Preterm newborns represent a population at risk of developing intestinal dysbiosis as well as being predisposed to sepsis and Necrotizing Enterocolitis. Necrotizing Enterocolitis is a condition burdened by many complications and mortality due to an alteration of the intestinal barrier, an immaturity of the immune system, and intestinal dysbiosis. Low gestational age at birth, low birth weight, and early use of antibiotics are other predisposing factors. Instead, breast milk and probiotics are protective factors in providing intestinal homeostasis and microbiome regulation. In this mini-review, we analysed the protective role of probiotics in the onset of Necrotizing Enterocolitis in preterm populations.

BACKGROUND: Necrotizing enterocolitis (NEC) is a complex disease characterized by gastrointestinal inflammation and is one of the most common gastrointestinal emergencies in neonates. Mild to moderate cases of NEC require medical treatment, whereas severe cases necessitate surgical intervention. However, evidence for surgical indications is limited and largely dependent on the surgeon\'s experience, leading to variability in outcomes. The primary aim of this study is to identify the risk factors for surgical intervention in neonatal NEC, which will aid in predicting the optimal timing for surgical intervention.
METHODS: A literature search was conducted in PubMed, Embase, and Web of Science databases for case-control studies exploring risk factors for NEC requiring surgical intervention. The search was completed on June 16, 2024, and data analysis was performed using R Studio 4.3.2.
RESULTS: 18 studies were included, comprising 1,104 cases in the surgery group and 1,686 in the medical treatment group. The meta-analysis indicated that high C-reactive protein (CRP) levels [OR = 1.42, 95% CI (1.01, 1.99)], lower gestational age [OR = 0.52, 95% CI (0.3, 0.91)], sepsis [OR = 2.94, 95% CI (1.87, 4.60)], coagulation disorder [OR = 3.45, 95% CI (1.81, 6.58)], lack of enteral feeding [OR = 3.18, 95% CI (1.37, 7.35)], and hyponatremia [OR = 1.22, 95% CI (1.07, 1.39)] are significant risk factors for surgical treatment in neonatal NEC.
CONCLUSIONS: High CRP levels, coagulation disorders, sepsis, lower gestational age, lack of enteral feeding, and hyponatremia are significant risk factors for surgical intervention in neonatal NEC. These findings have potential clinical significance for predicting surgical risk.

Necrotizing enterocolitis (NEC) is one of the most devasting diseases affecting preterm neonates. However, despite a lot of research, NEC\'s pathogenesis remains unclear. It is known that the pathogenesis is a multifactorial process, including (1) a pathological microbiome with abnormal bacterial colonization, (2) an immature immune system, (3) enteral feeding, (3) an impairment of microcirculation, and (4) possibly ischemia-reperfusion damage to the intestine. Overall, the immaturity of the mucosal barrier and the increased expression of Toll-like receptor 4 (TLR4) within the intestinal epithelium result in an intestinal hyperinflammation reaction. Concurrently, a deficiency in counter-regulatory mediators can be seen. The sum of these processes can ultimately result in intestinal necrosis leading to very high mortality rates of the affected neonates. In the last decade no substantial advances in the treatment of NEC have been made. Thus, NEC animal models as well as in vitro models have been employed to better understand NEC\'s pathogenesis on a cellular and molecular level. This review will highlight the different models currently in use to study immunological aspects of NEC.

OBJECTIVE: Recently, near-infrared spectroscopy (NIRS) has been proposed for diagnosing patients with neonatal necrotizing enterocolitis (NEC). However, a consensus on the credibility of NIRS in evaluating NEC risk has not been reached. This meta-analysis aimed to evaluate the relationship between NEC and splanchnic regional tissue oxygen saturation (SrSO2) and cerebral regional tissue oxygen saturation (CrSO2) detected by NIRS to clarify the clinical value of NIRS in evaluating the risk of NEC.
METHODS: Studies using NIRS to monitor regional tissue oxygen saturation (rSO2) in neonates with NEC published in PubMed, Web of Science, Embase, and the Cochrane Library were searched from their inception to 30 July 2023. Mean difference (MD), pooled sensitivity, and pooled specificity, along with their 95 % confidence intervals (CI), were calculated, and the random-effects model was used for analysis. This study was registered with PROSPERO (no. CRD42022326783).
RESULTS: Fourteen studies including 938 neonates (172 NEC, 766 controls) were identified. SrSO2 was significantly decreased in patients with NEC (MD: -12.52, 95 % CI: -15.95, -9.08; P < 0.00001), and this decrease was observed even before the diagnosis of NEC (MD: -13.79, 95 % CI: -17.97, -9.62; P < 0.00001). The pooled sensitivity and specificity of SrSO2 were 0.80 (95 % CI: 0.69, 0.88) and 0.90 (95 % CI: 0.61, 0.98), respectively. However, no significant difference in CrSO2 was found (MD: -4.37, 95 % CI: -10.62, 1.88; P = 0.17).
CONCLUSIONS: SrSO2, detected by NIRS, could be a valuable non-invasive method for differentiating NEC from non-NEC neonates. It could differentiate prior to NEC diagnosis.

While neonatal necrotising enterocolitis (NEC) is associated with high mortality rates in newborns, survivors can face long-term sequelae. However, the relationship between NEC and neurodevelopmental impairment (NDI) in preterm infants remains unclear. To explore the relationship between neonatal NEC and neurodevelopmental outcomes in preterm infants, we searched PubMed, EMBASE, and the Cochrane Library from their inception to February 2024 for relevant studies. Studies included were cohort or case-control studies reporting neurodevelopmental outcomes of NEC in preterm infants. Two independent investigators extracted data regarding brain damage and neurodevelopmental outcomes in these infants at a corrected age exceeding 12 months. Odds ratios (ORs) were pooled using a random effects model. We included 15 cohort studies and 18 case-control studies, encompassing 60,346 infants. Meta-analysis of unadjusted and adjusted ORs demonstrated a significant association between NEC and increased odds of NDI (OR 2.15, 95% CI 1.9-2.44; aOR 1.89, 95% CI 1.46-2.46). Regarding brain injury, pooled crude ORs indicated an association of NEC with severe intraventricular haemorrhage (IVH) (OR 1.42, 95% CI 1.06-1.92) and periventricular leucomalacia (PVL) (OR 2.55, 95% CI 1.76-3.69). When compared with conservatively treated NEC, surgical NEC potentially carries a higher risk of NDI (OR 1.78, 95% CI 1.09-2.93) and severe IVH (OR 1.57, 95% CI 1.20-2.06). However, the risk of PVL did not show a significant difference (OR 1.60, 95% CI 0.47-5.40).
CONCLUSIONS:  Our meta-analysis provides evidence suggesting an association between NEC and NDI. Additionally, the severity of intestinal lesions appears to correlate with a higher risk of NDI. Further high-quality studies with comprehensive adjustments for potential confounding factors are required to definitively establish whether the association with NDI is causal.
BACKGROUND: • NEC is a serious intestinal disease in the neonatal period with a high mortality rate, and surviving children may have digestive system sequelae. • Compared with non-NEC preterm infants, the reported incidences of brain injury and neurodevelopmental disorders in NEC preterm infants are not the same.
BACKGROUND: • The risk of neonatal brain injury and neurodevelopmental disorders in preterm infants with NEC is higher than that in non-NEC infants, and the risk of NDI in surgical NEC infants is higher than that in the conservative treatment group. • NEC may increase the risk of motor, cognitive, language development delays, and attention deficits in children.

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.

BACKGROUND: Necrotizing enterocolitis (NEC) is a multifactorial gastrointestinal disease with high morbidity and mortality among premature infants. However, studies with large samples on the factors of NEC in China have not been reported. This meta-analysis aims to systematically review the literature to explore the influencing factors of necrotizing enterocolitis in premature infants in China and provide a reference for the prevention of NEC.
METHODS: PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM), Wanfang and VIP databases were systematically searched from inception to February 2023. We used Stata14.0 software to perform the systematic review and meta-analysis. We used fixed or random effects models with combined odds ratios (ORs) and 95% confidence intervals (CIs), and quality was evaluated using the Newcastle‒Ottawa Scale (NOS).
RESULTS: The total sample was 8616 cases, including 2456 cases in the intervention group and 6160 cases in the control group. It was found that 16 risk factors and 3 protective factors were related to necrotizing enterocolitis in premature infants. Septicemia (OR = 3.91), blood transfusion (OR = 2.41), neonatal asphyxia (OR = 2.46), pneumonia (OR = 6.17), infection (OR = 5.99), congenital heart disease (OR = 4.80), intrahepatic cholestasis of pregnancy (ICP) (OR = 2.71), mechanical ventilation (OR = 1.44), gestational diabetes mellitus (GDM) (OR = 3.08), respiratory distress syndrome (RDS) (OR = 3.28), hypoalbuminemia (OR = 2.80), patent ductus arteriosus (PDA) (OR = 3.10), respiratory failure (OR = 7.51), severe anemia (OR = 2.86), history of antibiotic use (OR = 2.12), and meconium-stained amniotic fluid (MSAF) (OR = 3.14) were risk factors for NEC in preterm infants in China. Breastfeeding (OR = 0.31), oral probiotics (OR = 0.36), and prenatal use of glucocorticoids (OR = 0.38) were protective factors for NEC in preterm infants.
CONCLUSIONS: Septicemia, blood transfusion, neonatal asphyxia, pneumonia, infection, congenital heart disease, ICP, GDM, RDS, hypoproteinemia, PDA, respiratory failure, severe anemia, history of antibiotic use and MSAF will increase the risk of NEC in premature infants, whereas breastfeeding, oral probiotics and prenatal use of glucocorticoids reduce the risk. Due to the quantity and quality of the included literature, the above findings need to be further validated by more high-quality studies.

Various studies have shown that oropharyngeal colostrum application (OPCA) is beneficial to preterm neonates. We performed a systematic review and meta-analysis to assess whether OPCA reduces the incidence of culture-proven neonatal sepsis in preterm neonates. Randomized controlled trials comparing OPCA with placebo or standard care in preterm neonates were included. Medline, Embase, Web of Science, Cumulated Index to Nursing and Allied Health Literature, Scopus, and CENTRAL were searched for studies published up to June 15, 2023. We used the Cochrane Risk of Bias tool, version 2, for risk of bias assessment, the random-effects model (RevMan 5.4) for meta-analysis, and Gradepro software for assessing the certainty of evidence. Twenty-one studies involving 2393 participants were included in this meta-analysis. Four studies had a low risk of bias, whereas seven had a high risk. Oropharyngeal colostrum significantly reduced the incidence of culture-proven sepsis (18 studies, 1990 neonates, risk ratio [RR]: 0.78, 95% confidence interval [95% CI]: 0.65, 0.94), mortality (18 studies, 2117 neonates, RR: 0.73, 95% CI: 0.59, 0.90), necrotizing enterocolitis (NEC) (17 studies, 1692 neonates, RR: 0.59, 95% CI: 0.43, 0.82), feeding intolerance episodes (four studies, 445 neonates, RR: 0.59, 95% CI: 0.38, 0.92), and the time to full enteral feeding (19 studies, 2142 neonates, mean difference: -2 to 21 days, 95% CI: -3.44, -0.99 days). There was no reduction in intraventricular hemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia, ventilator-associated pneumonia, neurodevelopmental abnormalities, hospital stay duration, time to full oral feeding, weight at discharge, pneumonia, and duration of antibiotic therapy. The certainty of the evidence was high for the outcomes of culture-positive sepsis and mortality, moderate for NEC, low for time to full enteral feeding, and very low for feeding intolerance. OPCA reduces culture-positive sepsis and mortality (high certainty), NEC (moderate certainty), and time to full enteral feeding (low certainty) in preterm neonates. However, scarcity of data from extremely premature infants limits the generalizability of these results to this population.

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.

Neutrophils, the most abundant type of white blood cells, are pivotal in fighting bacterial infections due to their immunological and anti-infection capabilities. In recent years, scientists have discovered a novel mechanism known as neutrophil extracellular traps, which are fibrous networks primarily released by neutrophils that combat bacterial infections. There is a growing interest in studying NETs and their role in human infectious diseases, particularly in neonates susceptible to bacterial infections. NETs and their components have been found in various samples from neonatal-infected patients, providing a new route for early diagnosis of neonatal infectious diseases. This paper aims to summarize the studies on NETs in adult diseases and mainly discuss NETs in neonatal sepsis, necrotizing enterocolitis, and purulent meningitis, to provide scientific evidence for early monitoring, diagnosis, and treatment of neonatal infections.