Are antibiotics a risk factor for the development of necrotizing enterocolitis-case-control retrospective study

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).

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.

A prediction model for neonatal necrotizing enterocolitis in preterm and very low birth weight infants

Objectives

Neonatal necrotizing enterocolitis (NEC) is a severe gastrointestinal disease that primarily affects preterm and very low birth weight infants, with high morbidity and mortality. We aim to build a reliable prediction model to predict the risk of NEC in preterm and very low birth weight infants.

Methods

We conducted a retrospective analysis of medical data from infants (gestational age <32 weeks, birth weight <1,500 g) admitted to Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region. We collected clinical data, randomly dividing it into an 8:2 ratio for training and testing. Multivariate logistic regression was employed to identify significant predictors for NEC. Principal component analysis was used for dimensionality reduction of numerical variables. The prediction model was constructed through logistic regression, incorporating all relevant variables. Subsequently, we calculated performance evaluation metrics, including Receiver Operating Characteristic (ROC) curves and confusion matrices. Additionally, we conducted model performance comparisons with common machine learning models to establish its superiority.

Results

A total of 292 infants were included, with 20% (n = 58) randomly selected for external validation. Multivariate logistic regression revealed the significance of four predictors for NEC in preterm and very low birth weight infants: temperature (P = 0.003), Apgar score at 5 min (P = 0.004), formula feeding (P = 0.007), and gestational diabetes mellitus (GDM, P = 0.033). The model achieved an accuracy of 82.46% in the test set with an F1 score of 0.90, outperforming other machine learning models (support vector machine, random forest).

Conclusions

Our logistic regression model effectively predicts NEC risk in preterm and very low birth weight infants, as confirmed by external validation. Key predictors include temperature, Apgar score at 5 min, formula feeding, and GDM. This study provides a vital tool for NEC risk assessment in this population, potentially improving early interventions and child survival. However, clinical validation and further research are necessary for practical application.

Gut Microbiome-Brain Axis as an Explanation for the Risk of Poor Neurodevelopment Outcome in Preterm Infants with Necrotizing Enterocolitis

Necrotizing Enterocolitis (NEC) is characterized by an inflammation of intestinal tissue that primarily affects premature infants. It is the most common and devastating gastrointestinal morbidity of prematurity, but beyond intestinal morbidity, this condition has also been associated with an increased risk of neurodevelopmental delays that persist beyond infancy. Prematurity, enteral feeding, bacterial colonization, and prolonged exposure to antibiotics are all risk factors that predispose preterm infants to NEC. Interestingly, these factors are all also associated with the gut microbiome. However, whether or not there is a connection between the microbiome and the risk of neurodevelopmental delays in infants after NEC is still an emerging area of research. Furthermore, how microbes in the gut could impact a distant organ such as the brain is also poorly understood. In this review, we discuss the current understanding of NEC and the role of the gut microbiome-brain axis in neurodevelopmental outcomes after NEC. Understanding the potential role of the microbiome in neurodevelopmental outcomes is important as the microbiome is modifiable and thus offers the hope of improved therapeutic options. We highlight the progress and limitations in this field. Insights into the gut microbiome-brain axis may offer potential therapeutic approaches to improve the long-term outcomes of premature infants.

Necrotizing Enterocolitis: The Role of Hypoxia, Gut Microbiome, and Microbial Metabolites

Necrotizing enterocolitis (NEC) is a life-threatening disease that predominantly affects very low birth weight preterm infants. Development of NEC in preterm infants is accompanied by high mortality. Surgical treatment of NEC can be complicated by short bowel syndrome, intestinal failure, parenteral nutrition-associated liver disease, and neurodevelopmental delay. Issues surrounding pathogenesis, prevention, and treatment of NEC remain unclear. This review summarizes data on prenatal risk factors for NEC, the role of pre-eclampsia, and intrauterine growth retardation in the pathogenesis of NEC. The role of hypoxia in NEC is discussed. Recent data on the role of the intestinal microbiome in the development of NEC, and features of the metabolome that can serve as potential biomarkers, are presented. The Pseudomonadota phylum is known to be associated with NEC in preterm neonates, and the role of other bacteria and their metabolites in NEC pathogenesis is also discussed. The most promising approaches for preventing and treating NEC are summarized.

Optimal dose of cefotaxime in neonates with early-onset sepsis: A developmental pharmacokinetic model-based evaluation

Objective: The perspective of real-world study is especially relevant to newborns, enabling dosage regimen optimization and regulatory approval of medications for use in newborns. The aim of the present study was to conduct a pharmacokinetic analysis of cefotaxime and evaluate the dosage used in newborns with early-onset sepsis (EOS) using real-world data in order to support the rational use in the clinical practice.

Methods: This prospective, open-label study was performed in newborns with EOS. A developmental pharmacokinetic-pharmacodynamic model of cefotaxime in EOS patients was established based on an opportunistic sampling method. Then, clinical evaluation of cefotaxime was conducted in newborns with EOS using real-world data.

Results: A one-compartment model with first-order elimination was developed, using 101 cefotaxime concentrations derived from 51 neonates (30.1–41.3°C weeks postmenstrual age), combining current weight and postnatal age. The pharmacokinetic-pharmacodynamic target was defined as the free cefotaxime concentration above MIC during 70% of the dosing interval (70% fT > MIC), and 100% of neonates receiving the dose of 50 mg/kg, BID attained the target evaluated using the model. Additionally, only two newborns had adverse reactions possibly related to cefotaxime treatment, including diarrhea and feeding intolerance.

Conclusion: This prospective real-world study demonstrated that cefotaxime (50 mg/kg, BID) had a favorable efficacy and an accepted safety profile for neonates with EOS.

Risk factors for necrotizing enterocolitis in preterm infants: a Meta analysis

OBJECTIVES

To systematically evaluate the risk factors for necrotizing enterocolitis (NEC) in preterm infants.

METHODS

PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Data were searched for case-control studies and cohort studies on the risk factors for NEC in preterm infants published up to December 2021. RevMan 5.3 software was used to perform the Meta analysis.

RESULTS

A total of 38 studies were included (28 case-control studies and 10 cohort studies). The Meta analysis showed that maternal gestational diabetes (OR=2.96, P<0.001), intrahepatic cholestasis during pregnancy (OR=2.53, P<0.001), preeclampsia (OR=1.73, P=0.020), history of neonatal asphyxia (OR=2.13, P<0.001), low gestational age (OR=1.23, P=0.010), sepsis (OR=5.32, P<0.001), patent ductus arteriosus (OR=1.57, P=0.001), congenital heart disease (OR=3.78, P<0.001), mechanical ventilation (OR=2.23, P=0.020), history of antibiotic use (OR=1.07, P<0.001), use of vasopressors (OR=2.34, P=0.040), and fasting (OR=1.08, P<0.001) were risk factors for NEC in preterm infants, while cesarean section (OR=0.73, P=0.004), use of pulmonary surfactant (OR=0.43, P=0.008), and breastfeeding (OR=0.24, P=0.020) were protective factors against NEC.

CONCLUSIONS

Maternal gestational diabetes, intrahepatic cholestasis during pregnancy, preeclampsia, low gestational age, fasting, sepsis, patent ductus arteriosus, congenital heart disease, and histories of asphyxia, mechanical ventilation, antibiotic use, and use of vasopressors may increase the risk of NEC in preterm infants, while cesarean section, use of pulmonary surfactant, and breastfeeding may decrease the risk of NEC in preterm infants.

Understanding the development and function of the gut microbiota in health and inflammation

The gut microbiota is known to play an important role in maintaining gut health through a symbiotic relationship with the host. Altered gut microbiota is a common feature of several diseases of the gastrointestinal tract; however, the causal relationship between microbiota and disease pathogenesis is poorly understood. Necrotising enterocolitis (NEC) and inflammatory bowel disease (IBD) are both severe inflammatory diseases affecting the gastrointestinal tract. Although they affect very different patient populations, with NEC primarily being a disease of prematurity and IBD predominantly affecting adults although children can be affected, they both demonstrate common features of gut microbial dysbiosis and a dysregulated host immune response. By comparing and contrasting the changes in gut microbiota, host immune response and function, we aim to highlight common features in diseases that may seem clinically unrelated. Key areas of interest are the role of pattern recognition receptors in altered recognition and responses to the gut microbiota by the host immune system and the associated dysfunctional gut epithelial barrier. The challenge of identifying causal relationships between microbiota and disease is ever-present; however, considering a disease-agnostic approach may help to identify mechanistic pathways shared across several clinical diseases.

Safe pregnancy after liver transplantation: Evidence from a multicenter Italian collaborative study

BACKGROUND

Women who have undergone liver transplantation (LT) enjoy better health, and possibility of childbearing. However, maternal and graft risks, optimal immunosuppression, and fetal outcome is still to clarify.

AIM

Aim of the study was to assess outcomes of pregnancy after LT at national level.

METHODS

In 2019, under the auspices of the Permanent Transplant Committee of the Italian Association for the Study of the Liver, a multicenter survey including 14 Italian LT-centers was conducted aiming at evaluating the outcomes of recipients and newborns, and graft injury/function parameters during pregnancy in LT-recipients.

RESULTS

Sixty-two pregnancies occurred in 60 LT-recipients between 1990 and 2018. Median age at the time of pregnancy was 31-years and median time from transplantation to conception was 8-years. During pregnancy, 4 recipients experienced maternal complications with hospital admission. Live-birth-rate was 100%. Prematurity occurred in 25/62 newborns, and 8/62 newborns had low-birth-weight. Cyclosporine was used in 16 and Tacrolimus in 37 pregnancies, with no different maternal or newborn outcomes. Low-birth-weight was correlated to high values of AST, ALT and GGT.

CONCLUSION

Pregnancy after LT has good outcome; however, maternal complications and prematurity may occur. Compliance with the immunosuppression is fundamental to ensure the stability of graft function and prevent graft-deterioration.

Antibiotics in the medical and surgical treatment of necrotizing enterocolitis. A systematic review

BACKGROUND

The aim of this review was to identify relevant randomized controlled trials (RCTs) and non-RCTs to evaluate the existing knowledge on the effect of antibiotic treatment for infants with necrotizing enterocolitis (NEC).

OBJECTIVE

Identifying 1) the best antibiotic regimen to avoid disease progression as assessed by surgery or death, 2) the best antibiotic regimen for infants operated for NEC as assessed by re-operation or death.

METHODS

Embase, MEDLINE and Cochrane were searched systematically for human studies using antibiotics for patients with NEC, Bell's stage II and III.

RESULTS

Five studies were included, with a total of 375 infants. There were 2 RCT and 3 cohort studies. Four main antibiotic regimens appeared. Three with a combination of ampicillin + gentamycin (or similar) with an addition of 1) clindamycin 2) metronidazole or 3) enteral administration of gentamycin. One studied investigated cefotaxime + vancomycin. None of the included studies had a specific regimen for infants undergoing surgery.

CONCLUSIONS

No sufficient evidence was found for any recommendation on the choice of antibiotics, the route of administration or the duration in infants treated for NEC with Bell's stage II and III.

Risk factors for necrotizing enterocolitis and establishment of prediction model of necrotizing enterocolitis in preterm infants

OBJECTIVES

To investigate the risk factors for necrotizing enterocolitis (NEC) in preterm infants, and to establish a scoring model that can predict the development and guide the prevention of NEC.

METHODS

A retrospective analysis was performed on the medical data of preterm infants who were admitted to the Department of Neonatology,Bethune First Hospital of Jilin University, from January 2011 to December 2020. These infants were divided into two groups: NEC (298 infants with Bell II stage or above) and non-NEC (300 infants). Univariate and multivariate analyses were performed to identify the factors influencing the development of NEC. A nomogram for predicting the risk of NEC was established based on the factors. The receiver operator characteristic (ROC) curve and the index of concordance (C-index) were used to evaluate the predictive performance of the nomogram.

RESULTS

The multivariate logistic regression analysis showed that grade ≥2 intracranial hemorrhage, peripherally inserted central catheterization, breast milk fortifier, transfusion of red cell suspension, hematocrit >49.65%, mean corpuscular volume >114.35 fL, and mean platelet volume >10.95 fL were independent risk factors for NEC (P<0.05), while the use of pulmonary surfactant, the use of probiotics, and the platelet distribution width >11.8 fL were protective factors against NEC (P<0.05). The nomogram showed good accuracy in predicting the risk of NEC, with a bootstrap-corrected C-index of 0.844. The nomogram had an optimal cutoff value of 171.02 in predicting the presence or absence of NEC, with a sensitivity of 74.7% and a specificity of 80.5%.

CONCLUSIONS

The prediction nomogram for the risk of NEC has a certain clinical value in early prediction, targeted prevention, and early intervention of NEC.

Prolonged antibiotic therapy increased necrotizing enterocolitis in very low birth weight infants without culture-proven sepsis

OBJECTIVES

We aimed to identify the factors associated with necrotizing enterocolitis (NEC) and to assess the associations of the initial empirical antibiotic therapy (IEAT) duration and antibiotic therapy duration/hospital stay ratio (A/H ratio) before NEC with subsequent NEC in very low birth weight (VLBW) infants with gestational age less than 32 weeks without proven sepsis.

METHODS

A retrospective study was conducted at the NICU of the First Affiliated Hospital of Medical University of Anhui province from June 2015 to May 2022, and 567 VLBW infants with gestational age less than 32 weeks were included in the study. We divided the VLBW infants into those with and without NEC according to modified Bell's criteria. We then used descriptive statistics to identify the factors associated with NEC and multivariate analyses to evaluate the associations of IEAT duration and A/H ratio with the occurrence of NEC.

RESULTS

Of the 567 VLBW neonates admitted to our center, 547 survived and reached the normal discharge criteria. Fifty-one infants (8.99%) were diagnosed as showing NEC. Infants with NEC had a longer total parenteral nutrition time, total enteral nutrition time, and IEAT duration, as well as a higher A/H ratio than those without NEC. In multivariate analyses adjusted for the other factors, IEAT duration was associated with an increased odds of NEC [odds ratio (OR) = 1.267; 95% confidence interval (CI), 1.128-1.423], and the A/H ratio was also associated with increased odds of NEC (OR = 8.718; 95% CI, 2.450-31.030). For the A/H ratio, the area under the curve (AUC) was 0.767 and the ideal cutoff was 0.357, and the sensitivity and specificity were 0.843 and 0.645, respectively.

CONCLUSION

Prolonged antibiotic therapy may increase the risk of NEC in VLBW infants with a gestational age of fewer than 32 weeks and should be used with caution.

Fetal-neonatal exposure to antibiotics and NEC development: A systematic review and meta-analysis

BACKGROUND

Fetal and neonatal exposure to antibiotics may contribute to the development of necrotizing enterocolitis (NEC) in preterm infants. This systematic review and meta-analysis investigate whether exposure to third trimester maternal antibiotics (MAB) and/or prolongation of empirical antibiotics (PEAB) are associated with NEC development in preterms.

METHOD

We included observational and randomized controlled studies, including those on preterm or very low birth weight (VLBW) infants, from MEDLINE and EMBASE, published between 1990 and June 2021. Exposure was defined as third trimester MAB and/or PEAB. The two reviewers independently performed study selection, data extraction, and quality assessment.

RESULTS

Three cohort studies compared third trimester MAB with no antibiotics. MAB was associated with lower NEC incidence, unadjusted pooled odds ratio (OR) is 0.57 (95% CI: 0.35-0.93). Twelve cohort studies showed that PEAB was associated with an increased risk of NEC. Ten observational cohort studies show an unadjusted OR of 2.72 (1.65-4.47), and two case-control studies show an unadjusted mean difference of 2.31 (0.94-3.68). Moderate to substantial heterogeneity was observed but decreased in studies with low risk of bias and large sample size.

CONCLUSION

Evidence suggests an association between MAB and decreased risk of NEC and an association between PEAB and increased risk of NEC. Further studies should confirm these associations and explore causality.

SYSTEMATIC REVIEW REGISTRATION

identifier [CRD42022304937].

Nanomedicine to fight infectious disease

The ubiquity and potency of antibiotics may give the false impression that infection is a solved problem. Unfortunately, even bacterial infections, the target of antibiotics, remain a major cause of illness and death. Several major unmet needs persist: biofilms, such as those on implanted hardware, largely resist antibiotics; the inflammatory host response to infection often produces more damage than the infection itself; and systemic antibiotics often decimate the gut microbiome, which can predispose to additional infections and even predispose to non-infectious diseases. Additionally, there is an increasing threat from multi-drug resistant microorganisms, though market forces may continue to inhibit innovation in this realm. These numerous unmet infection-related needs provide attractive goals for innovation of targeted drug delivery technologies, especially those of nanomedicine. Here we review several of those innovations in pre-clinical development, the two such therapies which have made it to clinical use, and the opportunities for further technology development for treating infections.

Clinical Presentation and Multifactorial Pathogenesis of Necrotizing Enterocolitis in the Preterm Infant

BACKGROUND

Necrotizing enterocolitis (NEC) is a serious infection of the bowel wall induced by multiple pathological factors, which include inflammation and tissue invasion with bacteria known to cause severe infections. NEC is now understood to be several disease processes under one umbrella. The most common form occurs in premature infants and can exert significant impacts to preterm morbidity and mortality.

PURPOSE

This narrative review describes current knowledge of the clinical presentation and pathophysiology of NEC in premature infants.

METHODS/SEARCH STRATEGY

A review of literature was conducted using key words in PubMed and CINAHL with preference for years 2015 to 2020.

FINDINGS/RESULTS

Several converging and interrelated factors including characteristics of the premature intestinal mucosa, gut ischemia, dysregulation of the microbiome, enteral feeding, and genetics create an environment where NEC is more likely to occur.

IMPLICATIONS FOR PRACTICE

To recognize and diagnose NEC in preterm infants, an understanding of underlying factors that create an optimal environment for disease acquisition in premature infants is essential.

IMPLICATIONS FOR RESEARCH

Prevention of NEC remains the most important strategy for decreasing morbidity and mortality. Multiple areas of potential study exist for NEC pathophysiology including those that consider how the factors discussed in this review are interrelated and how each particular pathway can be optimized to prevent the onset of NEC.

Antibiotic Stewardship for the Neonatologist and Perinatologist

Antibiotic use is common in the neonatal intensive care unit. The density and heterogeneity of antibiotic prescribing suggests inappropriate and overuse of these agents. Potential antibiotic stewardship targets include sepsis, necrotizing enterocolitis, and perioperative prophylaxis. Diagnostic stewardship principles, including appropriately obtained cultures, may be leveraged to decrease unnecessary antibiotic prescribing. Strategies including guideline development, prospective audit and feedback, and formulary restriction have been successfully deployed in the neonatal intensive care unit to improve the quality of antibiotic prescribing. Implementation of antibiotic stewardship in the neonatal intensive care unit requires multidisciplinary collaboration between neonatologists, surgeons, infectious diseases specialists, pharmacists, and nurses.

Gut dysbiosis during early life: causes, health outcomes, and amelioration via dietary intervention

The colonization and maturation of gut microbiota (GM) is a delicate and precise process, which continues to influence not only infancy and childhood but also adulthood health by affecting immunity. However, many perinatal factors, including gestational age, delivery mode, antibiotic administration, feeding mode, and environmental and maternal factors, can disturb this well-designed process, increasing the morbidity of various gut dysbiosis-related diseases, such as type-1-diabetes, allergies, necrotizing enterocolitis, and obesity. In this review, we discussed the early-life colonization and maturation of the GM, factors influencing this process, and diseases related to the disruption of this process. Moreover, we focused on discussing dietary interventions, including probiotics, oligosaccharides, nutritional supplementation, and exclusive enteral nutrition, in ameliorating early-life dysbiosis and diseases related to it. Furthermore, possible mechanisms, and shortcomings, as well as potential solutions to the drawbacks of dietary interventions, were also discussed.

Interaction between IgA and gut microbiota and its role in controlling metabolic syndrome

Immunoglobulin A (IgA) is the most abundant immunoglobulin isotype secreted into the mucosal tissues, mainly intestinal mucus. Humans can produce several grams of IgA every day, accounting for three quarters of the body's total immunoglobulin content. IgA, together with mucus and antimicrobial peptides, forms the first line of defence for intestinal epithelial cells, protecting them from a significant number of intestinal antigens. IgA also plays a principal role in controlling the gut microbiota (GM), and disruption in IgA can result in dysbiosis, such as the enrichment of Proteobacteria, which are generally bound by IgA. Proteobacteria overexpansion is also usually seen in obesity and colitis. Consistent with this, IgA dysfunction frequently results in metabolic syndrome (MetS), including conditions such as obesity, adiposity, insulin resistance, and inflammation. In contrast, enhanced IgA function can improve, and even prevent, MetS. Interactions among IgA, GM, and metabolism provide a promising avenue to combat MetS.

Pathogenesis of necrotising enterocolitis: The impact of the altered gut microbiota and antibiotic exposure in preterm infants

Necrotising enterocolitis (NEC) is a devastating condition with high morbidity and mortality seen predominately in preterm infants. Multiple factors are associated with the pathogenesis of NEC. The widespread use of antibiotics in the neonatal intensive care unit might play a role in the pathogenesis of NEC in preterm infants. This review provides a summary on the intestinal microbiota in preterm infants with a focus on how antibiotic exposure may reduce the biodiversity of the intestinal microbiota and may predispose preterm infants to NEC. CONCLUSION: Prolonged antibiotic therapy has been suggested as a risk factor for the development of NEC in preterm infants.

Role of IgA in the early-life establishment of the gut microbiota and immunity: Implications for constructing a healthy start

Colonization and maturation of the gut microbiota (GM) during early life is a landmark event that fundamentally influences the (early) immunity and later-life health of various mammals. This is a delicate, systematic process that is biologically actively regulated by infants and their mothers, where (secretory) IgA, an important regulator of microbes found in breast milk and generated actively by infants, may play a key role. By binding to microbes, IgA can inhibit or enhance their colonization, influence their gene expression, and regulate immune responses. IgA dysfunction during early life is associated with disrupted GM maturation and various microbe-related diseases, such as necrotizing enterocolitis and diarrhea, which can also have a lasting effect on GM and host health. This review discusses the process of early GM maturation and its interaction with immunity and the role of IgA (focusing on milk secretory IgA) in regulating this process. The possible application of this knowledge in promoting normal GM maturation processes and immune education has also been highlighted.

Association of initial empirical antibiotic therapy with increased risk of necrotizing enterocolitis

Whether the prophylactic use of antibiotics increase the risk of necrotizing enterocolitis (NEC) remains controversial. This review aims to investigate initial empirical antibiotic therapy (IEAT) and is associated with the risk of NEC. PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched through March 1, 2020. All studies on the impacts of antibiotic exposure on NEC development were included. Thirteen studies including 7901 participants were selected. Two reviewers independently examined the extracted data and assessed the quality of the included studies. Random-effects model was used to pool the effect estimates. We found that IEAT (≥ 5 days) was associated with an increased risk of NEC in adjusted (Odds risk [OR] 1.51, 95% confidence interval [CI] 1.22-1.87) and unadjusted (OR 2.35, 95% CI 1.54-3.57) analyses. Sensitivity analysis also supported these findings.Conclusion: The evidence suggests an association between IEAT (≥ 5 days) and the risk of NEC. Further studies are needed to address whether the association with IEAT is causal.What is Known:•Necrotizing enterocolitis (NEC) is acute inflammatory necrosis of the intestinal tractin the newborn infant.•Some observational studies have associated initial empirical antibiotics with an increased risk of subsequent NEC.What is New:•Initial empirical antibiotic therapy (IEAT) (≥ 5 days) appear to increase the risk of NEC.

Determinants of the Very Low-Birth-Weight Infant's Intestinal Microbiome: A Systematic Review

The intestinal microbiome is the genetic material from microorganisms residing in the intestinal tract. Very low-birth-weight infants (VLBW; birth weight ≤1500 g) are a physiologically compromised population undergoing a unique period of initial intestinal microbiome establishment. Evidence supports a connection between the intestinal microbiome and gastrointestinal illness that disproportionately affects VLBW infants. Necrotizing enterocolitis, an inflammatory and often necrotic condition of the intestine, and late-onset sepsis, a bloodstream infection occurring after 3 days of life, are thought to be associated with delayed or abnormal intestinal microbiome development. Here, we review the determinants, or factors, that influence the VLBW infant's intestinal microbiome and discuss clinical implications. PubMed, Web of Science, EMBASE, and CINAHL were systematically searched for publications addressing factors with the potential to affect the intestinal microbiome of VLBW infants. Results indicate that infant's age and weight, mode of delivery, antibiotic exposure, medication use, feeding regime, environment, and perinatal-/infant-associated factors may be important determinants of the microbiome in this vulnerable population. Clinicians have opportunities to support positive development of the VLBW infant's intestinal microbiome through antibiotic stewardship, support of human milk feeding, and hygienic care practices.