Timing of Red Blood Cell Transfusions and Occurrence of Necrotizing Enterocolitis: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Observational studies often report that anemia and red blood cell (RBC) transfusions are associated with a higher risk of necrotizing enterocolitis (NEC) among extremely low-birthweight (ELBW) infants. Objective: To evaluate whether there is a temporal association between 72-hour hazard periods of exposure to RBC transfusions and NEC among ELBW infants randomized to either higher or lower hemoglobin transfusion thresholds. Design, Setting, and Participants: This post hoc secondary analysis of 1690 ELBW infants who survived to postnatal day 10 enrolled in the Transfusion of Prematures (TOP) randomized multicenter trial between December 1, 2012, and April 12, 2017, was performed between June 2021 and July 2023. Exposures: First, the distribution of RBC transfusions and the occurrence of NEC up to postnatal day 60 were examined. Second, 72-hour posttransfusion periods were categorized as hazard periods and the pretransfusion periods of variable duration as control periods. Then, the risk of NEC in posttransfusion hazard periods was compared with that in pretransfusion control periods, stratifying the risk based on randomization group (higher or lower hemoglobin transfusion threshold group). Main Outcomes and Measures: The primary outcome was incidence of NEC stage 2 or 3. Secondary outcomes included the incidence rates of NEC within five 10-day intervals, taking into account the number of days at risk. Results: Of 1824 ELBW infants randomized during the TOP trial, 1690 were included in the present analysis (mean [SD] gestational age, 26.0 [1.5] weeks; 899 infants [53.2%] were female). After categorizing 4947 hazard periods and 5813 control periods, we identified 133 NEC cases. Fifty-nine of these cases (44.4%) occurred during hazard periods. Baseline and clinical characteristics of infants with NEC during hazard periods did not differ from those of infants with NEC during control periods. The risk of NEC was 11.9 per 1000 posttransfusion hazard periods and 12.7 per 1000 control periods (adjusted risk ratio, 0.95; 95% CI, 0.68-1.32; P = .74). This risk did not differ significantly between randomization groups, but the incidence rate of NEC per 1000 days peaked between postnatal days 20 and 29 in the lower hemoglobin transfusion threshold group. Conclusions and Relevance: The findings of this post hoc analysis suggest that, among ELBW infants with the hemoglobin ranges occurring in the TOP trial, exposure to RBC transfusions was not temporally associated with a higher risk of NEC during 72-hour posttransfusion hazard periods. Given that the incidence rate of NEC peaked between postnatal days 20 and 29 among infants with lower hemoglobin values, a more in-depth examination of this at-risk period using larger data sets is warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT01702805.

Experimental necrotizing enterocolitis using oral lipopolysaccharide and protective role of breastmilk. / Enterocolitis necrotizante experimental con lipopolisacárido oral y función protectora de la leche materna.

INTRODUCTION: Necrotizing enterocolitis (NEC) is a life-threatening condition that afflicts neonates. Breastfeeding has demonstrated to play a protective role against it. By administering lipopolysaccharides (LPS) orally in newborn rats (NBR), we have developed an experimental model to induce NEC-like gut damage. Our aim was to assess the macroscopic and microscopic appearance of the gut, to evaluate the presence of NEC and study the role of breast milk (BM). MATERIALS AND METHODS: NBR were divided into 3 groups: Group A (control, n= 10) remained with the mother, group B (LPS, n= 25) was isolated after birth, gavage-fed with special rat formula and oral LPS, then submitted to stress (hypoxia after gavage) and group c (BM, n= 12) was breastfed once after birth, then isolated, and submitted to stress like group B. On day 4, NBR were sacrificed, and intestine was harvested and assessed. RESULTS: In the control group NEC was not present either macroscopically or histologically. Both groups submitted to stress (B and C) presented a global incidence of NEC of 73%. Most of group B developed histologic signs of NEC (85%) and group C showed a statistically lower incidence of NEC (50%, p= 0.04), playing the BM a protective role against NEC (OR= 0.19; 95% CI: 0.40-0.904). CONCLUSION: Our model showed a significant incidence of NEC in NBR (73%) with the same protective role of BM as in newborn humans, achieving a reliable and reproducible experimental NEC model. This will allow us to investigate new potential therapeutic targets for a devastating disease that currently lacks treatment.

INTRODUCCION: La enterocolitis necrotizante (ECN) es una enfermedad potencialmente mortal que afecta a los neonatos, y frente a la que la leche materna ha demostrado tener un papel protector. Administrando lipopolisacáridos (LPS) por vía oral en ratas recién nacidas (RRN), hemos desarrollado un modelo experimental para inducir un daño intestinal similar al que provoca la ECN con objeto de evaluar el aspecto macroscópico y microscópico del intestino, y de ese modo, analizar la presencia de ECN y estudiar el papel que desempeña la leche materna (LM). MATERIAL Y METODOS: Las RRN se dividieron en tres grupos: el grupo A (control, n= 10) permaneció con su madre; el grupo B (LPS, n= 25) fue aislado tras el nacimiento, alimentado por sonda con una fórmula especial para ratas y LPS oral, y sometido a estrés (hipoxia tras sonda); y el grupo C (LM, n= 12) fue alimentado con leche materna tras el nacimiento y posteriormente aislado y sometido a estrés al igual que el grupo B. El día 4 se sacrificó a las RRN y se recuperaron sus intestinos para su posterior evaluación. RESULTADOS: En el grupo de control, no se observó ECN ni macroscópica ni histológicamente, mientras que los dos grupos sometidos a estrés (B y C) presentaron una incidencia global de la ECN del 73%. La mayoría de los sujetos del grupo B desarrollaron signos histológicos de ECN (85%), y los del grupo C registraron una incidencia de la ECN estadísticamente menor (50%, p= 0,04), lo que significa que la LM desempeña una función protectora frente a la ECN (OR= 0,19; IC 95%: 0,40-0,904). CONCLUSION: Nuestro modelo reveló una incidencia significativa de la ECN en RRN (73%), desempeñando la LM la misma función protectora que en el caso de los humanos recién nacidos, lo que significa que este modelo experimental de ECN es fiable y reproducible. Gracias a dicho logro, podremos investigar nuevos y potenciales objetivos terapéuticos para una peligrosa enfermedad que, a día de hoy, carece de tratamiento.

Risk factors of necrotizing enterocolitis in twin preterm infants.

PURPOSE: This study was aimed to investigate the risk factors of necrotizing enterocolitis (NEC) in twin preterm infants. METHODS: The clinical data of 67 pairs of twin preterm infants admitted to the neonatal department of our hospital from January 2010 to December 2021 were retrospectively collected. One of the twins had NEC (Bell II and above) and the other twin without NEC. They were divided into NEC group and control group according to whether NEC occurred or not. RESULTS: Univariate analysis showed that NEC was associated with congenital heart disease, small for gestational age, mild asphyxia at birth and feeding intolerance (P < 0.05). CONCLUSION: Occurrence of NEC was associated with congenital heart disease, small for gestational age, and asphyxia at birth. For twin preterm infants with congenital heart disease, small for gestational age, or asphyxia at birth, special attention should be paid to the occurrence of NEC to minimize and avoid the occurrence of NEC.

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

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

The role of nutrition in analysis of risk factors and short-term outcomes for late-onset necrotizing enterocolitis among very preterm infants: a nationwide, multicenter study in China.

BACKGROUND: Necrotizing enterocolitis (NEC) is a serious gastrointestinal disease, primarily affects preterm newborns and occurs after 7 days of life (late-onset NEC, LO-NEC). Unfortunately, over the past several decades, not much progress has been made in its treatment or prevention. This study aimed to analyze the risk factors for LO-NEC, and the impact of LO-NEC on short-term outcomes in very preterm infants (VPIs) with a focus on nutrition and different onset times. METHOD: Clinical data of VPIs were retrospectively collected from 28 hospitals in seven different regions of China from September 2019 to December 2020. A total of 2509 enrolled VPIs were divided into 2 groups: the LO-NEC group and non-LO-NEC group. The LO-NEC group was divided into 2 subgroups based on the onset time: LO-NEC occurring between 8 ~ 14d group and LO-NEC occurring after 14d group. Clinical characteristics, nutritional status, and the short-term clinical outcomes were analyzed and compared among these groups. RESULTS: Compared with the non-LO-NEC group, the LO-NEC group had a higher proportion of anemia, blood transfusion, and invasive mechanical ventilation (IMV) treatments before NEC; the LO-NEC group infants had a longer fasting time, required longer duration to achieve the target total caloric intake (110 kcal/kg) and regain birthweight, and showed slower weight growth velocity; the cumulative dose of the medium-chain and long-chain triglyceride (MCT/LCT) emulsion intake in the first week after birth was higher and breastfeeding rate was lower. Additionally, similar results including a higher proportion of IMV, lower breastfeeding rate, more MCT/LCT emulsion intake, slower growth velocity were also found in the LO-NEC group occurring between 8 ~ 14d when compared to the LO-NEC group occurring after 14 d (all (P < 0.05). After adjustment for the confounding factors, high proportion of breastfeeding were identified as protective factors and long fasting time before NEC were identified as risk factors for LO-NEC; early feeding were identified as protective factors and low gestational age, grade III ~ IV neonatal respiratory distress syndrome (NRDS), high accumulation of the MCT/LCT emulsion in the first week were identified as risk factors for LO-NEC occurring between 8 ~ 14d. Logistic regression analysis showed that LO-NEC was a risk factor for late-onset sepsis, parenteral nutrition-associated cholestasis, metabolic bone disease of prematurity, and extrauterine growth retardation. CONCLUSION: Actively preventing premature birth, standardizing the treatment of grade III ~ IV NRDS, and optimizing enteral and parenteral nutrition strategies may help reduce the risk of LO-NEC, especially those occurring between 8 ~ 14d, which may further ameliorate the short-term clinical outcome of VPIs. TRIAL REGISTRATION: ChiCTR1900023418 (26/05/2019).

Time to full enteral feeds in hospitalised preterm and very low birth weight infants in Nigeria and Kenya.

BACKGROUND: Preterm (born < 37 weeks' gestation) and very low birthweight (VLBW; <1.5kg) infants are at the greatest risk of morbidity and mortality within the first 28 days of life. Establishing full enteral feeds is a vital aspect of their clinical care. Evidence predominantly from high income countries shows that early and rapid advancement of feeds is safe and reduces length of hospital stay and adverse health outcomes. However, there are limited data on feeding practices and factors that influence the attainment of full enteral feeds among these vulnerable infants in sub-Saharan Africa. AIM: To identify factors that influence the time to full enteral feeds, defined as tolerance of 120ml/kg/day, in hospitalised preterm and VLBW infants in neonatal units in two sub-Saharan African countries. METHODS: Demographic and clinical variables were collected for newborns admitted to 7 neonatal units in Nigeria and Kenya over 6-months. Multiple linear regression analysis was conducted to identify factors independently associated with time to full enteral feeds. RESULTS: Of the 2280 newborn infants admitted, 484 were preterm and VLBW. Overall, 222/484 (45.8%) infants died with over half of the deaths (136/222; 61.7%) occurring before the first feed. The median (inter-quartile range) time to first feed was 46 (27, 72) hours of life and time to full enteral feeds (tFEF) was 8 (4.5,12) days with marked variation between neonatal units. Independent predictors of tFEF were time to first feed (unstandardised coefficient B 1.69; 95% CI 1.11 to 2.26; p value <0.001), gestational age (1.77; 0.72 to 2.81; <0.001), the occurrence of respiratory distress (-1.89; -3.50 to -0.79; <0.002) and necrotising enterocolitis (4.31; 1.00 to 7.62; <0.011). CONCLUSION: The use of standardised feeding guidelines may decrease variations in clinical practice, shorten tFEF and thereby improve preterm and VLBW outcomes.

[Analysis of clinical characteristics and risk factors of postoperative complications in infants with early-onset necrotizing enterocolitis after enterostomy].

Objective: To investigate the clinical characteristics of children with early-onset necrotizing enterocolitis (NEC) undergoing enterostomy and analyze the risk factors for postoperative complications. Methods: Retrospective analysis was conducted on the clinical data (perinatal conditions, clinical characteristics, clinical outcomes, etc.) of NEC patients who underwent enterostomy at Beijing Children's Hospital from May 2016 to May 2023. The patients were divided into two groups based on the age of onset: an early-onset enterostomy group (<14 days) and a late-onset enterostomy group (≥14 days). Furthermore, the children with NEC were categorized into complication group and non-complication group based on whether there were complications after enterostomy. The differences in clinical data between these groups were analyzed, and the clinical characteristics of children with early-onset NEC and enterostomy were summarized. Multivariate logistic regression model was employed to analyze the risk factors for postoperative complications in NEC children with enterostomy. Results: A total of 68 cases were enrolled, including 43 cases in the early-onset enterostomy group [26 males and 17 females, aged (6.5±3.0) days] and 25 cases in the late-onset enterostomy group [15 males and 10 females, aged (21.0±3.0) days]. There were 28 cases (17 males and 11 females), age [M (Q1, Q3)] 9 (5, 14) days in the complication group and 33 cases (22 males and 11 females), aged of 14 (6, 21) days in the non-complication group. Compared to the late-onset enterostomy group, the early-onset enterostomy group had significantly higher rates of intraventricular hemorrhage [30.2% (13/43) vs 8.0% (2/25)], hemodynamically significant patent ductus arteriosus [37.2% (16/43) vs 12.0% (3/25)], mechanical ventilation≥72 hours after birth [39.5% (17/43) vs 16.0% (4/25)], stage Ⅲ NEC [(69.8% (30/43) vs 40.0% (10/25)], extensive NEC [27.9% (12/43) vs 8.0% (2/25)], and short-term postoperative complications [56.8% (21/37) vs 29.2% (7/24)] (all P<0.05).Multivariate logistic regression model analysis revealed that residual length of proximal small intestine was a protective factor for postoperative complications after enterostomy in NEC infants (OR=0.764, 95%CI: 0.648-0.901, P=0.001), but stage Ⅲ NEC was a risk factor (OR=1.042, 95%CI: 1.004-5.585, P=0.017). Conclusions: The incidence of postoperative complications is high, and the prognosis is poor in children with early-onset NEC enterostomy. The residual length of proximal enterostomy is a protective factor for postoperative complications of NEC enterostomy, but stage Ⅲ NEC is a risk factor.

Neonatal Diet Type and Associations With Adverse Feeding Outcomes in Neonates With Critical Congenital Heart Defects.

BACKGROUND: Neonates with critical congenital heart defects (CCHD neonates) experience high rates of feeding intolerance, necrotizing enterocolitis (NEC), and malnutrition. The benefits of human milk and direct chest/breastfeeding are well known, but research is limited in CCHD neonates. Therefore, the purpose of this study is to examine the impact of neonatal diet and feeding modality on the incidence of feeding intolerance, NEC, and malnutrition among a cohort of CCHD neonates. METHODS: A single-center retrospective study was conducted using electronic health record data of CCHD neonates admitted to a cardiac intensive care unit between April 2016 and April 2020. Regression models were fit to analyze associations between neonatal diet, feed modality, and adverse feeding outcomes. RESULTS: Seventy-four CCHD neonates were included. Increased days of direct chest/breastfeeding were associated with fewer signs of gastrointestinal distress ( P = .047) and bloody stools ( P = .021). Enteral feeding days of "all human milk" were associated with higher growth trajectory ( P < .001). CONCLUSIONS: Human milk and direct chest/breastfeeding may be protective against some adverse feeding outcomes for CCHD neonates. Larger, multicenter cohort studies are needed to continue investigating the effects of neonatal diet type and feeding modality on the development of adverse feeding outcomes in this unique population.

Association of Early Postoperative Regional Oxygen Saturation Measures and Development of Necrotizing Enterocolitis in Neonates Following Cardiac Surgery.

Necrotizing enterocolitis (NEC) is a relatively common complication in neonates with single ventricle physiology following heart surgery. Near-infrared spectroscopy (NIRS) is used to measure regional oxygen saturations in neonates in the postoperative period. We sought to investigate the association of somatic regional oxygen saturation (srSO2) and cerebral regional oxygen saturation (crSO2) in the early postoperative period and the subsequent development of NEC. We performed a retrospective cohort study of neonates who underwent cardiac surgery with cardiopulmonary bypass from October 2017 to September 2021 at the University of Virginia Children's Hospital. Values of srSO2 and crSO2 were captured over the first 48 h following surgery. 166 neonates were included and the median age at time of surgery was 8 days. NEC was diagnosed in 18 neonates following heart surgery with a median interval from surgery to diagnosis of 7 days. Neonates with single ventricle physiology had lower average crSO2 (62% vs 78%, p < 0.001), average srSO2 (72% vs 86%, p < 0.001), average crSO2 to srSO2 ratio (0.874 vs 0.913, p < 0.001), and an increased average srSO2-crSO2 difference (10% vs 8%, p = 0.03). Adjusting for single ventricle physiology, lower average crSO2 was associated with the development of definite NEC (modified Bell's criteria stage IIa and higher) (OR = 0.86, 95% CI 0.78-0.96, p = 0.007). Lower crSO2 values in the early postoperative period in neonates following cardiac surgery was associated with an increased risk in the subsequent development of NEC.

Cholestasis is associated with a higher rate of complications in both medical and surgical necrotizing enterocolitis.

OBJECTIVE: To evaluate the relationship between cholestasis and outcomes in medical and surgical necrotizing enterocolitis (NEC). STUDY DESIGN: A retrospective analysis of prospectively collected data from 1472 infants with NEC [455 medical (mNEC) and 1017 surgical (sNEC)] from the Children's Hospital Neonatal Database. RESULTS: The prevalence of cholestasis was lower in mNEC versus sNEC (38.2% vs 70.1%, p < 0.001). In both groups, cholestasis was associated with lower birth gestational age [mNEC: OR 0.79 (95% CI 0.68-0.92); sNEC: OR 0.86 (95% CI 0.79-0.95)] and increased days of parenteral nutrition [mNEC: OR 1.08 (95% CI 1.04-1.13); sNEC: OR 1.01 (95% CI 1.01-1.02)]. For both groups, the highest direct bilirubin was associated with the composite outcome mortality or length of stay >75th percentile [mNEC: OR 1.21 (95% CI 1.06-1.38); sNEC: OR 1.06 (95% CI 1.03-1.09)]. CONCLUSION: Cholestasis with both medical NEC and surgical NEC is associated with adverse patient outcomes including increased mortality or extreme length of stay.

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

INTRODUCTION: Enteral feeding prior to cardiac surgery has benefits in pre-operative and post-operative patient statuses. In 2020, to increase pre-operative feeding for single-ventricle patients prior to stage 1 palliation, an enteral feeding algorithm was created. The aim of this study is to monitor the impact of our practice change with the primary outcome of necrotising enterocolitis incidence from birth to 2 weeks following surgical intervention. METHODS: This is a single-site, retrospective cohort study including patients from 1 March, 2018 to 1 July, 2022. Variables assessed include demographics, age at cardiac surgery, primary cardiac diagnosis, necrotising enterocolitis pre-operative and 2 weeks post-operative cardiac surgery, feeding route, feeding type, volume of trophic enteral feeds, and near-infrared spectroscopy. RESULTS: Following implementation of a pre-operative enteral feeding algorithm, the rate of neonates fed prior to surgery increased (39.5-75%, p = .001). The feedings included a mean volume of 28.24 ± 11.16 ml/kg/day, 83% fed breastmilk only, 44.4% tube fed, and 55.5% of infants had all oral feedings. Comparing enterally fed neonates and those not enterally fed, the necrotising enterocolitis incidence from birth to 2 weeks post-op was not significantly increased (p = 0.926). CONCLUSION: As a result of implementing our feeding algorithm, the frequency of infants fed prior to stage I Norwood or Hybrid surgeries increased to 75%, and there was no significant change in the incidence of necrotising enterocolitis. This study confirmed that pre-operative enteral feeds are safe and are not associated with increased incidence of necrotising enterocolitis.

Potential role of bile acids in the pathogenesis of necrotizing enterocolitis.

Necrotizing enterocolitis (NEC) is one of the most common acute gastrointestinal diseases in preterm infants. Recent studies have found that NEC is not only caused by changes in the intestinal environment but also by the failure of multiple systems and organs, including the liver. The accumulation of bile acids (BAs) in the ileum and the disorder of ileal BA transporters are related to the ileum injury of NEC. Inflammatory factors such as tumor necrosis factor (TNF)-α and interleukin (IL)-18 secreted by NEC also play an important role in regulating intrahepatic BA transporters. As an important link connecting the liver and intestinal circulation, the bile acid metabolic pathway plays an important role in the regulation of intestinal microbiota, cell proliferation, and barrier protection. In this review, we focus on how bile acids explore the dynamic changes of bile acid metabolism in necrotizing enterocolitis and the potential therapeutic value of targeting the bile acid signaling pathways.

Applications of indocyanine greenenhanced fluorescence in the laparoscopic treatment of colonic stricture after necrotizing enterocolitis.

BACKGROUND: The status of anastomotic blood perfusion is associated with the occurrence of anastomotic leakage after intestinal anastomosis. Fluorescence angiography (FA) with indocyanine green (ICG) can objectively assess intestinal blood perfusion. This study aims to investigate whether anastomotic perfusion assessment with ICG influences surgical decision-making during laparoscopic intestinal resection and primary anastomosis for colonic stricture after necrotizing enterocolitis. METHODS: Patients who underwent laparoscopic intestinal resection and primary anastomosis between January 2022 and December 2022 were retrospectively analyzed. Before intestinal anastomosis, the ICG fluorescence technology was used to evaluate the blood perfusion of intestinal tubes on both sides of the anastomosis. After the completion of primary anastomosis, the anastomotic blood perfusion was assessed again. RESULTS: Of the 13 cases, laparoscopy was used to determine the extent of the diseased bowel to be excised, and the normal bowel was preserved for anastomosis. The anastomosis was established under the guidance of ICG fluorescence technology, and FA was performed after anastomosis to confirm good blood flow in the proximal bowel. The anastomotic intestinal tube was changed in one case because FA showed a difference between the normal range of intestinal blood flow and the macroscopic prediction. There was no evidence of ICG allergy, anastomotic leakage, anastomotic stricture, or other complications. The median follow-up was 6 months, and all patients recovered well. CONCLUSIONS: The ICG fluorescence technology is helpful in precisely and efficiently determining the anastomotic intestinal blood flow during stricture resection and in avoiding anastomotic leakage caused by poor anastomotic intestinal blood flow to some extent, with satisfactory short-term efficacy.

Role of the microbiome in pathophysiology of necrotising enterocolitis in preterm neonates.

Although necrotising enterocolitis (NEC) is a serious, life-threatening disease, improved neonatal care is increasing the number of survivors with NEC among extremely preterm neonates. Therapy is nevertheless mostly symptomatic and the mortality rate remains high, especially among neonates requiring surgery. Therefore, it is important to focus on preventing the disease and modifiable risk factors. NEC's pathophysiology is multifaceted, with key factors being immaturity of the immune and barrier protective mechanisms of the premature gut and exaggerated proinflammatory reaction to insults like gut hypoxia, enteral nutrition or microbial dysbiosis. The role of the intestinal microbiome in the pathophysiology of NEC has been a subject of research for many years, but to date no specific pathogen or type of dysbiosis has been connected with NEC development. This review assesses current knowledge as to the role of the intestinal microbiota in the pathophysiology of NEC and the possibilities for positively influencing it.

[Effect of gut microbiota homeostasis on hematopoiesis in a neonatal rat model of necrotizing enterocolitis]. / è‚ é“å¾®ç”Ÿç‰©ç¨³æ€å¯¹åæ­»æ€§å°è‚ ç»“è‚ ç‚Žæ–°ç”Ÿå¤§é¼ æ¨¡åž‹é€ è¡€ç³»ç»Ÿçš„å½±å“.

OBJECTIVES: To study the effect of gut microbiota on hematopoiesis in a neonatal rat model of necrotizing enterocolitis (NEC). METHODS: Neonatal Sprague-Dawley rats were randomly divided into a control group and a model group (NEC group), with 6 rats in each group. Formula milk combined with hypoxia and cold stimulation was used to establish a neonatal rat model of NEC. Hematoxylin and eosin staining was used to observe the pathological changes of intestinal tissue and hematopoiesis-related organs. Routine blood tests were conducted for each group. Immunohistochemistry was used to observe the changes in specific cells in hematopoiesis-related organs. Flow cytometry was used to measure the changes in specific cells in bone marrow. 16S rDNA sequencing was used to observe the composition and abundance of gut microbiota. RESULTS: Compared with the control group, the NEC group had intestinal congestion and necrosis, damage, atrophy, and shedding of intestinal villi, and a significant increase in NEC histological score. Compared with the control group, the NEC group had significantly lower numbers of peripheral blood leukocytes and lymphocytes (P<0.05), nucleated cells in the spleen, thymus, and bone marrow, and small cell aggregates with basophilic nuclei in the liver (P<0.05). The NEC group had significant reductions in CD71+ erythroid progenitor cells in the liver, CD45+ lymphocytes in the spleen and bone marrow, CD3+ T lymphocytes in thymus, and the proportion of CD45+CD3-CD43+SSChi neutrophils in bone marrow (P<0.05). There was a significant difference in the composition of gut microbiota between the NEC and control groups, and the NEC group had a significant reduction in the abundance of Ligilactobacillus and a significant increase in the abundance of Escherichia-Shigella (P<0.05), which replaced Ligilactobacillus and became the dominant flora. CONCLUSIONS: Multi-lineage hematopoietic disorder may be observed in a neonatal rat model of NEC, which may be associated with gut microbiota dysbiosis and abnormal multiplication of the pathogenic bacteria Escherichia-Shigella.

Risk factors associated with necrotizing enterocolitis in preterm infants: A case-control study.

BACKGROUND: Necrotizing enterocolitis (NEC) is the most common life-threatening gastrointestinal emergency in prematurity. The pathophysiology is multifactorial and remains incompletely understood. Early diagnosis and treatment could reduce the risk of mortality and morbidity. We aimed to identify factors associated with NEC in preterm newborns. METHOD: This case-control study included all preterm newborns presenting with NEC and managed between January 1, 2009 and December 31, 2018 in the neonatal intensive care unit of Nancy. For each case, two controls were matched according to three criteria: gestational age (WG), date of birth, and mode of delivery. Antenatal, peripartum, and postnatal risk factors prior to NEC were analyzed. RESULTS: A total of 292 infants were involved in the study, 113 of whom had NEC. Mean gestational age for newborns with NEC was 29 WG, and mean birth weight, 1340 g. Only early-onset infection was identified as a significant risk factor for NEC (15% vs. 6.6% for infection p<0.04, and 28.3% vs. 16.4% p<0.02 for infection and sepsis, NEC vs. controls, respectively). Late-onset feeding and initial continuous enteral feeding were significantly associated with the occurrence of more severe NEC (p<0.02 and p = 0.03, respectively). CONCLUSION: The results of this study are consistent with intestinal dysbiosis being a risk factor for NEC. Early-onset infection was found to be a significant risk factor. Enteral feeding practice may also be associated with NEC.

Phototherapy: a new risk factor for necrotizing enterocolitis in very low birth weight preterm infants? a retrospective case-control study.

OBJECTIVE: To investigate the association between phototherapy (PT) and the development of necrotizing enterocolitis (NEC) in very low birth weight (VLBW) infants. STUDY DESIGN: A retrospective case-control study was conducted on VLBW infants with or without NEC (stage IIA or greater) born at ≤35 weeks' gestation in a tertiary hospital over 7 years. Sample size calculation, trend test, as well as univariate and multiple logistic regression analyses were employed. RESULTS: A total of 824 VLBW infants were reviewed, with 74 cases and 122 controls finally enrolled. The odds of NEC increased with the duration and number of PT sessions. Exposure to >120 h and >4 instances of PT were significantly associated with NEC in multivariate analysis. CONCLUSION: This is the first study suggesting a potential association between PT and development of NEC in VLBW infants. This association needs further exploration.

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.