Global incidence of Necrotizing Enterocolitis: a systematic review and Meta-analysis

Effect of a Multi-Strain Probiotic on the Incidence and Severity of Necrotizing Enterocolitis and Feeding Intolerances in Preterm Neonates

Background: Necrotizing enterocolitis (NEC) is a multifactorial disease, causing inflammation of the bowel. The exact root of NEC is still unknown, but a low weight and gestational age at birth are known causes. Furthermore, antibiotic use and abnormal bacterial colonization of the premature gut are possible causes. Premature neonates often experience feeding intolerances that disrupts the nutritional intake, leading to poor growth and neurodevelopmental impairment. Methods: We conducted a double-blind, placebo-controlled, randomized clinical trial to investigate the effect of a multi-strain probiotic formulation (LabinicTM) on the incidence and severity of NEC and feeding intolerances in preterm neonates. Results: There were five neonates in the placebo group who developed NEC (Stage 1A−3B), compared to no neonates in the probiotic group. Further, the use of probiotics showed a statistically significant reduction in the development of feeding intolerances, p < 0.001. Conclusion: A multi-strain probiotic is a safe and cost-effective way of preventing NEC and feeding intolerances in premature neonates.

How Does Human Milk Protect Against Necrotizing Enterocolitis (NEC)? Targeted Validation and Time-Course Analysis of 35 Gene Responses as NEC-Signature in Fetal Intestinal Epithelial Cells

Breastfeeding reduces the risk of necrotizing enterocolitis (NEC), one of the most common causes of morbidity and mortality in preterm infants. However, the molecular substrates by which human milk (HM) offers protection against NEC are not well known. Using fetal intestinal epithelial cells treated with known NEC aggravators, namely lipopolysaccharide (LPS) and platelet-activating factor (PAF), we mapped the time-course of changes in targeted expression analysis of 35 NEC-associated genes, so-called the NEC signature. We found, first, that HM treatment fully rescued LPS/PAF-induced fetal intestinal cell death at 12 and 24 h (n = 5). Differential gene expression and bioinformatics revealed that HM did not mitigate inflammatory and cell death signals, but instead promoted cell proliferation and stress response pathways to mitigate LPS/PAF-induced inflammatory cell death. From this, epidermal growth factor (EGF) synthesis emerged as the central player in rescue of the fetal intestinal cell death. Functional validation was supported by reversal of the cellular rescue by HM following EGF knockdown by small interfering RNA. In conclusion, this study suggests that HM might offer protection against NEC through enhancing intestinal EGF production to rescue the inflammatory cell death. Future studies are warranted to verify these HM molecular protective effects in NEC models in vivo. The findings reported herein also support future research avenues to discover new therapeutics to boost intrinsic EGF production in the injured intestinal tissues in neonates with NEC, for example, by bioactive components in human milk, natural compounds, or small molecules.

Effect of Maternal Diet on Any Necrotizing Enterocolitis in Neonates: A Randomized Double-Blind Study

Background: The etiology of necrotizing enterocolitis (NEC) is controversially discussed. One of the most recently proposed causes of NEC is an allergy to cow's milk protein. This study was designed to evaluate the effect of a maternal diet without bovine protein on the incidence of any NEC in very low birth weight (VLBW) infants. Materials and Methods: A pilot randomized controlled clinical trial was performed at Akbarabadi Hospital, Tehran, Iran, from December 2019 to July 2020, in women with VLBW infants. One hundred twenty mothers with VLBW neonates were randomly assigned to the intervention or the control group (60 in each). In the intervention group, mothers were given a dairy-free diet during the first 14 days after the newborn's onset of feeding. No special diet was given to the control group. The primary outcome of the study was the rate of any NEC in neonates, which was compared between groups. Any NEC was defined as Bell stage I or greater. Results: The minimum and maximum gestational ages were 26 and 33 weeks, respectively. The minimum birth weight of neonates was 700 g. The two groups did not differ significantly in terms of demographic and preinterventional clinical characteristics. Any NEC was reported in 0% and 10% (5/52) of neonates in the intervention and control groups, respectively; the difference was statistically significant (p = 0.028). The NEC symptoms began ∼34 days after birth. Four cases of NEC were classified as Bell stage I, and one was classified as Bell stage II. No statistical association was registered between sex, gestational age, birth weight, and the onset of feeding with the incidence of any NEC. Conclusion: The use of a cow's milk protein-free diet in mothers and exclusive breastfeeding in preterm VLBW infants may reduce the incidence of NEC. We recommend further studies with larger sample sizes in a multicenter setting. The study was registered at the Iranian Registry of Clinical Trials (IRCT20200415047086N1).

Battling Enteropathogenic Clostridia: Phage Therapy for Clostridioides difficile and Clostridium perfringens

The pathogenic Clostridioides difficile and Clostridium perfringens are responsible for many health care-associated infections as well as systemic and enteric diseases. Therefore, they represent a major health threat to both humans and animals. Concerns regarding increasing antibiotic resistance (related to C. difficile and C. perfringens) have caused a surge in the pursual of novel strategies that effectively combat pathogenic infections, including those caused by both pathogenic species. The ban on antibiotic growth promoters in the poultry industry has added to the urgency of finding novel antimicrobial therapeutics for C. perfringens. These efforts have resulted in various therapeutics, of which bacteriophages (in short, phages) show much promise, as evidenced by the Eliava Phage Therapy Center in Tbilisi, Georgia (https://eptc.ge/). Bacteriophages are a type of virus that infect bacteria. In this review, the (clinical) impact of clostridium infections in intestinal diseases is recapitulated, followed by an analysis of the current knowledge and applicability of bacteriophages and phage-derived endolysins in this disease indication. Limitations of phage and phage endolysin therapy were identified and require considerations. These include phage stability in the gastrointestinal tract, influence on gut microbiota structure/function, phage resistance development, limited host range for specific pathogenic strains, phage involvement in horizontal gene transfer, and-for phage endolysins-endolysin resistance, -safety, and -immunogenicity. Methods to optimize features of these therapeutic modalities, such as mutagenesis and fusion proteins, are also addressed. The future success of phage and endolysin therapies require reliable clinical trial data for phage(-derived) products. Meanwhile, additional research efforts are essential to expand the potential of exploiting phages and their endolysins for mitigating the severe diseases caused by C. difficile and C. perfringens.

Intestinal epithelium in early life

Rapid development of the fetal and neonatal intestine is required to meet the growth requirements of early life and form a protective barrier against external insults encountered by the intestinal mucosa. The fetus receives nutrition via the placenta and is protected from harmful pathogens in utero, which leads to intestinal development in a relatively quiescent environment. Upon delivery, the intestinal mucosa is suddenly tasked with providing host defense and meeting nutritional demands. To serve these functions, an array of specialized epithelial cells develop from intestinal stem cells starting in utero and continuing postnatally. Intestinal disease results when these homeostatic processes are interrupted. For preterm neonates, the most common pathology resulting from epithelial barrier dysfunction is necrotizing enterocolitis (NEC). In this review, we discuss the normal development and function of the intestinal epithelium in early life as well as how disruption of these processes can lead to NEC.

Prediction of High Bell Stages of Necrotizing Enterocolitis Using a Mathematic Formula for Risk Determination

Necrotizing enterocolitis (NEC) continues to cause high morbidity and mortality. Identifying early predictors for severe NEC is essential to improve therapy and optimize timing for surgical intervention. We present a retrospective study of patients with NEC, treated between 2010 and 2020, trying to identify factors influencing the severity of NEC. Within the study period, 88 affected infants with NEC or NEC-like symptoms are analyzed. A multiple logistic regression analysis reveals the following three independent predictors for NEC in Bell stage III: red blood cell transfusion (p = 0.027 with odds ratio (OR) = 3.298), sonographic findings (p = 0.037; OR = 6.496 for patients with positive vs. patients without pathological findings) and cardiac anatomy (p = 0.015; OR = 1.922 for patients with patent ductus arteriosus (PDA) vs. patients with congenital heart disease (CHD); OR = 5.478/OR = 2.850 for patients with CHD/PDA vs. patients without cardiac disease). Results are summarized in a clinical score for daily application in clinical routine. The score is easy to apply and combines clinically established parameters, helping to determine the timing of surgical intervention.

The benefits, limitations and opportunities of preclinical models for neonatal drug development

Increased research to improve preclinical models to inform the development of therapeutics for neonatal diseases is an area of great need. This article reviews five common neonatal diseases - bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, perinatal hypoxic-ischemic encephalopathy and neonatal sepsis - and the available in vivo, in vitro and in silico preclinical models for studying these diseases. Better understanding of the strengths and weaknesses of specialized neonatal disease models will help to improve their utility, may add to the understanding of the mode of action and efficacy of a therapeutic, and/or may improve the understanding of the disease pathology to aid in identification of new therapeutic targets. Although the diseases covered in this article are diverse and require specific approaches, several high-level, overarching key lessons can be learned by evaluating the strengths, weaknesses and gaps in the available models. This Review is intended to help guide current and future researchers toward successful development of therapeutics in these areas of high unmet medical need.

The role of ultrasound in necrotizing enterocolitis

Ultrasound has proved to be a useful modality for enhancing the diagnostic accuracy of necrotizing enterocolitis and associated complications. The standard imaging algorithm for evaluating necrotizing enterocolitis includes radiographs and clinical symptoms, the combination of which constitutes the Bell criteria. Major limitations of using the Bell criteria for diagnosing and clinically managing necrotizing enterocolitis include low diagnostic accuracy of radiographs and nonspecific symptomatology of preterm infants. In this regard, US can offer additional insights into bowel health by helping to characterize bowel motility, echogenicity, thickness, pneumatosis and perfusion. Extramural findings such as portal venous gas, nature and extent of ascites, and pneumoperitoneum can also be assessed. Recently, contrast-enhanced US was explored in a case series of preterm bowel disease and its diagnostic utility warrants further investigation. This article reviews the US features of necrotizing enterocolitis and highlights the role of US as a complement to radiographs, as well as the emerging use of contrast-enhanced US in necrotizing enterocolitis.

Interpretable prediction of necrotizing enterocolitis from machine learning analysis of premature infant stool microbiota

Background

Necrotizing enterocolitis (NEC) is a common, potentially catastrophic intestinal disease among very low birthweight premature infants. Affecting up to 15% of neonates born weighing less than 1500 g, NEC causes sudden-onset, progressive intestinal inflammation and necrosis, which can lead to significant bowel loss, multi-organ injury, or death. No unifying cause of NEC has been identified, nor is there any reliable biomarker that indicates an individual patient’s risk of the disease. Without a way to predict NEC in advance, the current medical strategy involves close clinical monitoring in an effort to treat babies with NEC as quickly as possible before irrecoverable intestinal damage occurs. In this report, we describe a novel machine learning application for generating dynamic, individualized NEC risk scores based on intestinal microbiota data, which can be determined from sequencing bacterial DNA from otherwise discarded infant stool. A central insight that differentiates our work from past efforts was the recognition that disease prediction from stool microbiota represents a specific subtype of machine learning problem known as multiple instance learning (MIL).

Results

We used a neural network-based MIL architecture, which we tested on independent datasets from two cohorts encompassing 3595 stool samples from 261 at-risk infants. Our report also introduces a new concept called the “growing bag” analysis, which applies MIL over time, allowing incorporation of past data into each new risk calculation. This approach allowed early, accurate NEC prediction, with a mean sensitivity of 86% and specificity of 90%. True-positive NEC predictions occurred an average of 8 days before disease onset. We also demonstrate that an attention-gated mechanism incorporated into our MIL algorithm permits interpretation of NEC risk, identifying several bacterial taxa that past work has associated with NEC, and potentially pointing the way toward new hypotheses about NEC pathogenesis. Our system is flexible, accepting microbiota data generated from targeted 16S or “shotgun” whole-genome DNA sequencing. It performs well in the setting of common, potentially confounding preterm neonatal clinical events such as perinatal cardiopulmonary depression, antibiotic administration, feeding disruptions, or transitions between breast feeding and formula.

Conclusions

We have developed and validated a robust MIL-based system for NEC prediction from harmlessly collected premature infant stool. While this system was developed for NEC prediction, our MIL approach may also be applicable to other diseases characterized by changes in the human microbiota.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04618-w.

Nutrient Intake with Early Progressive Enteral Feeding and Growth of Very Low-Birth-Weight Newborns

Early nutrition is one of the most modifiable factors influencing postnatal growth. Optimal nutrient intakes for very preterm infants remain unknown, and poor postnatal growth is common in this population. The aim of this study was to assess nutrient intake during the first 4 weeks of life with early progressive enteral feeding and its impact on the in-hospital growth of very low-birth-weight (VLBW) infants. In total, 120 infants with birth weights below 1500 g and gestational ages below 35 weeks were included in the study. Nutrient intakes were assessed daily for the first 28 days. Growth was measured weekly until discharge. Median time of parenteral nutrition support was 6 days. Target enteral nutrient and energy intake were reached at day 10 of life, and remained stable until day 28, with slowly declining protein intake. Median z-scores at discharge were -0.73, -0.49, and -0.31 for weight, length, and head circumference, respectively. Extrauterine growth restriction was observed in 30.3% of the whole cohort. Protein, carbohydrates, and energy intakes correlated positively with weight gain and head circumference growth. Early progressive enteral feeding with human milk is well tolerated in VLBW infants. Target enteral nutrient intake may be reached early and improve in-hospital growth.

Identifying clinical phenotypes in extremely low birth weight infants-an unsupervised machine learning approach

There is increasing evidence that patient heterogeneity significantly hinders advancement in clinical trials and individualized care. This study aimed to identify distinct phenotypes in extremely low birth weight infants. We performed an agglomerative hierarchical clustering on principal components. Cluster validation was performed by cluster stability assessment with bootstrapping method. A total of 215 newborns (median gestational age 27 (26-29) weeks) were included in the final analysis. Six clusters with different clinical and laboratory characteristics were identified: the "Mature" (Cluster 1; n = 60, 27.9%), the mechanically ventilated with "adequate ventilation" (Cluster 2; n = 40, 18.6%), the mechanically ventilated with "poor ventilation" (Cluster 3; n = 39, 18.1%), the "extremely immature" (Cluster 4; n = 39, 18.1%%), the neonates requiring "Intensive Resuscitation" in the delivery room (Cluster 5; n = 20, 9.3%), and the "Early septic" group (Cluster 6; n = 17, 7.9%). In-hospital mortality rates were 11.7%, 25%, 56.4%, 61.5%, 45%, and 52.9%, while severe intraventricular hemorrhage rates were 1.7%, 5.3%, 29.7%, 47.2%, 44.4%, and 28.6% in clusters 1, 2, 3, 4, 5, and 6, respectively (p < 0.001).Conclusion: Our cluster analysis in extremely preterm infants was able to characterize six distinct phenotypes. Future research should explore how better phenotypic characterization of neonates might improve care and prognosis. What is Known: • Patient heterogeneity is becoming more acknowledged as a cause of clinical trial failure. • Machine learning algorithms can find patterns within a heterogeneous group. What is New: • We identified six different phenotypes of extremely preterm infants who exhibited distinct clinical and laboratorial characteristics.

Necrotizing Enterocolitis and Its Predictors Among Preterm Neonates Admitted in Neonatal Intensive Care Units of Gurage Zone Public Hospitals, Southwest Ethiopia, 2021

Background

Necrotizing Enter colitis (NEC) is the most common multifactorial and devastating gastrointestinal emergency which primarily affects premature infants. The purpose of this study was to identify the prevalence of Necrotizing Enterocolitis and its associated factors among preterm neonates admitted to Neonatal Intensive Care Units in Gurage Zone hospitals.

Methods

Institution-based cross-sectional study design was employed. The simple Random Sampling Technique was applied to collect the data using a structured questionnaire. Data were cleaned, checked for inconsistencies, coded and entered via EPI data 3.1, and exported to Stata version 14 for further analysis. The data were processed by Stata 14 to estimate the prevalence of necrotizing enterocolitis.

Results

The prevalence of Necrotizing Enterocolitis among neonates was 28 (9.7%) 95% CI of 6. 8–13.7%. Birth weight (AOR: 7.33 95% CI (2.04: 26.38)), presence of maternal infection (AOR: 6.09, 95% CI (1.31:28.26)), length of hospital stay (AOR: 3.28, 95% CI (1.20, 8.96)), and initiating trophic feeding (AOR: 5.89, 95% CI (2.27: 15.33)) were associated with neonatal necrotizing enterocolitis.

Conclusion

The prevalence of Necrotizing Enterocolitis among preterm neonates was significant and special attention is needed for premature neonates with low birth weight and born from mothers with infection during pregnancy. Minimizing the length of hospital stay will be very useful to prevent the occurrence of Necrotizing Enterocolitis.

Necrotizing Enterocolitis in a Dutch Cohort of Very Preterm Infants: Prevalence, Mortality, and Long-Term Outcomes

INTRODUCTION

 To improve counseling of parents and to guide care strategies, we studied the disease course and outcomes of necrotizing enterocolitis (NEC) up to 2 years of corrected age (CA) from a multidisciplinary perspective.

MATERIALS AND METHODS

 This was a retrospective cohort study in preterm infants (birth weight < 1,500 g, gestational age < 32 weeks), diagnosed with NEC (Bell's stage ≥ II) from 2008 through 2020. Data on prevalence, mortality, surgery, intestinal failure (IF), growth, and neurodevelopment at 2-year follow-up were separately analyzed for medically and surgically treated children.

RESULTS

 Of 3,456 preterm infants, 200 (6%) were diagnosed with NEC, of whom 135 developed an indication for surgery within 7 days after the diagnosis; 28/135 died before surgery, and 37/107 died after an open-and-close procedure. An enterostomy was constructed in 62 patients and an end-to-end anastomosis in 15. The postoperative course was described for 77 patients, of whom 23 developed surgical complications (12/23 incisional hernias, 9/23 anastomotic strictures), 13/77 a short bowel, and 25/77 IF. Sixty-day survival after birth for medical NEC patients was 88% (hazard ratio [HR]: 0.698; p = 0.318), and for surgically treated NEC patients was 40% (HR: 3.729; p < 0.001). At 2-year follow-up, one patient received parenteral nutrition. Severe delay in weight for age, motor, and cognitive development was seen in 3, 6, and 2%, respectively.

CONCLUSION

 In this cohort, the mortality rate was high, especially in surgically treated NEC patients. The surgical complication rate is comparable to previous studies, but in surviving patients, persisting IF and severe delay in growth and neurodevelopment at 2 years CA were relatively rare.

Experience using donor human milk: A single-center cohort study in Japan

BACKGROUND

Donor human milk (DHM) became available in Japan when the first human milk bank was established in 2017. This study investigated the effects of DHM on enteral nutrition (EN) in very low birth weight (VLBW) infants in the single center in Japan.

METHODS

Seventy-six VLBW infants hospitalized between April 2017 and March 2020 at Showa University Hospital were included in the study. We retrospectively evaluated age (hours) at which EN was initiated and age (days) until complete feeding (EN > 100 mL/kg/day) was achieved. We compared the DHM and non-DHM groups, or the early human milk (EHM) and non-EHM groups. The EHM group was defined as those in which EN was initiated with the mother's own milk or DHM within 12 h of birth.

RESULTS

In 30 extremely low birth weight (ELBW) infants, EN was initiated at significantly earlier postnatal hours in the DHM group compared to those in the non-DHM group. Complete feeding was achieved at significantly earlier ages in the EHM group after adjusting for gastrointestinal complications and gestational age. Additionally, the changes in body weight z-scores from birth to term-equivalent age were significantly greater in the EHM group after adjusting for exclusive breastfeeding and small for gestational age, compared to the non-EHM group. Statistical significance was not noted in 46 subjects (birth weight, 1000-1500 g).

CONCLUSION

The use of DHM may contribute to earlier initiation and achievement of EN, resulting in greater early postnatal growth in ELBW infants in Japan.

Feeding practices and the prevalence of cow's milk protein allergy in Irish preterm infants

BACKGROUND

The prevalence of cow's-milk protein allergy (CMPA) is between 2% and 3% and symptoms vary depending on underlying immune mechanism at play. Breast milk is the optimal nutrition for premature infants and breast milk fortifiers (BMF) are commonly used to optimise growth and nutrition. BMF are typically derived from cow's milk and, as such, preterm infants are exposed to cow's milk in the first weeks of life. Previously, preterm infants were suspected to have a higher risk of allergen development because of early antigen exposure and increased gut permeability. The primary aim of the present study was to evaluate the prevalence of CMPA among very preterm (<32 weeks) and/or very low birth weight (VLBW) infants. The secondary aim was to describe feeding practices, specifically the breastfeeding rates and specialist, non-standard formula use in this cohort over the first 6 months of life.

METHODS

This was a retrospective study performed in a large tertiary maternity hospital (8500 deliveries/year and 110 very preterm infants/year) in Dublin, Ireland over a 3-year period, 2017-2020. Infants born very preterm and/or VLBW who were followed in the outpatient clinic until 6 months corrected gestational age (CGA) were included. Hospital ethical approval was obtained.

RESULTS

One hundred and forty-four infants were included with a median birth weight of 1338 g. No infant had a diagnosis of CMPA when leaving the neonatal intensive care unit (NICU) but, by 6 months CGA, this increased to 1.4% (n = 2). Upon discharge from the NICU, 88 infants (61%) were receiving at least some breast milk, decreasing to 13 (9.1%) at 6 months CGA. Those who were receiving exclusive breast milk at discharge were significantly more likely to still be receiving any breast milk at three (p ≤ 0.001) and 6 months ( p ≤ 0.001) CGA compared to those combined feeding or exclusively formula feeding. At 6 months CGA, 18.9% (n = 27) were attending a dietician and 31.5% (n = 45) were using specialist, non-standard infant formula.

CONCLUSIONS

The prevalence of CMPA in this cohort was 1.4%, which is similar to the reported prevalence of CMPA in the general paediatric population. Infants who were discharged from NICU exclusively breastfeeding were more likely to be receiving any breast milk at outpatient follow-up. This highlights the importance of on going dietetic and lactation support in the outpatient setting for this vulnerable cohort.

Newborns with Bloody Stools-At the Crossroad between Efficient Management of Necrotizing Enterocolitis and Antibiotic Stewardship

The onset of bloody stools in neonates often results in antibiotic treatment for suspected necrotizing enterocolitis (NEC). Food protein-induced allergic proctocolitis (FPIAP) is an often-neglected differential diagnosis. We performed a retrospective analysis of antibiotic exposure at our tertiary center from 2011 to 2020 that included three time periods of differing antimicrobial stewardship goals. We compared these data with the conventional treatment guidelines (modified Bell's criteria). In our cohort of 102 neonates with bloody stools, the length of antibiotic exposure was significantly reduced from a median of 4 to 2 days. The proportion of treated neonates decreased from 100% to 55% without an increase in negative outcomes. There were 434 antibiotic days. Following a management strategy according to modified Bell's criteria would have led to at least 780 antibiotic days. The delayed initiation of antibiotic treatment was observed in 7 of 102 cases (6.9%). No proven NEC case was missed. Mortality was 3.9%. In conclusion, with FPIAP as a differential diagnosis of NEC, an observational management strategy in neonates with bloody stools that present in a good clinical condition seems to be justified. This may lead to a significant reduction of antibiotic exposure. Further prospective, randomized trials are needed to prove the safety of this observational approach.

Differential Expression Profiles and Functional Prediction of circRNAs in Necrotizing Enterocolitis

Circular RNAs (circRNAs), a novel type of noncoding RNAs, have been demonstrated to behave as microRNA (miRNA) sponges to exert their effects during pathological processes of diseases. However, the roles of circRNAs have not been explored in necrotizing enterocolitis (NEC). This study sought to identify differentially expressed circRNAs and predict their potential biological functions in NEC. circRNA expression profiles in terminal ileum from newborn rats with NEC and normal controls were explored using next-generation sequencing. In the NEC group, 53 circRNAs were significantly differentially expressed, including 9 upregulated and 44 downregulated. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were conducted, and circRNA-miRNA interaction networks were generated to predict the potential roles of circRNAs in NEC progression. Further investigation revealed that most circRNAs include miRNA binding sites and that some are implicated in NEC development. In conclusion, this study's findings demonstrate that differentially expressed circRNAs are involved in NEC development via their interactions with miRNAs, making them prospective targets for NEC diagnosis and treatment.

Low technology, mild controlled hypothermia for necrotizing enterocolitis treatment: an initiative to improve healthcare to preterm neonates

Necrotizing enterocolitis (NEC) treatment remains unchanged for years. Data suggest that mild controlled hypothermia could potentially improve NEC outcomes. Our units presented unfavourable outcomes on NEC. The aim was to assess our experience with low technology, mild controlled hypothermia on NEC outcomes, and improve preterm infants' healthcare. This was a single-center quality improvement study with retrospective cohort design at the neonatal intensive care unit in the university hospital. Forty-three preterm infants with NEC (Modified Bell's Stage II/III) were included: 19 in the control group (2015-2018) and 24 in the hypothermia group (2018-2020). The control group received standard treatment (fasting, abdominal decompression, and broad-spectrum antibiotics). The hypothermia group underwent cooling to 35.5 °C for 48 h after NEC diagnosis, along with conventional treatment. The primary outcomes are intestinal perforation, need for surgery, duration of parenteral nutrition, death, and extensive resection of the small intestine. There was no statistical difference in the NEC score. The hypothermia group required less surgery (aRR 0.40; 95% CI 0.19-0.85), presented less bowel perforation (aRR 0.39; 95% CI 0.18; 0.83), had a shorter duration of parenteral nutrition (aHR 5.28; 95% CI 1.88-14.89), did not need extensive intestinal resection, (0 vs 15.7%), and did not experience any deaths (0 vs 31.6%).Conclusions: In our experience, low technology, mild controlled hypothermia was feasible, not related to adverse effects, and effective treatment for NEC Modified Bell's Stage II/III. It avoided surgery, bowel perforation, and extensive intestinal resection; reduced mortality; and shortened parenteral nutrition duration. What is Known: • New approaches have been proposed to avoid enterocolitis incidence; however, the treatment of enterocolitis stage 2 has been the same for decades, and unfavourable outcomes remain despite conventional management. • Studies suggest that hypothermia can be an alternative to enterocolitis treatment. What is New: • Mild controlled hypothermia can be an additional practice to treat enterocolitis stage 2, is feasible, and is not related to adverse effects to preterm infants. • It can decrease surgery needs, duration of parenteral nutrition, and death and avoids extensive intestinal resection in preterm infants.

Probiotics, Prebiotics, and Synbiotics for the Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a major cause of morbidity and mortality in preterm infants. The exact mechanism by which NEC develops is poorly understood however there is growing evidence to suggest that perturbations in the early-life gut microbiota composition increase the risk for NEC. Modulation of the gut microbiota with probiotics, prebiotics, or in combination (synbiotics) is an area which has attracted intense interest in recent years. In this narrative review, we present an overview of the role of the gut microbiota in the pathogenesis of NEC. We also examine the evidence currently available from randomized controlled trials, observational studies, systematic reviews, and meta-analysis examining the role of probiotics, prebiotics, and synbiotics in reducing the risk of or preventing NEC. Current clinical practice guidelines with recommendations on the routine administration of probiotics to preterm infants for NEC are also explored.

Necrotizing Enterocolitis: Overview on In Vitro Models

Necrotizing enterocolitis (NEC) is a gut inflammatory disorder which constitutes one of the leading causes of morbidity and mortality for preterm infants. The pathophysiology of NEC is yet to be fully understood; several observational studies have led to the identification of multiple factors involved in the pathophysiology of the disease, including gut immaturity and dysbiosis of the intestinal microbiome. Given the complex interactions between microbiota, enterocytes, and immune cells, and the limited access to fetal human tissues for experimental studies, animal models have long been essential to describe NEC mechanisms. However, at present there is no animal model perfectly mimicking human NEC; furthermore, the disease mechanisms appear too complex to be studied in single-cell cultures. Thus, researchers have developed new approaches in which intestinal epithelial cells are exposed to a combination of environmental and microbial factors which can potentially trigger NEC. In addition, organoids have gained increasing attention as promising models for studying NEC development. Currently, several in vitro models have been proposed and have contributed to describe the disease in deeper detail. In this paper, we will provide an updated review of available in vitro models of NEC and an overview of current knowledge regarding its molecular underpinnings.

Urine NMR Metabolomics Profile of Preterm Infants With Necrotizing Enterocolitis Over the First Two Months of Life: A Pilot Longitudinal Case-Control Study

Objective: To investigate changes in the urine metabolome of very low birth weight preterm newborns with necrotizing enterocolitis (NEC) and feed intolerance, we conducted a longitudinal study over the first 2 months of life. The metabolome of NEC newborns was compared with two control groups that did not develop NEC: the first one included preterm babies with feed intolerance, while the second one preterm babies with good feed tolerance.

Methods: Newborns developing NEC within the 3 weeks of life were identified as early onset NEC, while the remaining as late onset NEC. Case-control matching was done according to the gestational age (±1 week), birth weight (± 200 g), and postnatal age. A total of 96 urine samples were collected and analyzed. In newborns with NEC, samples were collected before, during and after the diagnosis over the first 2 months of life, while in controls samples were collected as close as possible to the postnatal age of newborns with NEC. Proton nuclear magnetic resonance (¹H NMR) spectroscopy was used for metabolomic analysis. Data were analyzed by univariate and multivariate statistical analysis.

Results: In all the preterm newborns, urine levels of betaine, glycine, succinate, and citrate positively correlated with postnatal age. Suberate and lactate correlated with postnatal age in preterms with NEC and in controls with food intolerance, while N,N-dimethylglycine (N,N-DMG) correlated only in controls with good digestive tolerance. Preterm controls with feed intolerance showed a progressive significant decrease of N-methylnicotinamide and carnitine. Lactate, betaine, myo-inositol, urea, creatinine, and N,N-dimethylglycine discriminated late-onset NEC from controls with good feed tolerance.

Conclusion: Our findings are discussed in terms of contributions from nutritional and clinical managements of patients and gut microbiota.

Potential Prenatal Origins of Necrotizing Enterocolitis

Necrotizing enterocolitis is a serious and yet incompletely understood gastrointestinal disease of infancy that predominately impacts premature neonates. Prevention is a key strategy for the management of necrotizing enterocolitis. Although postnatal risk factors have been the focus of prevention efforts, obstetric complications, including intrauterine inflammation and infection, growth restriction, preeclampsia, and prenatal medications, have been associated with an increased risk of necrotizing enterocolitis. This article reviews the evidence behind the prenatal risk factors for necrotizing enterocolitis, and discusses how these risk factors may elucidate the pathogenesis of necrotizing enterocolitis and provide insight into prevention and treatment.

The Prevalence of Necrotizing Enterocolitis and Associated Factors Among Enteral Fed Preterm and Low Birth Weight Neonates Admitted in Selected Public Hospitals in Addis Ababa, Ethiopia: A Cross-sectional Study

Necrotizing enterocolitis (NEC) remains to be the most critical and frequent gastrointestinal disorder understood in neonatal intensive care units (NICU). The presented study was intended to assess the prevalence of NEC and associated factors among enteral Fed preterm and low birth weight neonates. Institution based retrospective cross-sectional study was conducted on 350 enteral Fed preterm and low birth weight neonates who were admitted at selected public hospitals of Addis Ababa from March 25/2020 to May 10/2020. The data were collected through neonates' medical record chart review. A total of 350 participants were enrolled in to the study with the response rate of 99.43%. One hundred eighty-four (52.6%) of them were male. The majority 123 (35.1%) of them were (32 + 1 to 34) weeks gestational age. The prevalence of NEC was (25.4%) (n = 89, [95% CI; 21.1, 30.0]). Being ≤28 weeks gestational age (AOR = 3.94, 95% CI [2.67, 9.97]), being (28 + 1 to 32 weeks) gestational age (AOR = 3.65, 95% CI [2.21, 8.31]), birth weight of 1000 to 1499 g (AOR = 2.29, 95% CI [1.22, 4.33]), APGAR score ≤3 (AOR = 2.34, 95% CI [1.32, 4.16]), prolonged labor (AOR = 2.21, 95% CI [1.35, 6.38]), maternal chronic disease particularly hypertension (AOR = 3.2, 95% CI [1.70, 5.90]), chorioamnionitis (AOR = 4.8, 95% CI [3.9, 13]), failure to breath/resuscitated (AOR = 2.1, 95% CI [1.7, 4.4]), CPAP ventilation (AOR = 3.7, 95% CI [1.50, 12.70]), mixed milk (AOR = 3.58, 95% CI [2.16, 9.32]) were factors significantly associated with NEC. Finally, the prevalence of NEC in the study area was high. So that, initiating the programs that could minimize this problem is required to avoid the substantial morbidity and mortality associated with NEC.

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

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

Probiotics for Preventing Necrotizing Enterocolitis in Preterm Infants: A Network Meta-Analysis

BACKGROUND

Recent evidence supports a role of probiotics in preventing necrotizing enterocolitis (NEC) in preterm infants.

METHODS

A systematic review and network meta-analysis of randomized controlled trials (RCTs) on the role of probiotics in preventing NEC in preterm infants, focusing on the differential effect of type of feeding, was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A random-effects model was used; a subgroup analysis on exclusively human milk (HM)-fed infants vs. infants receiving formula (alone or with HM) was performed.

RESULTS

Fifty-one trials were included (10,664 infants, 29 probiotic interventions); 31 studies (19 different probiotic regimens) were suitable for subgroup analysis according to feeding. In the overall analysis, Lactobacillus acidophilus LB revealed the most promising effect for reducing NEC risk (odds ratio (OR), 0.03; 95% credible intervals (CrIs), 0.00-0.21). The subgroup analysis showed that Bifidobacterium lactis Bb-12/B94 was associated with a reduced risk of NEC stage ≥2 in both feeding type populations, with a discrepancy in the relative effect size in favour of exclusively HM-fed infants (OR 0.04; 95% CrIs <0.01-0.49 vs. OR 0.32; 95% CrIs 0.10-0.36).

CONCLUSIONS

B. lactis Bb-12/B94 could reduce NEC risk with a different size effect according to feeding type. Of note, most probiotic strains are evaluated in few trials and relatively small populations, and outcome data according to feeding type are not available for all RCTs. Further trials are needed to confirm the present findings.

Effect of Enteral Vitamin A on Fecal Calprotectin in Extremely Preterm Infants: A Nested Prospective Observational Study

BACKGROUND

Vitamin A has anti-inflammatory and immune-modulating properties. We aimed to assess whether enteral water-soluble vitamin A supplementation in extremely preterm infants decreases fecal calprotectin, a marker of intestinal inflammation.

METHODS

This was a prospective observational study nested in a randomized, double-blind, placebo-controlled clinical trial investigating enteral vitamin A (5,000 IU/day) for reducing the severity of bronchopulmonary dysplasia (BPD) in extremely preterm infants. Fecal calprotectin levels were measured using enzyme-linked immunosorbent assay after 28 days of Vitamin A or placebo supplementation.

RESULTS

Fecal calprotectin was measured in 66 infants (Vitamin A: 33, Placebo: 33). The mean (standard deviation) gestational age (25.5 [1.55] vs. 25.8 [1.48]; p = 0.341) (week), birth weight (810 [200] vs. 877 [251]; p = 0.240) (gram), and factors influencing fecal calprotectin levels were comparable between the vitamin A versus placebo group infants. All infants were exclusively fed with mother's or donor's human breast milk if mother's milk was unavailable using a standardized feeding regimen and received prophylactic probiotic supplementation. Fecal calprotectin levels (median; 25th-75th centiles) (micrograms/gram of feces) were not significantly different between vitamin A (152; 97-212) and placebo groups (179; 91-313) (p = 0.195). Two infants in the vitamin A group developed definite necrotizing enterocolitis compared to none in the placebo group. Incidence of BPD at 36 weeks postmenstrual age was similar between the groups (vitamin A: 18/33, placebo: 13/33, p = 0.218).

CONCLUSION

Enteral supplementation with water-soluble vitamin A did not affect fecal calprotectin levels in extremely preterm infants. Studies with a larger sample size are required to confirm the findings.

Outcomes and Prognostic Factors for Survival of Neonates With Necrotizing Enterocolitis

Background: Due to the survival of preterm neonates being continually improved, the modifiable prognostic factors of necrotizing enterocolitis (NEC) are essential to be investigated and considered in making a suitable treatment to decrease the prevalence and effect of NEC. Many prognostic factors have been associated with the survival of neonates with NEC; however, the studies show conflicting results. Moreover, the study from developing countries regarding NEC outcomes is minimal. Here, we aimed to determine the survival of neonates with NEC and associate it with the prognostic factors. Methods: A retrospective study was conducted using medical records of neonates with NEC at our institution from January 2014 to December 2019. Results: Fifty-two neonates with NEC were involved with the overall survival of 44.2%. Log-rank analysis showed that NEC staging and birth weight were significantly associated with the survival of neonates with NEC with a p-value of 0.010 and 0.002, respectively, while sex, APGAR score, platelet count, and type of treatment were not (p = 0.068, 0.752, 0.087, and 0.343, respectively). Multivariate analysis revealed that sex and NEC staging were strongly associated with the survival of neonates with NEC with a p-value of 0.018 [HR = 3.10 (95% CI = 1.21-7.93)] and 0.019 [HR = 0.44 (0.22-0.87)], respectively. Conclusions: Our study shows that sex and NEC staging might affect the survival of neonates with NEC. It implies that NEC staging should be closely monitored and intervened as early as necessary to prevent further morbidity and mortality.

Routine Administration of a Multispecies Probiotic Containing Bifidobacterium and Lactobacillus to Very Low Birth Weight Infants Had No Significant Impact on the Incidence of Necrotizing Enterocolitis

Background: Necrotizing enterocolitis (NEC) is the leading cause of gastrointestinal morbidity in preterm infants, and prevention and treatment strategies have remained largely unchanged over the past several decades. As understanding of the microbiome has increased, probiotics have been hypothesized as a possible strategy for decreasing rates of NEC, and several studies have noted significant decreases in rates of NEC after initiation of probiotics in preterm infants. However, a recent AAP report cited caution on the use of probiotic use in part because studies of probiotic use in ELBW infants are lacking. As our unit began routine use of probiotics for all infants <33 weeks in 2015 and we are a leading institution for intact survival of ELBW infants, we attempted to answer if probiotic use can impact the rate of NEC in VLBW and ELBW infants. Methods: We conducted a single-center retrospective chart review of infants with modified Bell's stage ≥2a NEC for the 4 years prior to and 5 years after initiation of a protocol involving routine supplementation of a multispecies probiotic to premature infants at the University of Iowa, Stead Family Children's Hospital. The primary outcome measures were rates of modified Bell's stage ≥2a NEC and all-cause pre-discharge mortality at our institution before and after initiation of routine probiotic supplementation in 2015. Results: In our institution, neither the rates of modified Bell's stage ≥2a NEC, nor the rates of all-cause mortality were significantly altered in very low birth weight (VLBW) infants by the initiation of routine probiotic use (NEC rates pre-probiotic 2.1% vs. post-probiotic 1.5%; all-cause mortality rates pre-probiotic 8.4% vs. post-probiotic 7.4%). Characteristics of our two cohorts were overall similar except for a significantly lower 5-minute APGAR score in infants in the post-probiotic epoch (pre-probiotic 8 vs. post-probiotic 6 p = 0.0316), and significantly more infants in the post-probiotic epoch received probiotics (pre-probiotics 0% vs. post-probiotics 65%; p < 0.0001). Similarly, probiotic use had no impact on the incidence of NEC when we restricted our data to only extremely low birth weight (ELBW) infants (pre-probiotics 1.6% vs post-probiotics 4.1%). When we restricted our analysis to only inborn infants, probiotics still had no impact on NEC rates in VLBW infants (1.5% pre- and 1.1% post-probiotic, p = 0.61) or ELBW infants (2% pre- and 2.1% post-probiotic, p = 0.99) Conclusions: Contrary to other studies, we found no significant difference in rates of modified Bell's stage ≥2a NEC or all-cause pre-discharge mortality in VLBW infants following routine administration of a multispecies probiotic supplement.

Cardiac and Inflammatory Necrotizing Enterocolitis in Newborns Are Not the Same Entity

Background: Necrotizing enterocolitis (NEC) is an often-fatal neonatal disease involving intestinal hyperinflammation leading to necrosis. Despite ongoing research, (1) conflicting results and (2) comorbidities of NEC patients make early NEC detection challenging and may complicate therapy development. Most research suggests that NEC pathogenesis is multifactorial, involving a combination of (1) gut prematurity; (2) abnormal bacterial colonization; and (3) ischemia-reperfusion (I/R) injury. As neutrophil extracellular traps (NETs) partially mediate I/R injury and drive inflammation in NEC, we hypothesized that NETs contribute to NEC development; particularly in cardiac patients. Methods: A retrospective analysis of baseline characteristics, clinical signs, laboratory parameters, and imaging was conducted for surgically verified NEC cases over 10 years. Patients were stratified into two groups: (1) prior medically or surgically treated cardiac disease (cardiac NEC) and (2) no cardiac comorbidities (inflammatory NEC). Additionally, histology was reassessed for neutrophil activation and NETs formation. Results: A total of 110 patients (cNEC 43/110 vs. iNEC 67/110) were included in the study, with cNEC neonates being significantly older than iNEC neonates (p = 0.005). While no significant differences were found regarding clinical signs and imaging, laboratory parameters revealed that cNEC patients have significantly increased leucocyte (p = 0.024) and neutrophil (p < 0.001) counts. Both groups also differed in pH value (p = 0.011). Regarding histology: a non-significant increase in staining of myeloperoxidase within the cNEC group could be found in comparison to iNEC samples. Neutrophil elastase (p = 0.012) and citrullinated histone H3 stained (p = 0.041) slides showed a significant markup for neonates diagnosed with cNEC in comparison to neonates with iNEC. Conclusion: The study shows that many standardized methods for diagnosing NEC are rather unspecific. However, differing leucocyte and neutrophil concentrations for iNEC and cNEC may indicate a different pathogenesis and may aid in diagnosis. As we propose that iNEC is grounded rather in sepsis and neutropenia, while cNEC primarily involves I/R injuries, which involves neutrophilia and NETs formation, it is plausible that I/R injury due to interventions for cardiac comorbidities results in pronounced neutrophil activation followed by a hyperinflammation reaction and NEC. However, prospective studies are necessary to validate these findings and to determine the accuracy of the potential diagnostic parameters.

Emerging Biomarkers for Prediction and Early Diagnosis of Necrotizing Enterocolitis in the Era of Metabolomics and Proteomics

Necrotizing Enterocolitis (NEC) is a catastrophic disease affecting predominantly premature infants and is characterized by high mortality and serious long-term consequences. Traditionally, diagnosis of NEC is based on clinical and radiological findings, which, however, are non-specific for NEC, thus confusing differential diagnosis of other conditions such as neonatal sepsis and spontaneous intestinal perforation. In addition, by the time clinical and radiological findings become apparent, NEC has already progressed to an advanced stage. During the last three decades, a lot of research has focused on the discovery of biomarkers, which could accurately predict and make an early diagnosis of NEC. Biomarkers used thus far in clinical practice include acute phase proteins, inflammation mediators, and molecules involved in the immune response. However, none has been proven accurate enough to predict and make an early diagnosis of NEC or discriminate clinical from surgical NEC or other non-NEC gastrointestinal diseases. Complexity of mechanisms involved in NEC pathogenesis, which remains largely poorly elucidated, could partly explain the unsatisfactory diagnostic performance of the existing NEC biomarkers. More recently applied technics can provide important insight into the pathophysiological mechanisms underlying NEC but can also aid the detection of potentially predictive, early diagnostic, and prognostic biomarkers. Progress in omics technology has allowed for the simultaneous measurement of a large number of proteins, metabolic products, lipids, and genes, using serum/plasma, urine, feces, tissues, and other biological specimens. This review is an update of current data on emerging NEC biomarkers detected using proteomics and metabolomics, further discussing limitations and future perspectives in prediction and early diagnosis of NEC.