Probiotics to prevent necrotising enterocolitis in very preterm or very low birth weight infants

Early life gut microbiome and its impact on childhood health and chronic conditions

The development of the gut microbiome is crucial to human health, particularly during the first three years of life. Given its role in immune development, disturbances in the establishment process of the gut microbiome may have long term consequences. This review summarizes evidence for these claims, highlighting compositional changes of the gut microbiome during this critical period of life as well as factors that affect gut microbiome development. Based on human and animal data, we conclude that the early-life microbiome is a determinant of long-term health, impacting physiological, metabolic, and immune processes. The early-life gut microbiome field faces challenges. Some of these challenges are technical, such as lack of standardized stool collection protocols, inconsistent DNA extraction methods, and outdated sequencing technologies. Other challenges are methodological: small sample sizes, lack of longitudinal studies, and poor control of confounding variables. To address these limitations, we advocate for more robust research methodologies to better understand the microbiome's role in health and disease. Improved methods will lead to more reliable microbiome studies and a deeper understanding of its impact on health outcomes.

Digging deeper into necrotizing enterocolitis: bridging clinical, microbial, and molecular perspectives

Necrotizing Enterocolitis (NEC) is a severe, life-threatening inflammatory condition of the gastrointestinal tract, especially affecting preterm infants. This review consolidates evidence from various biomedical disciplines to elucidate the complex pathogenesis of NEC, integrating insights from clinical, microbial, and molecular perspectives. It emphasizes the modulation of NEC-associated inflammatory pathways by probiotics and novel biologics, highlighting their therapeutic potential. We further critically examine dysbiotic alterations within the gut microbiota, with a particular focus on imbalances in bacterial and viral communities, which may contribute to the onset of NEC. The intricate interactions among toll-like receptor 4 (TLR4), microvascular integrity, immune activation, and the inflammatory milieu are meticulously summarized, offering a sophisticated understanding of NEC pathophysiology. This academic review aims to enhance the etiological comprehension of NEC, promote the development of targeted therapeutic interventions, and impart the significant impact of perinatal factors on the formulation of preventive and curative strategies for the disease.

Progress in Probiotic Science: Prospects of Functional Probiotic-Based Foods and Beverages

This comprehensive review explores the evolving role of probiotic-based foods and beverages, highlighting their potential as functional and "future foods" that could significantly enhance nutrition, health, and overall well-being. These products are gaining prominence for their benefits in gut health, immune support, and holistic wellness. However, their future success depends on addressing critical safety concerns and navigating administrative complexities. Ensuring that these products "do more good than harm" involves rigorous evaluations of probiotic strains, particularly those sourced from the human gastrointestinal tract. Lactic acid bacteria (LABs) serve as versatile and effective functional starter cultures for the development of probiotic foods and beverages. The review emphasizes the role of LABs as functional starter cultures and the development of precision probiotics in advancing these products. Establishing standardized guidelines and transparent practices is essential, requiring collaboration among regulatory bodies, industry stakeholders, and the scientific community. The review underscores the importance of innovation in developing "friendly bacteria," "super probiotics," precision fermentation, and effective safety assessments. The prospects of functional probiotic-based foods and beverages rely on refining these elements and adapting to emerging scientific advancements. Ultimately, empowering consumers with accurate information, fostering innovation, and maintaining stringent safety standards will shape the future of these products as trusted and beneficial components of a health-conscious society. Probiotic-based foods and beverages, often infused with LABs, a "friendly bacteria," are emerging as "super probiotics" and "future foods" designed to "do more good than harm" for overall health.

The effectiveness of treatment with probiotics in preventing necrotizing enterocolitis and related mortality: results from an umbrella meta-analysis on meta-analyses of randomized controlled trials

INTRODUCTION

Probiotic supplementation has been proposed as a preventive measure for necrotizing enterocolitis (NEC) in preterm infants. This umbrella meta-analysis assesses the effects of probiotics, including single-strain and multi-strain formulations, on NEC and related mortality.

METHODS

A comprehensive search was conducted in PubMed, Scopus, ISI Web of Science, and Embase for studies up to August 2024. The AMSTAR2 tool assessed the quality of included studies. Meta-analysis studies were selected based on the PICOS framework, focusing on preterm neonates (< 37-week gestation), probiotic supplementation (single-strain or multi-strain), placebo or standard care comparison, and outcomes of NEC and mortality. Pooled relative risks (RR) and odds ratios (OR) with 95% confidence intervals (CI) were calculated using random-effects models.

RESULTS

Overall, 35 eligible studies were included into the study. Twenty-six and 32 probiotic intervention arms used single- and multi-strain probiotics, respectively. The findings revealed that probiotics decreased NEC significantly (ESRR: 0.51; 95% CI: 0.46, 0.55, p < 0.001, and ESOR: 0.59; 95%CI: 0.48, 0.72, P < 0.001), and mortality rate (ESRR: 0.72; 95% CI: 0.68, 0.76, P < 0.001, and ESOR: 0.77; 95%CI: 0.70, 0.84, p < 0.001).

CONCLUSION

The present review suggests that supplementation with probiotics reduced NEC and related mortality. Probiotic supplementation can be recognized as a NEC-preventing approach in preterm and very preterm infants, particularly Multi-strain probiotics.

Impact of probiotics on gut microbiome of extremely preterm or extremely low birthweight infants

IMPACT

Meta-analysis of probiotic administration to very preterm or very low birthweight (VP/VLBW) infants shows reduced risk of necrotising enterocolitis (NEC). Separately reported outcomes for extremely preterm infants (<28 weeks) or extremely low birth weight infants (<1000 g) (EP/ELBW) are lacking meaning some clinicians do not administer probiotics to EP/ELBW infants despite their high risk of NEC. We present data showing the gut microbiome is impacted in EP/ELBW infants in a similar manner to VP/VLBW infants, suggesting that risk reduction for necrotising enterocolitis that is microbiome driven will also be seen in EP/ELBW infants, making probiotic administration beneficial.

Multi-strain probiotic administration decreases necrotizing enterocolitis severity and alters the epigenetic profile in mice

BACKGROUND

Probiotic administration may decrease the incidence of necrotizing enterocolitis (NEC) through mechanisms that are largely unknown. We investigated the effects of probiotics on intestinal epigenetics and assessed their effects on intestinal inflammation and motility using both ileum-predominant and combined ileo-colitis mouse NEC models.

METHODS

C57BL/6 J mice were gavage-fed a multi-strain probiotic from postnatal days 3-11, consisting of B. infantis, B. lactis, and S. thermophilus. From p8, mice were exposed to ileo-colitis NEC involving formula containing NEC bacteria and 0.5% DSS. DNA methylation was measured using the Infinium Methylation Assay. Gastrointestinal motility was assessed by 70 Kd FITC-dextran transit time. Probiotic colonization was measured in probiotic-fed mice by qPCR.

RESULTS

Probiotic administration caused significant changes in the small intestine's epigenetic signature, a reduction in NEC severity, and improved intestinal motility. The effects of probiotics were more pronounced in the ileo-colitis NEC model.

CONCLUSIONS

These findings shed light on the role of probiotics in two clinically relevant models of NEC, add additional insights into their underlying mechanism of action, and reveal unanticipated epigenetic modifications to the intestinal mucosa after their use.

IMPACT

These findings shed light on the role of multi-strain probiotics in two clinically relevant animal models of NEC, and add additional insights into their underlying mechanism of action This study provides a new, clinically relevant model for the study of NEC including administration of 0.5% DSS, to include ileal dominant and ileo-colonic dominant phenotypes of the disease. These results reveal that clinically relevant strains of probiotic bacteria can exert epigenetic effects on the small intestine in mice, and can attenuate the epigenetic changes induced by NEC.

Use of Probiotics for Preventing Necrotizing Enterocolitis in Preterm Infants: A Survey of Current Practices Among Indian Neonatologists

OBJECTIVE

Probiotics are known to reduce the risk of necrotizing enterocolitis (NEC≥ Stage II) significantly, as well as all-cause mortality, late-onset sepsis (LOS), and feeding intolerance in preterm infants. Probiotics have been reported to have comparable benefits in high- and low-middle-income countries (LMICs). We aimed to assess the current practices of neonatologists in India for using probiotics in preterm infants.

MATERIAL AND METHODS

A questionnaire created using Survey Monkey's web-based tool was sent to neonatologists in India. Survey forms automatically converted responses into Excel files (Microsoft® Corp., Redmond, WA). Data were analyzed using SPSS (IBM Corp., Armonk, NY).

RESULTS

A total of 615 responses were received from various neonatal intensive care units (NICUs) in India (Level I: 43 (7%), II: 124 (20.8%), III: 448 (72.8%)). Around 431 (70%) of the units had either National Neonatology Forum (NNF) accreditation or IAP fellowships or were affiliated with private or government medical colleges. The remaining 184 (30%) were in private setups. Routine probiotic supplementation (RPS) was provided in 241 (39.1%) of the responding units; 179 (48%) quoted inadequate evidence as the reason for not providing RPS, 125 (33.43%) quoted difficulty in sourcing safe and effective products, whereas others were concerned about adverse effects. Most centers provided RPS for preterm infants <32 weeks and 1500 g at birth. The clinical practice was influenced by the judgment of the attending clinician. Significant variation was noticed in the protocol for RPS.

CONCLUSION

Findings of the survey suggest that approximately 39% of the participating neonatologists in India currently offer RPS for preterm infants. A significant variation exists in the selection of probiotic strains, products, dose, and duration of supplementation. Despite limitations, our findings are useful in guiding clinical practice and further research to optimize the safety and efficacy of RPS for preterm infants.

The Impact of Bioactive Molecules from Probiotics on Child Health: A Comprehensive Review

Background: This review investigates the impact of bioactive molecules produced by probiotics on child health, focusing on their roles in modulating gut microbiota, enhancing immune function, and supporting overall development. Key metabolites, including short-chain fatty acids (SCFAs), bacteriocins, exopolysaccharides (EPSs), vitamins, and gamma-aminobutyric acid (GABA), are highlighted for their ability to maintain gut health, regulate inflammation, and support neurodevelopment. Objectives: The aim of this review is to examine the mechanisms of action and clinical evidence supporting the use of probiotics and postbiotics in pediatric healthcare, with a focus on promoting optimal growth, development, and overall health in children. Methods: The review synthesizes findings from clinical studies that investigate the effects of probiotics and their metabolites on pediatric health. The focus is on specific probiotics and their ability to influence gut health, immune responses, and developmental outcomes. Results: Clinical studies demonstrate that specific probiotics and their metabolites can reduce gastrointestinal disorders, enhance immune responses, and decrease the incidence of allergies and respiratory infections in pediatric populations. Additionally, postbiotics-bioactive compounds from probiotic fermentation-offer promising benefits, such as improved gut barrier function, reduced inflammation, and enhanced nutrient absorption, while presenting fewer safety concerns compared to live probiotics. Conclusions: By examining the mechanisms of action and clinical evidence, this review underscores the potential of integrating probiotics and postbiotics into pediatric healthcare strategies to promote optimal growth, development, and overall health in children.

Donor human milk for preventing necrotising enterocolitis in very preterm or very low-birthweight infants

BACKGROUND

When sufficient maternal milk is not available, donor human milk or formula are the alternative forms of enteral nutrition for very preterm or very low-birthweight (VLBW) infants. Donor human milk may retain the non-nutritive benefits of maternal milk and has been proposed as a strategy to reduce the risk of necrotising enterocolitis (NEC) and associated mortality and morbidity in very preterm or VLBW infants.

OBJECTIVES

To assess the effectiveness of donor human milk compared with formula for preventing NEC and associated morbidity and mortality in very preterm or VLBW infants when sufficient maternal milk is not available.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Maternity and Infant Care (MIC) database, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), from the earliest records to February 2024. We searched clinical trials registries and examined the reference lists of included studies.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing feeding with donor human milk versus formula in very preterm (< 32 weeks' gestation) or VLBW (< 1500 g) infants.

DATA COLLECTION AND ANALYSIS

Two review authors evaluated the risk of bias in the trials, extracted data, and synthesised effect estimates using risk ratio, risk difference, and mean difference, with associated 95% confidence intervals. The primary outcomes were NEC, late-onset invasive infection, and all-cause mortality before hospital discharge. The secondary outcomes were growth parameters and neurodevelopment. We used the GRADE approach to assess the certainty of the evidence for our primary outcomes.

MAIN RESULTS

Twelve trials with a total of 2296 infants fulfilled the inclusion criteria. Most trials were small (average sample size was 191 infants). All trials were performed in neonatal units in Europe or North America. Five trials were conducted more than 40 years ago; the remaining seven trials were conducted in the year 2000 or later. Some trials had methodological weaknesses, including concerns regarding masking of investigators and selective reporting. Meta-analysis showed that donor human milk reduces the risk of NEC (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.37 to 0.76; I² = 4%; risk difference (RD) -0.03, 95% CI -0.05 to -0.01; 11 trials, 2261 infants; high certainty evidence). Donor human milk probably has little or no effect on late-onset invasive infection (RR 1.12, 0.95 to 1.31; I² = 27%; RD 0.03, 95% CI -0.01 to -0.07; 7 trials, 1611 infants; moderate certainty evidence) or all-cause mortality (RR 1.00, 95% CI 0.76 to 1.31; I² = 0%; RD -0.00, 95% CI -0.02 to 0.02; 9 trials, 2116 infants; moderate certainty evidence).

AUTHORS' CONCLUSIONS

The evidence shows that donor human milk reduces the risk of NEC by about half in very preterm or VLBW infants. There is probably little or no effect on late-onset invasive infection or all-cause mortality before hospital discharge.

Contemporary use of prophylactic probiotics in NICUs in the United States: a survey update

OBJECTIVE

In 2015, 14.0% of US NICUs administered probiotics to very low birth weight infants. Current probiotic use prior to and after the Fall of 2023 (when FDA warnings were issued) remains unknown.

STUDY DESIGN

A survey was distributed to the American Academy of Pediatrics Section on Neonatal and Perinatal Medicine (August-November/2022) and Neonatology Solutions' Level III/IV NICUs (January-April/2023). Probiotic administration practices were investigated.

RESULTS

In total, 289 unique NICUs and 406 providers responded to the survey. Of those, 29.1% of NICUs administered prophylactic probiotics to premature neonates, however, this decreased considerably after FDA warnings were issued. Additionally, 71.4% of providers stated willingness to administer probiotics to premature infants if there was an FDA-approved formulation.

CONCLUSIONS

Probiotic use in US NICUs increased between 2015 and the Fall of 2023 and then dropped dramatically following warning letters from the FDA. The introduction of an FDA-approved probiotic may further expand administration.

Probiotic supplementation and risk of necrotizing enterocolitis and mortality among extremely preterm infants-the Probiotics in Extreme Prematurity in Scandinavia (PEPS) trial: study protocol for a multicenter, double-blinded, placebo-controlled, and registry-based randomized controlled trial

BACKGROUND

Extremely preterm infants, defined as those born before 28 weeks' gestational age, are a very vulnerable patient group at high risk for adverse outcomes, such as necrotizing enterocolitis and death. Necrotizing enterocolitis is an inflammatory gastrointestinal disease with high incidence in this cohort and has severe implications on morbidity and mortality. Previous randomized controlled trials have shown reduced incidence of necrotizing enterocolitis among older preterm infants following probiotic supplementation. However, these trials were underpowered for extremely preterm infants, rendering evidence for probiotic supplementation in this population insufficient to date.

METHODS

The Probiotics in Extreme Prematurity in Scandinavia (PEPS) trial is a multicenter, double-blinded, placebo-controlled and registry-based randomized controlled trial conducted among extremely preterm infants (n = 1620) born at six tertiary neonatal units in Sweden and four units in Denmark. Enrolled infants will be allocated to receive either probiotic supplementation with ProPrems® (Bifidobacterium infantis, Bifidobacterium lactis, and Streptococcus thermophilus) diluted in 3 mL breastmilk or placebo (0.5 g maltodextrin powder) diluted in 3 mL breastmilk per day until gestational week 34. The primary composite outcome is incidence of necrotizing enterocolitis and/or mortality. Secondary outcomes include incidence of late-onset sepsis, length of hospitalization, use of antibiotics, feeding tolerance, growth, and body composition at age of full-term and 3 months corrected age after hospital discharge.

DISCUSSION

Current recommendations for probiotic supplementation in Sweden and Denmark do not include extremely preterm infants due to lack of evidence in this population. However, this young subgroup is notably the most at risk for experiencing adverse outcomes. This trial aims to investigate the effects of probiotic supplementation on necrotizing enterocolitis, death, and other relevant outcomes to provide sufficiently powered, high-quality evidence to inform probiotic supplementation guidelines in this population. The results could have implications for clinical practice both in Sweden and Denmark and worldwide.

TRIAL REGISTRATION

( Clinicaltrials.gov ): NCT05604846.

The Incidence of Necrotizing Enterocolitis and Late-Onset Sepsis during the COVID-19 Pandemic in Sweden: A Population-Based Cohort Study

INTRODUCTION

The effect of the pandemic restrictions in the NICUs is not well studied. Necrotizing enterocolitis (NEC) is characterized by intestinal inflammation and bacterial invasion. This study aimed to investigate whether the incidence of NEC has changed during the COVID-19 pandemic in Sweden and whether it was associated with a change in the frequency of extremely preterm births.

METHODS

Data were retrieved from the Swedish Neonatal Quality Register (SNQ) for infants registered between January 2017 and December 2021 born below a gestational age of 35 weeks. The registry completeness is 98-99%. The diagnosis of NEC was the primary outcome. Generalized linear model analysis was used to calculate the risk ratio for NEC.

RESULTS

Totally 13,239 infants were included. 235 (1.8%) infants developed NEC, out of which 91 required surgical treatment. 8,967 infants were born before COVID-19 pandemic and 4,272 during. Median gestational age at birth was 32.8 weeks in both periods. The incidence of NEC was significantly lower during COVID-19 pandemic compared to the prior period (1.43 vs. 1.94%, p 0.037), but not the incidence of surgical NEC. The crude risk ratio of developing NEC during COVID-19 pandemic was 0.74 (95% CI: 0.55-0.98). The incidence of late-onset sepsis with positive culture was also declined during COVID-19 (3.21 vs. 4.15%, p value 0.008).

CONCLUSION

While we found significant reduction in the incidence of NEC and culture-positive late-onset sepsis during the COVID-19 pandemic, the number of extremely preterm births was unchanged.

Lung Microbiota and Ventilator-Associated Pneumonia in the Neonatal Period

The lung microbiota is a complex community of microorganisms that colonize the respiratory tract of individuals from, or even before, birth. Although the lungs were traditionally believed to be sterile, recent research has shown that there is a diversity of bacterial species in the respiratory system. Knowledge about the lung microbiota in newborns and its relationship with bacterial infections is of vital importance to understand the pathogenesis of respiratory diseases in neonatal patients undergoing mechanical ventilation. In this article, the current evidence on the composition of the lung microbiota in newborns will be reviewed, as well as the risks that an altered microbiota can impose on premature newborns. Although advances in neonatal intensive care units have significantly improved the survival rate of preterm infants, the diagnosis and treatment of ventilator-associated pneumonia has not progressed in recent decades. Avoiding dysbiosis caused by inappropriate use of antibiotics around birth, as well as avoiding intubation of patients or promoting early removal of endotracheal tubes, are among the most important preventive measures for ventilator-associated pneumonia. The potential benefit of probiotics and prebiotics in preventing infectious, allergic or metabolic complications in the short or long term is not clearly established and constitutes a very important field of research in perinatal medicine.

Fecal virus-like particles are sufficient to reduce necrotizing enterocolitis

Fecal filtrate transfer (FFT) is emerging as a safer alternative to traditional fecal microbiota transplantation (FMT) - particularly in the context of necrotizing enterocolitis (NEC), a severe gastrointestinal condition affecting preterm infants. Using a preterm piglet model, FFT has demonstrated superiority over FMT in safety and NEC prevention. Since FFT is virtually devoid of bacteria, prokaryotic viruses (bacteriophages) are assumed to mediate the beneficial effects. However, this assumption remains unproven. To address this gap, we separated virus-like particles (30 kDa to 0.45 µm) of donor feces from the residual postbiotic fluid. We then compared clinical and gut microbiota responses to these fractions with the parent FFT solution after transferring them to NEC-susceptible preterm piglets. Virome transfer was equally effective as FFT in reducing the severity of NEC-like pathology. The bacterial compositional data corroborated clinical findings as virome transfer reduced the relative abundance of several NEC-associated pathogens e.g. Klebsiella pneumoniae and Clostridium perfringens. Virome transfer diversified gut viral communities with concomitant constraining effects on the bacterial composition. Unexpectedly, virome transfer, but not residual postbiotic fluid, led to earlier diarrhea. While diarrhea may be a minor concern in human infants, future work should identify ways of eliminating this side effect without losing treatment efficacy.