionally, plasma feeding may also affect kidney development and protect kidneys from asphyxia induced impairments. Birth asphyxia in pigs led to immediate disturbance of electrolyte balance, impaired fluid retention, and kidney impairments. Plasma feeding may improve postnatal newborn hydration and may also improve the condition of kidneys following asphyxia.

Milk-based formulations have been proposed as enabling formulations for the delivery of poorly water-soluble drugs to children due to their safety, dose versatility and ability to improve drug solubilisation through the digestion process. In this study the feasibility of using commercially available infant formula as an enabling formulation to enhance the solubilisation and oral bioavailability of clofazimine, a poorly soluble lipophilic drug, following oral administration was investigated. The solubilisation of crystalline clofazimine in digesting infant formula was assessed in vitro using synchrotron small-angle X-ray scattering. An in vivo pharmacokinetic study was then conducted to determine the oral bioavailability of a suspension of clofazimine in infant formula compared to a lipid-free aqueous suspension in both a rat and piglet animal model. Clofazimine administered in infant formula produced significantly higher plasma concentrations than the aqueous vehicle and resulted in comparable enhancements in relative oral bioavailability in both the piglet (235%) and rat animal models (256%). Results from this study demonstrated that infant formula was an effective enabling formulation, with a positive correlation between improved drug solubilisation during in vitro digestion of infant formula and enhanced in vivo drug exposure following oral administration. Infant formula therefore offers an inexpensive and scalable formulation approach for improving the bioavailability of paediatric drugs, like clofazimine, and enabling the treatment of infections in children.

Background: Premature infants are highly susceptible to infections that can lead to sepsis with life-threatening organ dysfunctions. The clinical practice of high parenteral glucose supply in preterm infants can exacerbate infection outcomes through excessive glycolysis-induced inflammatory response. This in turn can affect the health of vital preterm organs, including the brain and kidneys. We hypothesized that reduced parenteral glucose supply to infected preterm newborns may help protect against pathology in these two key organs. Methods: Cesarean-delivered preterm pigs were nourished with high or low parenteral glucose levels (21 % vs. 5 %), infused with Staphylococcus epidermidis or saline, and monitored in heated, oxygenated incubators until 22 h. Blood, brain, and kidney samples were collected for histological, immunohistological, q-PCR, ELISA, and biochemical analyses. Results: Infection led to multiple pathological changes (e.g. edema), increased inflammation and tissue injury (indicated by gene expression data) in both brain and kidneys of preterm piglets. Reduced glucose supply in infected animals alleviated histopathological manifestations in the brain, and reduced neuroinflammation with enhanced M2 microglial phenotype. Reduced glucose supply also decreased plasma creatinine, and the severity of renal edema, tubular vacuolization and dilatation. Multiple genes related to innate and Th1 immunity in both organs were dampened by reduced glucose supply. Correlation analysis showed that renal inflammation was more closely connected to systemic inflammation compared to neuroinflammation. Conclusion: Reduced glucose supply can reduce renal and neuro-inflammation during neonatal infection, thereby protecting brain and kidney health in infected preterm neonates.

Clofazimine is an emerging drug for the treatment of cryptosporidiosis in infants. As a poorly water-soluble drug, the formulation of clofazimine in age-appropriate vehicles is challenging and often results in the use of off-label formulations. Milk-based vehicles such as human milk and bovine milk have been investigated as age-appropriate formulations and shown to increase the solubilisation of poorly water-soluble drugs via enhanced solubility in lipid digestion products in vitro. We hypothesised that administration of clofazimine within a milk-based vehicle would enhance bioavailability for infant patients. Towards this objective, suspensions of clofazimine in human and bovine milk were orally administered separately to piglets and rats and the subsequent plasma concentrations were compared to those after administration of an aqueous drug suspension. Initial investigations with a rodent model showed a significant increase (258%) in the oral bioavailability of clofazimine when administered with human milk. Similarly, the oral bioavailability of clofazimine was significantly higher when administered in both human (154%) and bovine milk (175%) using a neonatal piglet model, suggesting comparable enhancement in oral bioavailability could be achieved with human or bovine milk. These findings demonstrate the potential of human milk in particular to provide an effective administration vehicle for clofazimine administration to infants without the need for additional excipients.

The adsorption of proteins and other biomolecules onto particles at the blood-particle interface, resulting in the formation of a biomolecular corona, is an established research area and can form the basis for a formulation concept to modify the in vivo behavior of particles. In contrast, the analogous formation of a gastrointestinal (GI) biomolecular corona on particles has only recently gained growing attention. Hydrophobic drugs are ingested in particle form, or may precipitate in the GI tract to form particles upon which a biomolecular corona may form. This study aimed to elucidate the composition of the GI biomolecular corona on drug particles in ex vivo porcine gastric, intestinal and colonic fluids (PGF, PIF & PCF) and its dependence on drug identity and solid-state form. Using LC-MS/MS proteomics, the results show that the composition of the GI corona formed on clotrimazole (CMZ) particles were luminal compartment specific, with the PGF corona showing the highest number of identified proteins. Notably, the composition of the PIF corona rapidly reached equilibrium and displayed no time-dependency at the tested time-points (10, 60 and 120 min). Sequential exposure of CMZ particles to the GI fluids from sequential compartments (mimicking the transit of particles through the GI tract), i.e. PGF-PIF and PGF-PIF-PCF, resulted in corona compositions highly similar to that formed in PIF alone, indicating that PIF proteins form the dominant corona. Furthermore, the PIF corona was drug-particle specific, with distinct compositions observed between CMZ and ritonavir (RTV) (both weak bases with logP values above 5) compared to the corona composition on crystalline indomethacin (IND). Further, amorphous IND exhibited a more diverse corona than crystalline IND, containing 153 unique proteins that were absent from the corona of crystalline IND. All investigated corona compositions showed enrichment of low-abundance proteins not detectable in the original GI fluid. In conclusion, this study provides insights into the issue of how the identity and solid state of drug particles influences the adsorption of biomolecules onto drug particles in ex vivo GI fluids, and that exposure to the different fluids reveals that certain protein components specific to intestinal fluids can dominate the composition of the corona after sequential exposure.

Background Premature infants are highly susceptible to infections that can lead to sepsis with life-threatening organ dysfunctions. The clinical practice of high parenteral glucose supply in preterm infants can exacerbate infection outcomes through excessive glycolysis-induced inflammatory response. This in turn can affect the health of vital preterm organs, including the brain and kidneys. We hypothesized that reducing glucose supply in infected preterm newborns may help protect against pathology in these two key organs.Methods Caesarean-delivered preterm pigs were nourished with high or low parenteral glucose levels, infected with Staphylococcus epidermidis or saline, and cared for until 22h. Blood, brain, and kidney samples were collected at the end of the study for analyses.Results Infection led to multiple pathological changes, increased inflammation and tissue injury and dysfunction in both brain and kidneys of preterm piglets. Reduced glucose supply in infected animals alleviated neurological degradation, hyperemia and enhanced M2 microglial phenotype in the brain. This intervention also reduced plasma creatinine, renal edema, tubular vacuolization and dilatation. Multiple genes related to innate and Th1 immunity in both organs were highly correlated and dampened by reduced glucose supply, but there were clear signs that renal inflammation was closely connected to systemic inflammation while neuroinflammation was likely driven by immune response to the bacteria translocated into the brain.Conclusion Reduced glucose supply can protect brain and kidney health in infected preterm neonates.### Competing Interest StatementThe authors have declared no competing interest.

Processing of whey protein concentrate (WPC) for infant formulas may induce protein modifications with severe consequences for preterm newborn development. The study investigates how conventional WPC and a gently processed skim milk-derived WPC (SPC) affect gut and immune development after birth.Newborn, preterm pigs used as a model of preterm infants were fed formula containing WPC, SPC, extra heat-treated SPC (HT-SPC), or stored HT-SPC (HTS-SPC) for 5 days. SPC contained no protein aggregates and more native lactoferrin, and despite higher Maillard reaction product (MRP) formation, the clinical response and most gut and immune parameters are similar to WPC pigs. SPC feeding negatively impacts intestinal MRP accumulation, mucosa, and bacterial diversity. In contrast, circulating T-cells are decreased and oxidative stress- and inflammation-related genes are upregulated in WPC pigs. Protein aggregation and MRP formation increase in HTS-SPC, leading to reduced antibacterial activity, lactase/maltase ratio, circulating neutrophils, and cytotoxic T-cells besides increased gut MRP accumulation and expression of TNFAIP3.The gently processed SPC has more native protein, but higher MRP levels than WPC, resulting in similar tolerability but subclinical adverse gut effects in preterm pigs. Additional heat treatment and storage further induce MRP formation, gut inflammation, and intestinal mucosal damage.

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.

Fecal filtrate transfer (FFT) is emerging as a safer alternative to traditional fecal microbiota transplantation (FMT) – particularly in the context of necrotizing enterocolitis (NEC), a severe gastrointestinal condition affecting preterm infants. Using a preterm piglet model, FFT has demonstrated superiority over FMT in safety and NEC prevention. Since FFT is virtually devoid of bacteria, prokaryotic viruses (bacteriophages) are assumed to mediate the beneficial effects. However, this assumption remains unproven. To address this gap, we separated virus-like particles (30 kDa to 0.45 µm) of donor feces from the residual postbiotic fluid. We then compared clinical and gut microbiota responses to these fractions with the parent FFT solution after transferring them to NEC-susceptible preterm piglets. Virome transfer was equally effective as FFT in reducing the severity of NEC-like pathology. The bacterial compositional data corroborated clinical findings as virome transfer reduced the relative abundance of several NEC-associated pathogens e.g. Klebsiella pneumoniae and Clostridium perfringens. Virome transfer diversified gut viral communities with concomitant constraining effects on the bacterial composition. Unexpectedly, virome transfer, but not residual postbiotic fluid, led to earlier diarrhea. While diarrhea may be a minor concern in human infants, future work should identify ways of eliminating this side effect without losing treatment efficacy.

IntroductionBirth 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.MethodsNear-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).ResultsCompared 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.ConclusionDietary 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.ImpactComplicated 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.

BACKGROUND:Preterm birth and formula feeding increase the risk of necrotizing enterocolitis (NEC), a gut inflammatory disease known to be associated with gut microbiota (GM) changes in infants. Supplemental bovine colostrum may protect against formula-induced NEC via GM changes. We hypothesised that feeding colostrum before, after, or during formula feeding affects NEC sensitivity via changes to GM. METHODS:Colonic GM (profiled by 16S ribosomal RNA gene amplicon sequencing) was compared in preterm pigs fed colostrum for 4 days, either before, after, or together with formula feeding for 4 days. Correlations between GM and gut parameters were assessed on day 5 or 9. RESULTS:Both exclusive and partial colostrum feeding induced higher GM diversity, lower Enterococcus abundance, and improved intestinal maturation parameters (villus structure, digestive enzyme activities, permeability), relative to exclusive formula feeding (all p < 0.05). Across feeding regimens, Enterococcus abundance was inversely correlated with intestinal maturation parameters. Conversely, there was no correlation between GM changes and early NEC lesions. CONCLUSION:Bovine colostrum inhibits formula-induced Enterococcus overgrowth and gut dysfunctions just after preterm birth but these effects are not causally linked. Optimising diet-related host responses, not GM, may be critical to prevent NEC in preterm newborn pigs and infants. IMPACT:Supplement of bovine colostrum to formula feeding modified the gut microbiota by increasing species diversity and reducing Enterococcus abundance, while concurrently improving intestinal functions in preterm pigs. Diet-related changes to the gut microbiota were not clearly associated with development of necrotizing enterocolitis (NEC) in preterm pigs, suggesting that diet-related gut microbiota effects are not critical for diet-related NEC protection. The study highlights the potential to use bovine colostrum as a supplement to formula feeding for preterm infants lacking human milk.

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, pCO(2 )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, pCO(2) 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.

Abstract Background: Fecal filtrate transfer (FFT, i.e. “sterile filtered” fecal matter) is gaining increasing attention as a safer alternative to traditional fecal microbiota transplantation (FMT) for treating gastrointestinal (GI) complications. Indeed, in the case of necrotizing enterocolitis (NEC), a life-threatening GI emergency occurring in preterm infants, FFT is superior to FMT in terms of both safety and efficacy when investigated in preterm piglets. Since fecal filtrate is virtually devoid of bacteria, prokaryotic viruses (bacteriophages) are assumed to mediate the beneficial effects by modulating the recipient gut microbiota. However, this assumption remains unproven. Results: To address this gap, we isolated the virome of donor feces from the residual postbiotic fluid with no loss of bacteriophage infective potential or bacteriophage spillover to the residual fluid. We then compared clinical and gut microbiota responses to these fractions with the parent FFT solution after transferring to NEC-susceptible preterm piglets. Importantly, transfer of isolated donor virome was equally effective as FFT in reducing the severity of NEC-like pathology, whereas the residual postbiotic fraction was ineffective. The bacterial compositional data corroborated clinical findings as virome transfer reduced the relative abundance of several NEC-associated pathogens e.g. Klebsiella pneumoniae and Clostridium perfringens. A viral metagenomics analysis indicated enrichment and diversification of recipient gut viral communities with concomitant constraining effect on bacterial composition in accordance with lytic phage predation of resident bacteria. Surprisingly, virome transfer but not residual postbiotic fluid was associated with suspected viral gastroenteritis as indicated by diarrhea, intestinal atrophy, and weight loss. Although virome sequencing did not reveal any obvious causative agent, we suggest that unidentified eukaryotic viruses are candidates responsible for these side effects. Conclusion: Using NEC as a relevant case for microbiota-directed therapy, we show that transfer of isolated fecal virome is sufficient to reduce pathogenic bacterial load and overall disease burden. However, we also highlight that receiving exogenous virome increases the risk of enteric virus infection. Despite diarrhea being a minor concern in the human infant context, future work should identify ways of eliminating eukaryotic viruses without losing treatment efficacy.

Newborns exposed to birth asphyxia transiently experience deficient blood flow and a lack of oxygen, potentially inducing hypoxic-ischaemic encephalopathy and subsequent neurological damage. Immunomodulatory components in plasma may dampen these responses. Using caesarean-delivered pigs as a model, we hypothesized that dietary plasma supplementation improves brain outcomes in pigs exposed to birth asphyxia. Mild birth asphyxia was induced by temporary occlusion of the umbilical cord prior to caesarean delivery. Motor development was assessed in asphyxiated (ASP) and control (CON) piglets using neonatal arousal, physical activity and gait test parameters before euthanasia on Day 4. The ASP pigs exhibited increased plasma lactate at birth, deficient motor skills and increased glial fibrillary acidic protein levels in CSF and astrogliosis in the putamen. The expression of genes related to oxidative stress, inflammation and synaptic functions was transiently altered in the motor cortex and caudate nucleus. The number of apoptotic cells among CTIP2-positive neurons in the motor cortex and striatal medium spiny neurons was increased, and maturation of preoligodendrocytes in the internal capsule was delayed. Plasma supplementation improved gait performance in the beam test, attenuated neuronal apoptosis and affected gene expression related to neuroinflammation, neurotransmission and antioxidants (motor cortex, caudate). We present a new clinically relevant animal model of moderate birth asphyxia inducing structural and functional brain damage. The components in plasma that support brain repair remain to be identified but may represent a therapeutic potential for infants and animals after birth asphyxia

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.

Background Preterm birth disrupts fetal kidney development, potentially leading to postnatal acute kidney injury. Preterm infants are deficient in insulin-like growth factor 1 (IGF-1), a growth factor that stimulates organ development. By utilizing a preterm pig model, this study investigated whether IGF-1 supplementation enhances preterm kidney maturation.Methods Cesarean-delivered preterm pigs were treated systemically IGF-1 or vehicle control for 5, 9 or 19 days after birth. Blood, urine, and kidney tissue were collected for biochemical, histological and gene expression analyses. Age-matched term-born pigs were sacrificed at similar postnatal ages and served as the reference group.Results Compared with term pigs, preterm pigs exhibited impaired kidney maturation, as indicated by analyses of renal morphology, histopathology, and inflammatory and injury markers. Supplementation with IGF-1 reduced signs of kidney immaturity, particularly in the first week of life, as indicated by improved morphology, upregulated expression of key developmental genes, reduced severity and incidence of microscopic lesions, and decreased levels of inflammatory and injury markers. No association was seen between the symptoms of necrotizing enterocolitis and kidney defects.Conclusion Preterm birth in pigs impairs kidney maturation and exogenous IGF-1 treatment partially reverses this impairment. Early IGF-1 supplementation could support the development of preterm kidneys.Impact Preterm birth may disrupt kidney development in newborns, potentially leading to morphological changes, injury, and inflammation. Preterm pigs have previously been used as models for preterm infants, but not for kidney development. IGF-1 supplementation promotes kidney maturation and alleviates renal impairments in the first week of life in preterm pigs. IGF-1 may hold potential as a supportive therapy for preterm infants sensitive to acute kidney injury.

IntroductionPreterm infants have increased risk of impaired neurodevelopment to which reduced systemic levels of insulin-like growth factor 1 (IGF-1) in the weeks after birth may play a role. Hence, we hypothesized that postnatal IGF-1 supplementation would improve brain development in preterm pigs, used as a model for preterm infants. MethodsPreterm pigs delivered by cesarean section received recombinant human IGF-1/IGF binding protein-3 complex (rhIGF-1/rhIGFBP-3, 2.25 mg/kg/day) or vehicle from birth to postnatal day 19. Motor function and cognition were assessed by monitoring of in-cage and open field activities, balance beam test, gait parameters, novel object recognition and operant conditioning tests. Collected brains were subject to magnetic resonance imaging (MRI), immunohistochemistry, gene expression analyses and protein synthesis measurements. ResultsThe IGF-1 treatment increased cerebellar protein synthesis rates (both in vivo and ex vivo). Performance in the balance beam test was improved by IGF-1 but not in other neurofunctional tests. The treatment decreased total and relative caudate nucleus weights, without any effects to total brain weight or grey/white matter volumes. Supplementation with IGF-1 reduced myelination in caudate nucleus, cerebellum, and white matter regions and decreased hilar synapse formation, without effects to oligodendrocyte maturation or neuron differentiation. Gene expression analyses indicated enhanced maturation of the GABAergic system in the caudate nucleus (decreased NKCC1:KCC2 ratio) with limited effects in cerebellum or hippocampus. ConclusionSupplemental IGF-1 during the first three weeks after preterm birth may support motor function by enhancing GABAergic maturation in the caudate nucleus, despite reduced myelination. Supplemental IGF-1 may support postnatal brain development in preterm infants, but more studies are required to identify optimal treatment regimens for subgroups of very or extremely preterm infants.