Survey and evidence based review of probiotics used in very low birth weight preterm infants within the United States

Clinical Picture, Diagnosis, Management of NEC, and Effects of Probiotics on its Prevention: A Narrative Review

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.

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.

Selection of a probiotic to prevent necrotizing enterocolitis for preterm infants in a French neonatology department

Very premature and/or low-birth-weight infants are at risk of developing necrotizing ulcerative enterocolitis (NEC). Prophylactic use of probiotics would change the composition of the gut microbiota and thus reduce the risk of NEC. In order to choose a probiotic at the local level, international recommendations were compared, and the available specialties were listed. Discrepancies between the different recommendations appeared, and the great variability of infant specialties available, as well as their status, did not allow us to select one. The local objective will therefore be to participate in the discussion of this subject at a national level.

Current Patterns of Probiotic Use in U.S. Neonatal Intensive Care Units: A Multi-Institution Survey

OBJECTIVE

Probiotic supplementation is associated with health benefits in preterm infants. The 2021 American Academy of Pediatrics (AAP) statement on probiotic use advised caution, citing heterogeneity and absence of federal regulation. We assessed the impact of the AAP statement and current institution-wide patterns of probiotic use across neonatal intensive care units (NICU) across the United States.

STUDY DESIGN

A cross-sectional web-based institutional survey using REDCap was emailed to 430 Children's Hospital Neonatal Consortium (CHNC) and Pediatrix Medical Group institutions. The survey captured data on probiotic formulations, supplementation, initiation and cessation criteria, reasons for discontinuation, interest in initiating, and AAP statement's impact.

RESULTS

Ninety-five (22.1%) hospitals, including 42/46 (91%) CHNC and 53/384 (14%) Pediatrix institutions, completed the survey. Thirty-seven (39%) currently use probiotics. Fourteen different probiotic formulations were reported. The common criteria for initiation were birth weight <1,500 g and gestational age <32 weeks. Parental consent or assent was obtained at only 30% of institutions. Five hospitals (11%) with prior probiotic use discontinued solely due to the AAP statement. Overall, 23 (24%) of hospitals indicated that the AAP statement significantly influenced their decision regarding probiotic use. Nineteen of 51 nonusers (37%) are considering initiation.

CONCLUSION

Probiotic use in preterm infants is likely increasing in NICUs across the United States, but significant variability exists. The 2021 AAP statement had variable impact on NICUs' decision regarding probiotic use. The growing interest in adopting probiotics and the significant interhospital variability highlight the need for better regulation and consensus guidelines to ensure standardized use.

KEY POINTS

· Probiotic use in preterm infants is likely increasing in U.S. NICUs, but clinical variability exists.. · The AAP statement on probiotic use in preterm infants had a modest impact on current practices.. · There's a need for better product regulation and consensus guidelines to ensure standardized use..

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.

State of the Art of Probiotic Use in Neonatal Intensive Care Units in French-Speaking European Countries

The effectiveness of probiotics in reducing the incidence of necrotizing enterocolitis has been supported by a very large number of studies. However, the utilization of probiotics in preterm infants remains a topic of debate. This study aims to assess the rate of probiotic use in European neonatal intensive care units (NICUs), compare administration protocols, and identify barriers and concerns associated with probiotic use. An online questionnaire was distributed via email to European NICUs between October 2020 and June 2021. Different questions related to the frequency of probiotic use were proposed. Data on probiotic administration protocols and reasons for non-utilization were collected. The majority of responses were from France and Switzerland, with response rates of 85% and 89%, respectively. A total of 21% of French NICUs and 100% of Swiss NICUs reported routine probiotic use. There was significant heterogeneity in probiotic administration protocols, including variations in probiotic strains, administration, and treatment duration. The main obstacles to routine probiotic use were the absence of recommendations, lack of consensus on strain selection, insufficient scientific evidence, and concerns regarding potential adverse effects. The rate of routine probiotic administration remains low in European NICUs, with heterogeneity among protocols. Further trials are necessary to elucidate optimal treatment modalities and ensure safety of administration.

Effective alternatives for dietary interventions for necrotizing enterocolitis: a systematic review of in vivo studies

Necrotizing enterocolitis (NEC) is a significant cause of morbidity and mortality among neonates and low birth weight children in the United States. Current treatment options, such as antibiotics and intestinal resections, often result in complications related to pediatric nutrition and development. This systematic review aimed to identify alternative dietary bioactive compounds that have shown promising outcomes in ameliorating NEC in vivo studies conducted within the past six years. Following PRISMA guidelines and registering in PROSPERO (CRD42023330617), we conducted a comprehensive search of PubMed, Scopus, and Web of Science. Our analysis included 19 studies, predominantly involving in vivo models of rats (Rattus norvegicus) and mice (Mus musculus). The findings revealed that various types of compounds have demonstrated successful amelioration of NEC symptoms. Specifically, six studies employed plant phenolics, seven utilized plant metabolites/cytotoxic chemicals, three explored the efficacy of vitamins, and three investigated the potential of whole food extracts. Importantly, all administered compounds exhibited positive effects in mitigating the disease. These results highlight the potential of natural cytotoxic chemicals derived from medicinal plants in identifying and implementing powerful alternative drugs and therapies for NEC. Such approaches have the capacity to impact multiple pathways involved in the development and progression of NEC symptoms.

Effect of Probiotic Dose Escalation on Gut Microbiota and Clinical Outcomes in Preterm Infants-A Systematic Review

Probiotics are known to decrease incidences of necrotising enterocolitis, feeding intolerance, late-onset sepsis, and mortality in preterm infants. Administering an adequate dose is important for optimizing the benefits and safety of probiotics. We conducted a systematic review to assess the effect of probiotic dose escalation on clinical outcomes and gut microbiota in preterm neonates. We searched PubMed, EMBASE, EMCARE, Medline, Cochrane Library, Google Scholar, and MedNar databases in July 2023. Three studies were included. In one of the randomized studies (n = 149, gestation 27 to 33 weeks), no significant differences in faecal Lactobacillus and Bifidobacterium counts and clinical outcomes were seen between the high- and low-dose groups. There was a trend towards increased Lactobacillus and Bifidobacterium counts in the high-dose group. In the other randomized study (n = 120, birth weight 500 to 2000 gm), smaller infants (500 to 1000 gm) required higher doses to display Lactobacillus in their faeces. The cohort study (n = 12, gestation < 33 weeks) showed a trend towards an increase in faecal abundance of bifidobacteria and bacterial diversity in the B. infantis group with increasing dose/time. Limited evidence suggests a higher dose might improve gut colonization in preterm infants. Further studies are urgently needed to address this gap in the knowledge considering the increasing use of probiotics for preterm infants.

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

BACKGROUND

Intestinal dysbiosis may contribute to the pathogenesis of necrotising enterocolitis (NEC) in very preterm or very low birth weight (VLBW) infants. Dietary supplementation with probiotics to modulate the intestinal microbiome has been proposed as a strategy to reduce the risk of NEC and associated mortality and morbidity in very preterm or VLBW infants.

OBJECTIVES

To determine the effect of supplemental probiotics on the risk of NEC and associated mortality and morbidity in very preterm or very low birth weight infants.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, the Maternity and Infant Care database, and CINAHL from inception to July 2022. We searched clinical trials databases and conference proceedings, and examined the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing probiotics with placebo or no probiotics in very preterm infants (born before 32 weeks' gestation) and VLBW infants (weighing less than 1500 g at birth).

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated risk of bias of the trials, extracted data, and synthesised effect estimates using risk ratios (RRs), risk differences (RDs), and mean differences (MDs), with associated 95% confidence intervals (CIs). The primary outcomes were NEC and all-cause mortality; secondary outcome measures were late-onset invasive infection (more than 48 hours after birth), duration of hospitalisation from birth, and neurodevelopmental impairment. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included 60 trials with 11,156 infants. Most trials were small (median sample size 145 infants). The main potential sources of bias were unclear reporting of methods for concealing allocation and masking caregivers or investigators in about half of the trials. The formulation of the probiotics varied across trials. The most common preparations contained Bifidobacterium spp., Lactobacillus spp., Saccharomyces spp., andStreptococcus spp., alone or in combination. Very preterm or very low birth weight infants Probiotics may reduce the risk of NEC (RR 0.54, 95% CI 0.46 to 0.65; I² = 17%; 57 trials, 10,918 infants; low certainty). The number needed to treat for an additional beneficial outcome (NNTB) was 33 (95% CI 25 to 50). Probiotics probably reduce mortality slightly (RR 0.77, 95% CI 0.66 to 0.90; I² = 0%; 54 trials, 10,484 infants; moderate certainty); the NNTB was 50 (95% CI 50 to 100). Probiotics probably have little or no effect on the risk of late-onset invasive infection (RR 0.89, 95% CI 0.82 to 0.97; I² = 22%; 49 trials, 9876 infants; moderate certainty). Probiotics may have little or no effect on neurodevelopmental impairment (RR 1.03, 95% CI 0.84 to 1.26; I² = 0%; 5 trials, 1518 infants; low certainty). Extremely preterm or extremely low birth weight infants Few data were available for extremely preterm or extremely low birth weight (ELBW) infants. In this population, probiotics may have little or no effect on NEC (RR 0.92, 95% CI 0.69 to 1.22, I² = 0%; 10 trials, 1836 infants; low certainty), all-cause mortality (RR 0.92, 95% CI 0.72 to 1.18; I² = 0%; 7 trials, 1723 infants; low certainty), or late-onset invasive infection (RR 0.93, 95% CI 0.78 to 1.09; I² = 0%; 7 trials, 1533 infants; low certainty). No trials provided data for measures of neurodevelopmental impairment in extremely preterm or ELBW infants.

AUTHORS' CONCLUSIONS

Given the low to moderate certainty of evidence for the effects of probiotic supplements on the risk of NEC and associated morbidity and mortality for very preterm or VLBW infants, and particularly for extremely preterm or ELBW infants, there is a need for further large, high-quality trials to provide evidence of sufficient validity and applicability to inform policy and practice.

Probiotics and novel probiotic delivery systems

Necrotizing enterocolitis (NEC) is an infectious and inflammatory intestinal disease that is the most common surgical emergency in the premature patient population. Although the etiology of the disease is multifactorial, intestinal dysbiosis is a hallmark of this disease. Based on this, probiotics may play a therapeutic role in NEC by introducing beneficial bacteria with immunomodulating, antimicrobial, and anti-inflammatory functions into the gastrointestinal tract. Currently, there is no Food and Drug Administration (FDA)-approved probiotic for the prevention and treatment of NEC. All probiotic clinical studies to date have administered the bacteria in their planktonic (free-living) state. This review will discuss established probiotic delivery systems including planktonic probiotics, prebiotics, and synbiotics, as well as novel probiotic delivery systems such as biofilm-based and designer probiotics. We will also shed light on whether or not probiotic efficacy is influenced by administration with breast milk. Finally, we will consider the challenges associated with developing an FDA-approved probiotic for NEC.

Association of Hospital Adoption of Probiotics With Outcomes Among Neonates With Very Low Birth Weight

Importance

For neonates with very low birth weight (VLBW), randomized clinical trials (RCTs) indicate that probiotic treatment decreases the risk of necrotizing enterocolitis (NEC), with smaller decreases in the risk of sepsis and death. There is little evidence on the rate of probiotic adoption in US neonatal intensive care units (NICUs) and whether the benefits seen in trials have materialized in practice.

Objective

To estimate changes in probiotic use among neonates with VLBW and to test whether neonates with VLBW treated at NICUs adopting routine probiotic use experience better outcomes compared with neonates treated at nonadopting NICUs.

Design, Setting, and Participants

This cohort study used Vermont Oxford Network data on neonates with VLBW in US NICUs from January 1, 2012, to December 31, 2019. Data were analyzed from January 2022 through February 2023.

Exposure

Probiotics adoption vs nonadoption. Adopting NICUs were defined as those that currently or previously treated at least 20% of neonates with VLBW with probiotics.

Main Outcomes

The primary outcomes were rates of NEC, in-hospital mortality, and sepsis, defined as bacterial or fungal infection occurring after day 3 from birth. A difference-in-differences analysis compared changes in VLBW infant outcomes between adopting and nonadopting NICUs before and after hospital-level adoption of probiotics. Additional analyses used the proportion of neonates treated with probiotics in each neonate's birth NICU and year.

Results

The analysis included 307 905 neonates with VLBW (mean [SD] gestational age, 28.4 [2.9] weeks; 50.0% male) at 807 US hospitals. The rate of probiotic treatment of neonates with VLBW rose from 1572 of 38 296 neonates (4.1%) in 2012 to 4788 of 37 910 (12.6%) in 2019. Only 123 of 745 NICUs (16.5%) adopted probiotics by 2019, with 4591 of 6017 neonates with VLBW (76.3%) receiving probiotics in 2019 at adopting NICUs. Incidence of NEC declined by 18% at adopting NICUs (odds ratio [OR], 0.82; 95% CI, 0.70-0.95; P = .10) compared with nonadopting NICUs. Probiotic adoption was not associated with a significant reduction in sepsis (OR, 1.11; 95% CI, 0.98-1.25; P = .09) or mortality (OR, 0.93; 95% CI, 0.80-1.08; P = .33).

Conclusion and Relevance

In this cohort study, adoption of routine use of probiotics increased slowly in US NICUs and was associated with lower NEC risk but not with sepsis or mortality among neonates with VLBW. The findings for probiotic adoption and NEC, sepsis, and mortality were smaller than would have been predicted by the totality of RCT evidence but are consistent with a meta-analysis restricted to studies at low risk of bias.

Effects of prophylactic probiotics supplementation on infants born very preterm or very low birth weight

OBJECTIVE

To evaluate the effects of guideline-driven prophylactic supplementation of a multi-strain neonatal intensive care unit-specific probiotic product on infants born very preterm (VP) or very low birth weight (VLBW).

STUDY DESIGN

A prospective cohort of 125 infants born in one year after implementation who received probiotics were compared to a retrospective cohort of eligible 126 VP or VLBW infants who did not receive probiotics. The primary outcome of interest was necrotizing enterocolitis (NEC).

RESULT

The incidence of NEC decreased from 6.3 to 1.6%. After adjusting for multiple variables, there were no significant differences in primary or other outcomes of interest; odds ratio (95% confidence interval) NEC 0.27 (0.05-1.33), death 0.76 (0.26-2.21) and late-onset sepsis 0.54 (0.18-1.63). No adverse effects related to probiotics supplementation were observed.

CONCLUSION

Although nonsignificant, prophylactic probiotics supplementation in infants born VP or VLBW was associated with reduction of NEC.

Current and future methods of probiotic therapy for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a complex intestinal disease that primarily affects premature neonates. Given its significant mortality and morbidity, there is an urgent need to develop improved prophylactic measures against the disease. One potential preventative strategy for NEC is the use of probiotics. Although there has been significant interest for decades in probiotics in neonatal care, no clear guidelines exist regarding which probiotic to use or for which patients, and no FDA-approved products exist on the market for NEC. In addition, there is lack of agreement regarding the benefits of probiotics in neonates, as well as some concerns about the safety and efficacy of available products. We discuss currently available probiotics as well as next-generation probiotics and novel delivery strategies which may offer an avenue to capitalize on the benefits of probiotics, while minimizing the risks. Thus, probiotics may still prove to be an effective prevention strategy for NEC, although further product development and research is needed to support use in the preterm population.

Probiotics for prevention of necrotizing enterocolitis: Where do we stand?

In this review, we provide a historical perspective on probiotic use in preterm infants. We review recent data on the treatment effects of probiotics on necrotizing enterocolitis, sepsis, and mortality. We highlight guidance statements from professional societies and organizations, discussing key points within the context of the currently available evidence from both randomized trials and cohort studies. Finally, we summarize experiences from several North American centers that have reported on the routine use of probiotics, including our center. Our goal is to highlight some of the considerations and complexities surrounding routine probiotics use in preterm infants.

Reducing Risk Factors for Necrotizing Enterocolitis: What Is the Recent Evidence and Biologic Plausibility Supporting Probiotics?

BACKGROUND

Development of necrotizing enterocolitis is multifactorial, with contributing factors that are unique to the preterm infant in the neonatal intensive care unit (NICU). The use of probiotics may reduce these risk factors.

PURPOSE

To evaluate evidence of biologic plausibility for probiotic supplementation to mitigate key risk factors implicated in the development of disease and show recent evidence of safety and effectiveness.

DATA SOURCES

A literature survey of electronic databases, including PubMed, Cochrane Database of Systematic Reviews, and CINAHL, was conducted.

STUDY SELECTION

Selection terms included "necrotizing enterocolitis," "probiotics," and "prematurity." Reviews that were included were full text, in English, and published in the last 5 years. Ten systematic reviews of randomized controlled trials were extracted from 749 records. Excluded were studies that used adjuncts to probiotics, such as lactoferrin or prebiotics, and studies of probiotics given antenatally.

DATA EXTRACTION

Two independent reviewers extracted data to AMSTAR 2, a critical appraisal tool for systematic reviews of randomized or nonrandomized studies of healthcare interventions.

RESULTS

All the reviews found statistically significant reductions in necrotizing enterocolitis rates after supplementation with probiotics. None of the reviews reported adverse effects.

IMPLICATION FOR PRACTICE AND RESEARCH

Probiotic supplementation with specific strains reduces risk for necrotizing enterocolitis. To advance probiotic use in the NICU, additional high-quality trials are needed to focus on specific strains or combinations of strains and to evaluate dosing and duration of treatment.Video Abstract available athttps://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx .

Effect of the Microbiome on Intestinal Innate Immune Development in Early Life and the Potential Strategy of Early Intervention

Early life is a vital period for mammals to be colonized with the microbiome, which profoundly influences the development of the intestinal immune function. For neonates to resist pathogen infection and avoid gastrointestinal illness, the intestinal innate immune system is critical. Thus, this review summarizes the development of the intestinal microbiome and the intestinal innate immune barrier, including the intestinal epithelium and immune cells from the fetal to the weaning period. Moreover, the impact of the intestinal microbiome on innate immune development and the two main way of early-life intervention including probiotics and fecal microbiota transplantation (FMT) also are discussed in this review. We hope to highlight the crosstalk between early microbial colonization and intestinal innate immunity development and offer some information for early intervention.

Effect of Various Preterm Infant Milk Formulas on NEC-Like Gut Injury in Mice

Formula feeding is an important risk factor for the development of necrotizing enterocolitis in preterm infants. The potential harmful effects of different preterm formulas on the developing intestinal tract remain incompletely understood. Here we demonstrate that feeding newborn mouse pups with various preterm formulas resulted in differing effects on intestinal inflammation, apoptosis, and activation of the pro-inflammatory transcription factor NFκB. 16S rRNA sequencing revealed that each preterm formula resulted in significant gut microbial alterations that were different from dam-fed controls. Formula feeding with EleCare and Similac Special Care caused greater intestinal injury compared to NeoSure. Pre-treatment with Lactobacillus rhamnosus GG ameliorated severity of intestinal injury from EleCare and Similac Special Care. Our findings indicate that not all preterm formulas are the same, and different formulations can have varying effects on intestinal inflammation, apoptosis, and microbiome composition.

Next-Generation Probiotic Therapy to Protect the Intestines From Injury

Probiotics are live microorganisms that, when administered in adequate amounts, provide health benefits to the host. Some strains of the probiotic Lactobacillus reuteri (L. reuteri) have both antimicrobial and anti-inflammatory properties that may be exploited for the treatment and prevention of different gastrointestinal diseases, including necrotizing enterocolitis (NEC) and Clostridioides difficile (C. difficile) infection. Our laboratory has developed a new delivery system for L. reuteri in which the probiotic is incubated with biocompatible, semipermeable, porous dextranomer microspheres (DM) that can be loaded with beneficial and diffusible cargo. L. reuteri can be induced to form a biofilm by incubating the bacteria on the surface of these microspheres, which enhances the efficacy of the probiotic. Loading the DM with sucrose or maltose induces L. reuteri to produce more biofilm, further increasing the efficacy of the probiotic. Using a rat model of NEC, L. reuteri administered in its biofilm state significantly increases animal survival, reduces the incidence of NEC, preserves gut barrier function, and decreases intestinal inflammation. In a murine model of Clostridiodes difficile infection, L. reuteri administered in its biofilm state decreases colitis when administered either before or after C. difficile induction, demonstrating both prophylactic and therapeutic efficacy. There are currently no FDA-approved probiotic preparations for human use. An FDA-approved phase I clinical trial of L. reuteri in its biofilm state in healthy adults is currently underway. The results of this trial will be used to support a phase 1 clinical trial in neonates, with the goal of utilizing L. reuteri in its biofilm state to prevent NEC in premature neonates in the future.

Preemies going pro: How probiotic treatment matures the microbiome of extreme premature infants

Preterm birth can have long-term health consequences, and the gut microbiome is an important contributor to infant health. In this issue of Cell Host & Microbe, Samara et al. explore the effects of probiotics treatment on the infant gut microbiome of extremely premature infants.

The effect of daily probiotics on the incidence and severity of necrotizing enterocolitis in infants with very low birth weight

Background:

Necrotizing enterocolitis remains a leading cause of morbidity and mortality in premature infants. The role of prophylactic probiotics in its prevention is unclear. This study evaluates the effect of routine probiotics on the incidence and severity of necrotizing enterocolitis in infants with very low birth weight in the neonatal intensive care unit.

Methods:

This retrospective cohort study compared infants cared for at a single institution before and after implementation of routine probiotic administration (2014– 2018). Babies born after July 2016 received probiotics containing Bifidobacterium and Lactobacillus daily until 35 weeks corrected gestational age. Baseline characteristics, necrotizing enterocolitis incidence and severity, infections, mortality, and length of stay were compared between groups.

Results:

Of the 665 infants included in the study, 310 received probiotics and 355 did not. The 2 groups did not differ with regard to gestational age, birth anthropometrics, mode of delivery, comorbidities, and type of enteral feed. The incidence of necrotizing enterocolitis (Bell’s stage 2 of 3) was similar between groups (4% v. 5%, p = 0.35), as was its severity (p = 0.10). In addition, there were no significant differences in mortality and length of stay between the groups. Significantly fewer infants receiving probiotics developed infections (27% v. 34%, p = 0.046), with the rate of urinary tract infections having the largest reduction.

Conclusion:

The routine use of Bifidobacterium and Lactobacillus probiotics in infants with very low birth weight did not significantly affect the incidence and severity of necrotizing enterocolitis. However, the use of probiotics was associated with fewer overall infections.

Use of Probiotics in Preterm Infants

Probiotic products in the United States are available for use in the general category of dietary supplements, bypassing the rigor of the US Food and Drug Administration (FDA) approval process in safety, efficacy, and manufacturing standards. As a result, currently available probiotics lack FDA-approved drug labeling and cannot be marketed to treat or prevent disease in preterm infants, including necrotizing enterocolitis and late-onset sepsis. Despite lack of availability of a pharmaceutical-grade product, the number of preterm infants receiving probiotics in the United States and Canada is steadily increasing. According to recent reports from large collaborative databases in the United States, approximately 10% of extremely low gestational age neonates receive a probiotic preparation during their stay in the NICU, with wide variation in practice among units. In sum, more than 10 000 preterm infants have been enrolled in randomized clinical trials of probiotic supplementation worldwide. Methodologic differences among study protocols included different strains and combinations of therapy, masking of trials, and a priori definitions of the primary outcome measure. Large meta-analyses of these trials have demonstrated the efficacy of multiple-strain probiotics in reducing necrotizing enterocolitis and all-cause mortality, whereas the efficacy of single-strain probiotic preparations is less certain. In the absence of an appropriate medical-grade product in the United States, dietary supplement-grade probiotics, some of which have been the subject of recent recalls for contamination, are being prescribed. Given the lack of FDA-regulated pharmaceutical-grade products in the United States, conflicting data on safety and efficacy, and potential for harm in a highly vulnerable population, current evidence does not support the routine, universal administration of probiotics to preterm infants, particularly those with a birth weight of <1000 g.

Evaluating the efficacy of a multistrain probiotic supplementation for prevention of neonatal sepsis in 0-2-month-old low birth weight infants in India-the "ProSPoNS" Study protocol for a phase III, multicentric, randomized, double-blind, placebo-controlled trial

Background

Progress has been made in the reduction of under-five mortality in India; however, neonatal mortality is reducing at a slower rate. Efforts are required to bring down neonatal mortality in order to attain the Sustainable Development Goal-3. Prevention of sepsis among the high-risk, vulnerable low birth weight neonates by a newer intervention with probiotic supplementation is promising.

Methods

A phase III, multicenter, randomized, double-blind, placebo-controlled study is being conducted at six sites in India. A total of 6144 healthy low birth weight (LBW) infants fulfilling the eligibility criteria would be enrolled within the first week of life, after obtaining written informed consent from the parents of the infant. Randomization in 1:1 ratio, stratified by site, sex, and birth weight, would be done through an interactive web response system (IWRS) using a standard web browser and email service. Vivomixx®, a probiotic containing a mix of 8 strains of bacteria, in a suspension form standardized to deliver 10 billion CFU/ml, or an organoleptically similar placebo would be fed to enrolled infants in a 1-ml/day dose for 30 days. The follow-up of enrolled infants for 60 days would take place as per a pre-specified schedule for recording morbidities and outcome assessments at the six participating sites. Screening for morbidities would be conducted by trained field workers in the community, and sick infants would be referred to designated clinics/hospitals. A physician would examine the referred infants presenting with complaints and clinical signs, and blood samples would be collected from sick infants for diagnosis of neonatal sepsis by performing sepsis screen and blood culture. Appropriate treatment would be provided as per hospital protocol. The study would be implemented as per the MRC guideline for the management of Global Health Trials in accordance with ICH-GCP and Indian Regulatory guidelines. A contract research organization would be engaged for comprehensive monitoring and quality assurance. The final analysis would be conducted in a blinded manner as per the statistical analysis plan (SAP) to estimate the primary outcomes of sepsis, possible serious bacterial infection (PSBI), and secondary outcomes. The codes will be broken after DMC permission. The protocol has been reviewed by the Research Ethics Committee of the Liverpool School of Tropical Medicine (REC-LSTM), from Research Ethics Committees of the six subject recruitment participating sites.

Discussion

This adequately powered and well-designed trial would conclusively answer the question whether probiotics can prevent neonatal sepsis in the high-risk group of low birth weight infants as indicated by a pilot study in 1340 LBW infants, evidence from systematic reviews of hospital-based studies, and a primary study on healthy newborns in Orissa. Results of the study would be generalizable to India and other low–middle-income countries.

Trial registration

Clinical Trial Registry of India (CTRI) CTRI/2019/05/019197. Registered on 16 May 2019

Routine Administration of a Multispecies Probiotic Containing Bifidobacterium and Lactobacillus to Very Low Birth Weight Infants Had No Significant Impact on the Incidence of Necrotizing Enterocolitis

Background: Necrotizing enterocolitis (NEC) is the leading cause of gastrointestinal morbidity in preterm infants, and prevention and treatment strategies have remained largely unchanged over the past several decades. As understanding of the microbiome has increased, probiotics have been hypothesized as a possible strategy for decreasing rates of NEC, and several studies have noted significant decreases in rates of NEC after initiation of probiotics in preterm infants. However, a recent AAP report cited caution on the use of probiotic use in part because studies of probiotic use in ELBW infants are lacking. As our unit began routine use of probiotics for all infants <33 weeks in 2015 and we are a leading institution for intact survival of ELBW infants, we attempted to answer if probiotic use can impact the rate of NEC in VLBW and ELBW infants. Methods: We conducted a single-center retrospective chart review of infants with modified Bell's stage ≥2a NEC for the 4 years prior to and 5 years after initiation of a protocol involving routine supplementation of a multispecies probiotic to premature infants at the University of Iowa, Stead Family Children's Hospital. The primary outcome measures were rates of modified Bell's stage ≥2a NEC and all-cause pre-discharge mortality at our institution before and after initiation of routine probiotic supplementation in 2015. Results: In our institution, neither the rates of modified Bell's stage ≥2a NEC, nor the rates of all-cause mortality were significantly altered in very low birth weight (VLBW) infants by the initiation of routine probiotic use (NEC rates pre-probiotic 2.1% vs. post-probiotic 1.5%; all-cause mortality rates pre-probiotic 8.4% vs. post-probiotic 7.4%). Characteristics of our two cohorts were overall similar except for a significantly lower 5-minute APGAR score in infants in the post-probiotic epoch (pre-probiotic 8 vs. post-probiotic 6 p = 0.0316), and significantly more infants in the post-probiotic epoch received probiotics (pre-probiotics 0% vs. post-probiotics 65%; p < 0.0001). Similarly, probiotic use had no impact on the incidence of NEC when we restricted our data to only extremely low birth weight (ELBW) infants (pre-probiotics 1.6% vs post-probiotics 4.1%). When we restricted our analysis to only inborn infants, probiotics still had no impact on NEC rates in VLBW infants (1.5% pre- and 1.1% post-probiotic, p = 0.61) or ELBW infants (2% pre- and 2.1% post-probiotic, p = 0.99) Conclusions: Contrary to other studies, we found no significant difference in rates of modified Bell's stage ≥2a NEC or all-cause pre-discharge mortality in VLBW infants following routine administration of a multispecies probiotic supplement.

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

BACKGROUND

Intestinal dysbiosis may contribute to the pathogenesis of necrotising enterocolitis (NEC) in very preterm or very low birth weight infants. Dietary supplementation with probiotics to modulate the intestinal microbiome has been proposed as a strategy to reduce the risk of NEC and associated mortality and morbidity.  OBJECTIVES: To determine the effect of supplemental probiotics on the risk of NEC and mortality and morbidity in very preterm or very low birth weight infants.

SEARCH METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 2) in the Cochrane Library; MEDLINE Ovid (1946 to 17 Feb 2020), Embase Ovid (1974 to 17 Feb 2020), Maternity & Infant Care Database Ovid (1971 to 17 Feb 2020), the Cumulative Index to Nursing and Allied Health Literature (1982 to 18 Feb 2020). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs and quasi-RCTs comparing probiotic supplementation with placebo or no probiotics in very preterm or very low birth weight infants.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal. Two review authors separately evaluated trial quality, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference. We used the GRADE approach to assess the certainty of evidence for effects on NEC, all-cause mortality, late-onset infection, and severe neurodevelopmental impairment.

MAIN RESULTS

We included 56 trials in which 10,812 infants participated. Most trials were small (median sample size 149). Lack of clarity on methods to conceal allocation and mask caregivers or investigators were the main potential sources of bias in about half of the trials. Trials varied by the formulation of the probiotics. The most commonly used preparations contained Bifidobacterium spp., Lactobacillus spp., Saccharomyces spp., and Streptococcus spp. alone or in combinations. Meta-analysis showed that probiotics may reduce the risk of NEC: RR 0.54, 95% CI 0.45 to 0.65 (54 trials, 10,604 infants; I² = 17%); RD -0.03, 95% CI -0.04 to -0.02; number needed to treat for an additional beneficial outcome (NNTB) 33, 95% CI 25 to 50. Evidence was assessed as low certainty because of the limitations in trials design, and the presence of funnel plot asymmetry consistent with publication bias. Sensitivity meta-analysis of trials at low risk of bias showed a reduced risk of NEC: RR 0.70, 95% CI 0.55 to 0.89 (16 trials, 4597 infants; I² = 25%); RD -0.02, 95% CI -0.03 to -0.01; NNTB 50, 95% CI 33 to 100. Meta-analyses showed that probiotics probably reduce mortality (RR 0.76, 95% CI 0.65 to 0.89; (51 trials, 10,170 infants; I² = 0%); RD -0.02, 95% CI -0.02 to -0.01; NNTB 50, 95% CI 50 to 100), and late-onset invasive infection (RR 0.89, 95% CI 0.82 to 0.97; (47 trials, 9762 infants; I² = 19%); RD -0.02, 95% CI -0.03 to -0.01; NNTB 50, 95% CI 33 to 100). Evidence was assessed as moderate certainty for both these outcomes because of the limitations in trials design. Sensitivity meta-analyses of 16 trials (4597 infants) at low risk of bias did not show an effect on mortality or infection. Meta-analysis showed that probiotics may have little or no effect on severe neurodevelopmental impairment (RR 1.03, 95% CI 0.84 to 1.26 (five trials, 1518 infants; I² = 0%). The certainty on this evidence is low because of limitations in trials design and serious imprecision of effect estimate. Few data (from seven of the trials) were available for extremely preterm or extremely low birth weight infants. Meta-analyses did not show effects on NEC, death, or infection (low-certainty evidence).

AUTHORS' CONCLUSIONS

Given the low to moderate level of certainty about the effects of probiotic supplements on the risk of NEC and associated morbidity and mortality for very preterm or very low birth weight infants, and particularly for extremely preterm or extremely low birth weight infants, further, large, high-quality trials are needed to provide evidence of sufficient quality and applicability to inform policy and practice.

NEC-like intestinal injury is ameliorated by Lactobacillus rhamnosus GG in parallel with SIGIRR and A20 induction in neonatal mice

BACKGROUND

Exaggerated Toll-like receptor (TLR) signaling and intestinal dysbiosis are key contributors to necrotizing enterocolitis (NEC). Lactobacillus rhamnosus GG (LGG) decreases NEC in preterm infants, but underlying mechanisms of protection remain poorly understood. We hypothesized that LGG alleviates dysbiosis and upregulates TLR inhibitors to protect against TLR-mediated gut injury.

METHODS

Effects of LGG (low- and high-dose) on intestinal pro-inflammatory TLR signaling and injury in neonatal mice subjected to formula feeding (FF) and NEC were determined. 16S sequencing of stool and expression of anti-TLR mediators SIGIRR (single immunoglobulin interleukin-1-related receptor) and A20 were analyzed.

RESULTS

FF induced mild intestinal injury with increased expression of interleukin-1β (IL-1β) and Kupffer cell (KC) (mouse homolog of IL-8) compared to controls. LGG decreased IL-1β and KC in association with attenuated TLR signaling and increased SIGIRR and A20 expression in a dose-dependent manner. Low- and high-dose LGG had varying effects on gut microbiome despite both doses providing gut protection. Subsequent experiments of LGG on NEC revealed that pro-inflammatory TLR signaling and intestinal injury were also decreased, and SIGIRR and A20 expression increased, in a dose-dependent manner with LGG pre-treatment.

CONCLUSIONS

LGG protects against intestinal TLR-mediated injury by upregulating TLR inhibitors without major changes in gut microbiome composition.

Probiotics and Human Milk Oligosaccharides in Premature Infants

Intestinal dysbiosis precedes and is a likely causative factor in necrotizing enterocolitis (NEC) and many cases of late-onset sepsis. Randomized controlled trials and observational cohort studies demonstrate decreased risk of NEC, sepsis, and death with the administration of probiotic microbes and decreased risk of NEC and sepsis with feeding of human milk. Animal studies suggest promising mechanisms by which probiotic microbes and human milk oligosaccharides alter the composition of the intestinal microbiota and may prevent disease in premature infants. Inclusion of parents in discussions of the risks and benefits of human milk and probiotics for premature infants is essential.

Quality of probiotic products for preterm infants: Contamination and missing strains

Probiotics are effective in reducing necrotising enterocolitis in preterm infants, but routine use is not generally adopted. We describe a safety issue concerning contamination by pathogenic bacteria and missing of labelled strains in a probiotic product widely used in neonatal care. We recommend all centres using probiotics in the care of vulnerable patients to consider product safety checks in addition to the quality reports of manufacturers. Meanwhile, clinicians and manufacturers should collaborate to define quality standards for probiotic products in clinical settings as long as specific international regulations are lacking.

Preventing dysbiosis of the neonatal mouse intestinal microbiome protects against late-onset sepsis

Late-onset sepsis (LOS) is thought to result from systemic spread of commensal microbes from the intestines of premature infants. Clinical use of probiotics for LOS prophylaxis has varied owing to limited efficacy, reflecting an incomplete understanding of relationships between development of the intestinal microbiome, neonatal dysbiosis and LOS. Using a model of LOS, we found that components of the developing microbiome were both necessary and sufficient to prevent LOS. Maternal antibiotic exposure that eradicated or enriched transmission of Lactobacillus murinus exacerbated and prevented disease, respectively. Prophylactic administration of some, but not all Lactobacillus spp. was protective, as was administration of Escherichia coli. Intestinal oxygen level was a major driver of colonization dynamics, albeit via mechanisms distinct from those in adults. These results establish a link between neonatal dysbiosis and LOS, and provide a basis for rational selection of probiotics that modulate primary succession of the microbiome to prevent disease.

To start or not: Factors to consider when implementing routine probiotic use in the NICU

Supplementation of probiotics to very low birth weight (VLBW) infants has been extensively studied, with multiple meta-analyses reporting probiotics decrease the risk of necrotizing enterocolitis (NEC) and death. Despite availability of this evidence, the decision to initiate routine probiotic supplementation to preterm infants continues to be a complex one. There are uncertainties regarding the use of probiotics, including selecting the appropriate product, dose and target population. Additionally, availability of specific probiotic products and regulatory oversight varies by country, raising concerns regarding the safety and efficacy of specific probiotic products. In this review, we summarize the latest evidence on probiotic use in preterm infants and discuss considerations that may help guide clinicians who are considering routine probiotic supplementation.

The future of probiotics in the preterm infant

Probiotic administration to preterm infants is not universal despite randomised trial data from >10,000 infants, significant observational data and multiple meta-analyses. Advocates point to reductions in necrotising enterocolitis and sepsis, 'sceptics' hold concerns over data quality/interpretation or risks. Issues revolve around different products, primary outcomes, uncertain dosing strategies and individual large 'negative' trials alongside probiotic associated sepsis and quality control concerns. We review concerns and how to move probiotic use forward. Surprisingly little is known about parental perspectives, vital to inform next steps. How to share information and decisions around probiotic use now, and how this impacts on future available strategies is discussed. We address placebo controlled trials and propose alternate designs, including head to head studies, using 'routine' data collection systems, opt out consents and 'learning technologies' embedded in health care systems. We also raise the importance of underpinning mechanistic work to inform future trials.

Types, Frequency, Duration, and Dosage of Probiotics to Prevent Necrotizing Enterocolitis in Preterm Infants Among Countries

BACKGROUND

Probiotic use in the neonatal intensive care unit (NICU) has been linked to reduced rates of necrotizing enterocolitis in preterm infants. Currently, in the United States, probiotic use within the NICU is limited despite being commonly used in other countries.

PURPOSE

To provide an overview of the current practices of using probiotics in preterm infants for the prevention of NEC in the NICU in preselected countries.

METHODS

A comprehensive literature search was conducted on PubMed and clinicaltrials.gov. Also, studies from 2 recent meta-analyses on the topic were reviewed for inclusion. Selection criteria were as follows: studies involving preterm infants using probiotics in the NICU, reporting on the impact of probiotic use on the incidence of necrotizing enterocolitis, published within the last 10 years and in the English language, and originating from the United States, Canada, or any European country.

RESULTS

Twenty-three studies were selected. The most common types of probiotics used were Bifidobacterium infantis and Lactobacillus rhamnosus. The most common frequency of administration was daily or twice day. Duration ranged from 10 days to the entire NICU stay. The dosage was commonly 1 billion colony-forming units daily but ranged from 12 million daily to 12 billion per kilogram daily.

IMPLICATIONS FOR PRACTICE

Examining the current practices of probiotic use in the NICU provides useful information as this adjunctive therapy rises in popularity.

IMPLICATIONS FOR RESEARCH

Refining methods of probiotic research for necrotizing enterocolitis prevention will improve safety and effectiveness and provide a framework for future clinical trials.

Arguments against routine administration of probiotics for NEC prevention

PURPOSE OF REVIEW

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality among premature neonates. Although randomized trials have shown that probiotics may be efficacious in the prevention of NEC, their use has not been universally adopted in the neonatal intensive care unit (NICU). Caveats regarding routine probiotic supplementation for the prevention of NEC are summarized in this review.

RECENT FINDINGS

Accumulating evidence indicates that prophylactic probiotic supplementation in preterm infants can reduce the incidence of NEC. However, substantial knowledge gaps, regulatory issues, and implementation challenges should be addressed before probiotics are introduced as standard of care for all preterm neonates. Limitations of published trial data have made it challenging to define regimens that optimize efficacy and safety in specific patient subgroups. Moreover, the current probiotic market lacks rigorous regulatory oversight, which could raise concerns about the quality and safety of probiotic products. Finally, implementation pitfalls include risks of cross-colonization and resource requirements to monitor and mitigate potential adverse events.

SUMMARY

Probiotics have shown promise in the prevention of NEC. However, there is insufficient evidence to guide the selection of optimal regimens. Furthermore, issues related to regulatory and institutional oversight should be addressed before supplementation is routinely implemented in NICUs.

Maternal probiotic supplementation for prevention of morbidity and mortality in preterm infants

BACKGROUND

Inflammation may contribute to preterm birth and to morbidity of preterm infants. Preterm infants are at risk for alterations in the normal protective microbiome. Oral probiotics administered directly to preterm infants have been shown to decrease the risk for severe necrotizing enterocolitis (NEC) as well as the risk of death, but there are safety concerns about administration of probiotics directly to preterm infants. Through decreasing maternal inflammation, probiotics may play a role in preventing preterm birth and/or decreasing the inflammatory milieu surrounding delivery of preterm infants, and may alter the microbiome of the preterm infant when given to mothers during pregnancy. Probiotics given to mothers after birth of preterm infants may effect infant bacterial colonization, which could potentially reduce the incidence of NEC.

OBJECTIVES

1. To compare the efficacy of maternal probiotic administration versus placebo or no intervention in mothers during pregnancy for the prevention of preterm birth and the prevention of morbidity and mortality of infants born preterm.2. To compare the efficacy of maternal probiotic administration versus placebo, no intervention, or neonatal probiotic administration in mothers of preterm infants after birth on the prevention of mortality and preterm infant morbidities such as NEC.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 2), MEDLINE via PubMed (1966 to 21 March 2017), Embase (1980 to 21 March 2017), and CINAHL (1982 to 21 March 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

SELECTION CRITERIA

We included randomized controlled trials in the review if they administered oral probiotics to pregnant mothers at risk for preterm birth, or to mothers of preterm infants after birth. Quasi-randomized trials were eligible for inclusion, but none were identified. Studies enrolling pregnant women needed to administer probiotics at < 36 weeks' gestation until the trimester of birth. Probiotics considered were of the genera Lactobacillus, Bifidobacterium or Saccharomyces.

DATA COLLECTION AND ANALYSIS

We used the standard methods of the Cochrane Collaboration and Cochrane Neonatal to determine the methodologic quality of studies, and for data collection and analysis.

MAIN RESULTS

We included 12 eligible trials with a total of 1450 mothers and 1204 known infants. Eleven trials administered probiotics to mothers during pregnancy and one trial administered probiotics to mothers after birth of their preterm infants. No studies compared maternal probiotic administration directly with neonatal administration. Included prenatal trials were highly variable in the indication for the trial, the gestational age and duration of administration of probiotics, as well as the dose and formulation of the probiotics. The pregnant women included in these trials were overall at low risk for preterm birth. In a meta-analysis of trial data, oral probiotic administration to pregnant women did not reduce the incidence of preterm birth < 37 weeks (typical risk ratio (RR) 0.92, 95% confidence interval (CI) 0.32 to 2.67; 4 studies, 518 mothers and 506 infants), < 34 weeks (typical risk difference (RD) 0.00, 95% CI -0.02 to 0.02; 2 studies, 287 mothers and infants), the incidence of infant mortality (typical RD 0.00, 95% CI -0.02 to 0.02; 2 studies, 309 mothers and 298 infants), or the gestational age at birth (mean difference (MD) 0.15, 95% CI -0.33 to 0.63; 2 studies, 209 mothers with 207 infants).One trial studied administration of probiotics to mothers after preterm birth and included 49 mothers and 58 infants. There were no significant differences in the risk of any NEC (RR 0.44, 95% CI 0.13 to 1.46; 1 study, 58 infants), surgery for NEC (RR 0.15, 95% CI 0.01 to 2.58; 1 study, 58 infants), death (RR 0.66, 95% CI 0.06 to 6.88; 1 study, 58 infants), and death or NEC (RR 0.53, 95% CI 0.19 to 1.49; 1 study, 58 infants). There was an improvement in time to reach 50% enteral feeds in infants whose mothers received probiotics, but the estimate is imprecise (MD -9.60 days, 95% CI -19.04 to -0.16 days; 58 infants). No other improvement in any neonatal outcomes were reported. The estimates were imprecise and do not exclude the possibility of meaningful harms or benefits from maternal probiotic administration. There were no cases of culture-proven sepsis with the probiotic organism. The GRADE quality of evidence was judged to be low to very low due to inconsistency and imprecision.

AUTHORS' CONCLUSIONS

There is insufficient evidence to conclude whether there is appreciable benefit or harm to neonates of either oral supplementation of probiotics administered to pregnant women at low risk for preterm birth or oral supplementation of probiotics to mothers of preterm infants after birth. Oral supplementation of probiotics to mothers of preterm infants after birth may decrease time to 50% enteral feeds, however, this estimate is extremely imprecise. More research is needed for post-natal administration of probiotics to mothers of preterm infants, as well as to pregnant mothers at high risk for preterm birth.

Filling the Gaps: Current Research Directions for a Rational Use of Probiotics in Preterm Infants

The use of probiotics among very low-birth-weight infants is constantly increasing, as probiotics are believed to reduce the incidence of severe diseases such as necrotizing enterocolitis and late-onset sepsis and to improve feeding tolerance. However, despite the enthusiasm towards these products in neonatal medicine, theoretical knowledge and clinical applications still need to be improved. The purpose of this review is to give an overview of the most important gaps in the current literature about potential uses of probiotics in preterm infants, highlighting promising directions for future research. Specifically, further well-designed studies should aim at clarifying the impact of the type of feeding (mother's milk, donor milk, and formula) on the relationship between probiotic supplementation and clinical outcome. Moreover, future research is needed to provide solid evidence about the potential greater efficacy of multi-strain probiotics compared to single-strain products. Safety issues should also be addressed properly, by exploring the potential of paraprobiotics and risks connected to antibiotic resistance in preterm infants. Last, in light of increasing commercial and public interests, the long-term effect of routine consumption of probiotics in such a vulnerable population should be also evaluated.

Standardized slow enteral feeding protocol reduces necrotizing enterocolitis in micropremies

BACKGROUND

Compared to early enteral feeds, delayed introduction and slow enteral feeding advancement to reduce necrotizing enterocolitis (NEC) is not well studied in micropremies (<750g birth weight).

METHODS

Pre-post case control study. Micropremies who followed a standardized slow enteral feeding (SSEF) protocol (September 2009 to March 2015) were compared with a similar group of historical controls (PreSSEF, January 2003 to July 2009). Enteral feeding withheld for first 10-14 days and advanced at <10 ml/kg/day in the SSEF group.

RESULTS

Ninety-two infants in the SSEF group were compared with 129 PreSSEF group. Birth weight and gestational age in SSEF and PreSSEF were similar. Breast milk initiation rate was higher in SSEF (87.0 vs. 72.0%, p = 0.01) compared to PreSSEF, but were similar at full enteral feeds. Compared with PreSSEF, feeding initiation day, full enteral feeding day, parenteral nutrition days, and total central line days were longer in SSEF. There was significant reduction in NEC (1.1 vs. 16.2%, p < 0.01), surgical NEC (0.0 vs. 7.8%, p < 0.01) and NEC/death (7.6 vs. 29.5%, p < 0.01), in SSEF compared to PreSSEF. SSEF, compared to PreSSEF, had more cholestasis (41.8 vs 28.8%, p = 0.04), higher peak serum alkaline phosphatase (638 vs. 534 IU/dL, p < 0.01), but similar rates of late-onset sepsis (39.1 vs 43.4%, p = 0.53). In infants who survived to discharge, SSEF had higher discharge weight, lower extra-uterine growth restriction, and similar length of stay, compared to PreSSEF.

CONCLUSIONS

A SSEF protocol significantly reduces the incidence of NEC and combined NEC/death in micropremies.

Routine Supplementation of Lactobacillus rhamnosus GG and Risk of Necrotizing Enterocolitis in Very Low Birth Weight Infants

OBJECTIVE

To evaluate if routine supplementation of Lactobacillus rhamnosus GG ATCC 53103 (LGG) is associated with a decreased risk of necrotizing enterocolitis in very low birth weight (VLBW) infants.

STUDY DESIGN

Retrospective observational cohort study of VLBW (<1500 g) infants at a single center from 2008 to 2016. LGG supplementation with Culturelle at a dose of 2.5 to 5 × 10⁹ CFU/day began in 2014. We used multivariable logistic regression to evaluate the association between LGG supplementation and necrotizing enterocolitis (modified Bell stage IIA or greater), after adjusting for potential confounders. We also compared changes in necrotizing enterocolitis incidence before and after implementation of LGG using a statistical process control chart.

RESULTS

We evaluated 640 VLBW infants with a median gestational age of 28.7 weeks (IQR 26.3-30.6); 78 (12%) developed necrotizing enterocolitis. The median age at first dose of LGG was 6 days (IQR 3-10), and duration of supplementation was 32 days (IQR 18-45). The incidence of necrotizing enterocolitis in the epoch before LGG implementation was 10.2% compared with 16.8% after implementation. In multivariable analysis, LGG supplementation was associated with a higher risk of necrotizing enterocolitis (aOR 2.10, 95 % CI 1.25-3.54, P = .005). We found no special cause variation in necrotizing enterocolitis after implementation of LGG supplementation. There were no episodes of Lactobacillus sepsis during 5558 infant days of LGG supplementation.

CONCLUSIONS

In this study, routine LGG supplementation was not associated with a decreased risk of necrotizing enterocolitis. Our findings do not support the use of the most common probiotic preparation currently supplemented to VLBW infants in the US.

Probiotics and necrotizing enterocolitis

In this review, we summarize existing knowledge regarding the effects of probiotics on necrotizing enterocolitis (NEC). We review the role of the microbiome in NEC and pre-clinical data on mechanisms of probiotic action. Next, we summarize existing randomized controlled trials and observational studies of probiotics to prevent NEC. We also summarize findings from several recent meta-analyses and report a new cumulative meta-analysis of probiotic trials. Finally, we review data from cohorts routinely using commercially available probiotics. Our goal is to inform clinicians about the risks and benefits of probiotics, which may be helpful for those considering use in preterm infants to prevent NEC, death, or sepsis.

Effects of Probiotic Supplementation on the Gut Microbiota and Antibiotic Resistome Development in Preterm Infants

Objectives: In 2014 probiotic supplementation (Lactobacillus acidophilus and Bifidobacterium longum subspecies infantis; Infloran^Ⓡ) was introduced as standard of care to prevent necrotizing enterocolitis (NEC) in extremely preterm infants in Norway. We aimed to evaluate the influence of probiotics and antibiotic therapy on the developing gut microbiota and antibiotic resistome in extremely preterm infants, and to compare with very preterm infants and term infants not given probiotics. Study design: A prospective, observational multicenter study in six tertiary-care neonatal units. We enrolled 76 infants; 31 probiotic-supplemented extremely preterm infants <28 weeks gestation, 35 very preterm infants 28-31 weeks gestation not given probiotics and 10 healthy full-term control infants. Taxonomic composition and collection of antibiotic resistance genes (resistome) in fecal samples, collected at 7 and 28 days and 4 months age, were analyzed using shotgun-metagenome sequencing. Results: Median (IQR) birth weight was 835 (680-945) g and 1,290 (1,150-1,445) g in preterm infants exposed and not exposed to probiotics, respectively. Two extremely preterm infants receiving probiotic developed NEC requiring surgery. At 7 days of age we found higher median relative abundance of Bifidobacterium in probiotic supplemented infants (64.7%) compared to non-supplemented preterm infants (0.0%) and term control infants (43.9%). Lactobacillus was only detected in small amounts in all groups, but the relative abundance increased up to 4 months. Extremely preterm infants receiving probiotics had also much higher antibiotic exposure, still overall microbial diversity and resistome was not different than in more mature infants at 4 weeks and 4 months. Conclusion: Probiotic supplementation may induce colonization resistance and alleviate harmful effects of antibiotics on the gut microbiota and antibiotic resistome. Clinical Trial Registration: Clinicaltrials.gov: NCT02197468. https://clinicaltrials.gov/ct2/show/NCT02197468.

Benefits of probiotics in preterm neonates in low-income and medium-income countries: a systematic review of randomised controlled trials

OBJECTIVE

Although there is an overall reduction in underfive mortality rate, the progress in reducing neonatal mortality rate has been very slow. Over the last 20 years, preterm births have steadily increased in low-income and medium-income countries (LMICs) particularly in sub-Saharan Africa and South Asia. Preterm birth is associated with increased mortality and morbidity, particularly in LMICs. Based on systematic reviews of randomised controlled trials (RCTs), many neonatal units in high-income countries have adopted probiotics as standard of care for preterm neonates. We aimed to systematically review the safety and efficacy of probiotics in reducing mortality and morbidity in preterm neonates in LMICs.

DESIGN

Systematic review and meta-analysis of RCTs.

DATA SOURCES

Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index of Nursing and Allied Health Literature and E-abstracts from Pediatric Academic Society meetings and other paediatric and neonatal conference proceedings were searched in January 2017.

ELIGIBILITY CRITERIA

RCTs comparing probiotics versus placebo/no probiotic in preterm neonates (gestation<37 weeks) conducted in LMICs.

RESULTS

Total 23 (n=4783) RCTs from 4 continents and 10 LMICs were eligible for inclusion in the meta-analysis using fixed effect model. The risk of necrotising enterocolitis (NEC greater than or equal to stage II) (risk ratio (RR) 0.46 (95% CI 0.34 to 0.61), P<0.00001, numbers needed to treat (NNT) 25 (95% CI 20 to 50)), late-onset sepsis (LOS) (RR 0.80 (95% CI 0.71 to 0.91), P=0.0009, NNT 25 (95% CI 17 to 100)) and all-cause mortality (RR 0.73 (95% CI 0.59 to 0.90), P=0.003, NNT 50 (95% CI 25 to 100)) were significantly lower in probiotic supplemented neonates. The results were significant on random effects model analysis and after excluding studies with high risk of bias. No significant adverse effects were reported.

CONCLUSION

Probiotics have significant potential to reduce mortality and morbidity (eg, NEC, LOS) in preterm neonates in LMICs.