Recent advances in understanding necrotizing enterocolitis

Oxylipin profile of human milk and human milk-derived extracellular vesicles

BACKGROUND

Small Extracellular Vesicles (sEVs) are nano-sized vesicles that are present in all biofluids including human milk (HM) playing a crucial role in cell-to-cell communication and the stimulation of the neonatal immune system. Oxylipins, which are bioactive lipids formed from polyunsaturated fatty acids, have gained considerable attention due to their potential role in mitigating disease progression and modulating the inflammatory status of breastfed infants. This study aims at an in-depth characterization of the oxylipin profiles of HM and, for the first time, of HM-derived sEVs (HMEVs) employing an ad-hoc developed and validated ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method.

RESULTS

The UPLC-MS/MS method covered a panel of 13 oxylipins for quantitation and 93 oxylipins for semi-quantitation. In 200 μL of HM and HMEV isolates of 15 individuals, 42 out of 106 oxylipins were detected in either HM or HMEVs, with 38 oxylipins being detected in both matrices. Oxylipins presented distinct profiles in HM and HMEVs, suggesting specific mechanisms responsible for the encapsulation of target molecules in HMEVs. Ten and eight oxylipins were quantified with ranges between 0.03 - 73 nM and 0.30 pM-0.07 nM in HM and HMEVs, respectively. The most abundant oxylipins found in HMEVs were docosahexaenoic acid derivatives (17-HDHA and 14-HDHA) with known anti-inflammatory properties, and linoleic acid derivatives (9-10-DiHOME and 12,13-DiHOME) in HM samples.

SIGNIFICANCE AND NOVELTY

This is the first time a selective, relative enrichment of anti-inflammatory oxylipins in HMEVs has been described. Future studies will focus on the anti-inflammatory and pro-healing capacity of oxylipins encapsulated in HMEVs, with potential clinical applications in the field of preterm infant care, specifically the prevention of severe intestinal complications including necrotizing enterocolitis.

Butyrate improves recovery from experimental necrotizing enterocolitis by metabolite hesperetin through potential inhibition the PI3K-Akt pathway

Necrotizing enterocolitis (NEC) is one of the most common and serious intestinal illnesses in newborns and seriously affects their long-term prognosis and survival. Butyrate is a short-chain fatty acid that can relieve intestinal inflammation, but its mechanism of action is unclear. Results from an in vivo neonatal rat model has shown that butyrate caused an improved recovery from NEC. These protective effects were associated with the metabolite of hesperetin, as determined by metabolomics and molecular biological analysis. Furthermore, transcriptomics combined with inhibitor assays were used to investigate the mechanism of action of hesperetin in an in vitro NEC model (IEC-6 cells exposed to LPS) to further investigate the mechanism by which butyrate attenuates NEC. The transcriptomics analysis showed that the PI3K-Akt signaling pathway was involved in the anti-NEC effect of hesperitin. Subsequently, the results using an inhibitor of PI3K (LY294002) indicated that the suppression could be explained by the hesperetin-induced expression of tight junction (TJ) proteins by potentially blocking the PI3K-Akt signaling pathway. In summary, the present study demonstrated that butyrate could improve recovery from NEC with a hesperetin metabolite, causing potential inhibition of the phosphorylation of the PI3K-Akt signaling pathway, resulting in the increased expression of TJ proteins. These findings reveal a potential new therapeutic pathway for the treatment of NEC.

Modification of Experimental Model of Necrotizing Enterocolitis (NEC) in Rat Pups by Single Exposure to Hypothermia and Hypoxia and Impact of Mother's Milk on Incidence of Disease

BACKGROUND Necrotizing enterocolitis (NEC) is a potentially life-threatening disease that affects the intestine of the neonate, causing necrosis and general inflammation. Treatment consists of feeding cessation and antibiotic therapy. In more severe cases, surgical intervention is necessary. Recently, different NEC models have been used to study the development of novel diagnostic and therapeutic methods. This work modified an experimental NEC model in rat pups by a single exposure of animals to NEC-causing factors and testing the impact of mother's milk on prevalence of the disease. MATERIAL AND METHODS Fifty rat pups were subjected to the NEC protocol, in which they were exposed to 100% nitrogen atmosphere and cold stress for set periods of time and formula feeding with exposure to mother's milk and artificial milk. Twenty-nine pups were used for control. After a set time of 72 h, bowel fragments were obtained and examined histologically by hematoxylin-eosin staining with a modified 3-grade scale. RESULTS Histological features of NEC were present in most of the samples (10/14) in the group exposed to 1 min of hypoxia (P=0.016), 10 min of cold stress (P=0.4) and formula feeding every 3 h with no mother's milk (P=0.001). In the group of 11 animals with the same stress conditions but fed mother's milk right after birth, only 1 sample of NEC was present. CONCLUSIONS The modified experimental NEC model based on formula feeding and single exposure to hypothermia and hypoxia was assessed statistically and histologically. In this model, mother's milk had a protective effect against necrotizing enterocolitis.

Comparison of preoperative and intraoperative surgeon diagnosis and pathologic findings in spontaneous intestinal perforation vs necrotizing enterocolitis

OBJECTIVE

To investigate the accuracy of preoperative and intraoperative diagnosis via comparison to pathologic diagnosis in spontaneous intestinal perforation (SIP) vs. necrotizing enterocolitis (NEC).

STUDY DESIGN

A retrospective review of neonates <1500 g treated for pneumoperitoneum between 07/2004-09/2022 was conducted. Patients treated for NEC medically prior to diagnosis and those treated with drain only were excluded. Fleiss' Kappa analysis assessed agreement between all three diagnoses: preoperative, intraoperative, and pathologic.

RESULT

Overall, 125 patients were included with mean birthweight 834.2 g (SD:259.2) and mean gestational age 25.8 weeks (SD:2.2). Preoperative and intraoperative diagnoses agreed in 90.3%, intraoperative and pathologic agreed in 71.1%, and preoperative and pathologic agreed in 75.2% of patients. Fleiss' Kappa was 0.55 (95% CI:0.43,0.68), indicating moderate agreement between the three diagnoses.

CONCLUSION

Our study shows moderate agreement between preoperative, intraoperative, and pathologic diagnoses. Further studies investigating the clinical characteristics of SIP and NEC are needed to improve diagnostic accuracy and management.

A Review of the Use of Extracellular Vesicles in the Treatment of Neonatal Diseases: Current State and Problems with Translation to the Clinic

Neonatal disorders, particularly those resulting from prematurity, pose a major challenge in health care and have a significant impact on infant mortality and long-term child health. The limitations of current therapeutic strategies emphasize the need for innovative treatments. New cell-free technologies utilizing extracellular vesicles (EVs) offer a compelling opportunity for neonatal therapy by harnessing the inherent regenerative capabilities of EVs. These nanoscale particles, secreted by a variety of organisms including animals, bacteria, fungi and plants, contain a repertoire of bioactive molecules with therapeutic potential. This review aims to provide a comprehensive assessment of the therapeutic effects of EVs and mechanistic insights into EVs from stem cells, biological fluids and non-animal sources, with a focus on common neonatal conditions such as hypoxic-ischemic encephalopathy, respiratory distress syndrome, bronchopulmonary dysplasia and necrotizing enterocolitis. This review summarizes evidence for the therapeutic potential of EVs, analyzes evidence of their mechanisms of action and discusses the challenges associated with the implementation of EV-based therapies in neonatal clinical practice.

Necrotizing Enterocolitis in an Infant With a History of Twin-Twin Transfusion Syndrome: A Case Report

This case report describes necrotizing enterocolitis (NEC) in an infant with a history of twin-twin transfusion syndrome (TTTS). TTTS is a volume imbalance where the anastomosis at the vascular equator between the two placentae shifts from the donor to the recipient twin. This causes a higher risk for NEC, a marked inflammation caused by bacterial infection into the intestinal wall, from prematurity and intestinal hypoperfusion. Complications include sepsis, bowel necrosis, perforation, peritonitis, and death. NEC is a leading cause of morbidity in preterm infants. A 3-month-old female with a history of TTTS and prematurity presented with her mother to the pediatric emergency department (ED) for bloody diarrhea, emesis, lack of appetite, and lethargy for 4 days. The pediatrician changed the formula due to a possible milk allergy, however, she continued to have bloody diarrhea. Over the 2 days, the patient had nonbilious and non-bloody emesis and couldn't tolerate oral intake. In the ED, labs showed neutropenia and sepsis. She had a positive fecal occult blood test (FOBT) and an abdominal x-ray that revealed dilated loops of bowel and pneumatosis intestinalis. She was started on intravenous (IV) fluids for maintenance of hydration. She was started on broad-spectrum antibiotics including intravenous (IV) vancomycin and meropenem, and had her feedings temporarily stopped. The patient was transferred to the pediatric intensive care unit (PICU) at a tertiary care/children's hospital that evening where she had a laparotomy performed to resect the diseased intestine. She was discharged 10 days after the surgery for home recovery with clinical follow-up.

Degree of Uncertainty in Reporting Imaging Findings for Necrotizing Enterocolitis: A Secondary Analysis from a Pilot Randomized Diagnostic Trial

Diagnosis of necrotizing enterocolitis (NEC) relies heavily on imaging, but uncertainty in the language used in imaging reports can result in ambiguity, miscommunication, and potential diagnostic errors. To determine the degree of uncertainty in reporting imaging findings for NEC, we conducted a secondary analysis of the data from a previously completed pilot diagnostic randomized controlled trial (2019-2020). The study population comprised sixteen preterm infants with suspected NEC randomized to abdominal radiographs (AXRs) or AXR + bowel ultrasound (BUS). The level of uncertainty was determined using a four-point Likert scale. Overall, we reviewed radiology reports of 113 AXR and 24 BUS from sixteen preterm infants with NEC concern. The BUS reports showed less uncertainty for reporting pneumatosis, portal venous gas, and free air compared to AXR reports (pneumatosis: 1 [1-1.75) vs. 3 [2-3], p < 0.0001; portal venous gas: 1 [1-1] vs. 1 [1-1], p = 0.02; free air: 1 [1-1] vs. 2 [1-3], p < 0.0001). In conclusion, we found that BUS reports have a lower degree of uncertainty in reporting imaging findings of NEC compared to AXR reports. Whether the lower degree of uncertainty of BUS reports positively impacts clinical decision making in infants with possible NEC remains unknown.

Role of innate T cells in necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a destructive gastrointestinal disease primarily affecting preterm babies. Despite advancements in neonatal care, NEC remains a significant cause of morbidity and mortality in neonatal intensive care units worldwide and the etiology of NEC is still unclear. Risk factors for NEC include prematurity, very low birth weight, feeding with formula, intestinal dysbiosis and bacterial infection. A review of the literature would suggest that supplementation of prebiotics and probiotics prevents NEC by altering the immune responses. Innate T cells, a highly conserved subpopulation of T cells that responds quickly to stimulation, develops differently from conventional T cells in neonates. This review aims to provide a succinct overview of innate T cells in neonates, encompassing their phenotypic characteristics, functional roles, likely involvement in the pathogenesis of NEC, and potential therapeutic implications.

Risk factors of necrotizing enterocolitis among neonates admitted to the neonatal intensive care unit at the selected public hospitals in southern Ethiopia, 2023

Introduction

Necrotizing enterocolitis (NEC) is a serious intestinal condition characterized by ischemic necrosis of the intestinal mucosa, inflammation, and invasion by gas-forming organisms, posing a significant threat to neonatal health. Necrotizing enterocolitis remains a significant cause of neonatal morbidity and mortality, particularly in developing countries. Due to limited research conducted in Ethiopia and the study area, there is a lack of information regarding the risk factors associated with necrotizing enterocolitis. Therefore, the goal of this study is to fill the aforementioned gap.

Objective

This study aims to identify the risk factors of necrotizing enterocolitis among neonates admitted to the neonatal intensive care unit (NICU) at selected general and referral hospitals in southern Ethiopia in the year 2023.

Methods and materials

A facility-based unmatched case-control study was conducted. All neonates admitted to the NICU and diagnosed with necrotizing enterocolitis by the attending physician during the data collection period were considered as cases, whereas neonates admitted to the NICU but not diagnosed with necrotizing enterocolitis during the data collection period were considered as controls. Data were collected through face-to-face interviews and record reviews using the Kobo toolbox platform. The binary logistic regression method was used to determine the relationship between a dependent variable and independent variables. Finally, a p-value of < 0.05 was considered statistically significant.

Results

This study included 111 cases and 332 controls. Normal BMI [AOR = 0.11, 95% CI: (0.02, 0.58)], history of khat chewing [AOR = 4.21, 95% CI: (1.96, 9.06)], term gestation [AOR = 0.06, 95% CI: (0.01, 0.18)], history of cigarette smoking [AOR = 2.86, 95% CI: (1.14, 7.14)], length of hospital stay [AOR = 3.3, 95% CI: (1.43, 7.67)], and premature rupture of membrane [AOR = 3.51, 95% CI: (1.77, 6.98)] were significantly associated with NEC.

Conclusion

The study identified several risk factors for necrotizing enterocolitis, including body mass index, history of khat chewing, gestational age, history of cigarette smoking, length of hospital stays, and premature rupture of membrane. Therefore, healthcare providers should be aware of these risk factors to identify newborns at high risk and implement preventive measures.

Gestational age-specific hematological features in preterm infants with necrotizing enterocolitis

BACKGROUND

This study aimed to investigate gestational age-specific hematological features in preterm infants with necrotizing enterocolitis (NEC) and identify predictive hematological biomarkers for surgical NEC.

METHODS

We conducted a retrospective study comparing gestational age (GA)-specific clinical data between medical NEC (m-NEC) and surgical NEC (s-NEC) subgroups, stratified by GA as <28 weeks, 28 ≤ GA < 32 weeks, and 32 ≤ GA < 37 weeks. Multivariate logistic analysis and receiver operating characteristic curve were used to identify the independent predictors of s-NEC.

RESULTS

In comparison to m-NEC at NEC onset, s-NEC infants exhibited the following findings: In GA < 28 weeks, s-NEC infants had lower platelet counts. In 28 ≤ GA < 32 weeks, lower absolute lymphocyte counts, and significant percent drop in platelets, lymphocytes, and monocytes were observed. In 32 ≤ GA < 37 weeks, lower absolute lymphocyte counts and significant percent drop in lymphocytes were found. Independent predictors were able to distinguish s-NEC from m-NEC. The area under the curve (AUC) for platelet counts in GA < 28 weeks was 0.880, while C-reactive protein in 28 ≤ GA < 32 weeks had an AUC of 0.889. The AUC for lymphocyte counts in 32 ≤ GA < 37 weeks was 0.892.

CONCLUSION

This study identified hematological abnormalities in the development of NEC based on gestational age. Independent predictors may help clinicians distinguish surgical NEC from medical NEC.

IMPACT

Necrotizing enterocolitis (NEC) patients with different gestational ages (GA) exhibit different hematological features and independent predictors of surgical NEC differ among different GAs. Our research made the current studies about peripheral hematological features with NEC more complete by analyzing peripheral data collected within 24 h of birth, at day 5-7, day 3-4, day 1-2 before NEC onset, at the time of NEC onset, day 1, day 2, day 3, day 4-5, day 6-7 after NEC onset. Our study is helpful to clinicians in developing a more detailed diagnostic strategy based on GA for the early identification of surgical NEC.

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.

Clinical Dilemma Involving Treatments for Very Low-Birth-Weight Infants and the Potential Risk of Necrotizing Enterocolitis: A Narrative Literature Review

Necrotizing enterocolitis (NEC) is a critical gastrointestinal emergency with substantial morbidity and mortality risks, especially for very low-birth-weight (VLBW) infants, and unclear multifactorial pathophysiology. Whether common treatments for VLBW infants increase the NEC risk remains controversial. Indomethacin (utilized for patent ductus arteriosus) offers benefits but is concerning because of its vasoconstrictive impact on NEC susceptibility. Similarly, corticosteroids used to treat bronchopulmonary dysplasia may increase vulnerability to NEC by compromising immunity and altering the mesenteric blood flow. Histamine-2 receptor blockers (used to treat gastric bleeding) may inadvertently promote NEC by affecting bacterial colonization and translocation. Doxapram (used to treat apnea) poses a risk of gastrointestinal disturbance via gastric acid hypersecretion and circulatory changes. Glycerin enemas aid meconium evacuation but disrupt microbial equilibrium and trigger stress-related effects associated with the NEC risk. Prolonged antibiotic use may unintentionally increase the NEC risk. Blood transfusions for anemia can promote NEC via interactions between the immune response and ischemia-reperfusion injury. Probiotics for NEC prevention are associated with concerns regarding sepsis and bacteremia. Amid conflicting evidence, this review unveils NEC risk factors related to treatments for VLBW infants, offers a comprehensive overview of the current research, and guides personalized management strategies, thereby elucidating this clinical dilemma.

Twinning as a risk factor for neonatal acute intestinal diseases: a case-control study

Introduction

Acute intestinal diseases (AID), including necrotizing enterocolitis and spontaneous intestinal perforation, are a group of conditions that typically present in preterm infants, and are associated with an elevated mortality and morbidity rate. The risk factors for these diseases remain largely unknown. The aim of the study is to identify the correlation between twinning and the development of AID.

Methods

A single-center retrospective case-control study was conducted. We recruited all infants with a diagnosis of AID, confirmed by anatomopathology, recovered in NICU between 2010 and 2020. Considering the rarity of the outcome, 4 matched controls for each subject were randomly chosen from the overall population of newborns. Odds Ratio (OR) and 95% Confidence Interval (CI) were calculated using a conditional logistic regression model and a multivariate model by the creation of a Directed Acyclic Graph (www.dagitty.net).

Results

The study population resulted in 65 cases and 260 controls. The two groups present similar median gestational age and mean birthweight in grams. The cases have a higher frequency of neonatal pathology (defined as at least one of patent ductus arteriosus, early or late sepsis, severe respiratory distress) (84.6% vs. 51.9%), medically assisted procreation (33.8% vs. 18.8%) and periventricular leukomalacia (10.8% vs. 2.7%), and a lower frequency of steroids prophylaxis (67.7% vs. 86.9%). About 50% of cases needed surgery. The OR for the direct effect were difference from one using logistic regression booth without and with repeated measures statements: from 1.14 to 4.21 (p = .019) and from 1.16 to 4.29 (p = .016), respectively.

Conclusions

Our study suggests that twinning may be a risk factor for the development of AID. Due to the small number of cases observed, further studies on larger populations are needed.

The incidence and modifiable risk factors for necrotizing enterocolitis in preterm infants: a retrospective cohort study

OBJECTIVES

To evaluate the incidence and modifiable risk factors for Necrotizing enterocolitis (NEC) in preterm infants born at ≤32 weeks of gestation weighing <1500 grams, at a private tertiary care hospital in Kenya.

MATERIALS AND METHODS

This retrospective cohort study was conducted at the Aga Khan University Hospital Neonatal Intensive Care Unit (NICU). Preterm infants born at ≤ 32 weeks' gestation and weighing <1500 grams admitted to NICU between 2009 and 2019, were recruited into the study. The primary outcome was NEC Bell Stage IIa-IIIb based on Modified Bell's criteria. Maternal and neonatal characteristics were evaluated. The association between variables of interest and NEC was determined using logistic regression analysis and the incidence of NEC for the study period was calculated.

RESULTS

A total of 261 charts of infants born at ≤ 32 weeks' gestation, weighing <1500 were reviewed, and 200 charts met the inclusion criteria. Fifteen preterm infants developed the primary outcome of interest: NEC Stage ≥2a within the first 30 days of admission. The overall incidence of NEC for the study period was 7.5%. Three risk factors were identified as significantly associated with NEC on multivariate logistic regression analysis: antenatal exposure to steroids (OR = 0.056 CI = 0.003-0.964 p = 0.047), cumulative duration of exposure to invasive mechanical ventilation (OR = 2.172 CI = 1.242-3.799 p = 0.007) and cumulative duration of exposure to umbilical vein catheter (OR = 1.344 CI = 1.08-1.672 p = 0.008).

CONCLUSIONS

The overall incidence for the study period of NEC Stage ≥ II a was 7.5%. Exposure to antenatal steroids, duration of mechanical ventilation, and duration of umbilical vein catheterization were three independent modifiable risk factors for NEC Stage II a-Stage III b.

Hydrogen Sulfide Improves Outcomes in a Murine Model of Necrotizing Enterocolitis via the Cys440 Residue on Endothelial Nitric Oxide Synthase

BACKGROUND

Hydrogen sulfide (H2S) has been shown to improve outcomes in a murine model of necrotizing enterocolitis (NEC). There is evidence in humans that H2S relies on endothelial nitric oxide synthase (eNOS) to exert its protective effects, potentially through the persulfidation of eNOS at the Cysteine 443 residue. We obtained a novel mouse strain with a mutation at this residue (eNOSC440G) and hypothesized that this locus would be critical for GYY4137 (an H2S donor) to exert its protective effects.

METHODS

Necrotizing enterocolitis was induced in 5-day old wild type (WT) and eNOSC440G mice using intermittent exposure to hypoxia and hypothermia in addition to gavage formula feeds. On postnatal day 9, mice were humanely euthanized. Data collected included daily weights, clinical sickness scores, histologic lung injury, intestinal injury (macroscopically and histologically), and intestinal perfusion. During the NEC model, pups received daily intraperitoneal injections of either GYY4137 (50 mg/kg) or PBS (vehicle). Data were tested for normality and compared using t-test or Mann-Whitney, and a p-value <0.05 was considered significant.

RESULTS

In WT mice, the administration of GYY4137 significantly improved clinical sickness scores, attenuated intestinal and lung injury, and improved mesenteric perfusion compared to vehicle (p < 0.05). In eNOSC440G mice, the treatment and vehicle groups had similar clinical sickness scores, intestinal and lung injury scores, and intestinal perfusion.

CONCLUSIONS

GYY4137 administration improves clinical outcomes, attenuates intestinal and lung injury, and improves perfusion in a murine model of necrotizing enterocolitis. The beneficial effects of GYY4137 are dependent on the Cys440 residue of eNOS.

Effective alternatives for dietary interventions for necrotizing enterocolitis: a systematic review of in vivo studies

Necrotizing enterocolitis (NEC) is a significant cause of morbidity and mortality among neonates and low birth weight children in the United States. Current treatment options, such as antibiotics and intestinal resections, often result in complications related to pediatric nutrition and development. This systematic review aimed to identify alternative dietary bioactive compounds that have shown promising outcomes in ameliorating NEC in vivo studies conducted within the past six years. Following PRISMA guidelines and registering in PROSPERO (CRD42023330617), we conducted a comprehensive search of PubMed, Scopus, and Web of Science. Our analysis included 19 studies, predominantly involving in vivo models of rats (Rattus norvegicus) and mice (Mus musculus). The findings revealed that various types of compounds have demonstrated successful amelioration of NEC symptoms. Specifically, six studies employed plant phenolics, seven utilized plant metabolites/cytotoxic chemicals, three explored the efficacy of vitamins, and three investigated the potential of whole food extracts. Importantly, all administered compounds exhibited positive effects in mitigating the disease. These results highlight the potential of natural cytotoxic chemicals derived from medicinal plants in identifying and implementing powerful alternative drugs and therapies for NEC. Such approaches have the capacity to impact multiple pathways involved in the development and progression of NEC symptoms.

Exploring the links between necrotizing enterocolitis and cow's milk protein allergy in preterm infants: a narrative review

A broad range of allergic disorders and intolerance are associated with cow's milk protein in the infant diet. Allergy and intolerance to cow's milk proteins are commonly recognized in the healthy term infant, and the prevalence cow's milk protein intolerance (CMPI) varies widely but 5 challenge confirmed studies free from selection bias ranged from 1.9%-4.9%. These disorders are classified by the presence of IgE, non-IgE or T-cell-mediated signaling. Additionally, the severity of these adverse food reactions can range from mild gastrointestinal symptoms to severe sepsis-like episodes, as in the case of food protein-induced enterocolitis syndrome (FPIES). Food protein-induced intolerance in the healthy young infant lies in stark contrast to enterocolitis that typically occurs in the preterm neonate. Necrotizing enterocolitis (NEC) is a distinct progressive disease process, usually characterized by a high mortality rate, with a risk of death from 30% to 50%. While its exact etiology is unclear, its main triggers include formula (cow's milk protein), hypoxia, perfusion-related issues, and unregulated inflammation in the premature intestine. The distinction between NEC and cow's milk protein intolerance is difficult to discern in some cases. In the late preterm population, infants with colitis can have both NEC and cow's milk intolerance on the differential. In infants with multiple episodes of mild NEC, cow's milk protein intolerance may be the underlying diagnosis. In this review, we compare the pathophysiological characteristics, diagnosis and treatment of disorders of cow's milk protein intolerance with the entity of preterm NEC. This review highlights similarities in both entities and may inspire future cross-disciplinary research.

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.

Protective Effect of the SIRT1-Mediated NF-κB Signaling Pathway against Necrotizing Enterocolitis in Neonatal Mice

OBJECTIVE

 To discover the mechanism of the sirtuin 1 (SIRT1)-mediated nuclear factor-κB (NF-κB) pathway in the protection against necrotizing enterocolitis (NEC) in neonatal mice.

MATERIALS AND METHODS

 Neonatal mice were treated with EX527 (an inhibitor of SIRT1) and/or pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB). The survival rate of the mice was recorded. Hematoxylin and eosin (HE) staining was performed to observe the pathological changes in the intestines. Furthermore, western blotting, enzyme-linked immunosorbent assay, and real-time quantitative polymerase chain reaction were conducted to measure the protein and gene expression, while corresponding kits were used to detect the levels of oxidative stress indicators.

RESULTS

 PDTC increased the survival rate of NEC mice. When compared with the NEC+ EX527 + PDTC group, the histological NEC score was higher in the NEC + EX527 group but lower in the NEC + PDTC group. SIRT1 expression in the intestines of NEC mice was downregulated, with an increase in p65 nuclear translocation. Additionally, malondialdehyde increased and glutathione peroxidase decreased in the intestines of NEC mice, with the upregulation of interleukin (IL)-6, IL-1β, and tumor necrosis factor-α, as well as the downregulation of ZO-1, occludin, and claudin-4 in the intestines. However, the above changes could be improved by PDTC, which could be further reversed by EX527.

CONCLUSION

 SIRT1 can mitigate inflammation and the oxidative stress response and improve intestinal permeability by mediating the NF-κB pathway, playing an important role in the alleviation of NEC.

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.

Fecal calprotectin as a non-invasive marker for the prediction of post-necrotizing enterocolitis stricture

PURPOSE

This study aimed to evaluate the clinical utility of fecal calprotectin (FC) levels during the necrotizing enterocolitis (NEC) episode to predict the onset of post-NEC intestinal stricture.

METHODS

The medical records of patients with NEC treated from April 2020 to April 2022 were recorded for this study. FC was quantified at the acute phase of NEC. FC levels were compared in patients with or without intestinal stricture. Receiver operating characteristics (ROC) analysis was constructed to determine optimal cut-offs of FC for post-NEC intestinal stricture.

RESULTS

A total of 50 infants with NEC were enrolled in this study and 14 (28%) of them eventually developed intestinal stricture. All children with intestinal stricture underwent one-stage surgery and all made it through the follow-up period alive. The median FC level was 1237.55 (741.25, 1378.80) ug/g in patients with intestinal stricture and it was significantly higher than that in the non-stricture group [158.30 (76.23, 349.13) ug/g, P < 0.001]. FC had good diagnostic accuracy for predicting intestinal stricture, according to ROC curve analysis, with an AUC area of 0.911. At an optimal cut-off value of 664.2 ug/g, sensitivity and specificity were 85.71% and 91.67%, respectively.

CONCLUSION

As a non-invasive parameter, FC has excellent efficacy and accuracy in predicting post-NEC intestinal stricture. Increased FC levels at the acute phase of NEC were associated with the development of intestinal stricture.

Inhaled Nitric Oxide and Higher Necrotizing Enterocolitis Rates in Congenital Heart Disease Patients

INTRODUCTION

Certain congenital cardiac lesions are at increased risk for the development of necrotizing enterocolitis (NEC). These patients are often reliant on pulmonary and systemic vasomodulators to maintain adequate perfusion and oxygenation. This study sought to determine whether pulmonary or systemic vasodilator treatment is protective against the development of NEC in this population.

METHODS

We utilized International Classification of Diseases (ICD) codes to identify high risk congenital cardiac disease patients ≤6 mo of age, cared for at a tertiary children's hospital between January 2011 and January 2021. Cardiac anomalies were stratified into ductal dependent (pulmonary DD-P or systemic DD-S) or independent lesions. The rate of NEC development in those who received vasodilators (inhaled nitric oxide [iNO], pulmonary vasodilators, systemic vasodilators) was compared to controls in a multivariate analysis.

RESULTS

Of the 352 patients, who met inclusion criteria, 77.6% had ductal dependent lesions (DD-S 41.9%, DD-P 35.7%), 19.5% received iNO, and 37.5% received other vasodilatory drugs. The overall NEC rate was 15.1%. On univariate analysis, DD-S, iNO use, and systemic vasodilators was associated with a significantly higher risk of NEC, while DD-P was associated with lower NEC risk. On multivariate analysis, only iNO (odds ratio 2.725, confidence interval [1.36-5.44]) and DD-S (odds ratio 2.279, confidence interval [1.02-5.11]) were independent risk factors for NEC.

CONCLUSIONS

In patients with at-risk congenital cardiac disease lesions, a ductus dependent systemic circulation or iNO treatment is associated with an increased risk of developing NEC. The presence of iNO or DD-S should be utilized as markers of increased risk both in the prevention and workup of suspected NEC.

Bovine milk-derived exosomes attenuate NLRP3 inflammasome and NF-κB signaling in the lung during neonatal necrotizing enterocolitis

PURPOSE

Necrotizing enterocolitis (NEC), an inflammatory intestinal disease common in premature infants, has been associated with the development of lung damage. Toll-like receptor 4 has been shown to regulate inflammation in the NEC lungs, however, other important inflammatory mechanisms have not been thoroughly investigated. In addition, we reported that milk-derived exosomes were able to attenuate intestinal injury and inflammation in experimental NEC. This study aims to (i) investigate the role of the NLRP3 inflammasome and NF-κB pathway in regulating lung damage during experimental NEC; and (ii) evaluate the therapeutic potential of bovine milk exosomes in reducing lung inflammation and injury during NEC.

METHODS

NEC was induced by gavage feeding of hyperosmolar formula, hypoxia, and lipopolysaccharide administration in neonatal mice from postnatal days 5-9. Exosomes were obtained by ultracentrifugation of bovine milk and administered during each formula feed.

RESULTS

The lung of NEC pups showed increased inflammation, tissue damage, NLRP3 inflammasome expression, and NF-κB pathway activation, which were attenuated upon exosome administration.

CONCLUSION

Our findings suggest that the lung undergoes significant inflammation and injury following experimental NEC which are attenuated by bovine milk-derived exosomes. This emphasizes the therapeutic potential of exosomes not just on the intestine but also on the lung.

Remote ischemic conditioning in necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a devastating intestinal inflammatory disorder, most prevalent in premature infants, and associated with a high mortality rate that has remained unchanged in the past two decades. NEC is characterized by inflammation, ischemia, and impaired microcirculation in the intestine. Preclinical studies by our group have led to the discovery of remote ischemic conditioning (RIC) as a promising non-invasive intervention in protecting the intestine against ischemia-induced damage during early-stage NEC. RIC involves the administration of brief reversible cycles of ischemia and reperfusion in a limb (similar to taking standard blood pressure measurement) which activate endogenous protective signaling pathways that are conveyed to distant organs such as the intestine. RIC targets the intestinal microcirculation and by improving blood flow to the intestine, reduces the intestinal damage of experimental NEC and prolongs survival. A recent Phase I safety study by our group demonstrated that RIC was safe in preterm infants with NEC. A phase II feasibility randomized controlled trial involving 12 centers in 6 countries is currently underway, to investigate the feasibility of RIC as a treatment for early-stage NEC in preterm neonates. This review provides a brief background on RIC as a therapeutic strategy and summarizes the progression of RIC as a treatment for NEC from preclinical investigation to clinical evaluation.

The contributions of parental lactation on offspring development: It's not udder nonsense!

The Developmental Origins of Health and Disease (DOHaD) hypothesis describes how maternal stress exposures experienced during critical periods of perinatal life are linked to altered developmental trajectories in offspring. Perinatal stress also induces changes in lactogenesis, milk volume, maternal care, and the nutritive and non-nutritive components of milk, affecting short and long-term developmental outcomes in offspring. For instance, selective early life stressors shape the contents of milk, including macro/micronutrients, immune components, microbiota, enzymes, hormones, milk-derived extracellular vesicles, and milk microRNAs. In this review, we highlight the contributions of parental lactation to offspring development by examining changes in the composition of breast milk in response to three well-characterized maternal stressors: nutritive stress, immune stress, and psychological stress. We discuss recent findings in human, animal, and in vitro models, their clinical relevance, study limitations, and potential therapeutic significance to improving human health and infant survival. We also discuss the benefits of enrichment methods and support tools that can be used to improve milk quality and volume as well as related developmental outcomes in offspring. Lastly, we use evidence-based primary literature to convey that even though select maternal stressors may modulate lactation biology (by influencing milk composition) depending on the severity and length of exposure, exclusive and/or prolonged milk feeding may attenuate the negative in utero effects of early life stressors and promote healthy developmental trajectories. Overall, scientific evidence supports lactation to be protective against nutritive and immune stressors, but the benefits of lactation in response to psychological stressors need further investigation.

Necrotizing enterocolitis: recent advances in treatment with translational potential

Necrotizing enterocolitis (NEC) is one of the most prevalent and devastating gastrointestinal disorders in neonates. Despite advances in neonatal care, the incidence and mortality due to NEC remain high, highlighting the need to devise novel treatments for this disease. There have been a number of recent advancements in therapeutic approaches for the treatment of NEC; these involve remote ischemic conditioning (RIC), stem cell therapy, breast milk components (human milk oligosaccharides, exosomes, lactoferrin), fecal microbiota transplantation, and immunotherapy. This review summarizes the most recent advances in NEC treatment currently underway as well as their applicability and associated challenges and limitations, with the aim to provide new insight into the paradigm of care for NEC worldwide.

Human Bone Marrow-Derived Mesenchymal Stromal Cells Reduce the Severity of Experimental Necrotizing Enterocolitis in a Concentration-Dependent Manner

Necrotizing enterocolitis (NEC) is a devastating gut disease in preterm neonates. In NEC animal models, mesenchymal stromal cells (MSCs) administration has reduced the incidence and severity of NEC. We developed and characterized a novel mouse model of NEC to evaluate the effect of human bone marrow-derived MSCs (hBM-MSCs) in tissue regeneration and epithelial gut repair. NEC was induced in C57BL/6 mouse pups at postnatal days (PND) 3-6 by (A) gavage feeding term infant formula, (B) hypoxia/hypothermia, and (C) lipopolysaccharide. Intraperitoneal injections of PBS or two hBM-MSCs doses (0.5 × 10⁶ or 1 × 10⁶) were given on PND2. At PND 6, we harvested intestine samples from all groups. The NEC group showed an incidence of NEC of 50% compared with controls (p < 0.001). Severity of bowel damage was reduced by hBM-MSCs compared to the PBS-treated NEC group in a concentration-dependent manner, with hBM-MSCs (1 × 10⁶) inducing a NEC incidence reduction of up to 0% (p < 0.001). We showed that hBM-MSCs enhanced intestinal cell survival, preserving intestinal barrier integrity and decreasing mucosal inflammation and apoptosis. In conclusion, we established a novel NEC animal model and demonstrated that hBM-MSCs administration reduced the NEC incidence and severity in a concentration-dependent manner, enhancing intestinal barrier integrity.

Necrotizing enterocolitis in premature infants-A defect in the brakes? Evidence from clinical and animal studies

A key aspect of postnatal intestinal adaptation is the establishment of symbiotic relationships with co-evolved gut microbiota. Necrotizing enterocolitis (NEC) is the most severe disease arising from failure in postnatal gut adaptation in premature infants. Although pathological activation of intestinal Toll-like receptors (TLRs) is believed to underpin NEC pathogenesis, the mechanisms are incompletely understood. We postulate that unregulated aberrant TLR activation in NEC arises from a failure in intestinal-specific mechanisms that tamponade TLR signaling (the brakes). In this review, we discussed the human and animal studies that elucidate the developmental mechanisms inhibiting TLR signaling in the postnatal intestine (establishing the brakes). We then evaluate evidence from preclinical models and human studies that point to a defect in the inhibition of TLR signaling underlying NEC. Finally, we provided a framework for the assessment of NEC risk by screening for signatures of TLR signaling and for NEC prevention by TLR-targeted therapy in premature infants.

Epigenetic Immune Cell Counting to Analyze Potential Biomarkers in Preterm Infants: A Proof of Principle in Necrotizing Enterocolitis

Epigenetic immune cell counting is a DNA (de)methylation-based technique which can be used to quantify lymphocyte subsets on dried blood spots (DBS). The foregoing techniques allow for a retrospective investigation of immune cell profiles in newborns. In this study, we used this technique for determining lymphocyte subcounts as a potential biomarker for necrotizing enterocolitis (NEC). We investigated whether this technique can be implemented in the field of neonatology, by testing whether regulatory T cell (Treg) levels are pre-existently low in preterms with NEC. Newborn screening (NBS) cards from 32 preterms with NEC and 32 age- and weight-matched preterm controls, and 60 healthy term newborns, were analyzed. Relative and absolute cell counts were determined for CD3+, CD4+, CD8+, Th17, and Treg T cells. For both relative and absolute cell counts of CD3+, CD4+, CD8+, and Th17 T cells, significant differences were found between healthy term controls and both preterm groups, but not between preterm groups. For Tregs, no significant differences were found in either relative or absolute counts between any of the newborn groups. This study demonstrates the principle of epigenetic immune cell counting to analyze lymphocyte subsets in preterm neonates.

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.

Review of Necrotizing Enterocolitis and Spontaneous Intestinal Perforation Clinical Presentation, Treatment, and Outcomes

The Necrotizing Enterocolitis Surgery Trial (NEST) highlights the importance of distinguishing necrotizing enterocolitis (NEC) from spontaneous intestinal perforation (SIP) when developing surgical treatment plans. Further research is needed to increase the accuracy of this distinction, but even with our current abilities to do this initial laparotomy appears to be optimal for infants with presumed NEC. The preferred initial operation for those with SIP is more equivocal. Rates of NEC are likely decreasing slowly, whereas those with SIP are not. New imaging modalities, especially ultrasound, are becoming more useful but require more detailed investigation. Understanding the mechanisms causing these two conditions remains of paramount importance.

Intestinal atresia and necrotizing enterocolitis: Embryology and anatomy

The primitive gut originates at week 3 of gestation from the endoderm, with posterior incorporation of the remaining embryo layers. Wnt, Notch and TLR4 pathways have been shown to play central roles in the correct development of the intestine. The classical hypothesis for intestinal atresia development consists of failure in bowel recanalization or a vascular accident with secondary bowel reabsorption. These have been challenged due to the high frequency of associated malformations, and furthermore, with the discovery of molecular pathways and genes involved in bowel formation and correlated defects producing atresia. Necrotizing enterocolitis (NEC) has a multifactorial pathogenesis with prematurity being the most important risk factor; therefore, bowel immaturity plays a central role in NEC. Some of the same molecular pathways involved in gut maturation have been found to correlate with the predisposition of the immature bowel to develop the pathological findings seen in NEC.

Intra-Amniotic Administration-An Emerging Method to Investigate Necrotizing Enterocolitis, In Vivo (Gallus gallus)

Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease in premature infants and a leading cause of death in neonates (1-7% in the US). NEC is caused by opportunistic bacteria, which cause gut dysbiosis and inflammation and ultimately result in intestinal necrosis. Previous studies have utilized the rodent and pig models to mimic NEC, whereas the current study uses the in vivo (Gallus gallus) intra-amniotic administration approach to investigate NEC. On incubation day 17, broiler chicken (Gallus gallus) viable embryos were injected intra-amniotically with 1 mL dextran sodium sulfate (DSS) in H₂O. Four treatment groups (0.1%, 0.25%, 0.5%, and 0.75% DSS) and two controls (H₂O/non-injected controls) were administered. We observed a significant increase in intestinal permeability and negative intestinal morphological changes, specifically, decreased villus surface area and goblet cell diameter in the 0.50% and 0.75% DSS groups. Furthermore, there was a significant increase in pathogenic bacterial (E. coli spp. and Klebsiella spp.) abundances in the 0.75% DSS group compared to the control groups, demonstrating cecal microbiota dysbiosis. These results demonstrate significant physiopathology of NEC and negative bacterial-host interactions within a premature gastrointestinal system. Our present study demonstrates a novel model of NEC through intra-amniotic administration to study the effects of NEC on intestinal functionality, morphology, and gut microbiota in vivo.

Bermúdez M, Campoy C. Impact of Total Parenteral Nutrition on Gut Microbiota in Pediatric Population Suffering Intestinal Disorders

Parenteral nutrition (PN) is a life-saving therapy providing nutritional support in patients with digestive tract complications, particularly in preterm neonates due to their gut immaturity during the first postnatal weeks. Despite this, PN can also result in several gastrointestinal complications that are the cause or consequence of gut mucosal atrophy and gut microbiota dysbiosis, which may further aggravate gastrointestinal disorders. Consequently, the use of PN presents many unique challenges, notably in terms of the potential role of the gut microbiota on the functional and clinical outcomes associated with the long-term use of PN. In this review, we synthesize the current evidence on the effects of PN on gut microbiome in infants and children suffering from diverse gastrointestinal diseases, including necrotizing enterocolitis (NEC), short bowel syndrome (SBS) and subsequent intestinal failure, liver disease and inflammatory bowel disease (IBD). Moreover, we discuss the potential use of pre-, pro- and/or synbiotics as promising therapeutic strategies to reduce the risk of severe gastrointestinal disorders and mortality. The findings discussed here highlight the need for more well-designed studies, and harmonize the methods and its interpretation, which are critical to better understand the role of the gut microbiota in PN-related diseases and the development of efficient and personalized approaches based on pro- and/or prebiotics.

Microbial regulation of offspring diseases mediated by maternal-associated microbial metabolites

The microbiota plays a crucial role in individuals’ early and long-term health. Previous studies indicated that the microbial regulation of health may start before birth. As the in utero environment is (nearly) sterile, the regulation is probably be originated from maternal microbiota and mediated by their metabolites transferred across the placenta. After the birth, various metabolites are continuously delivered to offspring through human milk feeding. Meanwhile, some components, for example, human milk oligosaccharides, in human milk can only be fermented by microbes, which brings beneficial effects on offspring health. Hence, we speculated that human milk-derived metabolites may also play roles in microbial regulation. However, reports between maternal-associated microbial metabolites and offspring diseases are still lacking and sparsely distributed in several fields. Also, the definition of the maternal-associated microbial metabolite is still unclear. Thus, it would be beneficial to comb through the current knowledge of these metabolites related to diseases for assisting our goals of early prediction, early diagnosis, early prevention, or early treatment through actions only on mothers. Therefore, this review aims to present studies showing how researchers came to the path of investigating these metabolites and then to present studies linking them to the development of offspring asthma, type 1 diabetes mellitus, food allergy, neonatal necrotizing enterocolitis, or autism spectrum disorder. Potential English articles were collected from PubMed by searching terms of disease(s), maternal, and a list of microbial metabolites. Articles published within 5 years were preferred.

Selective targeting of MD2 attenuates intestinal inflammation and prevents neonatal necrotizing enterocolitis by suppressing TLR4 signaling

Neonatal necrotizing enterocolitis (NEC) is an inflammatory disease that occurs in premature infants and has a high mortality rate; however, the mechanisms behind this disease remain unclear. The TLR4 signaling pathway in intestinal epithelial cells, mediated by TLR4, is important for the activation of the inflammatory storm in NEC infants. Myeloid differentiation protein 2 (MD2) is a key auxiliary component of the TLR4 signaling pathway. In this study, MD2 was found to be significantly increased in intestinal tissues of NEC patients at the acute stage. We further confirmed that MD2 was upregulated in NEC rats. MD2 inhibitor (MI) pretreatment reduced the occurrence and severity of NEC in neonatal rats, inhibited the activation of NF-κB and the release of inflammatory molecules (TNF-α and IL-6), and reduced the severity of intestinal injury. MI pretreatment significantly reduced enterocyte apoptosis while also maintaining tight junction proteins, including occludin and claudin-1, and protecting intestinal mucosal permeability in NEC rats. In addition, an NEC in vitro model was established by stimulating IEC-6 enterocytes with LPS. MD2 overexpression in IEC-6 enterocytes significantly activated NF-κB. Further, both MD2 silencing and MI pretreatment inhibited the inflammatory response. Overexpression of MD2 increased damage to the IEC-6 monolayer cell barrier, while both MD2 silencing and MI pretreatment played a protective role. In conclusion, MD2 triggers an inflammatory response through the TLR4 signaling pathway, leading to intestinal mucosal injury in NEC. In addition, MI alleviates inflammation and reduces intestinal mucosal injury caused by the inflammatory response by blocking the TLR4-MD2/NF-κB signaling axis. These results suggest that inhibiting MD2 may be an important way to prevent NEC.

Peptide Tat(48-60) YVEEL protects against necrotizing enterocolitis through inhibition of toll-like receptor 4-mediated signaling in a phosphatidylinositol 3-kinase/AKT dependent manner

Necrotizing enterocolitis (NEC) is a catastrophic disease largely occurring in preterm infants, and toll-like receptor 4 (TLR4) has been implicated in its pathogenesis. The current therapeutic strategies for NEC are, however, far from optimal. In the present study, a whey-derived antioxidative peptide conjugated with a cell-penetrating TAT [^{Tat (48-60)} YVEEL] was prepared to endow it with enhanced cell uptake capability and bioavailability. The protective effect of ^{Tat (48-60)} YVEEL on experimental NEC was evaluated both in vitro and in vivo. Inhibition of TLR4-mediated signaling by ^{Tat (48-60)} YVEEL was assessed in FHC and IEC-6 enterocytes, neonatal rat model of NEC, and the mechanism underlying this effect was determined. ^{Tat (48-60)} YVEEL significantly inhibited TLR4-mediated expression of pro-inflammatory cytokines, p65 nuclear translocation and restored the impaired enterocyte migration in cultured enterocytes. In addition, ^{Tat (48-60)} YVEEL administration strikingly increased the survival rate, and reduced the severity of NEC in rats through inhibition of TLR4-mediated signaling. These protective effects of ^{Tat (48-60)} YVEEL occurred in a PI3K/AKT dependent manner, as administration of PI3K activator Ys49 abrogated its protective effects. Combined with liposomes, ^{Tat (48-60)} YVEEL demonstrated longer retention in the intestines that better for potential clinical applications. These data demonstrate that ^{Tat (48-60)} YVEEL protects against NEC through inhibition of TLR4-mediated signaling in a PI3K/AKT dependent manner, and offer a potential therapeutic approach to this disease.

Proteomics Profiling of Stool Samples from Preterm Neonates with SWATH/DIA Mass Spectrometry for Predicting Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a life-threatening condition for premature infants in neonatal intensive care units. Finding indicators that can predict NEC development before symptoms appear would provide more time to apply targeted interventions. In this study, stools from 132 very-low-birth-weight (VLBW) infants were collected daily in the context of a multi-center prospective study aimed at investigating the potential of fecal biomarkers for NEC prediction using proteomics technology. Eight of the VLBW infants received a stage-3 NEC diagnosis. Stools collected from the NEC infants up to 10 days before their diagnosis were available for seven of them. Their samples were matched with those from seven pairs of non-NEC controls. The samples were processed for liquid chromatography-tandem mass spectrometry analysis using SWATH/DIA acquisition and cross-compatible proteomic software to perform label-free quantification. ROC curve and principal component analyses were used to explore discriminating information and to evaluate candidate protein markers. A series of 36 proteins showed the most efficient capacity with a signature that predicted all seven NEC infants at least a week in advance. Overall, our study demonstrates that multiplexed proteomic signature detection constitutes a promising approach for the early detection of NEC development in premature infants.

In vivo phenotyping of the microvasculature in necrotizing enterocolitis with multicontrast optical imaging

OBJECTIVE

Necrotizing enterocolitis (NEC) is the most prevalent gastrointestinal emergency in premature infants and is characterized by a dysfunctional gut microcirculation. Therefore, there is a dire need for in vivo methods to characterize NEC-induced changes in the structure and function of the gut microcirculation, that is, its vascular phenotype. Since in vivo gut imaging methods are often slow and employ a single-contrast mechanism, we developed a rapid multicontrast imaging technique and a novel analyses pipeline for phenotyping the gut microcirculation.

METHODS

Using an experimental NEC model, we acquired in vivo images of the gut microvasculature and blood flow over a 5000 × 7000 μm² field of view at 5 μm resolution via the following two endogenous contrast mechanisms: intrinsic optical signals and laser speckles. Next, we transformed intestinal images into rectilinear "flat maps," and delineated 1A/V gut microvessels and their perfusion territories as "intestinal vascular units" (IVUs). Employing IVUs, we quantified and visualized NEC-induced changes to the gut vascular phenotype.

RESULTS

In vivo imaging required 60-100 s per animal. Relative to the healthy gut, NEC intestines showed a significant overall decrease (i.e. 64-72%) in perfusion, accompanied by vasoconstriction (i.e. 9-12%) and a reduction in perfusion entropy (19%)within sections of the vascular bed.

CONCLUSIONS

Multicontrast imaging coupled with IVU-based in vivo vascular phenotyping is a powerful new tool for elucidating NEC pathogenesis.

The administration of a pre-digested fat-enriched formula prevents necrotising enterocolitis-induced lung injury in mice

Necrotising enterocolitis (NEC) is a devastating gastrointestinal disease of prematurity that typically develops after the administration of infant formula, suggesting a link between nutritional components and disease development. One of the most significant complications that develops in patients with NEC is severe lung injury. We have previously shown that the administration of a nutritional formula that is enriched in pre-digested Triacylglyceride that do not require lipase action can significantly reduce the severity of NEC in a mouse model. We now hypothesise that this 'pre-digested fat (PDF) system' may reduce NEC-associated lung injury. In support of this hypothesis, we now show that rearing newborn mice on a nutritional formula based on the 'PDF system' promotes lung development, as evidenced by increased tight junctions and surfactant protein expression. Mice that were administered this 'PDF system' were significantly less vulnerable to the development of NEC-induced lung inflammation, and the administration of the 'PDF system' conferred lung protection. In seeking to define the mechanisms involved, the administration of the 'PDF system' significantly enhanced lung maturation and reduced the production of reactive oxygen species (ROS). These findings suggest that the PDF system protects the development of NEC-induced lung injury through effects on lung maturation and reduced ROS in the lung and also increases lung maturation in non-NEC mice.

Morbidity and mortality in neonates with Down Syndrome based on gestational age

BACKGROUND

Greater than 50% of neonates with Down Syndrome (DS) have perinatal complications that require admission to the neonatal intensive care unit (NICU) at birth. Previous studies have shown increased morbidity and mortality rates in neonates without DS delivered prior to 39 weeks of completed gestation.

OBJECTIVE

To determine if an association exists between gestational age at delivery and adverse outcomes in neonates with DS.

STUDY DESIGN

Neonates with DS admitted to a large, tertiary care center NICU from 2010 to 2020 were evaluated. Gestational age (GA) was stratified into 4 groups: <34 (preterm), 34-36 (late-preterm), 37-38 (early-term) and ≥39 (term + post-term) completed weeks. Fisher's exact tests were used to evaluate morbidity and mortality rates between groups.

RESULT

Of the 314 neonates with DS, 10% (N = 31) were <34 weeks, 22% (N = 68) 34-36 weeks, 40% (N = 127) 37-38 weeks, and 28% (N = 88) ≥39 completed weeks at birth. Baseline characteristics were similar between groups. GA at birth <34 weeks was associated with a higher in-hospital mortality rate when compared to those born 37-38 (19% vs. 0%, P < 0.001) and ≥39 (19% vs. 3%, P = 0.01). Neonates with DS born <34 weeks had a higher likelihood of oxygen requirement at time of discharge compared to 34-36, 37-38, and ≥39 groups (P = 0.01; P < 0.001; P < 0.001 respectively). Neonates with DS < 34 weeks were more likely to develop necrotizing enterocolitis (P = 0.02) and require nitric oxide (P = 0.014) compared to neonates with DS ≥ 39. We observed no differences in the need for surgical interventions between groups aside from the rate of gastrostomy/jejunostomy tube placement between 34-36 weeks and 37-38 weeks GA.

CONCLUSION

Neonates with DS born preterm (<34 weeks) represent a highly vulnerable subgroup. Multidisciplinary strategies are needed to address their higher rates of morbidity and mortality.

Donor-dependent fecal microbiota transplantation efficacy against necrotizing enterocolitis in preterm pigs

The development of necrotizing enterocolitis (NEC), a life-threatening inflammatory bowel disease affecting preterm infants, is connected with gut microbiota dysbiosis. Using preterm piglets as a model for preterm infants we recently showed that fecal microbiota transplantation (FMT) from healthy suckling piglet donors to newborn preterm piglets decreased the NEC risk. However, in a follow-up study using donor stool from piglets recruited from another farm, this finding could not be replicated. This allowed us to study donor-recipient microbiota dynamics in a controlled model system with a clear difference in NEC phenotype. Preterm piglets (n = 38) were randomly allocated to receive control saline (CON), or rectal FMT using either the ineffective (FMT1) or the effective donor stool (FMT2). All animals were followed for four days before necropsy and gut pathological evaluation. Donor and recipient colonic gut microbiota (GM) were analyzed by 16 S rRNA gene amplicon sequencing and shotgun metagenomics. As expected, only FMT2 recipients were protected against NEC. Both FMT groups had shifted GM composition relative to CON, but FMT2 recipients had a higher lactobacilli relative abundance compared to FMT1. Limosilactobacillus reuteri and Lactobacillus crispatus strains of FMT recipients showed high phylogenetic similarity with their respective donors, indicating engraftment. Moreover, the FMT2 group had a higher lactobacilli replication rate and harbored specific glycosaminoglycan-degrading Bacteroides. In conclusion, subtle species-level donor differences translate to major changes in engraftment dynamics and the ability to prevent NEC. This could have implications for proper donor selection in future FMT trials for NEC prevention.

Remote ischemic conditioning in necrotizing enterocolitis: study protocol of a multi-center phase II feasibility randomized controlled trial

PURPOSE

Remote ischemic conditioning (RIC) is a maneuver involving brief cycles of ischemia reperfusion in an individual's limb. In the early stage of experimental NEC, RIC decreased intestinal injury and prolonged survival by counteracting the derangements in intestinal microcirculation. A single-center phase I study demonstrated that the performance of RIC was safe in neonates with NEC. The aim of this phase II RCT was to evaluate the safety and feasibility of RIC, to identify challenges in recruitment, retainment, and to inform a phase III RCT to evaluate efficacy.

METHODS

RIC will be performed by trained research personnel and will consist of four cycles of limb ischemia (4-min via cuff inflation) followed by reperfusion (4-min via cuff deflation), repeated on two consecutive days post randomization. The primary endpoint of this RCT is feasibility and acceptability of recruiting and randomizing neonates within 24 h from NEC diagnosis as well as masking and completing the RIC intervention.

RESULTS

We created a novel international consortium for this trial and created a consensus on the diagnostic criteria for NEC and protocol for the trial. The phase II multicenter-masked feasibility RCT will be conducted at 12 centers in Canada, USA, Sweden, The Netherlands, UK, and Spain. The inclusion criteria are: gestational age < 33 weeks, weight ≥ 750 g, NEC receiving medical treatment, and diagnosis established within previous 24 h. Neonates will be randomized to RIC (intervention) or no-RIC (control) and will continue to receive standard management of NEC. We expect to recruit and randomize 40% of eligible patients in the collaborating centers (78 patients; 39/arm) in 30 months. Bayesian methods will be used to combine uninformative prior distributions with the corresponding observed proportions from this trial to determine posterior distributions for parameters of feasibility.

CONCLUSIONS

The newly established NEC consortium has generated novel data on NEC diagnosis and defined the feasibility parameters for the introduction of a novel treatment in NEC. This phase II RCT will inform a future phase III RCT to evaluate the efficacy and safety of RIC in early-stage NEC.

Sutured Versus Sutureless Enterostomies: An Alternative Technique in Critically Sick Neonates

Background and objective

Intestinal perforations and necrotizing enterocolitis (NEC) requiring the formation of temporary intestinal stoma are prevalent conditions worldwide. This prospective study aimed to address the following research question: does sutureless enterostomy lead to fewer complications compared to conventional enterostomy in critically sick surgical neonates who need a stoma?

Methods

We conducted a randomized control trial (TCTR20211011004) from October 2020 to October 2021. A total of 120 patients were randomized to the following two study groups: Group A: conventional sutured enterostomy; Group B: sutureless enterostomy, with 60 patients in each group. The operative time, complications, and mortality were compared between the two groups using the chi-squared test.

Results

The groups were comparable with respect to the mean age at presentation, gestational age, weight, and sex ratio. In Group A, the main operative diagnoses were NEC in 22 patients, pneumoperitoneum in 25, complicated meconium ileus in nine, bowel atresia in three, and midgut volvulus in one; while in Group B, 25 patients had NEC, 20 had pneumoperitoneum, eight had meconium ileus, two had bowel atresia, and five had midgut volvulus. The mean operative time (93.5 ± 28.71 minutes) was significantly longer in the conventional group compared to the sutureless group (52.08 ± 18.53 minutes). Oral feed was started significantly earlier in the sutureless stoma group. Mortality was 43.3% in Group A and 46.6% in Group B. Complication rate was significantly higher in sutured stoma group.

Conclusion

The management of critically sick neonates, especially those with NEC and intestinal perforation, still presents a surgical dilemma. Based on our findings, the sutureless enterostomy may reduce operative time and complications in critically sick neonates.

The Mean Platelet Volume Combined with Procalcitonin as an Early Accessible Marker Helps to Predict the Severity of Necrotizing Enterocolitis in Preterm Infants

Purpose

Methods

Results

Conclusion

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.