Necrotizing enterocolitis: Bench to bedside approaches and advancing our understanding of disease pathogenesis

Nursing practice of routine gastric aspiration in preterm infants and its link to necrotizing enterocolitis: is the practice still clinically relevant?

The practice of routine gastric residual aspiration in preterm infants remains controversial, with conflicting evidence regarding its impact on necrotizing enterocolitis (NEC). As front-line caregivers, nurses play a vital role in gastric aspiration procedures and must be informed by evidence. This quasi-experimental nursing study aimed to assess whether gastric aspiration is clinically relevant in reducing the risk of NEC in preterm infants.A total of 250 preterm infants from two NICUs in Egypt were allocated to the gastric aspiration (n = 125) and non-aspiration (n = 125) groups. Feeding practices, gastric residuals, and incidence/severity of NEC were compared between groups according to modified Bell's criteria. Risk factors were analyzed using multivariate regression. There were no significant baseline differences between the groups. The gastric residual attributes and feeding outcomes did not differ substantially from aspiration. The overall incidence of NEC was 14-15%, with no significant differences in the odds of onset or progression of NEC by stage between the groups. Lower gestational age and birth weight emerged as stronger predictors of NEC. Routine gastric aspiration does not appear to directly prevent or reduce the severity of NEC in this population. Although gastric residuals retain clinical importance, study findings question assumptions that aspiration protects against NEC and informs nursing practice. Evidence-based feeding protocols must continually evolve through ongoing research on modifiable risk factors for this devastating intestinal disease in preterm infants.

DNA methylation in necrotizing enterocolitis

Epigenetic modifications, such as DNA methylation, are enzymatically regulated processes that directly impact gene expression patterns. In early life, they are central to developmental programming and have also been implicated in regulating inflammatory responses. Research into the role of epigenetics in neonatal health is limited, but there is a growing body of literature related to the role of DNA methylation patterns and diseases of prematurity, such as the intestinal disease necrotizing enterocolitis (NEC). NEC is a severe intestinal inflammatory disease, but the key factors that precede disease development remain to be determined. This knowledge gap has led to a failure to design effective targeted therapies and identify specific biomarkers of disease. Recent literature has identified altered DNA methylation patterns in the stool and intestinal tissue of neonates with NEC. These findings provide the foundation for a new avenue in NEC research. In this review, we will provide a general overview of DNA methylation and then specifically discuss the recent literature related to methylation patterns in neonates with NEC. We will also discuss how DNA methylation is used as a biomarker for other disease states and how, with further research, methylation patterns may serve as potential biomarkers for NEC.

The Novel MFG-E8-derived Oligopeptide, MOP3, Improves Outcomes in a Preclinical Murine Model of Neonatal Sepsis

INTRODUCTION

Neonatal sepsis is a devastating inflammatory condition that remains a leading cause of morbidity and mortality. Milk fat globule-EGF-factor VIII (MFG-E8) is a glycoprotein that reduces inflammation, whereas extracellular cold-inducible RNA binding protein (eCIRP) worsens inflammation. This study aimed to determine the therapeutic potential of a novel MFG-E8-derived oligopeptide 3 (MOP3) designed to clear eCIRP and protect against inflammation, organ injury, and mortality in neonatal sepsis.

METHODS

C57BL6 mouse pups were injected intraperitoneally with cecal slurry (CS) and treated with MOP3 (20 μg/g) or vehicle. 10 h after injection, blood, lungs, and intestines were collected for analyses, and in a 7-day experiment, pups were monitored for differences in mortality.

RESULTS

MOP3 treatment protected septic pups from inflammation by reducing eCIRP, IL-6, TNFα, and LDH. MOP3 reduced lung and intestinal inflammation and injury as assessed by reductions in tissue mRNA levels of inflammatory markers, histopathologic injury, and apoptosis in lung and intestines. MOP3 also significantly improved 7-day overall survival for CS-septic mouse pups compared to vehicle (75% vs. 46%, respectively).

CONCLUSION

Deriving from MFG-E8 and designed to clear eCIRP, MOP3 protects against sepsis-induced inflammation, organ injury, and mortality in a preclinical model of neonatal sepsis, implicating it as an exciting potential new therapeutic.

LEVEL OF EVIDENCE

Level 1.

Pre-operative enteral feeding in single-ventricle CHD patients and necrotising enterocolitis risk

INTRODUCTION

Enteral feeding prior to cardiac surgery has benefits in pre-operative and post-operative patient statuses. In 2020, to increase pre-operative feeding for single-ventricle patients prior to stage 1 palliation, an enteral feeding algorithm was created. The aim of this study is to monitor the impact of our practice change with the primary outcome of necrotising enterocolitis incidence from birth to 2 weeks following surgical intervention.

METHODS

This is a single-site, retrospective cohort study including patients from 1 March, 2018 to 1 July, 2022. Variables assessed include demographics, age at cardiac surgery, primary cardiac diagnosis, necrotising enterocolitis pre-operative and 2 weeks post-operative cardiac surgery, feeding route, feeding type, volume of trophic enteral feeds, and near-infrared spectroscopy.

RESULTS

Following implementation of a pre-operative enteral feeding algorithm, the rate of neonates fed prior to surgery increased (39.5-75%, p = .001). The feedings included a mean volume of 28.24 ± 11.16 ml/kg/day, 83% fed breastmilk only, 44.4% tube fed, and 55.5% of infants had all oral feedings. Comparing enterally fed neonates and those not enterally fed, the necrotising enterocolitis incidence from birth to 2 weeks post-op was not significantly increased (p = 0.926).

CONCLUSION

As a result of implementing our feeding algorithm, the frequency of infants fed prior to stage I Norwood or Hybrid surgeries increased to 75%, and there was no significant change in the incidence of necrotising enterocolitis. This study confirmed that pre-operative enteral feeds are safe and are not associated with increased incidence of necrotising enterocolitis.

Necrotizing enterocolitis in premature infants at different gestation ages

OBJECTIVE

Aim: To compare X-ray signs in different gestational and body weight groups of patients with NEC.

PATIENTS AND METHODS

Materials and Methods: We conducted a retrospective study, enrolling 52 preterm newborns with symptoms of NEC regardless of onset time, who underwent treatment at Neonatal Intensive Care Units in Municipal Non-commercial enterprise "City Children Hospital №2", Odesa. The patients were split into 3 clinical groups: very preterm newborns (VPN), moderately preterm newborns (MPN), and moderately preterm newborns with intrauterine growth restriction (MPN+IUGR).

RESULTS

Results: In the VPN group NEC was diagnosed at stage II (58,82±12,30) % and III (41,18±12,30) % by Bell MJ, р>0,05. In the group MPN+IUGR, NEC stage II (33,33±14,21) % and stage III (66,66 ±14,21) %, р>0,05, were equally observed. In the MPN group, NEC was diagnosed at stage I (41,67±10,28) % and II (58,33±10,28) %, р>0,05, without prevalence of any. Also only localized forms were observed. In VPN, we observed localized forms in most cases, while diffuse forms were diagnosed in (11,76±8,05) % cases, р<0,05. In the MPN+IUGR group, we found diffuse form of the NEC in half of the cases - (50,00±15,08) %. In the VPN and MPN+IUGR groups, NEC developed at 13,23±0,39 and 14,33±1,19 days, respectively. However, in MPN without IUGR, NEC developed at 17,75±0,55 days, significantly later than in the MPN+IUGR group, р<0,05.

CONCLUSION

Conclusions: We have described distinct features of NEC in MPN with IUGR. Compared to MPN without IUGR, NEC had more severe course and earlier manifestation in such neonates.

Modulation of intestinal TLR4 expression in infants with neonatal opioid withdrawal syndrome

OBJECTIVE

Neonatal Opioid Withdrawal Syndrome (NOWS) has been associated with the development of necrotizing enterocolitis (NEC) in term and late-preterm neonates. In this study, we used stool gene expression to determine if an increase in baseline inflammation in the intestine of infants with NOWS is associated with these findings.

STUDY DESIGN

Stool samples were prospectively collected between days 1-3 and days 4-9 after delivery for opioid-exposed ( n = 9) or non-exposed neonates (n = 8). Stool gene expression for TLR4 and HMGB1 was determined via real-time PCR.

RESULTS

TLR4 expression was higher in the stool of the non-exposed group in both time periods, between days 1-3 (P < 0.0001) and days 4-9 (P < 0.05) after delivery. No significant difference in HMGB1 expression was found at either time point (P > 0.05).

CONCLUSION

These findings point to an important interplay between opioid exposure and/or NOWS and the inflammatory milieu of the neonatal intestine.

Identification of omega-3 oxylipins in human milk-derived extracellular vesicles with pro-resolutive actions in gastrointestinal inflammation

Introduction

Premature infants (PIs) are at risk of suffering necrotizing enterocolitis (NEC), and infants consuming human milk (HM) show a lower incidence than infants receiving formula. The composition of HM has been studied in depth, but the lipid content of HM-derived small extracellular vesicles (HM sEVs) remains unexplored. Identifying these molecules and their biological effects has potential for the treatment of intestinal disorders in PIs and could contribute to the development of HM-based fortified formulas.

Methods

We isolated HM sEVs from HM samples and analyzed their oxylipin content using liquid chromatography coupled to mass spectrometry, which revealed the presence of anti-inflammatory oxylipins. We then examined the efficacy of a mixture of these oxylipins in combating inflammation and fibrosis, in vitro and in a murine model of inflammatory bowel disease (IBD).

Results

HM-related sEVs contained higher concentrations of oxylipins derived from docosahexaenoic acid, an omega-3 fatty acid. Three anti-inflammatory oxylipins, 14-HDHA, 17-HDHA, and 19,20-DiHDPA (ω3 OXLP), demonstrated similar efficacy to HM sEVs in preventing cell injury, inducing re-epithelialization, mitigating fibrosis, and modulating immune responses. Both ω3 OXLP and HM sEVs effectively reduced inflammation in IBD-model mice, preventing colon shortening, infiltration of inflammatory cells and tissue fibrosis.

Discussion

Incorporating this unique cocktail of oxylipins into fortified milk formulas might reduce the risk of NEC in PIs and also provide immunological and neurodevelopmental support.

Anti-Inflammatory and Anti-Allergic Properties of Colostrum from Mothers of Full-Term and Preterm Babies: The Importance of Maternal Lactation in the First Days

Our narrative review focuses on colostrum components, particularly those that influence the neonatal immune system of newborns. Colostrum is secreted in small volumes by the alveolar cells of the breast during the first two to five days after birth. Colostrum is poor in fat and carbohydrates, with larger protein and bioactive compounds than mature milk. It plays a crucial role in driving neonates' immunity, transferring those immunological factors which help the correct development of the neonatal immune system and support establishing a healthy gut microbiome. The newborn has an innate and adaptive immune system deficiency, with a consequent increase in infection susceptibility. In particular, neonates born prematurely have reduced immunological competencies due to an earlier break in the maternal trans-placenta transfer of bioactive components, such as maternal IgG antibodies. Moreover, during pregnancy, starting from the second trimester, maternal immune cells are conveyed to the fetus and persist in small quantities post-natal, whereby this transfer is known as microchimerism (MMc). Thus, preterm newborns are deficient in this maternal heritage, and have their own immune system under-developed, but colostrum can compensate for the lack. Early breastfeeding, which should be strongly encouraged in mothers of preterm and full-term babies, provides those immunomodulant compounds that can act as a support, allowing the newborn to face immune needs, including fronting infections and establishing tolerance. Moreover, making mothers aware that administering colostrum helps their infants in building a healthy immune system is beneficial to sustain them in the difficult post-partum period.

The Impact of Stress, Microbial Dysbiosis, and Inflammation on Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is the leading cause of intestinal morbidity and mortality in neonates. A large body of work exists; however, the pathogenesis of NEC remains poorly understood. Numerous predictors have been implicated in the development of NEC, with relatively less emphasis on maternal factors. Utilizing human tissue plays a crucial role in enhancing our comprehension of the underlying mechanisms accountable for this devastating disease. In this review, we will discuss how maternal stress affects the pathogenesis of NEC and how changes in the intestinal microbiome can influence the development of NEC. We will also discuss the results of transcriptomics-based studies and analyze the gene expression changes in NEC tissues and other molecular targets associated with the pathogenesis of NEC.

The role of human milk nutrients in preventing necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is an intestinal disease that primarily impacts preterm infants. The pathophysiology of NEC involves a complex interplay of factors that result in a deleterious immune response, injury to the intestinal mucosa, and in its most severe form, irreversible intestinal necrosis. Treatments for NEC remain limited, but one of the most effective preventative strategies for NEC is the provision of breast milk feeds. In this review, we discuss mechanisms by which bioactive nutrients in breast milk impact neonatal intestinal physiology and the development of NEC. We also review experimental models of NEC that have been used to study the role of breast milk components in disease pathophysiology. These models are necessary to accelerate mechanistic research and improve outcomes for neonates with NEC.

Identification of serum biomarkers for necrotizing enterocolitis using aptamer-based proteomics

Introduction

Necrotizing enterocolitis (NEC) is a potentially fatal intestinal disease primarily affecting preterm infants. Early diagnosis of neonates with NEC is crucial to improving outcomes; however, traditional diagnostic tools remain inadequate. Biomarkers represent an opportunity to improve the speed and accuracy of diagnosis, but they are not routinely used in clinical practice.

Methods

In this study, we utilized an aptamer-based proteomic discovery assay to identify new serum biomarkers of NEC. We compared levels of serum proteins in neonates with and without NEC and identified ten differentially expressed serum proteins between these groups.

Results

We detected two proteins, C-C motif chemokine ligand 16 (CCL16) and immunoglobulin heavy constant alpha 1 and 2 heterodimer (IGHA1 IGHA2), that were significantly increased during NEC and eight that were significantly decreased. Generation of receiver operating characteristic (ROC) curves revealed that alpha-fetoprotein (AUC = 0.926), glucagon (AUC = 0.860), and IGHA1 IGHA2 (AUC = 0.826) were the proteins that best differentiated patients with and without NEC.

Discussion

These findings indicate that further investigation into these serum proteins as a biomarker for NEC is warranted. In the future, laboratory tests incorporating these differentially expressed proteins may improve the ability of clinicians to diagnose infants with NEC rapidly and accurately.

Fecal Calprotectin Levels Dynamics in Newborns with High-Risk of Necrotizing Enterocolitis

Background. Necrotizing enterocolitis (NEC) is severe gastrointestinal disease in newborns, its early clinical symptoms are nonspecific. Fecal сalprotectin (Cp) is considered as one of the early biomarkers of NEC, thus, its use in newborns is poorly known.

Objective. The aim of the study is to evaluate clinical significance of fecal Cp measuring as an early NEC marker in newborns. Methods. The prospective cohort observational study included high-risk newborns (gestational age (GA) ˂ 33 weeks and/or body weight ˂ 1500 g) and moderate risk newborns (GV≥ 33 weeks at suspicion on NEC) of NEC admitted to the neonatal intensive care unit on the 1st day of life. The Cp level was studied via immune colorimetric method on the 3rd and 7th days of life in high-risk children and in all children at NEC manifestation. All patients were divided into 2 main subgroups after the end of the follow-up period: newborns with developed NEC (a) and children without NEC (b). Obtained Cp values were compared between these subgroups.

Results. There were no statistically significant differences in Cp levels at the 3rd and 7th days of life in the high-risk group of children with NEC and without NEC. However, it was noted that children without NEC showed a decrease in Cp levels on the 7th day, while children with NEC manifestation, indeed, had increased levels. Cp levels did not differ in the moderate risk group.

Conclusion. Single measurement of Cp level in newborns of any GA is uninformative towards the NEC prognosis and diagnosis. However, evaluation of the Cp level dynamics at the 7th day of life compared to the 3rd day of life may be considered as a promising non-invasive method for prognosis of NEC manifestation in premature infants (GA<33 weeks).