Role of amino acid supplementation in the prevention of necrotizing enterocolitis in preterm neonates – a review of current evidences

Elevated expression of histone deacetylase HDAC8 suppresses arginine-proline metabolism in necrotizing enterocolitis

Epigenetic alterations are especially important in necrotizing enterocolitis (NEC). Here, we reported that histone deacetylase 8 (HDAC8) plays a previously unknown role in modulating arginine metabolism via acetylation of histone 3 lysine 9 (acetyl-H3K9) regulation during the pathogenesis of NEC. We found that HDAC8 was upregulated in humans and mice intestinal samples with NEC, while selective inhibition of HDAC8 expression ameliorated NEC. HDAC8 regulates enzymes involved in the metabolic conversion of proline to arginine (PRODH, PRODH2, OAT, and OTC) and arginine to ornithine (ARG1). The results showed that H3K9ac signal in the PRODH/PRODH2 promoter region was mediated by HDAC8. Additionally, the decreased concentration of butyric acid was strongly correlated with elevated HDAC8 levels and circulating arginine, which may result from an unbalanced Firmicutes/Bacteroidetes ratio. These results reveal previously underappreciated roles of microbial metabolites and HDAC8 to coordinate the arginine metabolism during NEC development.

Amino acids for the prevention of mortality and morbidity in preterm infants: a systematic review and network meta-analysis

To determine the effectiveness and safety of amino acids in preventing the mortality and morbidity among preterm infants. We conducted a systematic review and network meta-analysis. We searched MEDLINE, EMBASE, Web of Science, CINAHL, Scopus, Cochrane, and Google Scholar, and grey literature, from databases inception to January 2021. We included randomized trials that evaluated any amino acids on preterm or low-birth weight infants. We performed frequentist pairwise and network meta-analyses and used the GRADE methodology to assess the certainty of the evidence and provide a summary of the results.We included 18 trials (3702 infants). Low certainty evidence showed that there seems to be no benefit for arginine, glutamine, or N-acetylcysteine in reducing all-cause mortality. Oral arginine likely results in reduction of necrotizin enterocolitis (NEC) stage ≥ II (OR 0.48; 95% CI 0.26-0.90; moderate certainty). Oral glutamine may reduce the likelihood of developing late-onset sepsis (LOS) compared to placebo (OR 0.62; 95% CI 0.47-0.82; low certainty); and likely reduces time to reach full enteral feeding (MD = - 2.63 days; 95% CI - 4.99 to - 0.27; moderate certainty). Amino acids may have no effect on mortality. Oral arginine may reduce severe NEC, and oral glutamine may reduce LOS and the time to reach full feeding.Systematic review registration: PROSPERO registration number: CRD4201603873.

An Overview of Systematic Reviews of Randomized-Controlled Trials for Preventing Necrotizing Enterocolitis in Preterm Infants

Necrotizing enterocolitis (NEC) remains a major cause for neonatal mortality and morbidity in preterm infants. The purpose of this review was to summarize evidence from systematic reviews of randomized-controlled trials (RCTs) regarding antenatal and postnatal interventions for preventing NEC. PubMed, EMBASE, the Cochrane Library Databases, Database of Abstracts of Reviews of Effects, and Campbell Library were searched for meta-analyses in which NEC was reported as an outcome after antenatal or postnatal strategies. The AMSTAR instrument was used to evaluate quality of included reviews. Grading of Recommendations, Assessment, Development and Evaluation assessment was used to evaluate certainty of evidence. We identified 98 meta-analyses of RCTs. The quality of included reviews was adequate, whereas the certainty of evidence was moderate to very low. Moderate certainty evidence showed a reduction in NEC following administration of a combination of species of probiotics, probiotics (any), antenatal corticosteroids in pregnant women at risk of preterm birth, and ibuprofen versus indomethacin for treatment of patent ductus arteriosus (PDA). For surgical NEC, moderate certainty evidence showed an increased risk with lower (85-89%) oxygen saturation target levels, compared with higher (91-95%) oxygen saturation target levels. In conclusion, decreased risk of NEC is observed with probiotics, antenatal corticosteroids for women at risk of preterm birth, and ibuprofen versus indomethacin for treatment of PDA. Targeting lower oxygen saturations may increase the risk of surgical NEC, compared to targeting higher saturations.

Recent Advances in Prevention and Therapies for Clinical or Experimental Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is one of the most severe diseases of preterm neonates and has a high mortality rate. With the development of inspection techniques and new biomarkers, the diagnostic accuracy of NEC is constantly improving. The most recognized potential risk factors include prematurity, formula-feeding, infection, and microbial dysbiosis. With further understanding of the pathogenesis, more effective prevention and therapies will be applied to clinical or experimental NEC. At present, such new potential prevention and therapies for NEC are mainly focused on the Toll-like receptor 4 inflammatory signaling pathway, the repair of intestinal barrier function, probiotics, antioxidative stress, breast-feeding, and immunomodulatory agents. Many new studies have changed our understanding of the pathogenesis of NEC and improve our approaches for preventing and treating of NEC each year. This review provides an overview of the recent researches focused on clinical or experimental NEC and highlights the advances made within the past 5 years toward the development of new potential preventive approaches and therapies for this disease.

Current Resources for Evidence-Based Practice, March 2019

A review of new resources to support the provision of evidence-based care for women and infants.

Role of delayed cord clamping in prevention of necrotizing enterocolitis in preterm neonates: a systematic review

BACKGROUND

Necrotizing enterocolitis (NEC) is one of the leading causes of neonatal mortality and morbidity particularly in very-low-birth-weight (VLBW) neonates. The incidence of NEC varies across countries and neonatal centers in between 7% and 14%.

AIMS

The aim of this study is to evaluate the role of delayed cord clamping (DCC) for prevention of NEC in preterm neonates.

METHOD

The literature search was done for various randomized control trial (RCT) by searching the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, ongoing clinical trials, and abstract of conferences.

RESULTS

This review included six RCTs that fulfilled inclusion criteria. There was statistically significant reduction in the incidence of NEC in DCC group (12.2% versus 20.6%; risk ratio (RR) 0.59; 95% CI 0.37-0.94; p = .02; number needed to treat (NNT) 12). However, mortality due to any cause before hospital discharge was not statistically significant (RR 0.80; 95% CI 0.33-2.00; p = .64).

CONCLUSION

The role of DCC in the prevention of NEC is supported by the current evidences. However, given the small sample sizes and other limitations of these studies, current evidences are not sufficient. We need large high-quality trials, with sufficient power to reliably assess clinically relevant differences in important outcomes.