Fetal and preterm infant microbiomes: a new perspective of necrotizing enterocolitis

Neonatal intestinal mucus barrier changes in response to maturity, inflammation, and sodium decanoate supplementation

The integrity of the intestinal mucus barrier is crucial for human health, as it serves as the body's first line of defense against pathogens. However, postnatal development of the mucus barrier and interactions between maturity and its ability to adapt to external challenges in neonatal infants remain unclear. In this study, we unveil a distinct developmental trajectory of the mucus barrier in preterm piglets, leading to enhanced mucus microstructure and reduced mucus diffusivity compared to term piglets. Notably, we found that necrotizing enterocolitis (NEC) is associated with increased mucus diffusivity of our large pathogen model compound, establishing a direct link between the NEC condition and the mucus barrier. Furthermore, we observed that addition of sodium decanoate had varying effects on mucus diffusivity depending on maturity and health state of the piglets. These findings demonstrate that regulatory mechanisms governing the neonatal mucosal barrier are highly complex and are influenced by age, maturity, and health conditions. Therefore, our results highlight the need for specific therapeutic strategies tailored to each neonatal period to ensure optimal gut health.

Effects of prophylactic antibiotics administration on barrier properties of intestinal mucosa and mucus from preterm born piglets

Early intervention and short-duration treatments with antibiotics in premature infants are reported to reduce the incidence of necrotizing enterocolitis (NEC), a terrible disease with severe inflammation and impaired intestinal barrier properties. Yet, it is unclear how antibiotics exposure, as well as route of administration used for dosing, can minimize the risk of NEC. With this study, we aimed to investigate if and how administration of antibiotics may affect the barrier properties of intestinal mucosa and mucus. We compared how parenteral (PAR) and a combination of enteral and parenteral (ENT+PAR) ampicillin and gentamicin given to preterm born piglets within 48 h after birth affected both barrier and physical properties of ex vivo small intestinal mucosa and mucus. Permeation of the markers mannitol, metoprolol, and fluorescein-isothiocyanate dextran of 4 kDa (FD4) and 70 kDa (FD70) through the mucosa and mucus was evaluated. For all markers, permeation through the mucosa and mucus collected from PAR piglets tended to be reduced when compared to that observed using untreated piglets. In contrast, permeation through the mucosa and mucus collected from ENT+PAR piglets tended to be similar to that observed for untreated piglets. Additionally, rheological measurements on the mucus from PAR piglets and ENT+PAR piglets displayed a decreased G' and G'/G" ratio and decreased viscosity at 0.4 s^-1 as well as lower stress stability compared to the mucus from untreated piglets.

Early antibiotic use and incidence of necrotising enterocolitis in very preterm infants: a protocol for a UK based observational study using routinely recorded data

INTRODUCTION

Necrotising enterocolitis (NEC) remains a major contributor to preterm mortality and morbidity. Prolonged duration of antibiotic therapy after delivery is associated with later NEC development but recent evidence suggests that absence of antibiotic treatment after delivery may also increase NEC risk. We will explore this controversy using a large pre-existing dataset of preterm infants in the UK.

METHODS AND ANALYSIS

This is a retrospective cohort study using data from UK National Neonatal Research Database (NNRD) for infants born 1 January 2012 to 31 December 2020. Eligible infants will be <32 weeks gestation, alive on day 3. Primary outcome is development of severe NEC, compared in infants receiving early antibiotics (days 1-2 after birth) and those not. Subgroup analysis on duration of early antibiotic exposure will also occur. Secondary outcomes are: late onset sepsis, total antibiotic use, predischarge mortality, retinopathy of prematurity, intraventricular haemorrhage, bronchopulmonary dysplasia, focal intestinal perforation and any abdominal surgery. To address competing risks, incidence of death before day 7, 14 and 28 will be analysed. We will perform logistic regression and propensity score matched analyses. Statistical analyses will be guided by NEC risk factors, exposures and outcome presented in a causal diagram. These covariates include but are not limited to gestational age, birth weight, small for gestational age, sex, ethnicity, delivery mode, delivery without labour, Apgar score, early feeding and probiotic use. Sensitivity analyses of alternate NEC definitions, specific antibiotics and time of initiation will occur.

ETHICS AND DISSEMINATION

We will use deidentified data from NNRD, which holds permissions for the original data, from which parents can opt out and seek study-specific research ethics approval. The results will help to determine optimal use of early antibiotics for very preterm infants.

IMPLICATIONS

This data will help optimise early antibiotic use in preterm infants.

TRIAL REGISTRATION NUMBER

ISRCTN55101779.

Early Use of Antibiotics Is Associated with a Lower Incidence of Necrotizing Enterocolitis in Preterm, Very Low Birth Weight Infants: The NEOMUNE-NeoNutriNet Cohort Study

OBJECTIVE

To determine whether commencement of antibiotics within 3 postnatal days in preterm, very low birth weight (VLBW; ≤1500 g) infants is associated with the development of necrotizing enterocolitis (NEC).

STUDY DESIGN

Preplanned statistical analyses were done to study the association between early antibiotic treatment and later NEC development, using the NEOMUNE-NeoNutriNet cohort of VLBW infants from 13 neonatal intensive care units (NICUs) in 5 continents (n = 2831). NEC incidence was compared between infants who received early antibiotics and those who did not, with statistical adjustments for NICU, gestational age, birth weight, sex, delivery mode, antenatal steroid use, Apgar score, and type and initiation of enteral nutrition.

RESULTS

The incidence of NEC was 9.0% in the group of infants who did not receive early antibiotics (n = 269), compared with 3.9% in those who did receive early antibiotics (n = 2562). The incidence remained lower in the early antibiotic group after stepwise statistical adjustments for NICU (OR, 0.57; 95% CI, 0.35-0.94, P < .05) and other potential confounders (OR, 0.25; 95% CI, 0.12-0.47; P < .0001).

CONCLUSIONS

In this large international cohort of preterm VLBW infants, a small proportion of infants did not receive antibiotics just after birth, and these infants had a higher incidence of NEC. It is important to better understand the role of such variables as time, type, and duration of antibiotic treatment on NEC incidence, immune development, gut colonization, and antibiotic resistance in the NICU.

Feeding the preterm infant: an overview of the evidence

Feeding from own mother's milk is not always an option for preterm infants, and choosing between alternative means of feeding should be made in light of their effect on infants' health. In this work, we aimed to present evidence regarding feeding pre-term infants with human milk, either own mother's or donor milk (DM), and the potential effects on growth and other health related outcomes. Exclusive breastfeeding (BF) remains the optimal option, whereas feeding with DM as a sole diet or supplemental to maternal milk confers immunological advantages and fewer rates of necrotising enterocolitis against preterm formula feeding, yet the latter results in greater growth velocity. Literature gaps in the use of DM, practical suggestions for choosing suitable feeding means (i.e. continuous support of BF, adequate education regarding feeding preterm infants, including DM), and future perspectives on the potential effects of dietary manipulations of the maternal diet, are also discussed.