Necrotizing enterocolitis: Pathophysiology from a historical context

The Nonbacterial Infant Microbiome and Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is among the most devastating neonatal illnesses of premature infants. Although it is a disease of multifactorial etiology associated with bacterial dysbiosis, several reports of viral and some fungal infections associated with NEC have been published. Despite the abundance of viruses-primarily bacteriophages, and "virus-like particles" in the normal infant gut flora, there is limited understanding of the contribution of these elements to newborn gut health and disease. This study aims to review existing evidence on normal newborn virome and mycobiome development and present insights into the complex inter-kingdom interactions between gut bacteria, viruses, and fungi in the intestinal ecosystem, exploring their potential role in predisposing the preterm infant to NEC. · We have reviewed a number of viral and fungal infections reported in association with NEC-like illnesses.. · Bacteriophages play a crucial role in the gut microbiome development, but their role in pathogenesis of NEC and potential for therapeutic use is unknown.. · Development of next-gen metagenomic tools are needed to enhance our understanding of viral diversity, bacteriophages, and the gut virome in the context of neonatal health and disease..

A Phosphodiesterase Type-5 (PDE-5) Inhibitor, Sildenafil, Ameliorates the NEC Induced Inflammation

The connection between intestine microbiota and lung disease is described as the gut-lung axis, these organ systems are somehow interrelated in both homeostasis and disease development. In newborns, the most important gastrointestinal complications are necrotizing enterocolitis (NEC), and the pulmonary complication both cause significant systemic morbidity. In this study, sildenafil administered at varying doses in neonatal rat model of experimental necrotizing enterocolitis and focused on both mRNA expression and histopathological alterations. 15-day-old Wistar Albino rat pups were randomly divided into six groups; Control, NEC, DMSO, Sil_1mg, Sil_5mg, Sil_10mg (n = 5). NEC induction was performed using hypoxia/asphyxia and cold stress. At the end of the experiment, lung tissues were harvested, molecular and histopathological alterations were analysed. Histopathological examination was performed with hematoxylin&eosin and masson trichrome staining in lung samples of neonatal rats and the mRNA expression levels of TNF-α, IL-6 and HSPa5 genes were analyzed. The mRNA expression levels of TNF-α, IL-6 and HSPa5 were increased in the NEC group compared to the control group and sildenafil treatment could significantly reduced the levels of the genes and inflammation (*p < 0.05 and **p ≤ 0.0001). Alveolar edema and hemorrhage findings were observed in the lung tissue of the NEC group. Interstitial edema and hemorrhage findings were reduced in the groups treated with sildenafil compared to the NEC group. The data we obtained indicate that sildenafil administering at different doses has therapeutic effect on NEC induced lung tissue inflammation both at the mRNA expression and tissue levels.

Optimizing nutritional strategies in term NEC and perforation infants after intestinal operation: a retrospective study

Necrotizing enterocolitis (NEC) represents a severe condition in infants, with perforation being a particularly critical pathological manifestation. However, there is an absence of guidelines regarding the refeeding of infants recovering from perforation subsequent to NEC. This study aimed to determine the optimal refeeding method for term infants recovering from perforation after NEC. The study encompassed three aspects: the timing of enteral nutrition (EN) resumption, the progression of EN, and the method of EN resumption. Ninety full-term neonates who developed perforation following NEC and underwent surgical intervention were included. These samples were divided into early enteral nutrition (EEN, < 7 days) and late enteral nutrition (LEN, ≥ 7 days) groups based on the timing of EN resumption; faster increase (FI, ≥ 20 ml/kg/d) and slower increase (SI, < 20 ml/kg/d) groups based on the progression of EN; intact protein formula (IPF), special medical formula (SMF, including EHF and AABF), and mixed feeding (MF) groups based on the method of EN resumption. EEN infants had a lower incidence of intestinal stenosis and reoperation (43.5% vs. 77.6%, p = 0.002; 60.9% vs. 82.1%, p = 0.038), and a shorter duration of hospital stay after surgery and parenteral nutrition (PN) than LEN infants (14 days vs. 20 days, p < 0.001; 11 days vs. 17 days, p < 0.001). Faster increasing feed volumes was associated with shorter duration of hospital stay and parenteral nutrition (15 days vs. 20 days, p < 0.001; 14 days vs. 17 days, p < 0.001), but a slower rate of weight gain (0.020 kg vs. 0.129 kg, p < 0.01). The time to repeat NPO in SMF group is shorter than IPF an MF groups (3 days vs. 4 days and 9 days, p = 0.025). Our study demonstrates the beneficial effects of early enteral feeding and fast advancement of feed volumes in term infants with NEC and perforation after surgery, specifically in reducing short-term complications and the duration of hospital stay following surgery and PN. Additionally, this study suggests that IPF and MF significantly contribute to stimulate intestinal adoption recovery.

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.

Evolutionary bridges: how factors present in amniotic fluid and human milk help mature the gut

Necrotizing enterocolitis (NEC) continues to be a leading cause of morbidity and mortality in preterm infants. As modern medicine significantly improves the survival of extremely premature infants, the persistence of NEC underscores our limited understanding of its pathogenesis. Due to early delivery, a preterm infant's exposure to amniotic fluid (AF) is abruptly truncated. Replete with bioactive molecules, AF plays an important role in fetal intestinal maturation and preparation for contact with the environment, thus its absence during development of the intestine may contribute to increased susceptibility to NEC. Human milk (HM), particularly during the initial phases of lactation, is a cornerstone of neonatal intestinal defense. The concentrations and activities of several bioactive factors in HM parallel those of AF, suggesting continuity of protection. In this review, we discuss the predominant overlapping bioactive components of HM and AF, with an emphasis on those associated with intestinal growth or reduction of NEC.

Value of portal venous gas and a nomogram for predicting severe neonatal necrotizing enterocolitis

BACKGROUND

Whether portal venous gas (PVG) is a sign of severe neonatal necrotizing enterocolitis (NEC) and predicts poor prognosis remains uncertain.

METHODS

Patients from two centres were randomly assigned to a training set or a validation set. A nomogram model for predicting severe NEC was developed on the basis of the independent risk factors selected by least absolute shrinkage and selection operator (LASSO) regression analysis and multivariate logistic regression analysis. The model was evaluated based on the area under the curve (AUC), calibration curve, and decision curve analysis (DCA).

RESULTS

A total of 585 patients met the study criteria, and propensity score matching resulted in 141 matched pairs for further analysis. Patients with PVG had a greater risk of surgical intervention or death compared with patients without PVG. A prediction model for severe NEC was established based on PVG, invasive mechanical ventilation (IMV), serum platelet count (PLT) and pH <7.35 at the onset of NEC. The model had a moderate predictive value with an AUC > 0.8. The calibration curve and DCA suggested that the nomogram model had good performance for clinical application.

CONCLUSION

A prediction nomogram model based on PVG and other risk factors can help physicians identify severe NEC early and develop reasonable treatment plans.

IMPACT

PVG is an important and common imaging manifestation of NEC. Controversy exists regarding whether PVG is an indication for surgical intervention and predicts poor prognosis. Our study suggested that patients with PVG had a greater risk of surgical intervention or death compared with patients without PVG. PVG, IMV, PLT and pH <7.35 at the onset of NEC are independent risk factors for severe NEC. A prediction nomogram model based on PVG and other risk factors may help physicians identify severe NEC early and develop reasonable treatment plans.

Struggling to Understand the NEC Spectrum-Could the Integration of Metabolomics, Clinical-Laboratory Data, and Other Emerging Technologies Help Diagnosis?

Necrotizing enterocolitis (NEC) is the most prevalent and potentially fatal intestinal injury mainly affecting premature infants, with significant long-term consequences for those who survive. This review explores the scale of the problem, highlighting advancements in epidemiology, the understanding of pathophysiology, and improvements in the prediction and diagnosis of this complex, multifactorial, and multifaced disease. Additionally, we focus on the potential role of metabolomics in distinguishing NEC from other conditions, which could allow for an earlier and more accurate classification of intestinal injuries in infants. By integrating metabolomic data with other diagnostic approaches, it is hoped to enhance our ability to predict outcomes and tailor treatments, ultimately improving care for affected infants.

Risk factors for necrotizing enterocolitis in small-for-gestational-age infants: a matched case-control study

Few studies have focused on the risk factors for necrotizing enterocolitis (NEC) in small for gestational age (SGA) infants. The aim of this study was to identify the risk factors for NEC in SGA newborns. This study included consecutive SGA neonates admitted to a tertiary hospital in Jiangxi Province, China from Jan 2008 to Dec 2022. Patients with NEC (Bell's stage ≥ II) were assigned to the NEC group. Gestational age- and birth weight-matched non-NEC infants born during the same period at the same hospital were assigned to the control group. The risk factors associated with NEC were analyzed with univariate and logistic regression models. During the study period, 2,912 SGA infants were enrolled, 150 (5.15%) of whom developed NEC. In total, 143 patients and 143 controls were included in the NEC and control groups, respectively. Logistic regression analysis revealed that sepsis (OR 2.399, 95% CI 1.271-4.527, P = 0.007) and anemia (OR 2.214, 95% CI 1.166-4.204, P = 0.015) might increase the incidence of NEC in SGA infants and that prophylactic administration of probiotics (OR 0.492, 95% CI 0.303-0.799, P = 0.004) was a protective factor against NEC. Therefore, sepsis, anemia and a lack of probiotic use are independent risk factors for NEC in SGA infants.

Selection of a probiotic to prevent necrotizing enterocolitis for preterm infants in a French neonatology department

Very premature and/or low-birth-weight infants are at risk of developing necrotizing ulcerative enterocolitis (NEC). Prophylactic use of probiotics would change the composition of the gut microbiota and thus reduce the risk of NEC. In order to choose a probiotic at the local level, international recommendations were compared, and the available specialties were listed. Discrepancies between the different recommendations appeared, and the great variability of infant specialties available, as well as their status, did not allow us to select one. The local objective will therefore be to participate in the discussion of this subject at a national level.

Endogenous Hyaluronan Promotes Intestinal Homeostasis and Protects against Murine Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a complex, multifactorial gastrointestinal disorder predominantly affecting preterm infants. The pathogenesis of this condition involves a complex interplay between intestinal barrier dysfunction, microbial dysbiosis, and an altered immune response. This study investigates the potential role of endogenous hyaluronan (HA) in both the early phases of intestinal development and in the context of NEC-like intestinal injury. We treated neonatal CD-1 mouse pups with PEP1, a peptide inhibiting HA receptor interactions, from postnatal days 8 to 12. We evaluated postnatal intestinal developmental indicators, such as villi length, crypt depth, epithelial cell proliferation, crypt fission, and differentiation of goblet and Paneth cells, in PEP1-treated animals compared with those treated with scrambled peptide. PEP1 treatment significantly impaired intestinal development, as evidenced by reductions in villi length, crypt depth, and epithelial cell proliferation, along with a decrease in crypt fission activity. These deficits in PEP1-treated animals correlated with increased susceptibility to NEC-like injuries, including higher mortality rates, and worsened histological intestinal injury. These findings highlight the role of endogenous HA in supporting intestinal development and protecting against NEC.

Macrophage α7nAChR alleviates the inflammation of neonatal necrotizing enterocolitis through mTOR/NLRP3/IL-1β pathway

BACKGROUND

Neonatal necrotizing enterocolitis (NEC) is one of the most prevalent and severe intestinal emergencies in newborns. The inflammatory activation of macrophages is associated with the intestinal injury of NEC. The neuroimmune regulation mediated by α7 nicotinic acetylcholine receptor (α7nAChR) plays an important role in regulating macrophage activation and inflammation progression, but in NEC remains unclear. This study aims to explore the effect of macrophage α7nAChR on NEC.

METHODS

Mice NEC model were conducted with high-osmolarity formula feeding, hypoxia, and cold stimulation. The α7nAChR agonist PNU-282987 and mTOR inhibitor rapamycin were treated by intraperitoneal injections in mice. The expression and distribution of macrophages, α7nAChR, and phospho-mammalian target of rapamycin (p-mTOR) in the intestines of NEC patients and mice was assessed using immunohistochemistry, immunofluorescence, and flow cytometry. The expression of NLRP3, activated caspase-1 and IL-1β in mice intestines was detected by flow cytometry, western blot or ELISA. In vitro, the mouse RAW264.7 macrophage cell line was also cultured followed by various treatments. Expression of p-mTOR, NLRP3, activated caspase-1, and IL-1β in macrophages was determined.

RESULTS

Macrophages accumulated in the intestines and the expression of α7nAChR in the mucosal and submucosal layers of the intestines was increased in both the NEC patients and mice. The p-mTOR and CD68 were increased and co-localized in intestines of NEC patients. In vitro, α7nAChR agonist PNU-282987 significantly reduced the increase of NLRP3, activated caspase-1, and IL-1β in macrophages. PNU-282987 also significantly reduced the increase of p-mTOR. The effect was blocked by AMPK inhibitor compound C. The expression of NLRP3, activated caspase-1, and IL-1β was inhibited after mTOR inhibitor rapamycin treatment. In NEC model mice, PNU-282987 reduced the expression of p-mTOR, NLRP3, activated caspase-1, and IL-1β in the intestine. Meanwhile, rapamycin significantly attenuated NLRP3 activation and the release of IL-1β. Moreover, the proportion of intestinal macrophages and intestinal injury decreased after PNU-282987 treatment.

CONCLUSION

Macrophage α7nAChR activation mitigates NLRP3 inflammasome activation by modulating mTOR phosphorylation, and subsequently alleviates intestinal inflammation and injury in NEC.

The relationship between severe hypertensive diseases of pregnancy and moderate-severe bronchopulmonary dysplasia

OBJECTIVE

Determine the association between severe hypertensive disease of pregnancy (HDP) with moderate-severe bronchopulmonary dysplasia (BPD) in preterm infants (< 31 weeks' gestation).

STUDY DESIGN

Preterm birth cohort study of 693 mother-infant dyads. Severe HDP was defined as severe preeclampsia, HELLP syndrome or eclampsia. The outcome was moderate-severe BPD classified at 36 weeks corrected gestational age, per the NICHD Consensus statement.

RESULTS

225 (32%) mothers developed severe HDP and 234 (34%) infants had moderate-severe BPD. There was an interaction between severe HDP and gestational age (p = 0.03). Infants born at < 25 weeks gestation to mothers with HDP had increased odds for moderate-severe BPD compared to infants of normotensive mothers delivering at the same gestational age. Infants born > 28 weeks to mothers with severe HDP had decreased odds for the outcome, though not statistically significant.

CONCLUSIONS

Severe HDP has a differential effect on the development of moderate-severe BPD based on gestational age.

Antimicrobial Peptides (AMPs) and the Microbiome in Preterm Infants: Consequences and Opportunities for Future Therapeutics

Antimicrobial peptides (AMPs) are crucial components of the innate immune system in various organisms, including humans. Beyond their direct antimicrobial effects, AMPs play essential roles in various physiological processes. They induce angiogenesis, promote wound healing, modulate immune responses, and serve as chemoattractants for immune cells. AMPs regulate the microbiome and combat microbial infections on the skin, lungs, and gastrointestinal tract. Produced in response to microbial signals, AMPs help maintain a balanced microbial community and provide a first line of defense against infection. In preterm infants, alterations in microbiome composition have been linked to various health outcomes, including sepsis, necrotizing enterocolitis, atopic dermatitis, and respiratory infections. Dysbiosis, or an imbalance in the microbiome, can alter AMP profiles and potentially lead to inflammation-mediated diseases such as chronic lung disease and obesity. In the following review, we summarize what is known about the vital role of AMPs as multifunctional peptides in protecting newborn infants against infections and modulating the microbiome and immune response. Understanding their roles in preterm infants and high-risk populations offers the potential for innovative approaches to disease prevention and treatment.

Gut Microbiota and Immune System in Necrotizing Enterocolitis and Related Sepsis

A severe condition of sepsis can be a complication of necrotizing enterocolitis (NEC), which can occur in premature infants and becomes a medical challenge in the neonatal intensive care unit (NICU). It is a multifactorial intestinal disease (can affect both the small and large intestine) that can lead to ischemia of the intestinal tissues that evolves into acute organ necrosis. One of these factors is that different types of nutrition can influence the onset or the progression of the disease. Cow-milk-based infant formulas have been shown to cause it in premature infants more frequently than human milk. Recently, nutrition has been shown to be beneficial after surgery. Several issues still under study, such as the pathogenesis and the insufficient and often difficult therapeutic approach, as well as the lack of a common and effective prevention strategy, make this disease an enigma in daily clinical practice. Recent studies outlined the emerging role of the host immune system and resident gut microbiota, showing their close connection in NEC pathophysiology. In its initial stages, broad-spectrum antibiotics, bowel rest, and breastfeeding are currently used, as well as probiotics to help the development of the intestinal microbiota and its eubiosis. This paper aims to present the current knowledge and potential fields of research in NEC pathophysiology and therapeutic assessment.

Protective Effects of Lactobacillus reuteri on Intestinal Barrier Function in a Mouse Model of Neonatal Necrotizing Enterocolitis

OBJECTIVE

The intestinal mucosal and immune barriers play considerable roles in the pathogenesis of necrotizing enterocolitis (NEC). The present research was designed to assess the protective effects of Lactobacillus reuteri (LR) DSM 17938 (LR 17938) on the intestinal barriers and its beneficial effects on inflammation in a neonatal mouse model of NEC.

STUDY DESIGN

Overall, 7-day-old 75 C57BL/6 neonatal mice were separated into three groups (n = 25) as follows: (1) control, (2) NEC, and (3) NEC + LR17938 (LR group). NEC mice were administered a hypertonic feeding formula and subjected to asphyxia and hypothermia. Hematoxylin and eosin (HE) staining and pathological scores were used to assess the pathological changes in the intestine. Oxidative stress was evaluated based on the levels of superoxide dismutase (SOD) and malondialdehyde (MDA). Tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels were detected to assess inflammation. Gut permeability levels, bacterial translocation, and the levels of secretory idioglobulin A (sIgA), β-defensin, and tight junction (TJ) proteins were detected to evaluate gut mucosal and immune barrier function, and gut microbial diversity was detected to assess the composition of the gut flora.

RESULTS

LR 17938 administration decreased the NEC-induced increase in intestinal scores, mortality rate, gut damage, the MDA level, and TNF-α and IL-1β expressions. Besides, LR 17938 improved the survival rate of NEC mice. Moreover, LR 17938 administration improved gut permeability levels, SOD activity and the bacterial translocation, ameliorated the expression of TJ proteins, and improved the gut microbiota compared with those of NEC mice.

CONCLUSION

LR 17938 reduced intestinal inflammation and played a protective role in a neonatal animal model of NEC, possibly by regulating oxidative stress and exerting a protective effect on the gut mucosal and immune barriers.

KEY POINTS

· Our research indicated a protective effect of LR 17938 on gut barrier function in NEC mice.. · LR 17938may affect the diversity of gut flora, which are known to target beneficial bacteria.. · LR 17938 protected gut barrier function in the NEC pups by improving gut permeability..

A Nomogram for Predicting Surgical Risk in Neonates with Necrotizing Enterocolitis: A Retrospective Cohort Study

OBJECTIVES

To construct a nomogram that predicts the risk of surgery in patients with necrotizing enterocolitis (NEC).

METHODS

This retrospective cohort study recruited patients diagnosed with NEC at the Children's Hospital of Soochow University from 2013 to 2023. The neonates were divided into conservative and surgical-treatment groups. Univariate and multivariate logistic regressions were performed to identify factors influencing surgical risk, and a predictive model was constructed.

RESULTS

This study comprised 154 cases of NEC, 103 cases (66.9%) in the conservative group and 51 cases (33.1%) in the surgical group. Multivariate logistic regression analysis revealed that increased bloody stools [odds ratio (OR) 5.066; 95% confidence interval (CI) 1.7396-14.7532; p = 0.0029), oxygen inhalation (OR 1.8278; 95% CI 1.2113-2.7581; p = 0.0041), use of vasoconstrictors (OR 4.4446; 95% CI 1.7157-11.5137; p = 0.0021), portal venous gas (OR 4.5569; 95% CI 1.6324-12.7209; p = 0.0038), and blood sodium (OR 0.8339; 95% CI 0.7477-0.9301; p = 0.0011) were independent factors of surgical risk. The area under the nomogram's receiver operating characteristic (ROC) curve was 0.886. Decision curve analysis (DCA) and calibration curves demonstrated good predictive performance for the nomogram.

CONCLUSIONS

The nomogram effectively assessed the risk of surgical intervention in NEC patients, providing new insights and references for diagnosing and treating NEC.

Plant-Derived Substances for Prevention of Necrotising Enterocolitis: A Systematic Review of Animal Studies

Inflammation, oxidative injury, and gut dysbiosis play an important role in the pathogenesis of necrotising enterocolitis (NEC). Plant-derived substances have historically been used as therapeutic agents due to their anti-inflammatory, antioxidant, and antimicrobial properties. We aimed to review pre-clinical evidence for plant-derived substances in the prevention and treatment of NEC. A systematic review was conducted using the following databases: PubMed, EMBASE, EMCARE, MEDLINE and Cochrane Library (PROSPERO CRD42022365477). Randomized controlled trials (RCTs) and quasi-RCTs that evaluated a plant-derived substance as an intervention for NEC in an animal model of the illness and compared pre-stated outcomes (e.g., clinical severity, severity of intestinal injury, mortality, laboratory markers of inflammation and oxidative injury) were included. Sixteen studies (n = 610) were included in the systematic review. Ten of the sixteen included RCTs (Preterm rat pups: 15, Mice: 1) reported mortality and all reported NEC-related histology. Meta-analysis showed decreased mortality [12/134 vs. 27/135; RR: 0.48 (95% CI: 0.26 to 0.87); p = 0.02, 10 RCTs] and decreased NEC in the experimental group [24/126 vs. 55/79; RR: 0.34 (95% CI: 0.22 to 0.52); p < 0.001, 6 RCTs]. Markers of inflammation (n = 11) and oxidative stress (n = 13) improved in all the studies that have reported this outcome. There was no significant publication bias for the outcome of mortality. Plant-derived substances have the potential to reduce the incidence and severity of histologically diagnosed NEC and mortality in rodent models. These findings are helpful in guiding further pre-clinical studies towards developing a food supplement for the prevention of NEC in preterm infants.

Evaluation of amniotic fluid neutrophil gelatinase-associated lipocalin and L-type fatty acid-binding protein levels during pregnancy

Objective

We aimed to examine amniotic fluid neutrophil gelatinase-associated lipocalin (NGAL) and L-type fatty acid-binding protein (L-FABP) levels during pregnancy.

Study design

This study included singleton pregnancies. Amniotic fluid samples were collected at the time of vaginal delivery, cesarean section, amniocentesis, amnioreduction, and amnioinfusion. We analyzed changes of the NGAL and L-FABP levels during pregnancy and the factors affecting these values and their association with clinical outcomes.

Results

Three hundred and one pregnancies were analyzed. Respective Pearson correlation coefficients for the NGAL and L-FABP levels and gestational age at inspection were - 0.351 and - 0.819 (p <0.001 and p < 0.001, respectively); weak and strong negative correlation were observed. The NGAL level was significantly higher in the intra-amniotic infection group than in the control group (p < 0.001). The L-FABP level was significantly higher in the fetal blood flow abnormalities group than in the control group (p < 0.001). The NGAL and L-FABP levels were significantly higher in the adverse outcomes group than in the control group (p = 0.019 and p < 0.001, respectively), and the respective areas under the concentration-time curve, with optimal cutoff values, for the NGAL and L-FABP levels were 0.693 (14,800 µg/gCr) and 0.864 (378 µg/gCr).

Conclusions

Amniotic fluid NGAL and L-FABP levels reflect fetal and neonatal immaturity. Additionally, the NGAL level is a useful predictive factor of intra-amniotic infection, and the L-FABP level is a useful predictive factor of fetal condition and short- and long-term prognoses.

Can Postbiotics Represent a New Strategy for NEC?

Intestinal bacteria, also known as gut microbiota, are a rich ecology of microorganisms found in the human digestive tract. Extensive study has highlighted their critical relevance in preserving human health. New research has revealed that bacterial viability is not invariably necessary to induce health benefits. Postbiotics (defined soluble substances produced as a byproduct of the metabolic processes of living microbes) have thus emerged as an important topic of research. They contribute to shaping the gut microbiota, exert immune-modulation activity, and improve the integrity of the gut barrier.Alterations in preterm gut colonization associated with intestinal barrier immaturity and the increased reactivity of the intestinal mucosa to colonizing bacteria have been implicated in the pathogenesis of necrotizing enterocolitis. Postbiotics have shown promising outcomes in reducing the risk of developing NEC, lowering inflammation, encouraging the development of good bacteria, and strengthening the intestinal barrier. This is an important advancement in newborn care and highlights the potential of postbiotics to avoid severe intestinal disorders.

Metabolomics in NEC: An Updated Review

Necrotizing enterocolitis (NEC) represents the most common and lethal acute gastrointestinal emergency of newborns, mainly affecting those born prematurely. It can lead to severe long-term sequelae and the mortality rate is approximately 25%. Furthermore, the diagnosis is difficult, especially in the early stages, due to multifactorial pathogenesis and complex clinical pictures with mild and non-specific symptoms. In addition, the existing tests have poor diagnostic value. Thus, the scientific community has been focusing its attention on the identification of non-invasive biomarkers capable of prediction, early diagnosis and discriminating NEC from other intestinal diseases in order to intervene early and block the progression of the pathology. In this regard, the use of "omics" technologies, especially metabolomics and microbiomics, could be a fundamental synergistic strategy to study the pathophysiology of NEC. In addition, a deeper knowledge of the microbiota-host cross-talk can clarify the metabolic pathways potentially involved in the pathology, allowing for the identification of specific biomarkers. In this article, the authors analyze the state-of-the-art concerning the application of metabolomics and microbiota analysis to investigate this pathology and discuss the future possibility of the metabolomic fingerprint of patients for diagnostic purposes.

Butyrate suppresses experimental necrotizing enterocolitis-induced brain injury in mice

Background

Necrotizing enterocolitis (NEC) is a devastating disease in premature infants, and 50% of infants with surgical NEC develop neurodevelopmental defects. The mechanisms by which NEC-induced cytokine release and activation of inflammatory cells in the brain mediate neuronal injury, and whether enteral immunotherapy attenuates NEC-associated brain injury remain understudied. Based on our prior work, which demonstrated that experimental NEC-like intestinal injury is attenuated by the short-chain fatty acid, butyrate, in this study, we hypothesize that NEC-induced brain injury would be suppressed by enteral butyrate supplementation.

Methods

A standardized NEC mouse model [enteral formula feeding, lipopolysaccharide (LPS), and hypoxia] was used. Mice were randomized into the following groups: control, NEC, butyrate pretreated NEC, and butyrate control. NEC scoring (1-4 with 4 representing severe injury) was performed on ileal sections using a validated scoring system. Intestinal and brain lysates were used to assess inflammation, proinflammatory signaling, and apoptosis.

Results

NEC-induced intestinal injury was attenuated by butyrate supplementation. NEC-induced microglial activation in the cerebral cortex and hippocampus was suppressed with butyrate. NEC increased the number of activated microglial cells but decreased the number of oligodendrocytes. Butyrate pretreatment attenuated these changes. Increased activation of proinflammatory Toll-like receptor signaling, cytokine expression, and induction of GFAP and IBA1 in the cerebral cortex observed with NEC was suppressed with butyrate.

Conclusion

Experimental NEC induced inflammation and activation of microglia in several regions of the brain, most prominently in the cortex. NEC-induced neuroinflammation was suppressed with butyrate pretreatment. The addition of short-chain fatty acids to diet may be used to attenuate NEC-induced intestinal injury and neuroinflammation in preterm infants.

Impact of advanced maternal age on neonatal morbidity: a systematic review

OBJECTIVE

This systematic review aimed to understand the impact of advanced maternal age (AMA) on the neonatal morbidity, based on the available scientific evidence.

METHODS

A systematic search was conducted on 22 November 2021, using the PubMed and Scopus databases to identify studies that compared the morbidity of neonates delivered to AMA mothers with that of neonates delivered to non-AMA mothers.

RESULTS

Sixteen studies that evaluated the effect of AMA on the neonatal morbidity were included in this review. Nine of these studies found some association between AMA and increased neonatal morbidity (with two of them only reporting an increase in asymptomatic hypoglycemia, and one only reporting an association in twins), six found no association between AMA and neonatal morbidity and one study found a decrease in morbidity in preterm neonates. The studies that found an increase in overall neonatal morbidity with AMA considered older ages for the definition of AMA, particularly ≥40 and ≥45 years.

CONCLUSION

The current evidence seems to support a lack of association between AMA and the neonatal morbidity of the delivered neonates. However, more studies focusing on the neonatal outcomes of AMA pregnancies are needed to better understand this topic.

Factors Influencing Neonatal Gut Microbiome and Health with a Focus on Necrotizing Enterocolitis

Maturational changes in the gut start in utero and rapidly progress after birth, with some functions becoming fully developed several months or years post birth including the acquisition of a full gut microbiome, which is made up of trillions of bacteria of thousands of species. Many factors influence the normal development of the neonatal and infantile microbiome, resulting in dysbiosis, which is associated with various interventions used for neonatal morbidities and survival. Extremely low gestational age neonates (<28 weeks' gestation) frequently experience recurring arterial oxygen desaturations, or apneas, during the first few weeks of life. Apnea, or the cessation of breathing lasting 15-20 s or more, occurs due to immature respiratory control and is commonly associated with intermittent hypoxia (IH). Chronic IH induces oxygen radical diseases of the neonate, including necrotizing enterocolitis (NEC), the most common and devastating gastrointestinal disease in preterm infants. NEC is associated with an immature intestinal structure and function and involves dysbiosis of the gut microbiome, inflammation, and necrosis of the intestinal mucosal layer. This review describes the factors that influence the neonatal gut microbiome and dysbiosis, which predispose preterm infants to NEC. Current and future management and therapies, including the avoidance of dysbiosis, the use of a human milk diet, probiotics, prebiotics, synbiotics, restricted antibiotics, and fecal transplantation, for the prevention of NEC and the promotion of a healthy gut microbiome are also reviewed. Interventions directed at boosting endogenous and/or exogenous antioxidant supplementation may not only help with prevention, but may also lessen the severity or shorten the course of the disease.

Prophylactic indomethacin, antenatal betamethasone, and the risk of intestinal perforation in infants <28 weeks' gestation

OBJECTIVE

To determine if intestinal perforations before 14 days (either spontaneous (SIP) or necrotizing enterocolitis-induced) are increased when infants who received antenatal betamethasone shortly before birth are treated with prophylactic indomethacin (PINDO).

STUDY DESIGN

Observational study of 475 infants <28 week's gestation assigned to either a PINDO-protocol (n = 231) or expectant management protocol (n = 244) during consecutive protocol epochs.

RESULTS

Intestinal perforations before 14 days occurred in 33/475 (7%). In unadjusted and adjusted models, we found no associations between PINDO-protocol and intestinal perforations. PINDO-protocol did not increase intestinal perforations or SIP-alone even when given to infants who received betamethasone <7 or <2 days before delivery. 213/231 (92%) PINDO-protocol infants actually received indomethacin. The results were unchanged when examined just in those who received indomethacin.

CONCLUSION

In our study, early intestinal perforations and SIP-alone were not increased when PINDO was used by protocol in infants who received antenatal betamethasone shortly before birth.

The Relationship Between Severe Hypertensive Diseases of Pregnancy and Moderate-Severe Bronchopulmonary Dysplasia

Objective

Determine the association between severe hypertensive disease of pregnancy (HDP) with moderate-severe bronchopulmonary dysplasia (BPD) in preterm infants (< 31 weeks' gestation).

Study Design

Preterm birth cohort study of 693 mother-infant dyads. Severe HDPwas defined as severe preeclampsia, HELLP syndrome or eclampsia. The outcome was moderate-severe BPD classified at 36 weeks corrected gestational age, based on the NICHD Consensusstatement.

Results

225 (32%) mothers developed severe HDP and 234 (34%) infants hadmoderate-severe BPD. There was an interaction between severe HDP and gestational age (p=0.03). Infants born at earlier gestational ages to mothers with HDP had increased odds for moderate-severe BPD compared to infants of normotensive mothers delivering at the same gestational age. Infants born at later gestational ages to mothers with severe HDP had decreased odds for the outcome.

Conclusions

Severe HDP has a differential effect on the development of moderate-severe BPD based on gestational age.

Red Blood Cell Transfusion, Anemia, Feeding, and the Risk of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in preterm infants. Severe anemia and red blood cell (RBC) transfusion are associated with gut inflammation and injury in preclinical models and observational studies. However, there is uncertainty about the causal role of these factors in the pathogenesis of NEC. Observational studies have shown that withholding feeding during RBC transfusion may reduce the risk of NEC, although confirmatory data from randomized trials are lacking. In this review, we summarize data on feeding during RBC transfusion and its role in NEC and highlight ongoing randomized trials.

Human milk oligosaccharides reduce necrotizing enterocolitis-induced neuroinflammation and cognitive impairment in mice

Necrotizing enterocolitis (NEC) is the leading cause of morbidity and mortality in premature infants. One of the most devastating complications of NEC is the development of NEC-induced brain injury, which manifests as impaired cognition that persists beyond infancy and which represents a proinflammatory activation of the gut-brain axis. Given that oral administration of the human milk oligosaccharides (HMOs) 2'-fucosyllactose (2'-FL) and 6'-sialyslactose (6'-SL) significantly reduced intestinal inflammation in mice, we hypothesized that oral administration of these HMOs would reduce NEC-induced brain injury and sought to determine the mechanisms involved. We now show that the administration of either 2'-FL or 6'-SL significantly attenuated NEC-induced brain injury, reversed myelin loss in the corpus callosum and midbrain of newborn mice, and prevented the impaired cognition observed in mice with NEC-induced brain injury. In seeking to define the mechanisms involved, 2'-FL or 6'-SL administration resulted in a restoration of the blood-brain barrier in newborn mice and also had a direct anti-inflammatory effect on the brain as revealed through the study of brain organoids. Metabolites of 2'-FL were detected in the infant mouse brain by nuclear magnetic resonance (NMR), whereas intact 2'-FL was not. Strikingly, the beneficial effects of 2'-FL or 6'-SL against NEC-induced brain injury required the release of the neurotrophic factor brain-derived neurotrophic factor (BDNF), as mice lacking BDNF were not protected by these HMOs from the development of NEC-induced brain injury. Taken in aggregate, these findings reveal that the HMOs 2'-FL and 6'-SL interrupt the gut-brain inflammatory axis and reduce the risk of NEC-induced brain injury.NEW & NOTEWORTHY This study reveals that the administration of human milk oligosaccharides, which are present in human breast milk, can interfere with the proinflammatory gut-brain axis and prevent neuroinflammation in the setting of necrotizing enterocolitis, a major intestinal disorder seen in premature infants.

Impact of neonatal nutrition on necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the leading cause of morbidity and mortality in preterm infants. NEC is multifactorial and the result of a complex interaction of feeding, dysbiosis, and exaggerated inflammatory response. Feeding practices in the neonatal intensive care units (NICUs) can vary among institutions and have significant impact on the vulnerable gastointestinal tract of preterm infants. . These practices encompass factors such as the type of feeding and fortification, duration of feeding, and rate of advancement, among others. The purpose of this article is to review the data on some of the most common feeding practices in the NICU and their impact on the development of NEC in preterm infants. Data on the human milk bioactive component glycosaminoglycans, specifically hyaluronan, will also be discussed in the context of postnatal intestinal development and NEC prevention.

Antibiotic therapy and necrotizing enterocolitis

Antibiotic therapy remains a cornerstone of treatment of both medical and surgical presentations of necrotizing enterocolitis (NEC). However, guidelines regarding the administration of antibiotics for the treatment of NEC are lacking and practices vary amongst clinicians. Although the pathogenesis of NEC is unknown, there is consensus that the infant gastrointestinal microbiome contributes to the disease. The presumed connection between dysbiosis and NEC has prompted some to study whether early prophylactic enteral antibiotics can prevent NEC. Yet others have taken an opposing approach, studying whether perinatal antibiotic exposure increases the risk of NEC by inducing a state of dysbiosis. This narrative review summarizes what is known about antibiotics and their association with the infant microbiome and NEC, current antibiotic prescribing practices for infants with medical and surgical NEC, as well as potential strategies to further optimize the use of antibiotics in this population of infants.

Microbiota from Preterm Infants Who Develop Necrotizing Enterocolitis Drives the Neurodevelopment Impairment in a Humanized Mouse Model

Necrotizing enterocolitis (NEC) is the leading basis for gastrointestinal morbidity and poses a significant risk for neurodevelopmental impairment (NDI) in preterm infants. Aberrant bacterial colonization preceding NEC contributes to the pathogenesis of NEC, and we have demonstrated that immature microbiota in preterm infants negatively impacts neurodevelopment and neurological outcomes. In this study, we tested the hypothesis that microbial communities before the onset of NEC drive NDI. Using our humanized gnotobiotic model in which human infant microbial samples were gavaged to pregnant germ-free C57BL/6J dams, we compared the effects of the microbiota from preterm infants who went on to develop NEC (MNEC) to the microbiota from healthy term infants (MTERM) on brain development and neurological outcomes in offspring mice. Immunohistochemical studies demonstrated that MNEC mice had significantly decreased occludin and ZO-1 expression compared to MTERM mice and increased ileal inflammation marked by the increased nuclear phospho-p65 of NFκB expression, revealing that microbial communities from patients who developed NEC had a negative effect on ileal barrier development and homeostasis. In open field and elevated plus maze tests, MNEC mice had worse mobility and were more anxious than MTERM mice. In cued fear conditioning tests, MNEC mice had worse contextual memory than MTERM mice. MRI revealed that MNEC mice had decreased myelination in major white and grey matter structures and lower fractional anisotropy values in white matter areas, demonstrating delayed brain maturation and organization. MNEC also altered the metabolic profiles, especially carnitine, phosphocholine, and bile acid analogs in the brain. Our data demonstrated numerous significant differences in gut maturity, brain metabolic profiles, brain maturation and organization, and behaviors between MTERM and MNEC mice. Our study suggests that the microbiome before the onset of NEC has negative impacts on brain development and neurological outcomes and can be a prospective target to improve long-term developmental outcomes.

A Nomogram for Predicting Surgical Timing in Neonates with Necrotizing Enterocolitis

OBJECTIVE

To explore the surgical risk variables in patients with necrotizing enterocolitis (NEC) and develop a nomogram model for predicting the surgical intervention timing of NEC.

METHODS

Infants diagnosed with NEC were enrolled in our study. We gathered information from clinical data, laboratory examinations, and radiological manifestations. Using LASSO (least absolute shrinkage and selection operator) regression analysis and multivariate logistic regression analysis, a clinical prediction model based on the logistic nomogram was developed. The performance of the nomogram model was evaluated using the receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis (DCA).

RESULTS

A surgical intervention risk nomogram based on hypothermia, absent bowel sounds, WBC > 20 × 10⁹/L or < 5 × 10⁹/L, CRP > 50 mg/L, pneumatosis intestinalis, and ascites was practical, had a moderate predictive value (AUC > 0.8), improved calibration, and enhanced clinical benefit.

CONCLUSIONS

This simple and reliable clinical prediction nomogram model can help physicians evaluate children with NEC in a fast and effective manner, enabling the early identification and diagnosis of children at risk for surgery. It offers clinical revolutionary value for the development of medical or surgical treatment plans for children with NEC.

Development of a novel definitive scoring system for an enteral feed-only model of necrotizing enterocolitis in piglets

Introduction

Necrotizing enterocolitis (NEC) is a complex inflammatory disorder of the human intestine that most often occurs in premature newborns. Animal models of NEC typically use mice or rats; however, pigs have emerged as a viable alternative given their similar size, intestinal development, and physiology compared to humans. While most piglet NEC models initially administer total parenteral nutrition prior to enteral feeds, here we describe an enteral-feed only piglet model of NEC that recapitulates the microbiome abnormalities present in neonates that develop NEC and introduce a novel multifactorial definitive NEC (D-NEC) scoring system to assess disease severity.

Methods

Premature piglets were delivered via Caesarean section. Piglets in the colostrum-fed group received bovine colostrum feeds only throughout the experiment. Piglets in the formula-fed group received colostrum for the first 24 h of life, followed by Neocate Junior to induce intestinal injury. The presence of at least 3 of the following 4 criteria were required to diagnose D-NEC: (1) gross injury score ≥4 of 6; (2) histologic injury score ≥3 of 5; (3) a newly developed clinical sickness score ≥5 of 8 within the last 12 h of life; and (4) bacterial translocation to ≥2 internal organs. Quantitative reverse transcription polymerase chain reaction was performed to confirm intestinal inflammation in the small intestine and colon. 16S rRNA sequencing was performed to evaluate the intestinal microbiome.

Results

Compared to the colostrum-fed group, the formula-fed group had lower survival, higher clinical sickness scores, and more severe gross and histologic intestinal injury. There was significantly increased bacterial translocation, D-NEC, and expression of IL-1α and IL-10 in the colon of formula-fed compared to colostrum-fed piglets. Intestinal microbiome analysis of piglets with D-NEC demonstrated lower microbial diversity and increased Gammaproteobacteria and Enterobacteriaceae.

Conclusions

We have developed a clinical sickness score and a new multifactorial D-NEC scoring system to accurately evaluate an enteral feed-only piglet model of NEC. Piglets with D-NEC had microbiome changes consistent with those seen in preterm infants with NEC. This model can be used to test future novel therapies to treat and prevent this devastating disease.

Gut Microbiome-Brain Axis as an Explanation for the Risk of Poor Neurodevelopment Outcome in Preterm Infants with Necrotizing Enterocolitis

Necrotizing Enterocolitis (NEC) is characterized by an inflammation of intestinal tissue that primarily affects premature infants. It is the most common and devastating gastrointestinal morbidity of prematurity, but beyond intestinal morbidity, this condition has also been associated with an increased risk of neurodevelopmental delays that persist beyond infancy. Prematurity, enteral feeding, bacterial colonization, and prolonged exposure to antibiotics are all risk factors that predispose preterm infants to NEC. Interestingly, these factors are all also associated with the gut microbiome. However, whether or not there is a connection between the microbiome and the risk of neurodevelopmental delays in infants after NEC is still an emerging area of research. Furthermore, how microbes in the gut could impact a distant organ such as the brain is also poorly understood. In this review, we discuss the current understanding of NEC and the role of the gut microbiome-brain axis in neurodevelopmental outcomes after NEC. Understanding the potential role of the microbiome in neurodevelopmental outcomes is important as the microbiome is modifiable and thus offers the hope of improved therapeutic options. We highlight the progress and limitations in this field. Insights into the gut microbiome-brain axis may offer potential therapeutic approaches to improve the long-term outcomes of premature infants.

Astaxanthin Alleviates Inflammatory Response in Neonatal Necrotizing Enterocolitis Rats by Regulating NOD2/TLR4 Pathway

Background

Necrotizing enterocolitis (NEC) is often associated with exaggerated activation of inflammatory response. Astaxanthin has been shown in studies to have a positive and advantageous effect on anti-inflammatory response. Hence, it is of great significance to study the protective effect of astaxanthin in NEC disease and its molecular mechanism.

Objective

The present study was to investigate whether astaxanthin attenuates NEC rats and to explore its potential mechanism. Material and Methods. Hematoxylin-eosin staining was used to observe the pathological change of the intestinal tissue in NEC rats. Subsequently, we determined the anti-oxidative stress, anti-apoptosis, and anti-inflammation in astaxanthin with enzyme-linked immunosorbent assay kits, TUNEL staining, western blot, and immunohistochemistry assay. Furthermore, we added nucleotide-binding oligomerization domain 2 (NOD2) inhibitor to certify the molecular pathway of the astaxanthin in NEC rats.

Results

Astaxanthin improved the pathological changes of the intestinal tissues. It restrained inflammation, oxidative stress, and protected cells from apoptosis in the intestinal tissue and serum of the NEC rats. Moreover, astaxanthin enhanced NOD2, whereas it suppressed toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB) pathway-related proteins. Apart from that, the NOD2 inhibitor offset the protective effect of the astaxanthin towards the NEC rats.

Conclusion

The present study indicated that astaxanthin alleviated oxidative stress, inflammatory response, and apoptosis in NEC rats by enhancing NOD2 and inhibiting TLR4 pathway.

Biomarkers of necrotizing enterocolitis in the era of machine learning and omics

Necrotizing enterocolitis (NEC) continues to be a major cause of morbidity and mortality in preterm infants. Despite decades of research in NEC, no reliable biomarkers can accurately diagnose NEC or predict patient prognosis. The recent emergence of multi-omics could potentially shift NEC biomarker discovery, particularly when evaluated using systems biology techniques. Furthermore, the use of machine learning and artificial intelligence in analyzing this 'big data' could enable novel interpretations of NEC subtypes, disease progression, and potential therapeutic targets, allowing for integration with personalized medicine approaches. In this review, we evaluate studies using omics technologies and machine learning in the diagnosis of NEC. Future implications and challenges inherent to the field are also discussed.

Impact of maternal factors, environmental factors, and race on necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a complex disease with a multifactorial etiology. As the leading cause of intestinal morbidity and mortality among premature infants, many resources are being dedicated to neonatal care and molecular targets in the newborn intestine. However, NEC is heavily influenced by maternal and perinatal factors as well. Given its nature, preventive approaches to NEC are more likely to improve outcomes than new treatment strategies. Therefore, this review focuses on maternal, environmental, and racial factors associated with the development of NEC, with an emphasis on those that may be modifiable to decrease the incidence of the disease.

Predictive Factors for Mortality in Pre-Term Neonates with Necrotizing Enterocolitis: A Retrospective Cohort Study

Background: Necrotizing enterocolitis (NEC) is a serious neonatal condition. Over the last three decades, there has been progress in neonatal intensive care with an increase in the incidence of pre-term births. This has led to an increase in the incidence of NEC. However, research studies regarding NEC outcomes in low-income countries are scarce. Our study aimed to assess predictive factors for mortality in patients with NEC in a single center in Tunisia. Patients and Methods: We conducted a retrospective data collection through a review of the patients' medical records. All neonates with a medical or surgical management of NEC between January 1, 2010 and March 31, 2022 were included. Results: A total of 102 neonates were included with the overall survival of 47%. Outcomes of the univariable analysis showed that patients in the deceased group had lower gestational age, lower five-minute Apgar score, lower birth weight, and lower platelet count than those in the survivor group. Multivariable logistic analyses demonstrated that gestational age <32 weeks (p = 0.024; odds ratio [OR], 2.5), five-minute Apgar score <8 (p = 0.017; OR, 3.621), birth weight <1,500 g (p = 0.001; OR, 4.136), platelet count <50,000/mm³ (p = 0.029; OR, 2.5), Bell's stage 3 (p = 0.035; OR, 2.496), and sepsis during hospitalization (p < 0.001; OR, 5.971) were associated with mortality in neonates with NEC. Conclusions: Our study showed that gestational age <32 weeks, five-minute Apgar score <8, very low birth weight, severe thrombocytopenia, Bell's stage 3, and sepsis during hospitalization were predictive factors for mortality in neonates with NEC. These factors would be useful to refine treatment modalities for better disease outcomes.

Neurodevelopmental outcome of infants who develop necrotizing enterocolitis: The gut-brain axis

Necrotizing enterocolitis (NEC) poses a significant risk for neurodevelopmental impairment in extremely preterm infants. The gut microbiota shapes the development of the gut, immune system, and the brain; and dysbiosis drive neonatal morbidities including NEC. In this chapter, we delineate a gut-brain axis linking gut microbiota to the adverse neurological outcomes in NEC patients. We propose that in NEC, immaturity of the microbiome along with aberrant gut microbiota-driven immaturity of the gut barrier and immune system can lead to effects including systemic inflammation and circulating microbial mediators. This nexus of gut microbiota-driven systemic effects further interacts with a likewise underdeveloped blood-brain barrier to regulate neuroinflammation and neurodevelopment. Targeting deviant gut-brain axis signaling presents an opportunity to improve the neurodevelopmental outcomes of NEC patients.

IS -94INS/DELATTG POLYMORPHISM IN THE NUCLEAR FACTOR KAPPA-B1 GENE (NFKB1) ASSOCIATED WITH NECROTIZING ENTEROCOLITIS?

BACKGROUND

Abnormalities in the different stages of the intestinal maturation process cause metabolic and molecular changes. Among the genetic alterations associated with necrotizing enterocolitis, the -94ins/delATTG polymorphism in NFKB1 gene leads to unregulated activation of the NFKB protein due to an increase in the inherent pro-inflammatory state of the premature intestine.

AIMS

To determine the prevalence of the -94ins/delATTG polymorphism in NFKB1 gene in neonates with and without necrotizing enterocolitis.

METHODS

This is a case-control study, in which 25 neonates were evaluated as the case group and 50 neonates as the control group, of both genders. DNA was extracted from peripheral blood leukocytes, and the site encompassing the polymorphism was amplified by molecular techniques (polymerase chain reaction/polymorphism in restriction fragment length).

RESULTS

Necrotizing enterocolitis was diagnosed in 25 (33%) neonates and, of these, 3 (12%) died. Male gender was more prevalent in both groups (p=0.1613): cases (52%) and controls (62%). Moderate and extreme preterm newborns were predominant in both groups: cases (80%) and controls (88%) (p=0.3036). Low birth weight and extremely low birth weight newborns were the most prevalent in cases (78%), and very low birth weight and extremely low birth weight were the most prevalent in controls (81%) (p=0.1073). Clinical treatment was successful in 72%, and hospital discharge was achieved in 88% of newborns with NEC. The -94ins/delATTG polymorphism in NFKB1 gene was not identified in all the 150 alleles analyzed (100%).

CONCLUSIONS

The absence of the -94ins/delATTG polymorphism in NFKB1 gene in newborns with and without necrotizing enterocolitis does not rule out the possibility of alterations in this and/or in other genes in newborns with this condition, which reinforces the need for further research.

Analysis of serum metabolism in premature infants before and after feeding using GC-MS and the relationship with necrotizing enterocolitis

Preterm birth and enteral feeding are two main factors leading to necrotizing enterocolitis (NEC). The metabolomics of preterm infants before and after feeding can provide a basis for the prediction of NEC. Using the method of cross-sectional study, the mode was established with the serum samples of 19 premature infants at birth and after feeding as the control group. The serum was analyzed using GC-MS. Chemometric analysis includes principal component analysis, partial least squares-discriminant analysis, and orthogonal partial least squares-discriminant analysis. Spectral separation of serum metabolites occurred in premature infants before and after feeding. The levels of xylose, d-talose, phosphoglycolic acid, maleimide, l-gulonolactone, maleic acid, β-hydroxypyruvate, itaconic acid, and pantothenic acid in the serum of premature infants after feeding were significant in both multidimensional and single-dimensional modes (variable importance in projection >2, P < 0.01). There was a moderate correlation between total bilirubin and l-gulonolactone and β-hydroxypyruvate (0.8 > r > 0.5). Maleimide, maleic acid, and itaconic acid have diagnostic value (area under the curve >0.9). The results indicated that serum metabolism of preterm infants changes significantly after feeding. Some metabolites have potential value in predicting NEC.

Machine learning-based risk factor analysis of necrotizing enterocolitis in very low birth weight infants

This study used machine learning and a national prospective cohort registry database to analyze the major risk factors of necrotizing enterocolitis (NEC) in very low birth weight (VLBW) infants, including environmental factors. The data consisted of 10,353 VLBW infants from the Korean Neonatal Network database from January 2013 to December 2017. The dependent variable was NEC. Seventy-four predictors, including ambient temperature and particulate matter, were included. An artificial neural network, decision tree, logistic regression, naïve Bayes, random forest, and support vector machine were used to evaluate the major predictors of NEC. Among the six prediction models, logistic regression and random forest had the best performance (accuracy: 0.93 and 0.93, area under the receiver-operating-characteristic curve: 0.73 and 0.72, respectively). According to random forest variable importance, major predictors of NEC were birth weight, birth weight Z-score, maternal age, gestational age, average birth year temperature, birth year, minimum birth year temperature, maximum birth year temperature, sepsis, and male sex. To the best of our knowledge, the performance of random forest in this study was among the highest in this line of research. NEC is strongly associated with ambient birth year temperature, as well as maternal and neonatal predictors.

Age disparities in intestinal stem cell quantities: a possible explanation for preterm infant susceptibility to necrotizing enterocolitis

PURPOSE

Preterm infants are more susceptible to necrotizing enterocolitis (NEC) than term Queryinfants. This may be due to a relative paucity of Lgr5⁺ or Bmi1⁺-expressing intestinal stem cells (ISCs) which are responsible for promoting intestinal recovery after injury. We hypothesized that the cellular markers of Lgr5⁺ and Bmi1⁺, which represent the two distinct ISC populations, would be lower in younger mice compared to older mice. In addition, we hypothesized that experimental NEC would result in a greater loss of Lgr5⁺ expression compared to Bmi1⁺ expression.

METHODS

Transgenic mice with EGFP-labeled Lgr5 underwent euthanasia at 10 different time points from E15 to P56 (n = 8-11/group). Lgr5⁺-expressing ISCs were quantified by GFP ELISA and Bmi1⁺ was assessed by qPCR. In addition, Lgr5^EGFP mice underwent experimental NEC via formula feeding and hypoxic and hypothermic stress. Additional portions of the intestine underwent immunostaining with anti-GFP or anti-Bmi1⁺ antibodies to confirm ELISA and PCR results. For statistical analysis, p < 0.05 was significant.

RESULTS

Lgr5⁺ and Bmi1⁺expression was lowest in embryonal and early postnatal mice and increased with age in all segments of the intestine. Experimental NEC was associated with loss of Lgr5⁺-expressing ISCs but no significant change in Bmi1⁺ expression.

CONCLUSION

Lgr5⁺ and Bmi1⁺ expression increase with age. Lgr5⁺-expressing ISCs are lower following experimental necrotizing enterocolitis while Bmi1⁺ expression remains relatively unchanged. Developing a targeted medical therapy to protect the low population of ISCs in preterm infants may promote tissue recovery and regeneration after injury from NEC.

Astaxanthin Reduces the Severity of Intestinal Damage in a Neonatal Rat Model of Necrotizing Enterocolitis

OBJECTIVE

This study aimed to ascertain the effects of astaxanthin (ASX) in an experimental necrotizing enterocolitis (NEC) model using rat pups.

STUDY DESIGN

Forty-two pups born from five Wistar albino rats were randomly divided into three groups as the control group, NEC + placebo (saline), and NEC + ASX. Pups in the NEC + ASX group were given 100 mg/kg/day oral ASX from day 1 to day 4 of the study. Saline of 2 mL/kg was given to the NEC + placebo group. Histopathological, immunohistochemical (caspase-3), and biochemical evaluations including the total antioxidant status (TAS), total oxidant status (TOS), superoxide dismutase (SOD), glutathione (GSH), lipid hydroperoxide (LPO), 8-hydroxydeoxyguanosine (8-OHdG), advanced oxidation protein products (AOPP), myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and nuclear factor erythroid 2-related factor 2 (Nfr-2) activities were all performed.

RESULTS

A better survival rate and weight gain were demonstrated in the NEC + ASX group (p < 0.05). In the histopathological evaluation, the severity of intestinal damage was significantly reduced in the NEC + ASX group, as well as decreased apoptosis (enzyme-linked immunosorbent assay [ELISA] for caspase-3; p = 0.001). The biochemical analyses of intestinal tissue TOS, oxidative stress index (OSI; TOS/TAS), IL-1β, LPO, 8-OHdG, AOPP, caspase-3 (p < 0.001 for all), and TNF-α and MPO (p = 0.001 for both parameters) levels were lower in the NEC + ASX group than in the NEC + placebo group. Nrf-2, TAS, GSH, and SOD levels were higher in the NEC + ASX group than in the NEC + placebo group (p = 0.001, 0.001, <0.001, and 0.01, respectively).

CONCLUSION

ASX treatment has been shown to effectively reduce the severity of intestinal damage in NEC due to its antioxidant, anti-inflammatory, and antiapoptotic properties.

KEY POINTS

· NEC causes extremely high morbidity and mortality, as well as many complications.. · We investigated the effectiveness of ASX in the experimental NEC model created in rat pups.. · First study examining the effect of ASX on the experimental NEC rat model..

Ultrasound for necrotizing enterocolitis: how can we optimize imaging and what are the most critical findings?

Necrotizing enterocolitis (NEC) is a common condition in the neonatal intensive care unit that continues to present challenges in terms of diagnosis and management. Traditionally NEC has been diagnosed and managed by clinical and radiographic findings, but US has shown promise in characterizing and prognosticating NEC. In this manuscript we review the abdominal US technique for NEC, the clinical significance of individual sonographic findings of NEC, and how US can be integrated in the clinical decision process for diagnosing and managing NEC. We also discuss the potential value-added role of a limited abdominal US protocol that focuses on the sonographic findings most indicative of a poor prognosis to include pneumoperitoneum, complex free fluid and focal fluid collections.

Antibiotic resistance and host immune system-induced metal bactericidal control are key factors for microbial persistence in the developing human preterm infant gut microbiome

The human gut microbiome, which develops and stabilizes during the early stages of infant life, plays an essential role in host health through the production of metabolic resources and the stimulation and training of the immune system. To study colonization and community functional dynamics of the microbiota based on responses to host immune processes during the normal and dysbiotic establishment of the gut, metaproteomics was conducted on 91 fecal samples collected over the first 90 days of life from 17 hospitalized premature infants. Microbial responses to antibiotic administration and host-imposed metal bactericidal control correlated with community assembly and resiliency of microbes in the developing preterm gut. Specifically, proteins related to antibiotic resistance and metal homeostasis mechanisms were predominant in persisting members in the infant gut environment over the first several weeks of life. Overall, this metaproteomics study provides a unique approach to examine the temporal expansion and resilience of microbial colonization, as it allows simultaneous examination of both host and microbial metabolic activities. Understanding the interplay between host and microbes may elucidate the microbiome's potential immunomodulatory roles relevant to necrotizing enterocolitis and other dysbiotic conditions in preterm infants.

Alterations of the gut microbiota and short chain fatty acids in necrotizing enterocolitis and food protein-induced allergic protocolitis infants: A prospective cohort study

Background

Even though presenting with similar clinical manifestations, necrotizing enterocolitis (NEC) and food protein-induced allergic protocolitis (FPIAP) have completely different treatments and prognosis. Our study aimed to quantify and evaluate differences in gut microbiota and short chain fatty acids (SCFAs) between infants with NEC and FPIAP to better identify these two diseases in clinical settings.

Methods

A total of 43 infants with NEC or FPIAP in Children's Hospital of Chongqing Medical University, China between December 2020 and December 2021 were enrolled. Stool samples were prospectively collected and froze. Infants defined as NEC were those who presented with clinical courses consistent with NEC and whose radiographs fulfilled criteria for Bell's stage 2 or 3 NEC, while those who were healthy in appearance and had blood in the stool (visible or may be microscopic), had normal bowel sounds in physical examination, were resolved after eliminating the causative food, and/or had recurrence of symptoms after oral food challenge (OFC) were defined as FPIAP. Primers specific for bacterial 16S rRNA genes were used to amplify and pyrosequence fecal DNA from stool samples. Gas chromatography-mass spectrometry (GC-MS) technology was used to determine the concentrations of SCFAs.

Results

Among the 43 infants, 22 were diagnosed with NEC and 21 were diagnosed with FPIAP. The microbial community structure in NEC infant stools differed significantly from those in FPIAP infant stools. NEC infants had significantly higher proportion of Actinobacteria and reduced proportion of Bacteroidetes compared with FPIAP infants, and the proportions of Halomonas, Acinetobacter, Bifidobacterium, and Stenotrophomonas in NEC infants were significantly higher than that of FPIAP infants. In addition, infants with NEC had significantly lower levels of acetic acid, propionic acid, butyric acid, isovaleric acid, and total SCFAs, and higher level of hexanoic acid as compared to the infants of the FPIAP group.

Conclusions

The differences of gut microbiota composition and concentrations of SCFAs might represent suitable biomarker targets for early identification of NEC and FPIAP.

Shared and Non-Shared sIgA-Coated and -Uncoated Bacteria in Intestine of Mother–Infant Pairs

The infant gut microbiota is critical for promoting and maintaining early-life health. The study aimed to analyze the composition of sIgA-coated and sIgA-uncoated bacterial communities at genus level and lactobacilli and bifidobacterial communities at species level in human breast milk (HBM) and infant and maternal feces. Eleven pregnant women were recruited successfully. HBM; infant feces during colostrum, transition, and mature stages; and maternal feces within the mature stage were collected. sIgA-coated and sIgA-uncoated bacteria were separated with magnetic-activated cell sorting. Then, 16S rRNA sequencing, bifidobacterial groEL gene sequencing, and lactobacilli groEL gene sequencing were performed to analyze the bacterial community. PCoA revealed that the compositions of sIgA-coated and sIgA-uncoated bacteria were different among HBM and infant and maternal feces. Higher relative abundance of sIgA-uncoated Bifidobacterium was found in the three lactation stages in infant feces compared to the corresponding HBM, and a higher relative abundance of sIgA-uncoated Faecalibacterium was found in maternal feces compared to HBM and infant feces. For bifidobacterial community, sIgA-coated and sIgA-uncoated B. longum subsp. infantis and B. pseudocatenulatum was dominant in infant feces and maternal feces, respectively. The relative abundance of sIgA-uncoated B. longum subsp. infantis was significantly higher in infant feces compared to that in maternal feces. For the Lactobacillus community, L. paragasseri and L. mucosae were dominant in infant and maternal feces, respectively. HBM and infant and maternal feces showed distinct diversity and composition of both sIgA-coated and sIgA-uncoated bacteria at genus level. Infant and maternal feces showed similar composition of Bifidobacterium at species level. The same Bifidobacterium species could be detected both in sIgA-coated and -uncoated form. This article provided deeper understanding on the microbiota profile in HBM and infant and maternal feces.

Antimicrobial Peptides in Early-Life Host Defense, Perinatal Infections, and Necrotizing Enterocolitis—An Update

Host defense against early-life infections such as chorioamnionitis, neonatal sepsis, or necrotizing enterocolitis (NEC) relies primarily on innate immunity, in which antimicrobial peptides (AMPs) play a major role. AMPs that are important for the fetus and neonate include α and β defensins, cathelicidin LL-37, antiproteases (elafin, SLPI), and hepcidin. They can be produced by the fetus or neonate, the placenta, chorioamniotic membranes, recruited neutrophils, and milk-protein ingestion or proteolysis. They possess antimicrobial, immunomodulating, inflammation-regulating, and tissue-repairing properties. AMPs are expressed as early as the 13th week and increase progressively through gestation. Limited studies are available on AMP expression and levels in the fetus and neonate. Nevertheless, existing evidence supports the role of AMPs in pathogenesis of chorioamnionitis, neonatal sepsis, and NEC, and their association with disease severity. This suggests a potential role of AMPs in diagnosis, prevention, prognosis, and treatment of sepsis and NEC. Herein, we present an overview of the antimicrobial and immunomodulating properties of human AMPs, their sources in the intrauterine environment, fetus, and neonate, and their changes during pre- and post-natal infections and NEC. We also discuss emerging data regarding the potential utility of AMPs in early-life infections, as diagnostic or predictive biomarkers and as therapeutic alternatives or adjuncts to antibiotic therapy considering the increase of antibiotic resistance in neonatal intensive care units.

Necrotizing enterocolitis in preterm newborn with a history of maternal COVID-19: a case report

A 6-day-old newborn male presented with a primary complaint of abdominal distension for 3 days before hospital admission. The newborn was delivered from a confirmed COVID-19–positive mother through caesarean section at 38-39 weeks with a birth weight of 2800 grams. Various tests, including blood tests, cultures, and radiography were performed. The patient was diagnosed with necrotizing enterocolitis and sepsis; the prevalence of necrotizing enterocolitis in at-term newborns with >36 weeks of gestational age is 10%. In this case, NEC was suggested to be due to maternal infection during the prenatal phase, as the mother was a confirmed COVID-19 patient. Further exploration is needed to illustrate neonatal outcomes following necrotizing enterocolitis diagnosis in correlation with maternal intrauterine COVID-19 infection.

Bench to bedside - new insights into the pathogenesis of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the leading cause of death and disability from gastrointestinal disease in premature infants. Recent discoveries have shed light on a unifying theorem to explain the pathogenesis of NEC, suggesting that specific treatments might finally be forthcoming. A variety of experiments have highlighted how the interaction between bacterial signalling receptors on the premature intestine and an abnormal gut microbiota incites a pro-inflammatory response in the intestinal mucosa and its underlying endothelium that leads to NEC. Central amongst the bacterial signalling receptors implicated in NEC development is the lipopolysaccharide receptor Toll-like receptor 4 (TLR4), which is expressed at higher levels in the premature gut than in the full-term gut. The high prenatal intestinal expression of TLR4 reflects the role of TLR4 in the regulation of normal gut development, and supports additional studies indicating that NEC develops in response to signalling events that occur in utero. This Review provides new evidence explaining the pathogenesis of NEC, explores new findings indicating that NEC development has origins before birth, and discusses future questions and opportunities for discovery in this field.