Cytokines and growth factors in the developing intestine and during necrotizing enterocolitis

Blood absolute monocyte count trends in preterm infants with suspected necrotizing enterocolitis: an adjunct tool for diagnosis?

OBJECTIVE

We investigated the trends of blood absolute monocyte count (AMC) over 72 h after suspecting necrotizing enterocolitis (NEC).

STUDY DESIGN

A single center, retrospective study, the AMC was plotted over 72 h after NEC evaluation. Receiver operating characteristic (ROC) curve analysis assessed change in AMC to identify absence of NEC and different NEC stages.

RESULTS

In 130 infants, the AMC decreased in patients with NEC stage 2 or 3. Stages 2 and 3 NEC experienced a drop in AMC compared to an increase in no NEC, possible NEC, or positive culture (p < 0.05). AMC increase 24% or less can differentiate NEC stage 2/3 from possible NEC with an area under the curve (AUC) of 0.78. While decrease of more than 32% can differentiate stage 2/3 vs. possible or no NEC with AUC of 0.71.

DISCUSSION/CONCLUSIONS

A decrease in AMC can be an adjunct biomarker to confirm the diagnosis of NEC.

A graded neonatal mouse model of necrotizing enterocolitis demonstrates that mild enterocolitis is sufficient to activate microglia and increase cerebral cytokine expression

Background

Necrotizing enterocolitis (NEC) is an inflammatory gastrointestinal process that afflicts approximately 10% of preterm infants born in the United States each year, with a mortality rate of 30%. NEC severity is graded using Bell's classification system, from stage I mild NEC to stage III severe NEC. Over half of NEC survivors present with neurodevelopmental impairment during adolescence, a long-term complication that is poorly understood but can occur even after mild NEC. Although multiple animal models exist, none allow the experimenter to control nor represent the gradient of symptom severities seen in NEC patients. We bridge this knowledge gap by developing a graded murine model of NEC and studying its relationship with neuroinflammation across a range of NEC severities.

Methods

Postnatal day 3 (P3) C57BL/6 mice were fed a formula containing different concentrations (0% control, 0.25%, 1%, 2%, and 3%) of dextran sodium sulfate (DSS). P3 mice were fed every 3 hours for 72-hours. We collected data on weight gain and behavior (activity, response, body color) during feeding. At the end of the experiment, we collected tissues (intestine, liver, plasma, brain) for immunohistochemistry, immunofluorescence, and cytokine and chemokine analysis.

Results

Throughout NEC induction, mice fed higher concentrations of DSS died sooner, lost weight faster, and became sick or lethargic earlier. Intestinal characteristics (dilation, color, friability) were worse in mice fed with higher DSS concentrations. Histology revealed small intestinal disarray among mice fed all DSS concentrations, while higher DSS concentrations resulted in reduced small intestinal cellular proliferation and increased hepatic and systemic inflammation. In the brain, IL-2, G-CSF, and CXCL1 concentrations increased with higher DSS concentrations. Although the number of neurons and microglia in the CA1 hippocampal region did not differ, microglial branching was significantly reduced in DSS-fed mice.

Conclusion

We characterize a novel graded model of NEC that recapitulates the full range of NEC severities. We show that mild NEC is sufficient to initiate neuroinflammation and microglia activation. This model will facilitate studies on the neurodevelopmental effects of NEC.

New insights into intestinal macrophages in necrotizing enterocolitis: the multi-functional role and promising therapeutic application

Necrotizing enterocolitis (NEC) is an inflammatory intestinal disease that profoundly affects preterm infants. Currently, the pathogenesis of NEC remains controversial, resulting in limited treatment strategies. The preterm infants are thought to be susceptible to gut inflammatory disorders because of their immature immune system. In early life, intestinal macrophages (IMφs), crucial components of innate immunity, demonstrate functional plasticity and diversity in intestinal development, resistance to pathogens, maintenance of the intestinal barrier, and regulation of gut microbiota. When the stimulations of environmental, dietary, and bacterial factors interrupt the homeostatic processes of IMφs, they will lead to intestinal disease, such as NEC. This review focuses on the IMφs related pathogenesis in NEC, discusses the multi-functional roles and relevant molecular mechanisms of IMφs in preterm infants, and explores promising therapeutic application for NEC.

Current Practices, Challenges, and Recommendations in Enteral Nutrition After Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a neonatal disease with high mortality and morbidity. There is a lack of evidence-based recommendations on nutritional rehabilitation following NEC, and much of the current practice is guided by institutional policies and expert opinions. After a diagnosis of NEC, infants are exposed to an extended period of bowel rest and a prolonged course of antibiotics. Recognizing the patient characteristics that predict nutritional tolerance, early initiation of enteral nutrition, minimizing periods of bowel rest and antibiotic exposure, and standardization of dietary practices are the mainstay of post-NEC nutrition.

Association of Surgical Necrotizing Enterocolitis and Its Timing with Retinopathy of Prematurity

OBJECTIVE

The study aimed to determine the association of surgical necrotizing enterocolitis (NEC) and its timing, with the development and timing of retinopathy of prematurity (ROP).

STUDY DESIGN

This was a secondary data analysis of 7,483 preterm infants from the Postnatal Growth and Retinopathy of Prematurity Study. Associations between infants with surgical NEC, early-onset surgical NEC (8-28 days), and late-onset surgical NEC (over 28 days) with ROP were evaluated by using multivariable logistic regression models, controlling for birth weight, gestational age, small for gestational age status, chronic lung disease, intraventricular hemorrhage, hydrocephalus, patent ductus arteriosus, and periventricular leukomalacia.

RESULTS

Three hundred fifty-six (4.8%) infants had surgical NEC, with 56% having early surgical NEC. Infants with surgical NEC had a higher risk of any ROP and severe ROP (adjusted odds ratio [OR]: 2.7; 95% CI: 1.9-3.7) and 2.5 (95% CI: 1.9-3.3), respectively; p < 0.001) compared with infants without surgical NEC. Infants with early surgical NEC were at the highest risk of developing ROP and severe ROP (adjusted OR: 3.1 [95% CI: 2.1-4.8], and 3.3 [95% CI: 2.3-4.7] respectively, p < 0.001). Infants with late surgical NEC were also at increased risk of developing ROP and severe ROP (adjusted OR: 2.1 [95% CI: 1.3-3.4], and 1.9 [95% CI: 1.3-2.8] respectively, p < 0.001) compared with infants without surgical NEC.

CONCLUSION

Infants with surgical NEC, especially early surgical NEC, are at higher risk of ROP and severe ROP.

KEY POINTS

· Infants with surgical NEC are at higher risk of ROP and severe ROP than those without surgical NEC.. · Increased ROP risk is seen in infants with both early- or later onset surgical NEC.. · Early-onset surgical NEC is associated with a higher ROP risk compared with later onset surgical NEC..

Single-cell RNA sequencing of intestinal immune cells in neonatal necrotizing enterocolitis

PURPOSE

Necrotizing enterocolitis (NEC) causes fatal intestinal necrosis in neonates, but its etiology is unknown. We analyzed the intestinal immune response to NEC.

METHODS

Using single-cell RNA sequencing (scRNA-seq), we analyzed the gene expression profiles of intestinal immune cells from four neonates with intestinal perforation (two with NEC and two without NEC). Target mononuclear cells were extracted from the lamina propria of the resected intestines.

RESULTS

In all four cases, major immune cells, such as T cells (15.1-47.7%), B cells (3.1-19.0%), monocytes (16.5-31.2%), macrophages (1.6-17.4%), dendritic cells (2.4-12.2%), and natural killer cells (7.5-12.8%), were present in similar proportions to those in the neonatal cord blood. Gene set enrichment analysis showed that the MTOR, TNF-α, and MYC signaling pathways were enriched in T cells of the NEC patients, suggesting upregulated immune responses related to inflammation and cell proliferation. In addition, all four cases exhibited a bias toward cell-mediated inflammation, based on the predominance of T helper 1 cells.

CONCLUSION

Intestinal immunity in NEC subjects exhibited stronger inflammatory responses compared to non-NEC subjects. Further scRNA-seq and cellular analysis may improve our understanding of the pathogenesis of NEC.

Therapeutic Potential of Gut Microbiota and Its Metabolite Short-Chain Fatty Acids in Neonatal Necrotizing Enterocolitis

Short chain fatty acids (SCFAs), the principle end-products produced by the anaerobic gut microbial fermentation of complex carbohydrates (CHO) in the colon perform beneficial roles in metabolic health. Butyrate, acetate and propionate are the main SCFA metabolites, which maintain gut homeostasis and host immune responses, enhance gut barrier integrity and reduce gut inflammation via a range of epigenetic modifications in DNA/histone methylation underlying these effects. The infant gut microbiota composition is characterized by higher abundances of SCFA-producing bacteria. A large number of in vitro/vivo studies have demonstrated the therapeutic implications of SCFA-producing bacteria in infant inflammatory diseases, such as obesity and asthma, but the application of gut microbiota and its metabolite SCFAs to necrotizing enterocolitis (NEC), an acute inflammatory necrosis of the distal small intestine/colon affecting premature newborns, is scarce. Indeed, the beneficial health effects attributed to SCFAs and SCFA-producing bacteria in neonatal NEC are still to be understood. Thus, this literature review aims to summarize the available evidence on the therapeutic potential of gut microbiota and its metabolite SCFAs in neonatal NEC using the PubMed/MEDLINE database.

The Phylogeny, Ontogeny, and Organ-specific Differentiation of Macrophages in the Developing Intestine

Macrophages are large highly motile phagocytic leukocytes that appear early during embryonic development and have been conserved during evolution. The developmental roles of macrophages were first described nearly a century ago, at about the time these cells were being identified as central effectors in phagocytosis and elimination of microbes. Since then, we have made considerable progress in understanding the development of various subsets of macrophages and the diverse roles these cells play in both physiology and disease. This article reviews the phylogeny and the ontogeny of macrophages with a particular focus on the gastrointestinal tract, and the role of these mucosal macrophages in immune surveillance, innate immunity, homeostasis, tissue remodeling, angiogenesis, and repair of damaged tissues. We also discuss the importance of these macrophages in the inflammatory changes in neonatal necrotizing enterocolitis (NEC). This article presents a combination of our own peer-reviewed clinical and preclinical studies, with an extensive review of the literature using the databases PubMed, EMBASE, and Scopus.

Altered Gut Microbiome and Fecal Immune Phenotype in Early Preterm Infants With Leaky Gut

Intestinal barrier immaturity, or "leaky gut", is the proximate cause of susceptibility to necrotizing enterocolitis in preterm neonates. Exacerbated intestinal immune responses, gut microbiota dysbiosis, and heightened barrier injury are considered primary triggers of aberrant intestinal maturation in early life. Inordinate host immunity contributes to this process, but the precise elements remain largely uncharacterized, leaving a significant knowledge gap in the biological underpinnings of gut maturation. In this study, we investigated the fecal cytokine profile and gut microbiota in a cohort of 40 early preterm infants <33-weeks-gestation to identify immune markers of intestinal barrier maturation. Three distinct microbiota types were demonstrated to be differentially associated with intestinal permeability (IP), maternal breast milk feeding, and immunological profiles. The Staphylococcus epidermidis- and Enterobacteriaceae-predominant microbiota types were associated with an elevated IP, reduced breast milk feeding, and less defined fecal cytokine profile. On the other hand, a lower IP was associated with increased levels of fecal IL-1α/β and a microbiota type that included a wide array of anaerobes with expanded fermentative capacity. Our study demonstrated the critical role of both immunological and microbiological factors in the early development of intestinal barrier that collectively shape the intestinal microenvironment influencing gut homeostasis and postnatal intestinal maturation in early preterm newborns.

Necrotizing Enterocolitis: Clinical Features, Histopathological Characteristics, and Genetic Associations

Necrotizing enterocolitis (NEC) is an inflammatory bowel necrosis seen in premature infants. Although the etiopathogenesis of NEC is unclear, genetic factors may alter a patient's susceptibility, clinical course, and outcomes. This review draws from existing studies focused on individual genes and others based on microarray-based high-throughput discovery techniques. We have included evidence from our own studies and from an extensive literature search in the databases PubMed, EMBASE, and Scopus. To avoid bias in the identification of studies, keywords were short-listed a priori from anecdotal experience and PubMed's Medical Subject Heading (MeSH) thesaurus.

Breastfeeding and the developmental origins of mucosal immunity: how human milk shapes the innate and adaptive mucosal immune systems

PURPOSE OF REVIEW

Breastfeeding provides passive immunity while the neonatal immune system matures, and may also protect against chronic immune-mediated conditions long after weaning. This review summarizes current knowledge and new discoveries about human milk and mucosal immunity.

RECENT FINDINGS

New data suggest that certain microbes in maternal milk may seed and shape the infant gut microbiota, which play a key role in regulating gut barrier integrity and training the developing immune system. Human milk oligosaccharides, best known for their prebiotic functions, have now been shown to directly modulate gene expression in mast and goblet cells in the gastrointestinal tract. Epidemiologic data show a reduced risk of peanut sensitization among infants breastfed by peanut-consuming mothers, suggesting a role for milk-borne food antigens in tolerance development. Cross-fostering experiments in mice suggest the soluble Toll-like receptor 2, found in human milk, may be critical in this process. Finally, interest in human milk antibodies surged during the pandemic with the identification of neutralizing severe acute respiratory syndrome coronavirus 2 antibodies in maternal milk following both natural infection and vaccination.

SUMMARY

Human milk provides critical immune protection and stimulation to breastfed infants. Understanding the underlying mechanisms could identify new therapeutic targets and strategies for disease prevention across the lifespan.

Clinical Presentation and Multifactorial Pathogenesis of Necrotizing Enterocolitis in the Preterm Infant

BACKGROUND

Necrotizing enterocolitis (NEC) is a serious infection of the bowel wall induced by multiple pathological factors, which include inflammation and tissue invasion with bacteria known to cause severe infections. NEC is now understood to be several disease processes under one umbrella. The most common form occurs in premature infants and can exert significant impacts to preterm morbidity and mortality.

PURPOSE

This narrative review describes current knowledge of the clinical presentation and pathophysiology of NEC in premature infants.

METHODS/SEARCH STRATEGY

A review of literature was conducted using key words in PubMed and CINAHL with preference for years 2015 to 2020.

FINDINGS/RESULTS

Several converging and interrelated factors including characteristics of the premature intestinal mucosa, gut ischemia, dysregulation of the microbiome, enteral feeding, and genetics create an environment where NEC is more likely to occur.

IMPLICATIONS FOR PRACTICE

To recognize and diagnose NEC in preterm infants, an understanding of underlying factors that create an optimal environment for disease acquisition in premature infants is essential.

IMPLICATIONS FOR RESEARCH

Prevention of NEC remains the most important strategy for decreasing morbidity and mortality. Multiple areas of potential study exist for NEC pathophysiology including those that consider how the factors discussed in this review are interrelated and how each particular pathway can be optimized to prevent the onset of NEC.

Role of macrophages in fetal development and perinatal disorders

In the fetus and the neonate, altered macrophage function has been implicated not only in inflammatory disorders but also in developmental abnormalities marked by altered onset, interruption, or imbalance of key structural changes. The developmental role of macrophages were first noted nearly a century ago, at about the same time when these cells were being identified as central effectors in phagocytosis and elimination of microbes. Since that time, we have made considerable progress in understanding the diverse roles that these cells play in both physiology and disease. Here, we review the role of fetal and neonatal macrophages in immune surveillance, innate immunity, homeostasis, tissue remodeling, angiogenesis, and repair of damaged tissues. We also discuss the possibility of therapeutic manipulation of the relative abundance and activation status of macrophage subsets in various diseases. This article combines peer-reviewed evidence from our own studies with results of an extensive literature search in the databases PubMed, EMBASE, and Scopus. IMPACT: We have reviewed the structure, differentiation, and classification of macrophages in the neonatal period. Neonatal macrophages are derived from embryonic, hepatic, and bone marrow precursors. Macrophages play major roles in tissue homeostasis, innate immunity, inflammation, tissue repair, angiogenesis, and apoptosis of various cellular lineages in various infectious and inflammatory disorders. Macrophages and related inflammatory mediators could be important therapeutic targets in several neonatal diseases.

Cytokines-Biogenesis and Their Role in Human Breast Milk and Determination

Cytokines play a huge role in many biological processes. Their production, release and interactions are subject to a very complex mechanism. Cytokines are produced by all types of cells, they function very differently and they are characterized by synergism in action, antagonism, and aggregation activity, opposing action of one cytokine, overlapping activity, induction of another cytokine, inhibition of cytokine synthesis at the mRNA level as well as autoregulation-stimulation or inhibition of own production. The predominance of pro-inflammatory cytokines leads to a systemic inflammatory response, and anti-inflammatory-to an anti-inflammatory response. They regulate the organism's immune response and protect it against sudden disturbances in homeostasis. The synthesis and activity of cytokines are influenced by the central nervous system through the endocrine system (pituitary gland, adrenal glands).

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

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

Human Breast Milk: Bioactive Components, from Stem Cells to Health Outcomes

PURPOSE OF REVIEW

Breast milk (BM) is a peculiar fluid owing unique properties and resulting the ideal food during early neonatal period. As widely known, it can improve the outcome of both neonate and lactating mother, influencing their whole life. BM is characterized by several beneficial components; among these, a great role is played by BM own and specific microbiome, deeply investigated in many studies. Moreover, the use of metabolomics in BM analysis allowed a better characterization of its metabolic pathways that vary according to lactation stage and neonatal gestational age. The aim of this review is to describe growth factors, cytokines, immunity mediators, and stem cells (SCs) contained in BM and investigate their functions and effects on neonatal outcome, especially focusing on immuno- and neurodevelopment.

RECENT FINDINGS

We evaluated recent and updated literature on this field. The article that we analyzed to write this review have been found in MEDLINE using breast milk-derived stem cells, biofactors, growth factors, breastfeeding-related outcomes, neurodevelopment, and neonatal immunological system as keywords. Discovering and characterizing BM components could result very useful to clarify the pathophysiology of their influence on neonatal growth and even to improve artificial formulations' composition. Moreover, since SCs abilities and their involvement in the development of several diseases, they could help to discover specific targets for new therapies. It could be useful to characterize BM-derived SC markers, properties, and variations during lactation stages, to understand their potential role in therapeutic applications, since they could be noninvasively isolated from BM. More studies will help to describe more in detail the characteristics of mother-to-child communication through breastfeeding and its potential role in the next future.

The impact of indole-3-lactic acid on immature intestinal innate immunity and development: a transcriptomic analysis

An excessive intestinal inflammatory response may have a role in the pathogenesis of necrotizing enterocolitis (NEC) in very preterm infants. Indole-3-lactic acid (ILA) of breastmilk tryptophan was identified as the anti-inflammatory metabolite involved in probiotic conditioned media from Bifidobacteria longum subsp infantis. This study aimed to explore the molecular endocytic pathways involved in the protective ILA effect against inflammation. H4 cells, Caco-2 cells, C57BL/6 pup and adult mice were used to compare the anti-inflammatory mechanisms between immature and mature enterocytes in vitro and in vivo. The results show that ILA has pleiotropic protective effects on immature enterocytes including anti-inflammatory, anti-viral, and developmental regulatory potentials in a region-dependent and an age-dependent manner. Quantitative transcriptomic analysis revealed a new mechanistic model in which STAT1 pathways play an important role in IL-1β-induced inflammation and ILA has a regulatory effect on STAT1 pathways. These studies were validated by real-time RT-qPCR and STAT1 inhibitor experiments. Different protective reactions of ILA between immature and mature enterocytes indicated that ILA's effects are developmentally regulated. These findings may be helpful in preventing NEC for premature infants.

Role of platelets in neonatal necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is an inflammatory bowel necrosis of premature infants and is a leading cause of morbidity and mortality in infants born between 23 and 28 weeks of gestation. Fifty to 95% of all infants with NEC develop thrombocytopenia (platelet counts <150 × 109/L) within 24-72 h of receiving this diagnosis. In many patients, thrombocytopenia is severe and is treated with one or more platelet transfusions. However, the underlying mechanism(s) and biological implications of NEC-related thrombocytopenia remain unclear. This review presents current evidence from human and animal studies on the clinical features and mechanisms of platelet depletion in NEC. Anecdotal clinical experience is combined with evidence from laboratory studies and from an extensive literature search in databases PubMed, EMBASE, and Scopus and the electronic archives of abstracts presented at the annual meetings of the Pediatric Academic Societies. To avoid bias in identification of existing studies, key words were short-listed prior to the actual search both from anecdotal experience and from PubMed's Medical Subject Heading (MeSH) thesaurus. IMPACT: Fifty to 95% of infants with necrotizing enterocolitis (NEC) develop idiopathic thrombocytopenia (platelet counts <150 × 109/L) within 24-72 h of disease onset. Early clinical trials suggest that moderate thrombocytopenia may be protective in human NEC, although further work is needed to fully understand this relationship. We have developed a neonatal murine model of NEC-related thrombocytopenia, where enteral administration of an immunological stimulant, trinitrobenzene sulfonate, on postnatal day 10 induces an acute necrotizing ileocolitis resembling human NEC. In this murine model, thrombocytopenia is seen at 15-18 h due to platelet consumption and mild-moderate thrombocytopenia is protective.

Blockage of NLRP3 inflammasome activation ameliorates acute inflammatory injury and long-term cognitive impairment induced by necrotizing enterocolitis in mice

Background

Necrotizing enterocolitis (NEC) is an inflammatory gastrointestinal disease in premature neonates with high mortality and morbidity, while the underlining mechanism of intestinal injury and profound neurological dysfunction remains unclear. Here, we aimed to investigate the involvement of NLPR3 inflammasome activation in NEC-related enterocolitis and neuroinflammation, especially long-term cognitive impairment, meanwhile, explore the protective effect of NLRP3 inhibitor MCC950 on NEC in mice.

Methods

NLRP3 inflammasome activation in the intestine and brain was assessed in the NEC mouse model, and NLRP3 inhibitor MCC950 was administrated during the development of NEC. Survival rate, histopathological injury of the intestine and brain, and expression of mature IL-1β and other pro-inflammatory cytokines were analyzed. Long-term cognitive impairment was evaluated by behavioral test.

Results

The expression of NLRP3 and mature IL-1β in the intestine and brain was greatly upregulated in NEC mice compared to the controls. MCC950 treatment efficiently improved NEC survival rate, reduced intestinal and brain inflammation, and ameliorated the severity of pathological damage in both organs. Additionally, in vivo blockage of NLRP3 inflammasome with MCC950 in early life of NEC pups potently protected against NEC-associated long-term cognitive impairment.

Conclusions

Our findings suggest that NLRP3 inflammasome activation participates in NEC-induced intestinal and brain injury, and early intervention with NLRP3 inhibitor may provide beneficial therapeutic effect on NEC infants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02111-4.

Maternal breastmilk, infant gut microbiome and the impact on preterm infant health

AIM

This narrative review summarises the benefits of maternal breastmilk to both the infant and the mother, specifically the benefits that relate to modification of the infant microbiome, and how this might vary in the preterm infant.

METHODS

We used PubMed to primarily identify papers, reviews, case series and editorials published in English until May 2020. Based on this, we report on the components of breastmilk, their associated hypothesised benefits and the implications for clinical practice.

RESULTS

Breastmilk is recommended as the exclusive diet for newborn infants because it has numerous nutritional and immunological benefits. Additionally, exposure to the maternal breastmilk microbiome may confer a lasting effect on gut health. In the preterm infant, breastmilk is associated with a significant reduction in necrotising enterocolitis, an inflammatory gastrointestinal disease and reduction in other key morbidities, together with improved neurodevelopmental outcomes.

CONCLUSION

These impacts have long-term benefits for the child (and the mother) even after weaning. This benefit is likely due, in part, to modification of the infant gut microbiome by breastmilk microbes and bioactive components, and provide potential areas for research and novel therapies in preterm and other high-risk infants.

Early Postnatal Comprehensive Biomarkers Cannot Identify Extremely Preterm Infants at Risk of Developing Necrotizing Enterocolitis

Background: Necrotizing enterocolitis (NEC) is a fatal disease where current diagnostic tools are insufficient for preventing NEC. Early predictive biomarkers could be beneficial in identifying infants at high risk of developing NEC. Objective: To explore early biomarkers for predicting NEC in extremely preterm infants (EPIs). Methods: Blood samples were collected on day 2 (median 1.7; range 1.5-2.0) from 40 EPI (median 25 gestational weeks; range 22-27): 11 developed NEC and 29 did not (controls). In each infant, 189 inflammatory, oncological, and vascular proteomic biomarkers were quantified through Proximity Extension Assay. Biomarker expression and clinical data were compared between the NEC group and Controls. Based on biomarker differences, controls were sorted automatically into three subgroups (1, 2, and 3) by a two-dimensional hierarchical clustering analysis. Results: None of the biomarkers differed in expression between all controls and the NEC group. Two biomarkers were higher in Control 1, and 16 biomarkers were lower in Control group 2 compared with the NEC group. No biomarker distinguished Control 3 from the NEC group. Perinatal data were similar in the whole population. Conclusions: Early postnatal comprehensive biomarkers do not identify EPIs at risk of developing NEC in our study. Future studies of predictors of NEC should include sequential analysis of comprehensive proteomic markers in large cohorts.

A Mouse Model of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is an acute inflammatory disease that unforeseeably develops in very low birth weight premature infants. NEC is characterized by impairment of the intestinal barrier resulting in intestinal necrosis and multisystem organ failure. Animal models of NEC have contributed significantly to a better understanding of the underlying molecular mechanisms of the disease and facilitated the exploration of potential new therapeutic strategies. Here, we provide a detailed protocol that recapitulates some of the main histological and transcriptional features of human NEC in newborn mice.

Interleukin 8 may predict surgical necrotizing enterocolitis in infants born less than 1500 g

Necrotizing enterocolitis (NEC) often leads to gastrointestinal emergency resulting high mortality in very low birth weight infants (VLBWIs) requiring surgery. To date, few studies have explored the role of serum cytokines in the development of feeding intolerance (FI) or NEC outcomes in VLBWIs. Infants born weighing <1500 g or of 32 weeks of gestational age were prospectively enrolled from May 2018 to Dec 2019. We measured several cytokines routinely within 72 h of life, even before NEC-like symptoms developed. NEC or FI group comprised 17 (27.4%) infants, and 6 (9.7%) infants had surgical NEC. The gestational age and birth weight were significantly lower in the NEC or FI group with more prematurity-related complications. The surgical NEC group also demonstrated significantly lower gestational age and birth weight along with more infants experiencing refractory hypotension within a 1 week of life, pulmonary hypertension, and patent ductus arteriosus. IL-10 levels were significantly higher in the NEC or FI group, whereas IL-8 levels were significantly higher in the infants with surgical NEC. Our findings indicated to IL-8 can predict surgical NEC while increased IL-10 can predict NEC development in VLBWIs.

Free Amino Acids in Human Milk: A Potential Role for Glutamine and Glutamate in the Protection Against Neonatal Allergies and Infections

Breastfeeding is indicated to support neonatal immune development and to protect against neonatal infections and allergies. Human milk composition is widely studied in relation to these unique abilities, which has led to the identification of various immunomodulating components in human milk, including various bioactive proteins. In addition to proteins, human milk contains free amino acids (FAAs), which have not been well-studied. Of those, the FAAs glutamate and glutamine are by far the most abundant. Levels of these FAAs in human milk sharply increase during the first months of lactation, in contrast to most other FAAs. These unique dynamics are globally consistent, suggesting that their levels in human milk are tightly regulated throughout lactation and, consequently, that they might have specific roles in the developing neonate. Interestingly, free glutamine and glutamate are reported to exhibit immunomodulating capacities, indicating that these FAAs could contribute to neonatal immune development and to the unique protective effects of breastfeeding. This review describes the current understanding of the FAA composition in human milk. Moreover, it provides an overview of the effects of free glutamine and glutamate on immune parameters relevant for allergic sensitization and infections in early life. The data reviewed provide rationale to study the role of free glutamine and glutamate in human milk in the protection against neonatal allergies and infections.

The Course Of IGF-1 Levels and Nutrient Intake in Extremely and Very Preterm Infants During Hospitalisation

BACKGROUND

Insulin-like growth factor 1 (IGF-1) plays an important role in the complex association between nutrition, growth, and maturation in extremely and very preterm infants. Nevertheless, in this population, research on associations between IGF-1 and nutrition is limited. Therefore this study aimed to evaluate the possible associations between the course of IGF-1 levels and nutrient intake between preterm birth and 36 weeks postmenstrual age (PMA).

METHODS

87 infants born between 24 and 32 weeks gestational age were followed up to 36 weeks PMA. Actual daily macronutrient intake was calculated, and growth was assessed weekly. IGF-1 was sampled from umbilical cord blood at birth and every other week thereafter.

RESULTS

There was an inverse relationship between the amount of parenteral nutrition in the second week of life and IGF-1. Total protein, fat, and carbohydrate intake, as well as total energy intake, primarily showed a positive association with IGF-1 levels, particularly between 30 and 33 weeks PMA. Gestational age, bronchopulmonary dysplasia (BPD), and weight were significant confounders in the association between nutrient intake and IGF-1 levels.

CONCLUSION

Parenteral nutrition was found to be a negative predictor of IGF-1 levels, and there could potentially be a time frame in which macronutrient intake is unable to impact IGF-1 levels. Future research should aim to narrow down this time frame and to gain more insight into factors enhancing or decreasing the response of IGF-1 to nutrition, e.g., age and inflammatory state, to align nutritional interventions accordingly.

[Research advances in the effect of bioactive substances in breast milk on the growth and development of infants]

There are various types of bioactive substances in human breast milk, such as active proteins, growth factors, cytokines, oligosaccharides, probiotics and cells. Many studies have shown that these bioactive substances in breast milk have important protective effects on infant growth and development, including anti-bacterial and anti-viral effects and the promotion of infant growth and development and immunologic maturation. They can also reduce the incidence rate of infectious diseases in infants, improve neural development in preterm infants, and reduce the risk of obesity and diabetes in future. However, there is still no clinical evidence for the effects of several active substances in breast milk, and their immunoregulatory mechanism remains unclear. Therefore, further studies are needed for clarification.

Intestinal dysbiosis and necrotizing enterocolitis: assessment for causality using Bradford Hill criteria

In recent years, several studies have shown that premature infants who develop NEC frequently display enteric dysbiosis with increased Gram-negative bacteria for several days to weeks prior to NEC onset. The importance of these findings, for the possibility of a causal role of these bacteria in NEC pathogenesis, and for potential value of gut dysbiosis as a biomarker of NEC, is well-recognized. In this review, we present current evidence supporting the association between NEC in premature infants and enteric dysbiosis, and its evaluation using the Bradford Hill criteria for causality. To provide an objective appraisal, we developed a novel scoring system for causal inference. Despite important methodological and statistical limitations, there is support for the association from several large studies and a meta-analysis. The association draws strength from strong biological plausibility of a role of Gram-negative bacteria in NEC and from evidence for temporality, that dysbiosis may antedate NEC onset. The weakness of the association is in the low level of consistency across studies, and the lack of specificity of effect. There is a need for an improved definition of dysbiosis, either based on a critical threshold of relative abundances or at higher levels of taxonomic resolution.

A glucocorticoid receptor agonist improves post-weaning growth performance in segregated early-weaned pigs

While beneficial for sow reproductive efficiency and biosecurity, segregated early weaning (SEW) leads to a systemic immune response that adversely affects the digestive physiology and post-weaning growth of pigs. Two experiments were conducted to evaluate the effects of a glucocorticoid receptor agonist (GA) on growth performance, measures of immune function and intestinal integrity of SEW pigs. In both experiments, pigs were fed corn-soybean meal-based starter diets. In the first experiment, 48 pigs (initial BW 4.8 ± 0.7 kg) were weaned at 21 ± 1 days and randomly assigned to three GA treatment groups: 0, 0.2 and 0.6 mg GA/kg of BW injected intramuscularly. Treatments were administered one day before weaning. Pigs in the 0 mg GA group received sterile saline in place of GA. Body weight was measured daily from one day before to 7 days post-weaning, and then weekly until 28 days post-weaning. Piglets treated with 0.2 mg GA had a higher BW than piglets in other treatment groups during the 28-day course of the study (P <0.02). To further explore the mechanisms behind this result, a second experiment was performed in which a total of 18 gilts (BW 5.6 ± 0.85 kg) were randomly assigned into three treatment groups: suckling plus saline (UWS), weaned treated with GA (WGA; 0.2 mg GA/kg BW) and weaned plus saline (CON). Treatments were administered one day before and 3 days post-weaning. The WGA and CON groups were weaned at 23 ± 2 days, while the UWS group remained with sow for the duration of the study. Body weight was measured daily and blood plasma was collected at 0, 1, 4 and 5 days post-weaning. All gilts were euthanized 5 days after weaning and jejunum samples were collected for mucosal scrapings, histomorphological analysis and gene expression analysis. Plasma levels of interleukin-1β (IL-1β) and haptoglobin were lower in WGA pigs compared with CON (P <0.02), while plasma total antioxidant capacity was higher in WGA pigs compared with both CON and UWS groups (P <0.01). Relative to CON, GA downregulated IL-18 gene expression in the jejunum, as assessed by both tissue homogenate and mucosal scrapings, but it upregulated claudin-IV gene expression only in the tissue homogenate (P <0.01). These results suggest that GA treatment improves the growth performance of SEW pigs in part by mitigating the negative effects of systemic inflammation. However, the effect of GA on barrier integrity requires further investigation.

Arguments for routine administration of probiotics for NEC prevention

PURPOSE OF REVIEW

Probiotic administration to premature infants for the purpose of prevention of necrotizing enterocolitis is common in many parts of the world but uncommon in the United States. The present review will emphasize recent findings in support of routine administration of probiotics to this highly vulnerable population.

RECENT FINDINGS

Additional evidence from animal models describing mechanisms of protection of probiotics in the immature gut and updated meta-analyses of randomized placebo-controlled trials and observational cohorts are presented (now including more than 40 000 premature infants from countries across the globe).

SUMMARY

The preponderance of evidence suggests that probiotic administration to premature infants is well tolerated and decreases the risk of death, necrotizing enterocolitis, and sepsis. Further comparisons of probiotic administration to placebo are not likely to alter these conclusions. Rather, future work should focus on assurance of high-quality products with demonstrated purity and viability of probiotic microbes, and future clinical trials should focus on comparisons between high-quality products and doses.

Necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is an acute inflammatory disease of the intestine which primarily affects preterm infants and is a leading cause of morbidity and mortality in the neonatal intensive care unit. From a clinical standpoint, and during the early course of the disease, NEC can be difficult to distinguish from other diseases and conditions common to the preterm infant, and this warrants the need for specific disease biomarkers. The pathogenesis of NEC is only partly understood but likely involves an altered intestinal barrier immune response to feeding and the developing microbiome. Recent evidence points toward a role of the enteric nervous system in NEC pathogenesis. In this issue, Meister and colleagues use a rodent model of NEC to demonstrate that NEC is associated with diminished vagal tone, as determined by decreased high-frequency heart rate variability (HF-HRV), and altered myenteric nitrergic inhibitory neurotransmission. These results augment their previous findings that describe decreased HF-HRV in human preterm infants with NEC. This mini-review provides a brief summary of clinical and pathophysiologic aspects of NEC with focus on certain aspects of neurogastroenterology.

The impact of environmental pollution on the quality of mother's milk

Breastfeeding is a gold standard of neonate nutrition because human milk contains a lot of essential compounds crucial for proper development of a child. However, milk is also a biofluid which can contain environmental pollution, which can have effects on immune system and consequently on the various body organs. Polychlorinated biphenyls are organic pollutants which have been detected in human milk. They have lipophilic properties, so they can penetrate to fatty milk and ultimately to neonate digestive track. Another problem of interest is the presence in milk of heavy metals-arsenic, lead, cadmium, and mercury-as these compounds can lead to disorders in production of cytokines, which are important immunomodulators. The toxicants cause stimulation or suppression of this compounds. This can lead to health problems in children as allergy, disorders in the endocrine system, end even neurodevelopment delay and disorder. Consequently, correlations between pollutants and bioactive components in milk should be investigated. This article provides an overview of environmental pollutants found in human milk as well as of the consequences of cytokine disorder correlated with presence of heavy metals. Graphical abstract.

Physiology of Stress and Use of Skin-to-Skin Care as a Stress-Reducing Intervention in the NICU

Advances in neonatal care have allowed for the increasing survival of critically ill infants. These infants experience significant stress related to painful procedures and physical separation from their parents. The purpose of this article is to describe the physiologic stress mechanisms that contribute to mortality and morbidity in infants in the NICU and the physiologic mechanisms by which skin-to-skin care (SSC) acts on the stress response system. Findings from current literature supporting the use of SSC and barriers and facilitators to implementation are reviewed. SSC is a safe and effective intervention to reduce stress for infants and their parents. Nurses play a key role in facilitating SSC to optimize outcomes of care in the NICU.

Cytokines and Soluble Receptors in Breast Milk as Enhancers of Oral Tolerance Development

The postpartum period is an important window during which environmental factors can shape the life-long health of the infant. This time period often coincides with substantial milk consumption either in the form of breast milk or from cow's milk sources, such as infant formulas. Although breast milk is the most beneficial source of nutrients for infants during the first 6 months after birth, its role in regulating food allergy development, through regulation of oral tolerance, is still controversial. Breast milk contains several factors that can impact mucosal immune function, including immune cells, antibodies, microbiota, oligosaccharides, cytokines, and soluble receptors. However, there is considerable variation in the assessed levels of cytokines and soluble receptors between studies and across the lactation period. Most of these cytokines and soluble receptors are absent, or only found in limited quantities, in commercial baby formulas. Differences in content of these pluripotent factors, which impact on both the mother and the neonate, could contribute to the controversy surrounding the role of breast milk regulating oral tolerance. This review highlights current knowledge about the importance of cytokines and soluble receptors in breast milk on the development of oral tolerance and tolerance-relateddisorders. Understanding the mechanisms by which such milk components might promote oral tolerance could aid in the development of improved strategies for allergy prevention.

Ontogeny of alkaline phosphatase activity in infant intestines and breast milk

BACKGROUND

Necrotizing enterocolitis (NEC) is a devastating disease of intestinal inflammation that primarily affects premature infants. A potential risk factor for necrotizing enterocolitis is exposure of the premature neonatal intestine to environmental bacteria and their proinflammatory products such as lipopolysaccharide. The metalloenzyme alkaline phosphatase (ALP) has been shown to reduce lipopolysaccharide-mediated inflammation. Additionally, premature rat pups have reduced alkaline phosphatase activity and expression as compared to full term pups. To explore the possibility that the human premature neonatal intestine has a paucity of alkaline phosphatase activity, we measured endogenously produced intestinal alkaline phosphatase activity in meconium as a function of gestational age. To test whether breast milk could serve as a source of exogenous alkaline phosphatase to the neonatal intestine through ingestion, we measured alkaline phosphatase activity in breast milk across a range of time points post-birth.

METHODS

Alkaline phosphatase activity was quantified in 122 meconium samples from infants of gestational ages ranging from 24 to 40 weeks and in 289 breast milk samples collected from 78 individual mothers between days 2-49 post-birth.

RESULTS

We observed a strong positive correlation between the meconium alkaline phosphatase activity and gestational age, with preterm infants having lower meconium alkaline phosphatase activities than early term or term infants. Breast milk alkaline phosphatase activity was highest in the first week post-birth, with peak alkaline phosphatase activity at day 2 post-birth, followed by relatively low alkaline phosphatase activity in weeks 2-7.

CONCLUSIONS

Our results are consistent with the two major risk factors for necrotizing enterocolitis development, preterm birth and lack of breast milk feeding, both contributing to a paucity of alkaline phosphatase activity and impaired capacity to detoxify proinflammatory bacterial products such as lipopolysaccharide.

FTY720 attenuates intestinal injury and suppresses inflammation in experimental necrotizing enterocolitis via modulating CXCL5/CXCR2 axis

Necrotizing enterocolitis (NEC) remains one of the leading causes of death in neonatal infants and new therapeutic strategies for NEC are urgently required. The immunomodulatory agent FTY720 has been shown to have protective effects in various inflammatory diseases. In this study, we hypothesized that treatment with FTY720 confers protection against experimental NEC. Experimental NEC was induced in five-day-old C57BL/6 neonatal mice by hyperosmolar formula feeding plus hypoxia and lipopolysaccharide (LPS) challenges. Induction of NEC resulted in substantial weight loss and high mortality compared to the control group, whereas FTY720 treatment significantly attenuated weight loss and improved survival in NEC-challenged neonatal mice. FTY720 treatment strongly ameliorated NEC-induced intestinal injury with reduced apoptosis and up-regulation of intestinal barrier proteins in the ileal tissues. Furthermore, FTY720 treatment abrogated NEC-initiated intestinal and systemic inflammation with markedly diminished inflammatory cytokines and chemokines. Moreover, FTY720 treatment suppressed NEC-activated CXCL5/CXCR2 axis with down-regulated expression of CXCL5 and CXCR2 at both mRNA and protein levels. Thus, we demonstrate that FTY720 protects neonatal mice against NEC-associated lethality by ameliorating intestinal injury and attenuating inflammation, possibly via its down-regulation of NEC-induced activation of intestinal CXCL5/CXCR2 axis.

Lenticulostriate vasculopathy in preterm infants: a new classification, clinical associations and neurodevelopmental outcome

OBJECTIVE

To examine the inter-rater reliability for the diagnosis of LSV on cranial ultrasound (cUS), determine the risk factors associated with LSV and its progression, and examine neurodevelopmental outcome.

STUDY DESIGN

Prospective case-control study of neonates ≤32wks of gestation assessed for LSV by serial cUS (n = 1351) between 2012 and 2014 and their neurodevelopment at 18-36mon-corrected age compared to controls.

RESULTS

Agreement for LSV on cUS improved from Κappa 0.4-0.7 after establishing definitive criteria and guidelines. BPD was the only variable associated with the occurrence and the progression of LSV. Cytomegalovirus (CMV) infection occurred in one neonate (1.5%). Neurodevelopmental outcome of neonates with LSV did not differ from controls.

CONCLUSIONS

Establishment of well-defined stages of LSV improves the reliability of the diagnosis and allows identification of neonates with progression of LSV. Although LSV was associated with BPD, it was not associated with congenital CMV infection.

Necrotizing Enterocolitis and Neurodevelopmental Outcome

Necrotizing enterocolitis is a serious complication of prematurity that is associated with an increased risk for adverse neurodevelopmental outcome secondary to a complex relationship between various morbidities that increase the risk for central nervous system injury. Affected infants are exposed to a variety of circulating cytokines known to be associated with white matter injury. These infants also have an increased risk of secondary blood stream infections and nutritional compromise.

Digested Early Preterm Human Milk Suppresses Tumor Necrosis Factor-induced Inflammation and Cytotoxicity in Intestinal Epithelial Cells

OBJECTIVES

The aim of this study was to determine the effect of digested whole human milk (HM; first sample available after birth from mothers of premature infants) on inflammation, oxidative stress, and cytotoxicity in Caco-2 human intestinal epithelial cells stimulated with lipopolysaccharides or tumor necrosis factor (TNF) to mimic the potential in vivo insults facing the premature infant's gastrointestinal tract.

METHODS

Fully differentiated Caco-2 cells were exposed to digested HM (n = 10; samples from 10 different individuals) before stimulation with lipopolysaccharides, TNF, or no stimulation overnight. Inflammation was determined by production of interleukin-8, oxidative stress by levels of F2-isoprostane, and cytotoxicity by released lactate dehydrogenase.

RESULTS

HM significantly suppressed interleukin-8 production and cytotoxicity in TNF-stimulated cells, while also suppressing cell death under baseline conditions. Individual HM samples differed widely in their ability to modulate cellular responses.

CONCLUSIONS

Results from this study provide evidence that digested HM can reduce both an exaggerated inflammatory response and intestinal damage that contribute to the pathogenesis of necrotizing enterocolitis.

Productive and economic parameters of pigs supplemented from weaning to finishing with prebiotic and probiotic feed additives

Practical evidence suggests possible beneficial effects with the combined use of prebiotics and probiotics which can improve production parameters. The objective of the study was to investigate the addition of Saccharomyces cerevisiae (SC) as prebiotic and the combination of Lactobacillus spp. (L), Bacillus spp. (B) as probiotics on productive parameters and economic feasibility. Four hundred male pigs, hybrids of commercial genetic lines (Pietrain), were used: T1 = control group, T2 = 4 kg/tonne SC, T3 = 0.8 kg/tonne feed L and B, T4 = 4 kg/tonne SC + 0.8 kg/tonne L and B. Productive parameters were recorded in the treatment groups for four periods. Then, the viscera of five pigs per treatment were collected after slaughter to evaluate the histological changes and cytokine concentrations in the ileum. The weight gains of groups at 70–100, 100–125 and 125–150 days in the T4 group showed statistically increases (p < .05). Feed intake had a significant difference (p < .05) in T3 versus T1. The feed‐conversion ratio improved for all periods in the T4 group (p < .05). The eosinophil, mononuclear infiltration and cytokines (tumor necrosis factor‐α and interleukin‐6) in the mucosa were lower for treatments with probiotics. In conclusion, there was an economic benefit when using both prebiotics and probiotics in the diet of pigs from weaning to finishing.

Necrotizing enterocolitis: Pathophysiology from a historical context

Necrotizing enterocolitis (NEC) continues to afflict approximately 7% of preterm infants born weighing less than 1500g, though recent investigations have provided novel insights into the pathogenesis of this complex disease. The disease has been a major cause of morbidity and mortality in neonatal intensive care units worldwide for many years, and our current understanding reflects exceptional observations made decades ago. In this review, we will describe NEC from a historical context and summarize seminal findings that underscore the importance of enteral feeding, the gut microbiota, and intestinal inflammation in this complex pathophysiology.

Changing the paradigm of defining, detecting, and diagnosing NEC: Perspectives on Bell's stages and biomarkers for NEC

Better means to diagnose and define necrotizing enterocolitis are needed to guide clinical practice and research. Adequacy of Bell's staging system for clinical practice and clarity of cases used in NEC clinical datasets has been a topic of controversy for some time. This article provides reasons why a better global definition for NEC is needed and offers a simple alternative bedside definition for preterm NEC called the "Two out of Three" rule. Some argue that biomarkers may fill knowledge gaps and provide greater precision in defining relevant features of a clinical disease like NEC. NEC biomarkers include markers of inflammation, intestinal dysfunction, hematologic changes, and clinical features. Development and reporting of NEC biomarkers should be guided by the FDA's BEST Consensus resource, "Biomarkers, EndpointS, & other Tools" and consistently report metrics so that studies can be compared and results pooled. Current practice in the NICU would be enhanced by clinical tools that effectively inform the clinical team that a baby is at increasing risk of NEC. Ideally, these tools will incorporate both clinical information about the baby as well as molecular signals that are indicative of NEC. While meaningful biomarkers for NEC and clinical tools exist, translation into practice is mediocre.

Slow enteral feeding decreases risk of transfusion associated necrotizing enterocolitis

BACKGROUND

Necrotizing Enterocolitis (NEC) is a multifactorial condition where PRBC transfusion is associated with necrotizing enterocolitis (TANEC) in about a third of all cases of NEC. We have investigated the role of feeding practices in incidence of TANEC. We sought to compare infants diagnosed with TANEC versus infants diagnosed with classic NEC and investigated the effects of a standardized slow enteral feeding (SSEF) protocol on TANEC incidence as well as the effects of SSEF on growth of infants with NEC.

METHODS

We conducted a retrospective cohort study, where medical records of infants born in a tertiary care neonatal intensive care unit (level IIIb) from January 1997 to May 2014 with birth weight < 1500 grams and gestational age≤34 weeks with NEC stage IIa or greater according to the modified Bell's staging were reviewed.

RESULTS

During the study period, 111 infants developed NEC, and 41/111 (37%) were diagnosed with TANEC. Infants with TANEC were smaller, more premature, had higher SNAPPE scores and were more anemic prior to transfusion compared with infants with 'classic NEC'. The severity of NEC did not differ between the two groups, however, infants with TANEC had worse outcomes and longer NICU stays. Introduction of SSEF protocol, led to a significant decrease in TANEC. There was no difference in weight and head circumference of infants in the two groups at 2 years corrected age.

CONCLUSION

SSEF led to a significant reduction in the incidence of TANEC without impairing growth at 2 years corrected age.

Protective effects of amniotic fluid in the setting of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common life threatening condition affecting preterm infants. NEC occurs in 1-5% of all neonatal intensive care admissions and 5-10% of very low birth weight infants. The protective role of human breast milk (BM) has been well established. It has also been shown that amniotic fluid (AF) and BM have many similarities in terms of presence of growth and other immune-modulatory factors. This finding led to the initial hypothesis that AF may exert similar protective effects against the development of NEC, as does BM. Multiple studies have elucidated the presence of growth factors in AF and the protective effect of AF against NEC. Studies have also described possible mechanisms how AF protects against NEC. At present, research in this particular area is extremely active and robust. This review summarizes the various studies looking at the protective effects of AF against the development of NEC. It also provides an insight into future directions, the vast potential of AF as a readily available biologic medium, and the ethical barriers that must be overcome before using AF.

"Omics" in Human Colostrum and Mature Milk: Looking to Old Data with New Eyes

Human Milk (HM) is the best source for newborn nutrition until at least six months; it exerts anti-inflammatory and anti-infective functions, promotes immune system formation and supports organ development. Breastfeeding could also protect from obesity, diabetes and cardiovascular disease. Furthermore, human colostrum (HC) presents a peculiar role in newborn support as a protective effect against allergic and chronic diseases, in addition to long-term metabolic benefits. In this review, we discuss the recent literature regarding "omics" technologies and growth factors (GF) in HC and the effects of pasteurization on its composition. Our aim was to provide new evidence in terms of transcriptomics, proteomics, metabolomics, and microbiomics, also in relation to maternal metabolic diseases and/or fetal anomalies and to underline the functions of GF. Since HC results are so precious, particularly for the vulnerable pre-terms category, we also discuss the importance of HM pasteurization to ensure donated HC even to neonates whose mothers are unable to provide. To the best of our knowledge, this is the first review analyzing in detail the molecular pattern, microbiota, bioactive factors, and dynamic profile of HC, finding clinical correlations of such mediators with their possible in vivo effects and with the consequent impact on neonatal outcomes.