The time for a confirmative necrotizing enterocolitis probiotics prevention trial in the extremely low birth weight infant in North America is now!

Probiotic sepsis in preterm neonates-a systematic review

Sepsis due to the administered probiotic strain/s is a barrier against adoption of prophylactic probiotic supplementation in preterm infants to reduce the risk of necrotising enterocolitis (NEC ≥ Stage II), all-cause mortality, late-onset sepsis, and feeding intolerance. We aimed to conduct a systematic review for reports of probiotic sepsis in preterm infants (gestation < 37 weeks). Databases including PubMed, Embase, Emcare, Cochrane Central library, and Google Scholar were searched in August 2021 and updated in Jan 2022. Probiotic sepsis was defined as positive blood/CSF culture isolating administered probiotic strain with symptoms suggestive of infection. Data collection included birth weight, gestation, comorbidities (e.g. gut surgery, NEC), presence of central venous catheters, treatment, and outcome. Literature search revealed 1569 studies. A total of 16 reports [randomised control trial (RCT): none; non-RCT: 1; case series: 8; case report: 7] involving 32 preterm infants with probiotic sepsis were included after exclusions for various reasons. Majority of the cases were born < 32 weeks' gestation. Bifidobacterium (N = 19) was the most commonly isolated organism followed by Lactobacillus (N = 10), and Saccharomyces (N = 3). A total of 25/32 cases were confirmed to be due to the administered probiotic strain on full genomic analysis. Two studies reported one neonatal death each. Twelve neonates had comorbidities. Majority were treated with antibiotics (29/32) whereas others (3/32) required antifungal treatment.

CONCLUSION

Probiotics sepsis is relatively an uncommon event in preterm infants. Majority of the cases recovered after antibiotic or antifungal treatment. The importance of optimal surveillance and treatment of probiotic sepsis and research towards alternatives to probiotics (e.g. postbiotics) is emphasised.

WHAT IS KNOWN

• Probiotics have been shown to reduce necrotising enterocolitis, late-onset sepsis, all-cause mortality, and time to reach full enteral feeds in preterm infants. • Despite the evidence, use of probiotics is not universal due to concerns regarding probiotic-associated sepsis in preterm infants.

WHAT IS NEW

• This comprehensive systematic review showed that probiotic sepsis is a relatively rare phenomenon in preterm infants. • All except one case where the diagnosis was uncertain recovered after antimicrobial therapy.

Prophylactic Probiotic Supplementation for Preterm Neonates-A Systematic Review and Meta-Analysis of Nonrandomized Studies

Systematic review and meta-analyses of randomized controlled trials (RCTs) show that probiotics reduce the risk of necrotizing enterocolitis (NEC ≥ Stage II), late onset sepsis (LOS), all-cause mortality, and feeding intolerance in preterm neonates. Data from observational studies is important to confirm probiotic effects in clinical practice. We aimed to compare outcomes before and after implementing routine probiotic supplementation (RPS) in preterm neonates (<37 weeks of gestation) by performing a systematic review of non-RCTs using Cochrane methodology. Databases including PubMed, The Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Cochrane Central library, and Google Scholar were searched in May 2020. A meta-analysis was performed using a random effects model. Categorical measure of effect size was expressed as OR and 95% CI. Statistical heterogeneity was assessed by the chi-squared test, I2 statistic. The level of evidence (LOE) was summarized using GRADE (Grading of Recommendations Assessment, Development, and Evaluation) guidelines. Primary outcomes were NEC ≥ Stage II, LOS, and all-cause mortality. Secondary outcomes included probiotic sepsis. Thirty good-quality non-RCTs (n = 77,018) from 18 countries were included. The meta-analysis showed RPS was associated with significantly reduced: 1) NEC ≥ Stage II (30 studies, n = 77,018; OR: 0.60; 95% CI: 0.50, 0.73; P <0.00001, I2: 65%; LOE: Moderate), 2) LOS: (21 studies, n = 65,858; OR: 0.85; 95% CI: 0.74, 0.97; P = 0.02, I2: 74%; LOE: Low), and 3) all-cause mortality (27 non-RCTs, n = 70,977; OR: 0.77; 95% CI: 0.68, 0.88; P = 0.0001, I2: 49%; LOE: Low). Subgroups: 1) extremely low birth weight (ELBW: birth weight <1000 g) neonates: RPS was associated with significantly reduced NEC ≥ Stage II (4.5% compared with 7.9%). However, there was no difference in LOS and mortality. 2) Multistrain RPS was more effective than single strain. One study reported 3 nonfatal cases of probiotic sepsis. In summary, moderate- to low-quality evidence indicates that RPS was associated with significantly reduced NEC ≥ Stage II, LOS, and all-cause mortality in neonates <37 weeks of gestation and NEC ≥ Stage II in ELBW neonates.

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.

Probiotics promoted head growth in extremely low birthweight infants in a double-blind placebo-controlled trial

AIM

This study evaluated if oral supplementation with the probiotic bacterium Lactobacillus reuteri DSM 17938 improved enteral feeding tolerance and growth rates in extremely low birthweight (ELBW) infants.

METHOD

A randomised, double-blind, placebo-controlled trial comprising 134 ELBW (<1000 g) infants born before gestational week 28 + 0. Daily supplementation of L. reuteri (1.25 × 10⁸ bacteria/day) or placebo started within 3 days and continued until gestational week 36 + 0. Primary outcome was feeding tolerance and secondary outcome growth rate calculated as z-score development.

RESULTS

Feeding tolerance was similar in the probiotic and placebo group. Time to full enteral feeds was 15 days in both groups. The z-score of the head circumference decreased in both groups from birth to day 28 of life, but it decreased less in the L. reuteri group compared to the placebo group: -1.2 SD (95% CI: -1.4 to -1.0) versus -1.7 SD (95% CI: -2.0 to -1.5; p = 0.001). Other growth parameters were similar in the study groups.

CONCLUSION

Lactobacillus reuteri did not reduce time to reach full enteral feeds in ELBW infants. The L. reuteri supplemented infants, however, had a better growth rate of the head during the first month of life.

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.

A randomised controlled trial of the probiotic Bifidobacterium breve BBG-001 in preterm babies to prevent sepsis, necrotising enterocolitis and death: the Probiotics in Preterm infantS (PiPS) trial

BACKGROUND

Necrotising enterocolitis (NEC) and late-onset sepsis remain important causes of death and morbidity in preterm babies. Probiotic administration might strengthen intestinal barrier function and provide protection; this is supported by published meta-analyses, but there is a lack of large well-designed trials.

OBJECTIVE

To test the use of the probiotic Bifidobacterium breve strain BBG-001 to prevent NEC, late-onset sepsis and death in preterm babies while monitoring probiotic colonisation of participants.

DESIGN

Double-blind, randomised, placebo-controlled trial.

SETTING

Recruitment was carried out in 24 hospitals, and the randomisation programme used a minimisation algorithm. Parents, clinicians and outcome assessors were blinded to the allocation.

PARTICIPANTS

Babies born between 23 and 30 weeks' gestation and randomised within 48 hours of birth. Exclusions included life-threatening or any gastrointestinal malformation detected within 48 hours of birth and no realistic chance of survival.

INTERVENTIONS

Active intervention: 1 ml of B. breve BBG-001 in one-eighth-strength infant formula Neocate(®) (Nutricia Ltd, Trowbridge, UK), (6.7 × 10(7) to 6.7 × 10(9) colony-forming units) per dose administered enterally. Placebo: 1 ml of one-eighth-strength infant formula Neocate. Started as soon as practicable and continued daily until 36 weeks' postmenstrual age.

MAIN OUTCOME MEASURES

Primary outcomes were an episode of bloodstream infection, with any organism other than a skin commensal, in any baby between 72 hours and 46 weeks' postmenstrual age; an episode of NEC Bell stage ≥ 2 in any baby; and death before discharge from hospital. Secondary outcomes included stool colonisation with B. breve.

RESULTS

In total, 654 babies were allocated to receive probiotic and 661 to receive placebo over 37 months from July 2010. Five babies were withdrawn; 650 babies from the probiotic group and 660 from the placebo group were included in the primary analysis. Baseline characteristics were well balanced. There was no evidence of benefit for the primary outcomes {sepsis: 11.2% vs. 11.7% [adjusted relative risk (RR) 0.97, 95% confidence interval (CI) 0.73 to 1.29]; NEC Bell stage ≥ 2: 9.4% vs. 10.0% [adjusted RR 0.93, 95% CI 0.68 to 1.27]; and death: 8.3% vs. 8.5% [adjusted RR 0.93, 95% CI 0.67 to 1.30]}. B. breve colonisation status was available for 1186 (94%) survivors at 2 weeks' postnatal age, of whom 724 (61%) were positive: 85% of the probiotic group and 37% of the placebo group. There were no differences for subgroup analyses by minimisation criteria and by stool colonisation with B. breve at 2 weeks. No harms associated with the interventions were reported.

LIMITATIONS

Cross-colonisation of the placebo arm could have reduced statistical power and confounded results; analyses suggest that this did not happen.

CONCLUSIONS

This is the largest trial to date of a probiotic intervention. It shows no evidence of benefit and does not support routine use of probiotics for preterm infants.

FUTURE WORK RECOMMENDATIONS

The increasing understanding of the pathogenesis of NEC and sepsis will inform the choice of probiotics for testing and better define the target population. Future Phase III trials should incorporate monitoring of the quality and viability of the intervention and colonisation rates of participants; cluster design should be considered.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN05511098 and EudraCT 2006-003445-17.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 66. See the NIHR Journals Library website for further project information.

Probiotics for the prevention of necrotising enterocolitis in very low-birth-weight infants: a meta-analysis and systematic review

We performed an updated meta-analysis incorporating the results of recent randomised controlled trials (RCTs) to measure the effectiveness of probiotic supplementation in preventing necrotising enterocolitis (NEC) and death in very low-birth-weight (VLBW) infants, and to investigate any differences in efficacy by probiotic agent. Using meta-regression analysis, we assessed the contribution of other measured variables on the overall effect size and between-study variability.

CONCLUSION

Overall, probiotics lead to significant reductions in NEC incidence and mortality in VLBW infants. Differences in probiotic agents and the influence of prenatal steroids and feeding regimens may explain the differences in outcomes between studies.

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

OBJECTIVE

Data from multiple clinical trials, mostly conducted outside the US, indicate that probiotic prophylaxis is an effective intervention for prevention of necrotizing enterocolitis (NEC) in preterm infants. Probiotics are routinely used in many countries. However, in the US, probiotic use in preterm infants is limited (6.7% of very low birth weight (VLBW) infants in the US were exposed to probiotics in 2014, Vermont Oxford Network (VON)). Probiotic products are often considered in 'generic' terms, but considerable variation exists between commercially available probiotics in terms of their quantity and quality. The study objectives were to identify the probiotic products used in VLBW infants within the US, and to determine whether their use was supported by reliable evidence.

STUDY DESIGN

A phone survey of all neonatal intensive care units (NICU) participating in VON within the US was conducted between May and September 2015 to identify NICUs that are using probiotics in VLBW infants. Data was collected regarding specific probiotic brands, timing, dose and duration of probiotic use. An evidence based literature search, limited to randomized controlled trials in VLBW infants, was conducted to determine whether the use of identified probiotics were supported by reliable evidence.

RESULTS

There was a 70.3% (500/711) response rate to the phone survey. During the survey period, 14.0% of NICUs were using probiotics in VLBW infants (70/500). Probiotics were routinely given to all VLBW infants in 8.8% (44/500) NICUs, while it was given in selected VLBW infants in 5.2% (26/500) of NICUs. The common indications for selective use of probiotics were feeding intolerance and antibiotic use. Sixteen commercial probiotics products were identified through the phone survey. Probiotic products most commonly used were Culturelle (27.1%), Biogaia (14.3%), Gerber Soothe (14.3%) and Florababy (8.6%). The literature search identified evidence that evaluated 4/16 probiotic products identified (Culturelle, Align, Biogaia and ABC Dophilus). Only ABC Dophilus was reported to have a protective effect against NEC, but is used sparingly in US NICUs (2.9%).

CONCLUSIONS

The probiotics use in VLBW infants within the US is increasing, but is still limited. There was no evidence for safety or efficacy of 90% of the probiotics currently used in US NICUs, and therefore, caution is warranted.

Perinatal Microbiomes' Influence on Preterm Birth and Preterms' Health: Influencing Factors and Modulation Strategies

Microbial communities inhabiting the human host play important roles in maintaining health status, including reproduction and early life programming, which is particularly important in the context of preterm neonates' health. Preterm birth (PTB) is often the result of a microbial dysbiosis or infection. In addition, preterm neonates experience different levels of organ immaturity and an abnormal gut microbiota establishment, as compared to full-term neonates. This exacerbates their developmental problems and can have negative consequences at systemic level. In addition, preterm babies are commonly exposed to delayed enteral feeding and hospital environments, which increases the risk of short- and long-term health problems. Some of these clinical conditions, such as necrotizing enterocolitis or sepsis, may be life threatening, whereas others may translate into life-long conditions, including cognitive problems. Increasing scientific interest has focused on understanding developmental problems in preterm neonates related to abnormalities in the settlement of their microbial communities, with the final goal of selecting appropriate microbiome-targeted strategies (eg, probiotics), to reduce preterm health risks and improve overall quality of life.This review aims to summarize current knowledge on microbiological factors influencing PTB initiation and gastrointestinal development, and on the health consequences to the preterm neonate. Scientific evidences on dietary strategies reducing PTB incidence and minimizing sequelae in this particularly sensitive human group subpopulation are also discussed.

Neonatal Outcomes of Very Low Birth Weight and Very Preterm Neonates: An International Comparison

OBJECTIVE

To compare rates of a composite outcome of mortality or major morbidity in very-preterm/very low birth weight infants between 8 members of the International Network for Evaluating Outcomes.

STUDY DESIGN

We included 58 004 infants born weighing <1500 g at 24(0)-31(6) weeks' gestation from databases in Australia/New Zealand, Canada, Israel, Japan, Spain, Sweden, Switzerland, and the United Kingdom. We compared a composite outcome (mortality or any of grade ≥3 peri-intraventricular hemorrhage, periventricular echodensity/echolucency, bronchopulmonary dysplasia, or treated retinopathy of prematurity) between each country and all others by using standardized ratios and pairwise using logistic regression analyses.

RESULTS

Despite differences in population coverage, included neonates were similar at baseline. Composite outcome rates varied from 26% to 42%. The overall mortality rate before discharge was 10% (range: 5% [Japan]-17% [Spain]). The standardized ratio (99% CIs) estimates for the composite outcome were significantly greater for Spain 1.09 (1.04-1.14) and the United Kingdom 1.16 (1.11-1.21), lower for Australia/New Zealand 0.93 (0.89-0.97), Japan 0.89 (0.86-0.93), Sweden 0.81 (0.73-0.90), and Switzerland 0.77 (0.69-0.87), and nonsignificant for Canada 1.04 (0.99-1.09) and Israel 1.00 (0.93-1.07). The adjusted odds of the composite outcome varied significantly in pairwise comparisons.

CONCLUSIONS

We identified marked variations in neonatal outcomes between countries. Further collaboration and exploration is needed to reduce variations in population coverage, data collection, and case definitions. The goal would be to identify care practices and health care organizational factors, which has the potential to improve neonatal outcomes.

Probiotics, Prebiotics, and Synbiotics for the Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a devastating intestinal disease in preterm infants characterized by barrier disruption, intestinal microbial dysbiosis, and persistent inflammation of the colon, which results in high mortality rates. Current strategies used to manage this disease are not sufficient, although the use of human breast milk reduces the risk of NEC. Mother's milk is regarded as a fundamental nutritional source for neonates, but pasteurization of donor breast milk affects the composition of bioactive compounds. Current research is evaluating the benefits and potential pitfalls of adding probiotics and prebiotics to pasteurized milk so as to improve the functionality of the milk and thereby reduce the burden of illness caused by NEC. Probiotics (live micro-organisms that confer health to the host) and prebiotics (nondigestible oligosaccharides that stimulate the growth of healthy bacteria) are functional foods known to mediate immune responses and modulate microbial populations in the gut. Clinical research shows strain- and compound-specific responses when probiotics or prebiotics are administered in conjunction with donor breast milk for the prevention of NEC. Despite ongoing controversy surrounding optimal treatment strategies, randomized controlled studies are now investigating the use of synbiotics to reduce the incidence and severity of NEC. Synbiotics, a combination of probiotics and prebiotics, have been proposed to enhance beneficial health effects in the intestinal tract more than either agent administered alone. This review considers the implications of using probiotic-, prebiotic-, and synbiotic-supplemented breast milk as a strategy to prevent NEC and issues that could be encountered with the preparations.

Quality Improvement Initiative to Reduce the Necrotizing Enterocolitis Rate in Premature Infants

OBJECTIVE

To reduce the incidence of necrotizing enterocolitis (NEC) among very low birth weight (VLBW) infants admitted to 8 intensive care nurseries from a 2010 baseline of 8.0% to <4.0% by 2012 and sustain for 6 months using quality improvement (QI) methodology.

METHODS

A multidisciplinary NEC QI team used the Vermont Oxford Network definition of NEC and the Institute for Healthcare Improvement model. The specific aims were evidenced based and included (1) standardized early human milk feedings, (2) conservative feeding guidelines during blood transfusions and indomethacin treatment, and (3) restriction of ranitidine use in VLBW infants. Inclusion criteria included VLBW infants admitted within the study period without NEC. Exclusion criteria included established NEC or spontaneous intestinal perforation unrelated to NEC. The incidence of NEC and NEC-related surgery were tracked using statistical process control methodology.

RESULTS

The baseline NEC rate in 2010 was 8% (27 NEC cases in 335 VLBW infants). After initiation of early human-milk feeding and conservative feeds during blood transfusions guidelines in November 2011, only 3.1% (19 of 606 VLBW infants) had developed NEC through December 2013 (P = .001). Special cause variation was noted in June 2012 establishing a new centerline at 3.1%. NEC-related mortality decreased from a 2010 baseline mean of 2.7% to a new baseline mean of 0.9% from January 2011 to December 2013.

CONCLUSIONS

Implementation of QI initiatives decreased the NEC rate from 8.0% to <4.0%. Early human milk feedings and conservative feeding during blood transfusion policies appear to have significant impact on NEC reduction.

Plasma D-lactate Levels in Necrotizing Enterocolitis in Premature Infants

Background

D-Lactate is normally present in the blood of humans at nanomolar concentrations due to methylglyoxal metabolism; millimolar D-lactate concentrations can arise due to excess gastrointestinal microbial production.

Objectives

To examine the levels of plasma D-lactate in the necrotizing enterocolitis in premature infants.

Patients and Methods

128 premature infants were divided into control (group I, n = 69), feeding intolerance (group II, n = 42) and NEC (group III, n = 27) groups. Plasma D-lactate levels were measured at the onset of feeding intolerance or NEC and at weeks 2-3 in control infants (group I) by ELISA. Data were analyzed using descriptive statistics, non-parametric tests and Student’s t-test.

Results

In groups I, II, III, median birth weights were 1845.7 ± 267.5 g, 1913.1 ± 306.5 g, and 1898.4 ± 285.3 g, median gestational ages were 34.3 ± 1.7 weeks, 33.9 ± 2.2 weeks and 35.1 ± 2.6 weeks, ages of sampling were 12.3 ± 2.9 days, 14.6 ± 3.7 days and 15.1 ± 1.8 days, respectively. The differences of median birth weights, median gestational ages and ages of sampling were not statistically significant (P > 0.05). The plasma D-lactate levels in groups I, II, III were 3.6 ± 1.9 μg/mL, 12.7 ± 8.3 μg/mL, and 35.4 ± 29.1 μg/mL, respectively, group III had higher plasma D-lactate level than groups I, II, and the difference among these groups was significant (x² = 21.6, P < 0.01).

Conclusions

Plasma D-lactate significantly increased early in NEC. Plasma D-lactate levels were associated with extensive disease in NEC infants. Therefore, it could be used as a diagnosis indicator in the early stage of NEC.

Probiotics for Preventing Late-Onset Sepsis in Preterm Neonates: A PRISMA-Compliant Systematic Review and Meta-Analysis of Randomized Controlled Trials

The effect of probiotics on late-onset sepsis (LOS) in preterm neonates remains controversial. The authors systematically reviewed the literature to investigate whether enteral probiotic supplementation reduced the risk of LOS in preterm neonates in neonatal intensive care units.PubMed, Embase, and Cochrane Central Register of Controlled Trials were systematically searched for randomized controlled trials (RCTs) regarding the effect of probiotics in preterm neonates. The primary outcome was culture-proven bacterial and/or fungal sepsis. The Mantel-Haenszel method with random-effects model was used to calculate pooled relative risks (RRs) and 95% confidence intervals (CIs).Twenty-seven trials were included in our review, and 25 trials involving 6104 preterm neonates were statistically analyzed. Pooled analysis indicated that enteral probiotic supplementation significantly reduced the risk of any sepsis (25 RCTs; RR 0.83, 95% CI 0.73-0.94; I = 26%), bacterial sepsis (11 RCTs; RR 0.82, 95% CI 0.71-0.95; I = 0%), and fungal sepsis (6 RCTs; RR 0.57, 95% CI 0.41-0.78; I = 0%). This beneficial effect remains in very low birth weight infants (<1500 g) (19 RCTs; RR 0.86, 95% CI 0.75-0.97; I = 18%), but not in extremely low birth weight infants (<1000 g) (3 RCTs; RR 0.73, 95% CI 0.45-1.19; I = 53%). All the included trials reported no systemic infection caused by the supplemental probiotic organisms.Current evidence indicates that probiotic supplementation is safe, and effective in reducing the risk of LOS in preterm neonates in neonatal intensive care units. Further studies are needed to address the optimal probiotic organism, dosing, timing, and duration. High-quality and adequately powered RCTs regarding the efficacy and safety of the use of probiotics in extremely low birth weight infants are still warranted.

Oral antibiotics increase blood neutrophil maturation and reduce bacteremia and necrotizing enterocolitis in the immediate postnatal period of preterm pigs

Immature immunity may predispose preterm neonates to infections and necrotizing enterocolitis (NEC). Intravenous antibiotics are frequently given to prevent and treat sepsis, while oral antibiotics are seldom used. We hypothesized that oral antibiotics promote maturation of systemic immunity and delay gut bacterial colonization and thereby protect preterm neonates against both NEC and bacteremia in the immediate postnatal period. Preterm pigs were given formula and administered saline (CON) or broad-spectrum antibiotics orally (ORA) or systemically (SYS) for 5 d after birth. Temporal changes in blood parameters and bacterial composition in the intestine, blood and immune organs were analyzed. Newborn preterm pigs had few blood neutrophils and a high frequency of progenitor cells. Neutrophils gradually matured after preterm birth with increasing CD14 and decreasing CD172a expressions. Preterm neutrophil and monocyte TLR2 expression and TLR2-mediated blood cytokine responses were low relative to adults. ORA pigs showed enhanced blood neutrophil maturation with reduced cell size and CD172a expression. Only ORA pigs, but not SYS pigs, were protected from a high density of gut Gram-positive bacteria, high gut permeability, Gram-positive bacteremia and NEC. Neonatal oral antibiotics may benefit mucosal and systemic immunity via delayed gut colonization and enhanced blood neutrophil maturation just after preterm birth.

Bacterial munch for infants: potential pediatric therapeutic interventions of probiotics

Probiotics are viable microorganisms with the capacity to alter the gastrointestinal microbiota of the host. The recent scientific advancements and development of probiotic formulations have rekindled the importance of these clinical interpretations, underlining the starring role of the gut flora in host metabolism, defense and immune regulation. Despite encouraging preliminary results from randomized clinical trials of probiotics for various clinical conditions including irritable bowel syndrome, necrotizing enterocolitis, gastroenteritis, antibiotic-associated diarrhea, infantile colic, and improvement of digestion and immune function, further evidence is needed to determine the reproducibility of the findings and elucidate the underlying mechanisms. In this review, we have considered the postnatal development of gut flora and appraised the role of probiotics in health and disease condition among infants.

Low birthweight, gestational age, need for surgical intervention and gram-negative bacteraemia predict intestinal failure following necrotising enterocolitis

AIM

Necrotising enterocolitis (NEC) is associated with high morbidity and mortality. The aim of this study was to identify predictors of intestinal failure (IF), morbidity and mortality following NEC.

METHODS

We performed a retrospective study of all neonates treated for NEC stage II or greater at a tertiary referral NICU between 2000 and 2009. Demographic data, need for surgery, residual bowel length and rates of bacteraemia, cholestasis, IF and mortality were analysed.

RESULTS

During the 10-year period, 301 patients were referred with NEC and 152 had surgical intervention. Overall mortality was 32%. Of the 230 infants who survived >42 days, 97 (42%) had IF at 42 days, decreasing to 15% at >90 days. The rate of IF was significantly higher in the surgical group than the medical group (OR 2.04, 95% CI, 1.25-3.35, p < 0.004), but 23% of the medically treated infants with NEC also developed IF. There was a significant relationship between IF and gram-negative bacteraemia, the need for surgery, cholestasis, liver failure and mortality.

CONCLUSION

Intestinal failure occurred in a significant proportion of infants with NEC. Predictors for IF among infants with NEC were low birthweight, low gestational age, need for surgical intervention and gram-negative bacteraemia.

Antibiotics and the developing infant gut microbiota and resistome

The microbial communities colonizing the human gut are tremendously diverse and highly personal. The composition and function of the microbiota play important roles in human health and disease, and considerable research has focused on understanding the ecological forces shaping these communities. While it is clear that factors such as diet, genotype of the host, and environment influence the adult gut microbiota community composition, recent work has emphasized the importance of early-life assembly dynamics in both the immediate and long-term personalized nature of the gut microbiota. While the mature adult gut microbiota is believed to be relatively stable, the developing infant gut microbiota (IGM) is highly dynamic and prone to disruption by external factors, including antibiotic exposure. Studies have revealed both transient and persistent alterations to the adult gut microbiota community resulting from antibiotic treatment later in life. As antibiotics are routinely prescribed at a greater rate in the first years of life, the impact of these interventions on the developing IGM is emerging as a key research priority. In addition to understanding the impact of these disruptions on the infant gut microbial architecture and related host diseases, we need to understand the contribution of early life antibiotics to the selection of antibiotic resistance gene reservoirs in the microbiota, and their threat to successful treatment of infectious disease. Here we review the current understanding of the developmental progression of the IGM and the impact of antibiotic therapies on its composition and encoded reservoir of antibiotic resistance genes.

Understanding the Biologic Therapies of Probiotics, Prebiotics, and Synbiotics: Exploring Current Evidence for Use in Premature Infants for the Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis remains a significant cause of morbidity and mortality in very low-birth-weight infants (<1500 g), with current preventive strategies unclear. Scientific evidence has recently emerged, suggesting that probiotics, prebiotics, and synbiotics may effectively and safely alter the premature intestinal microbiota, enhancing a deficient innate immune response and maturing the intestinal barrier to prevent necrotizing enterocolitis development. Currently, formal recommendations do not support routine use of these dietary supplementations for premature infants. Here, we examine how probiotic, prebiotic, and synbiotic preparations physiologically alter the underdeveloped intestinal microbial environment to potentially reduce necrotizing enterocolitis incidence and discuss current evidence that has examined safety and efficacy factors potentially supporting routine use among the premature infant population.

Early microbial contact, the breast milk microbiome and child health

The significance of contact with microbes in early life for subsequent health has been the subject of intense research during the last 2 decades. Disturbances in the establishment of the indigenous intestinal microbiome caused by cesarean section delivery or antibiotic exposure in early life have been linked to the risk of immune-mediated and inflammatory conditions such as atopic disorders, inflammatory bowel disease and obesity later in life. Distinct microbial populations have recently been discovered at maternal sites including the amniotic cavity and breast milk, as well as meconium, which have previously been thought to be sterile. Our understanding of the impact of fetal microbial contact on health outcomes is still rudimentary. Breast milk is known to modulate immune and metabolic programming. The breast milk microbiome is hypothesized to guide infant gut colonization and is affected by maternal health status and mode of delivery. Immunomodulatory factors in breast milk interact with the maternal and infant gut microbiome and may mediate some of the health benefits associated with breastfeeding. The intimate connection between the mother and the fetus or the infant is a potential target for microbial therapeutic interventions aiming to support healthy microbial contact and protect against disease.

Factors influencing gastrointestinal tract and microbiota immune interaction in preterm infants

The role of microbial colonization is indispensable for keeping a balanced immune response in life. However, the events that regulate the establishment of the microbiota, their timing, and the way in which they interact with the host are not yet fully understood. Factors such as gestational age, mode of delivery, environment, hygienic measures, and diet influence the establishment of microbiota in the perinatal period. Environmental microbes constitute the most important group of exogenous stimuli in this critical time frame. However, the settlement of a stable gut microbiota in preterm infants is delayed compared to term infants. Preterm infants have an immature gastrointestinal tract and immune system which predisposes to infectious morbidity. Neonatal microbial dynamics and alterations in early gut microbiota may precede and/or predispose to diseases such as necrotizing enterocolitis (NEC), late-onset sepsis or others. During this critical period, nutrition is the principal contributor for immunological and metabolic development, and microbiological programming. Breast milk is a known source of molecules that act synergistically to protect the gut barrier and enhance the maturation of the gut-related immune response. Host-microbe interactions in preterm infants and the protective role of diet focused on breast milk impact are beginning to be unveiled.

The human neonatal gut microbiome: a brief review

The field of genomics has expanded into subspecialties such as metagenomics over the course of the last decade and a half. The development of massively parallel sequencing capabilities has allowed for increasingly detailed study of the genome of the human microbiome, the microbial super organ that resides symbiotically within the mucosal tissues and integumentary system of the human host. The gut microbiome, and particularly the study of its origins in neonates, has become subtopics of great interest within the field of genomics. This brief review seeks to summarize recent literature regarding the origins and establishment of the neonatal gut microbiome, beginning in utero, and how it is affected by neonatal nutritional status (breastfed versus formula fed) and gestational age (term versus preterm). We also explore the role of dysbiosis, a perturbation within the fragile ecosystem of the microbiome, and its role in the origin of select pathologic states, specifically, obesity and necrotizing enterocolitis (NEC) in preterm infants. We discuss the evidence supporting enteral pre- and pro-biotic supplementation of commensal organisms such as Bifidobacterium and Lactobacillus in the neonatal period, and their role in the prevention and amelioration of NEC in premature infants. Finally, we review directions to consider for further research to promote human health within this field.

External influence of early childhood establishment of gut microbiota and subsequent health implications

Postnatal maturation of immune regulation is largely driven by exposure to microbes. The gastrointestinal tract is the largest source of microbial exposure, as the human gut microbiome contains up to 10(14) bacteria, which is 10 times the number of cells in the human body. Several studies in recent years have shown differences in the composition of the gut microbiota in children who are exposed to different conditions before, during, and early after birth. A number of maternal factors are responsible for the establishment and colonization of gut microbiota in infants, such as the conditions surrounding the prenatal period, time and mode of delivery, diet, mother's age, BMI, smoking status, household milieu, socioeconomic status, breastfeeding and antibiotic use, as well as other environmental factors that have profound effects on the microbiota and on immunoregulation during early life. Early exposures impacting the intestinal microbiota are associated with the development of childhood diseases that may persist to adulthood such as asthma, allergic disorders (atopic dermatitis, rhinitis), chronic immune-mediated inflammatory diseases, type 1 diabetes, obesity, and eczema. This overview highlights some of the exposures during the pre- and postnatal time periods that are key in the colonization and development of the gastrointestinal microbiota of infants as well as some of the diseases or disorders that occur due to the pattern of initial gut colonization.