Effect of Bifidobacterium lactis on the incidence of nosocomial infections in very-low-birth-weight infants: a randomized controlled trial

Prevention of necrotizing enterocolitis with probiotics: a systematic review and meta-analysis

CONTEXT

Necrotizing enterocolitis (NEC) is the most frequent gastrointestinal emergency in neonates. The microbiome of the preterm gut may regulate the integrity of the intestinal mucosa. Probiotics may positively contribute to mucosal integrity, potentially reducing the risk of NEC in neonates.

OBJECTIVE

To perform an updated systematic review and meta-analysis on the efficacy and safety of probiotics for the prevention of NEC in premature infants.

DATA SOURCES

Structured searches were performed in: Medline, Embase, and the Cochrane Central Register of Controlled Trials (all via Ovid, from 2013 to January 2015). Clinical trial registries and electronically available conference materials were also searched. An updated search was conducted June 3, 2016.

STUDY SELECTION

Randomized trials including infants less than 37 weeks gestational age or less than 2,500 g on probiotic vs. standard therapy.

DATA EXTRACTION

Data extraction of the newly-identified trials with a double check of the previously-identified trials was performed using a standardized data collection tool.

RESULTS

Thirteen additional trials (n = 5,033) were found. The incidence of severe NEC (RR 0.53 95% CI [0.42-0.66]) and all-cause mortality (RR 0.79 95% CI [0.68-0.93]) were reduced. No difference was shown in culture-proven sepsis RR 0.88 95% CI [0.77-1.00].

LIMITATIONS

Heterogeneity of organisms and dosing regimens studied prevent a species-specific treatment recommendation from being made.

CONCLUSIONS

Preterm infants benefit from probiotics to prevent severe NEC and death.

Modulation of microbiota as treatment for intestinal inflammatory disorders: An uptodate

Alterations of intestinal microflora may significantly contribute to the pathogenesis of different inflammatory and autoimmune disorders. There is emerging interest on the role of selective modulation of microflora in inducing benefits in inflammatory intestinal disorders, by as probiotics, prebiotics, synbiotics, antibiotics, and fecal microbiota transplantation (FMT). To summarize recent evidences on microflora modulation in main intestinal inflammatory disorders, PubMed was searched using terms microbiota, intestinal flora, probiotics, prebiotics, fecal transplantation. More than three hundred articles published up to 2015 were selected and reviewed. Randomized placebo-controlled trials and meta-analysis were firstly included, mainly for probiotics. A meta-analysis was not performed because of the heterogeneity of these studies. Most of relevant data derived from studies on probiotics, reporting some efficacy in ulcerative colitis and in pouchitis, while disappointing results are available for Crohn's disease. Probiotic supplementation may significantly reduce rates of rotavirus diarrhea. Efficacy of probiotics in NSAID enteropathy and irritable bowel syndrome is still controversial. Finally, FMT has been recently recognized as an efficacious treatment for recurrent Clostridium difficile infection. Modulation of intestinal flora represents a very interesting therapeutic target, although it still deserves some doubts and limitations. Future studies should be encouraged to provide new understanding about its therapeutical role.

Probiotics and Time to Achieve Full Enteral Feeding in Human Milk-Fed and Formula-Fed Preterm Infants: Systematic Review and Meta-Analysis

Probiotics have been linked to a reduction in the incidence of necrotizing enterocolitis and late-onset sepsis in preterm infants. Recently, probiotics have also proved to reduce time to achieve full enteral feeding (FEF). However, the relationship between FEF achievement and type of feeding in infants treated with probiotics has not been explored yet. The aim of this systematic review and meta-analysis was to evaluate the effect of probiotics in reducing time to achieve FEF in preterm infants, according to type of feeding (exclusive human milk (HM) vs. formula). Randomized-controlled trials involving preterm infants receiving probiotics, and reporting on time to reach FEF were included in the systematic review. Trials reporting on outcome according to type of feeding (exclusive HM vs. formula) were included in the meta-analysis. Fixed-effect or random-effects models were used as appropriate. Results were expressed as mean difference (MD) with 95% confidence interval (CI). Twenty-five studies were included in the systematic review. In the five studies recruiting exclusively HM-fed preterm infants, those treated with probiotics reached FEF approximately 3 days before controls (MD -3.15 days (95% CI -5.25/-1.05), p = 0.003). None of the two studies reporting on exclusively formula-fed infants showed any difference between infants receiving probiotics and controls in terms of FEF achievement. The limited number of included studies did not allow testing for other subgroup differences between HM and formula-fed infants. However, if confirmed in further studies, the 3-days reduction in time to achieve FEF in exclusively HM-fed preterm infants might have significant implications for their clinical management.

Probiotic supplementation for preventing invasive fungal infections in preterm neonates--a systematic review and meta-analysis

Invasive fungal infections (IFI) are associated with significant health burden in preterm neonates. The objective of this study was to systematically review effect of probiotic supplementation (PS) for preventing IFI in preterm neonates. We searched Cochrane Central Register of Controlled Trials, Medline, Embase, Cumulative Index of Nursing and Allied Health Literature, and proceedings of the Pediatric Academic Society meetings in August 2014. Study selection was performed on randomised controlled trials (RCT) of PS in neonates born <37 weeks. Primary outcome of this study was IFI (Isolation of fungus in blood/body fluids) and secondary outcome was fungal gut colonisation. Information on IFI/colonisation was available in 8 of 27 RCT. Meta-analysis (fixed effects model) showed that PS reduced the risk of IFI (RR: 0.50, 95% CI: 0.34, 0.73, I(2) = 39%). Results were not significant with random effects model (RR: 0.64, 95%, CI: 0.30, 1.38, P = 0.25, I(2) = 39%). Analysis after excluding the study with a high baseline incidence (75%) of IFI showed that PS had no significant benefits (RR: 0.89; 95% CI: 0.44, 1.78). Of the five studies reporting on fungal gut colonisation, three reported benefits of probiotics; two did not. Current evidence is limited to derive firm conclusions on the effect of PS for preventing IFI/gut colonisation in preterm neonates.

Probiotic Supplementation and Late-Onset Sepsis in Preterm Infants: A Meta-analysis

CONTEXT

Late-onset sepsis (LOS) is a major cause of mortality and morbidity in preterm infants. Despite various preventive measures, its incidence continues to remain high, hence the urgent need for additional approaches. One such potential strategy is supplementation with probiotics. The updated Cochrane Review (2014) did not find benefits of probiotics in reducing the risk of LOS in preterm infants (19 studies, N = 5338). Currently there are >30 randomized controlled trials (RCTs) of probiotics in preterm infants that have reported on LOS.

OBJECTIVES

To conduct a systematic review including all relevant RCTs.

DATA SOURCES

PubMed, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index of Nursing and Allied Health Literature, and E-abstracts from the Pediatric Academic Society meetings and other pediatric and neonatal conference proceedings were searched in June and August 2015.

STUDY SELECTION

RCTs comparing probiotics versus placebo/no probiotic were included.

DATA EXTRACTION

Relevant data were extracted independently by 3 reviewers.

RESULTS

Pooled results from 37 RCTs (N = 9416) using fixed effects model meta analysis showed that probiotics significantly decreased the risk of LOS (675/4852 [13.9%] vs 744/4564 [16.3%]; relative risk, 0.86; 95% confidence interval, 0.78-0.94; P = .0007; I(2) = 35%; number needed to treat, 44). The results were significant even after excluding studies with high risk of bias.

CONCLUSIONS

Probiotic supplementation reduces the risk of LOS in preterm infants.

Prevention of Necrotizing Enterocolitis Through Manipulation of the Intestinal Microbiota of the Premature Infant

PURPOSE

In spite of four decades of research, necrotizing enterocolitis (NEC) remains the most common gastrointestinal complication in premature infants with high mortality and long-term morbidity. The composition of the intestinal microbiota of the premature infant differs dramatically from that of the healthy term infant and appears to be an important risk factor for NEC.

METHODS

We review the evidence of an association between intestinal dysbiosis and NEC and summarize published English language clinical trials and cohort studies involving attempts to manipulate the intestinal microbiota in premature infants.

FINDINGS

Promising NEC prevention strategies that alter the intestinal microbiota include probiotics, prebiotics, synbiotics, lacteroferrin, and human milk feeding.

IMPLICATIONS

Shaping the intestinal microbiota of the premature infant through human milk feeding and dietary supplements decreases the risk of NEC. Further studies to identify the ideal microbial composition and the most effective combination of supplements are indicated.

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.

Probiotics and Innate and Adaptive Immune Responses in Premature Infants

Premature infants are at increased risk for morbidity and mortality due to necrotizing enterocolitis (NEC) and sepsis. Probiotics decrease the risk of NEC and death in premature infants; however, mechanisms of action are unclear. A wide variety of probiotic species have been evaluated for potential beneficial properties in vitro, in animal models, and in clinical trials of premature infants. Although there is variation by species and even strain, common mechanisms of protection include attenuation of intestinal inflammation, apoptosis, dysmotility, permeability, supplanting other gut microbes through production of bacteriocins, and more effective use of available nutrients. Here, we review the most promising probiotics and what is known about their impact on the innate and adaptive immune response.

Probiotics for prevention of necrotizing enterocolitis in preterm infants: systematic review and meta-analysis

Necrotizing enterocolitis (NEC) affects predominantly preterm infants, who have specific risk factors leading to intestinal dysbiosis. Manipulations of gut microbiota through probiotics have the potential to prevent NEC.

The aim of this systematic review and meta-analysis was to evaluate the effect of probiotics for NEC prevention in preterm infants, with a focus on specific strains, microbiological strength of currently available studies, and high-risk populations.

PubMed and the Cochrane Library were searched for trials published within 4th February 2015. Randomized-controlled trials reporting on NEC and involving preterm infants who were given probiotics in the first month of life were included in the systematic review.

Twenty-six studies were suitable for inclusion in the meta-analysis.

Data about study design, population, intervention and outcome were extracted and summarized independently by two observers. Study quality and quality of evidence were also evaluated.

Fixed-effects models were used and random-effects models where significant heterogeneity was present. Subgroup analyses were performed to explore sources of heterogeneity among studies. Results were expresses as risk ratio (RR) with 95 % confidence interval (CI).

The main outcome was incidence of NEC stage ≥2 according to Bell’s criteria.

Probiotics prevented NEC in preterm infants (RR 0.47 [95 % CI 0.36–0.60], p < 0.00001). Strain-specific sub-meta-analyses showed a significant effect for Bifidobacteria (RR 0.24 [95 % CI 0.10–0.54], p = 0.0006) and for probiotic mixtures (RR 0.39 [95 % CI 0.27–0.56], p < 0.00001). Probiotics prevented NEC in very-low-birth-weight infants (RR 0.48 [95 % CI 0.37–0.62], p < 0.00001); there were insufficient data for extremely-low-birth-weight infants. The majority of studies presented severe or moderate microbiological flaws.

Probiotics had an overall preventive effect on NEC in preterm infants. However, there are still insufficient data on the specific probiotic strain to be used and on the effect of probiotics in high-risk populations such as extremely-low-birth-weight infants, before a widespread use of these products can be recommended.

Bacillus clausii for Prevention of Late-onset Sepsis in Preterm Infants: A Randomized Controlled Trial

BACKGROUND OF THE STUDY

Preterm infants are managed with antibiotics for sepsis, including suspected or probable sepsis. This leads to a delayed and abnormal colonization of the gut with potentially pathogenic organisms and a microbiome, which lacks biodiversity and increases the risk for late-onset sepsis (LOS). Probiotics have been proven to reduce the risk for necrotizing enterocolitis, but evidence for prevention of LOS is inconclusive. Probiotic effect depends also on the strain used, dose and indication for use. This study evaluated Bacillus clausii probiotic administered prophylactically to preterm neonates for prevention of LOS.

OBJECTIVES

To study B.clausii given prophylactically to preterm neonates for prevention of LOS.

DESIGN

Double-blinded, placebo-controlled, randomized trial.

SETTINGS

Tertiary care neonatal unit in India.

PARTICIPANTS

Consecutive preterm neonates <34 weeks, admitted from 1 March 2012 to 28 February 2014 were stratified as extreme preterm and very preterm.

INTERVENTION

Randomized to receive either probiotic or placebo for 6 weeks, discharge from hospital, death or occurrence of sepsis, whichever was earlier.

PRIMARY OUTCOME

Incidence of definite and probable LOS in probiotic group compared with placebo.

RESULTS

Of 326 eligible preterm infants, 244 were enrolled and 82 were excluded. Of these, 120 were stratified as extreme preterm and randomized to receive placebo (n = 59) and probiotic (n = 61). Of 124 babies stratified as very preterm, an equal number was randomized to receive placebo (n = 62) and probiotic (n = 62). There was no significant difference in the incidence of LOS between the two arms in the extreme preterm group [29% vs. 23%; relative risk (RR) 1.27; 95% confidence interval (CI) 0.88-1.66; p = 0.36] and the very preterm group (13% vs. 10%; RR 1.33; 95% CI 0.96-1.70; p = 0.32). Full feeds were achieved significantly faster in the probiotic group in both the extreme preterm (RR 0.82; 95% CI 0.74-0.88) and the very preterm (RR 0.67; 95% 0.32-0.77).

CONCLUSIONS

Prophylactic administration of B.clausii to preterm neonates did not result in a significant difference in the incidence of LOS as compared with placebo.

Probiotic administration can prevent necrotizing enterocolitis in preterm infants: A meta-analysis

PURPOSE

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in preterm infants, affecting ~6-7% of very-low-birth-weight (VLBW) infants. Early intervention and aggressive treatment has improved clinical outcomes, but considerable morbidity continues to accrue to NEC survivors. This meta-analysis examines the impact of probiotics on the incidence of NEC and complications among VLBW infants.

METHODS

A comprehensive literature search for all published randomized control trials (RCTs) assessing the use of probiotics to prevent NEC in VLBW infants was conducted using PubMed, Cochrane Central Registry of Controlled Trials, and Google Scholar (1966-2014). The incidences of NEC, sepsis, overall mortality, and time to reach full enteral feeds were analyzed.

RESULTS

20 RCTs involving 5982 preterm VLBW infants were analyzed. Risk of NEC was reduced by 49.1% (RR=0.509; 95% CI, 0.385-0.672; p<0.001), and overall mortality by 26.9% among infants receiving probiotics (RR=0.731; 95% CI, 0.577-0.926; p=0.009). An 8.1% reduction in sepsis was also observed in infants receiving probiotics (RR=0.919; 95% CI, 0.823-1.027; p=0.137). Time to reach full enteral feeds was reduced by 1.2 days among infants receiving probiotics (MD: -1.217; 95% CI, -2.151 to -0.283; p=0.011).

CONCLUSION

The use of probiotic supplementation in preterm VLBW infants is associated with a significant reduction in the risk of NEC and overall mortality. Additional studies are required to determine the optimal genus, species, and dose of probiotic.

Probiotics in neonatal intensive care - back to the future

Survival of extremely preterm and critically ill neonates has improved significantly over the last few decades following advances in neonatal intensive care. These include antenatal glucocorticoids, surfactant, continuous positive airway pressure support, advanced gentle modes of ventilation and inhaled nitric oxide. Probiotic supplementation is a recent significant milestone in the history of neonatal intensive care. Very few, if any, interventions match the ability of probiotics to significantly reduce the risk of death and definite necrotising enterocolitis while facilitating enteral feeds in high-risk preterm neonates. Probiotics also have a potential to benefit neonates with surgical conditions with significant gastrointestinal morbidity. Current evidence for the benefits of probiotic supplementation for neonates in an intensive care unit is reviewed. The mechanisms for the benefits of probiotics in this population are discussed, and guidelines for clinicians are provided in the context of the regulatory framework in Australia.

Probiotics for prevention of necrotizing enterocolitis in preterm infants

BACKGROUND

Necrotizing enterocolitis (NEC) and nosocomial sepsis are associated with increased morbidity and mortality in preterm infants. Through prevention of bacterial migration across the mucosa, competitive exclusion of pathogenic bacteria, and enhancing the immune responses of the host, prophylactic enteral probiotics (live microbial supplements) may play a role in reducing NEC and the associated morbidity.

OBJECTIVES

To compare the efficacy and safety of prophylactic enteral probiotics administration versus placebo or no treatment in the prevention of severe NEC or sepsis, or both, in preterm infants.

SEARCH METHODS

For this update, searches were made of MEDLINE (1966 to October 2013), EMBASE (1980 to October 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 10), and abstracts of annual meetings of the Society for Pediatric Research (1995 to 2013).

SELECTION CRITERIA

Only randomized or quasi-randomized controlled trials that enrolled preterm infants < 37 weeks gestational age or < 2500 g birth weight, or both, were considered. Trials were included if they involved enteral administration of any live microbial supplement (probiotics) and measured at least one prespecified clinical outcome.

DATA COLLECTION AND ANALYSIS

Standard methods of The Cochrane Collaboration and its Neonatal Group were used to assess the methodologic quality of the trials and for data collection and analysis.

MAIN RESULTS

Twenty-four eligible trials were included. Included trials were highly variable with regard to enrolment criteria (that is birth weight and gestational age), baseline risk of NEC in the control groups, timing, dose, formulation of the probiotics, and feeding regimens. In a meta-analysis of trial data, enteral probiotics supplementation significantly reduced the incidence of severe NEC (stage II or more) (typical relative risk (RR) 0.43, 95% confidence interval (CI) 0.33 to 0.56; 20 studies, 5529 infants) and mortality (typical RR 0.65, 95% CI 0.52 to 0.81; 17 studies, 5112 infants). There was no evidence of significant reduction of nosocomial sepsis (typical RR 0.91, 95% CI 0.80 to 1.03; 19 studies, 5338 infants). The included trials reported no systemic infection with the supplemental probiotics organism. Probiotics preparations containing either lactobacillus alone or in combination with bifidobacterium were found to be effective.

AUTHORS' CONCLUSIONS

Enteral supplementation of probiotics prevents severe NEC and all cause mortality in preterm infants. Our updated review of available evidence strongly supports a change in practice. Head to head comparative studies are required to assess the most effective preparations, timing, and length of therapy to be utilized.

PLAIN LANGUAGE SUMMARY

Probiotics for prevention of necrotizing enterocolitis in preterm infants Necrotizing enterocolitis (NEC) is a serious disease that affects the bowel of premature infants in the first few weeks of life. Although the cause of NEC is not entirely known, milk feeding and bacterial growth play a role. Probiotics (dietary supplements containing potentially beneficial bacteria or yeast) have been used to prevent NEC. Our review of studies found that the use of probiotics reduces the occurrence of NEC and death in premature infants born weighing less than 1500 grams. There is insufficient data with regard to the benefits and potential adverse effects in the most at risk infants weighing less than 1000 grams at birth.

Probiotics (Lactobacillus acidophilus and Bifidobacterium infantis) prevent NEC in VLBW infants fed breast milk but not formula [corrected]

BACKGROUND

Specific probiotics prevent necrotizing enterocolitis (NEC). A mixture of lactobacilli and bifidobacteria (Infloran) was highly effective in Asian very-low-birth-weight (VLBW) infants. We analyzed the effect of Infloran on NEC, NEC severity, and the influence of enteral feedings (breast milk vs. formula) on NEC prevention in a cohort of European VLBW infants.

METHODS

Infloran was implemented for routine use at our department. VLBW infants receiving probiotics were prospectively followed (2010-2012) and compared with historic controls (2008-2009). Data on NEC, neonatal morbidity, feeding tolerance, and descriptive parameters on NEC cases were analyzed.

RESULTS

Infloran had no statistically significant impact on NEC (controls: 24/233 (10.3%); probiotics: 16/230 (7%); P = 0.2). However, NEC was significantly reduced in infants of the probiotics group who were fed any breast milk (20/179 (11.2%) vs. 10/183 (5.5%); P = 0.027), whereas it was ineffective in infants exclusively fed formula (4/54 (7.4%) vs. 6/44 (13.6%); P = 0.345). Occurrence of severe NEC (IIIb), time until full feeds, and gastric residuals were similar.

CONCLUSION

Infloran was of lower efficacy in a European VLBW cohort and showed a reduction of NEC only in infants fed breast milk. Future studies should investigate the influence of feeding formula or breast milk on the effect of probiotics.

Benefits of probiotics on enteral nutrition in preterm neonates: a systematic review

INTRODUCTION

The optimization of enteral nutrition is a priority in preterm neonates worldwide. Probiotics are known to improve gut maturity and function in preterm neonates. To our knowledge, previous systematic reviews have not adequately assessed the effects of probiotic supplementation on enteral nutrition in preterm neonates.

OBJECTIVE

We assessed the evidence on effects of probiotics on enteral nutrition in preterm neonates.

DESIGN

A systematic review of randomized controlled trials (RCTs) of probiotic supplementation in preterm (gestation <37 wk) or low-birth-weight (birth weight <2500 g) neonates was conducted. With the use of the Cochrane Neonatal Review Group strategy, we searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and Cumulative Index of Nursing and Allied Health Literature databases and proceedings of Pediatric Academic Society meetings in April 2014.

RESULTS

A total of 25 RCTs (n = 5895) were included in the review. A meta-analysis (random-effects model) of data from 19 of 25 trials (n = 4527) estimated that the time to full enteral feeds was shorter in the probiotic group (mean difference: -1.54 d; 95% CI: -2.75, -0.32 d; P < 0.00001, I(2) = 93%). Other benefits included fewer episodes of feed intolerance, better weight gain and growth velocity, decreased transition time from orogastric to breast feeds, and increased postprandial mesenteric flow. There were no adverse effects of probiotic supplementation.

CONCLUSIONS

Probiotics reduced the time to full enteral feeds in preterm neonates. Additional research is necessary to assess the optimal dose, duration, and probiotic strain or strains used specifically for facilitating enteral nutrition in this population.

A meta-analysis of probiotics for preventing necrotizing enterocolitis in preterm neonates

Necrotizing enterocolitis (NEC) is one of the most common acquired diseases of the gastrointestinal tract in preterm infants. Some randomized, controlled trials (RCTs) have indicated that probiotics may potentially lower the incidence of NEC and mortality. However, debate still remains about the safety of probiotics and their influence on normal infant growth. We performed this meta-analysis to assess the safety and benefits of probiotic supplementation in preterm infants. We searched in PubMed, Embase, and Cochrane databases for English references, and in Wanfang, VIP, and CNKI databases for Chinese references. Ultimately, 27 RCTs (including 9 Chinese articles) were incorporated into this meta-analysis. Relative risk (RR) and weighted mean difference (WMD) were calculated using a random-effects or fixed-effects model, depending on the data type and heterogeneity. A total of 6655 preterm infants, including the probiotic group (n=3298) and the placebo group (n=3357), were eligible for inclusion in this meta-analysis. For Bell stage ≥I and gestational age <37 weeks, risk of NEC incidence was significantly lower in the probiotic group [RR=0.35, 95% confidence interval (CI)=0.27-0.44, P<0.00001]. For Bell stage ≥II or gestational age <34 weeks, there were likewise significant differences between the probiotic and placebo groups concerning NEC incidence (RR=0.34, 95%CI=0.25-0.48, P<0.00001; and RR=0.39, 95%CI=0.27-0.56, P<0.00001). Risk of death was significantly reduced in the probiotic group (RR=0.58, 95%CI=0.46-0.75, P<0.0001). In contrast, there was no significant difference concerning the risk of sepsis (RR=0.94, 95%CI=0.83-1.06, P=0.31). With respect to weight gain and the age at which infants reached full feeds, no significant differences were found between the probiotic and placebo groups (WMD=1.07, 95%CI=−0.21-2.34, P=0.10; and WMD=−1.66, 95%CI=−3.6-0.27, P=0.09). This meta-analysis has shown that, regardless of gestational age and NEC stage, probiotic supplementation could significantly reduce the risk of NEC in preterm infants. Analysis also indicated that such supplementation did not increase the incidence risk of sepsis or of mortality. Finally, the study showed that probiotic supplementation may have no adverse effect on normal feeding and growth.

Cohort study of probiotics in a North American neonatal intensive care unit

OBJECTIVE

To determine whether routine probiotic administration to very preterm infants would reduce the incidence of necrotizing enterocolitis (NEC) without adverse consequences.

STUDY DESIGN

Since the end of July 2011, we have administered a probiotic mixture to all admitted infants of <32 weeks' gestation. We give 0.5 g of a mixture of 4 bifidobacteria (Bifidobacterium breve, bifidum, infantis, and longum) and Lactobacillus rhamnosus HA-111 [corrected] (2 × 10(9) colony-forming units) per day, starting with the first feed, until the infant reaches 34 weeks. We compared complications among infants admitted during the first 17 months of routine use with those admitted during the previous 17 months.

RESULTS

Two hundred ninety-four infants received probiotics, and 317 infants formed the comparison group. Introduction of probiotics was associated with a reduction in NEC (from 9.8% to 5.4%, P < .02), a nonsignificant decrease in death (9.8% to 6.8%), and a significant reduction in the combined outcome of death or NEC (from 17% to 10.5%, P < .05). After adjustment for gestational age, intrauterine growth restriction, and sex, the improvements remained significant (OR for NEC, 0.51; 95% CI, 0.26-0.98; OR for death or NEC, 0.56; 95% CI, 0.33-0.93). There was no effect of probiotics on health care-associated infection.

DISCUSSION

A product that is readily available in North America, that has excellent quality control, and that contains strains similar to those that have been shown effective in randomized controlled trials substantially reduced the frequency of NEC in our neonatal intensive care unit.

Probiotics for prevention of necrotizing enterocolitis in preterm infants

BACKGROUND

Necrotizing enterocolitis (NEC) and nosocomial sepsis are associated with increased morbidity and mortality in preterm infants. Through prevention of bacterial migration across the mucosa, competitive exclusion of pathogenic bacteria, and enhancing the immune responses of the host, prophylactic enteral probiotics (live microbial supplements) may play a role in reducing NEC and the associated morbidity.

OBJECTIVES

To compare the efficacy and safety of prophylactic enteral probiotics administration versus placebo or no treatment in the prevention of severe NEC or sepsis, or both, in preterm infants.

SEARCH METHODS

For this update, searches were made of MEDLINE (1966 to October 2013), EMBASE (1980 to October 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 10), and abstracts of annual meetings of the Society for Pediatric Research (1995 to 2013).

SELECTION CRITERIA

Only randomized or quasi-randomized controlled trials that enrolled preterm infants < 37 weeks gestational age or < 2500 g birth weight, or both, were considered. Trials were included if they involved enteral administration of any live microbial supplement (probiotics) and measured at least one prespecified clinical outcome.

DATA COLLECTION AND ANALYSIS

Standard methods of The Cochrane Collaboration and its Neonatal Group were used to assess the methodologic quality of the trials and for data collection and analysis.

MAIN RESULTS

Twenty-four eligible trials were included. Included trials were highly variable with regard to enrolment criteria (that is birth weight and gestational age), baseline risk of NEC in the control groups, timing, dose, formulation of the probiotics, and feeding regimens. In a meta-analysis of trial data, enteral probiotics supplementation significantly reduced the incidence of severe NEC (stage II or more) (typical relative risk (RR) 0.43, 95% confidence interval (CI) 0.33 to 0.56; 20 studies, 5529 infants) and mortality (typical RR 0.65, 95% CI 0.52 to 0.81; 17 studies, 5112 infants). There was no evidence of significant reduction of nosocomial sepsis (typical RR 0.91, 95% CI 0.80 to 1.03; 19 studies, 5338 infants). The included trials reported no systemic infection with the supplemental probiotics organism. Probiotics preparations containing either lactobacillus alone or in combination with bifidobacterium were found to be effective.

AUTHORS' CONCLUSIONS

Enteral supplementation of probiotics prevents severe NEC and all cause mortality in preterm infants. Our updated review of available evidence strongly supports a change in practice. Head to head comparative studies are required to assess the most effective preparations, timing, and length of therapy to be utilized.

Probiotic guideline for necrotizing enterocolitis prevention in very low-birth-weight neonates

Necrotizing enterocolitis (NEC) is a gastrointestinal emergency that leads to inflammation and intestinal necrosis. Although probiotics can decrease the incidence of NEC, consistent recommendations for probiotic administration to very low-birth-weight (VLBW) neonates are lacking. Here, the best available evidence is reviewed and a practice guideline for probiotic administrations to VLBW neonates is described. A systematic review was conducted using MEDLINE and EMBASE, and the strength of evidence was classified using the Centre for Evidence-Based Medicine classification schema. Probiotics for VLBW neonates may decrease the incidence of NEC. Providers may choose to give probiotics to VLBW neonates at risk of acquiring NEC in facilities with a high NEC incidence. Clinicians must monitor infants for possible adverse effects. Contraindications for probiotic use include extremely low birth weight, clinical instability, abnormal abdominal examination, the presence of congenital abnormalities, post-NEC, stage III asphyxia, and umbilical catheters.

Probiotic and synbiotic safety in infants under two years of age

In this study, we systematically evaluated safety aspects in clinical trials with probiotics and synbiotics in young infants (0-2 years of age). This study is an update of earlier reports and covers the recent literature from 2008-2013. The safety evaluation is performed along the Common Terminology Clinical Adverse Events (CTCAE) version 4.0 scale, hereby also providing guidance for future studies. Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. The results show a deficiency in the precise reporting and classification of adverse events in most studies. Analysis of 57 clinical trials with probiotics and synbiotics in combination with eight follow-up studies indicate that probiotic administration to infants between 0 and 24 months is safe with regard to the evaluated strains in infants with a particular health status or susceptibility. Most adverse events and serious adverse events were considered unrelated to the study product, and there were no major safety concerns. Almost all studies concluded that none of the adverse effects were related to the study product; the study products are generally well tolerated. Finally, inconsistent, imprecise and potentially incomplete reporting as well as the variation in probiotic strains, dosages, administration regimes, study populations and reported outcomes, greatly limit the generalizability of conclusions and argue convincingly for obligatory and standardised behaviour on adverse events (CTCAE) reporting in ‘food’ studies.

Probiotics and prebiotics in neonatal necrotizing enterocolitis: New opportunities for translational research

Neonatal necrotizing enterocolitis (NEC) in premature infants has been recognized as a defined disease entity for at least four decades. Although survival has increased due to the advent of more sophisticated intensive care, incidence and long term health impacts due to NEC remain unchanged and no preventive therapy is currently available. Different probiotic strains of bacteria have been examined in their ability to prevent NEC with varied but encouraging results. Undigestable prebiotic sugars known to promote the growth of probiotic bacteria in the colon have been used in neonates with no clear benefit. The literature on NEC and probiotics is now cluttered with more reviews and meta-analyses than number of clinical trials. On the other hand, significant new information is available on microbiota and their impact on gut immunity. This review attempts to reiterate the risk factors of NEC and the pathogenesis of NEC with special reference to gut permeability. The reader is then introduced to gut microbiota, uniqueness and differences among probiotic strains, and how multiple resident flora talk to each other in the community setting in the human gut. After presenting a concise review of available clinical research results, the reader is challenged to question as to why no precise answer is available at present. Some modalities to examine the complex microflora and changes in the neonatal gut are then proposed including non-invasive methods and mathematical modeling. The review concludes by attracting the reader's attention to known immunomodulators of inflammation and injury. Justice to this review will be done only if the readers, clinical, and basic science investigators from multiple fields gather courage for a paradigm shift and embark on understanding the pathophysiology of the disease and attempt to discern the difference from equally preterm, equally vulnerable neonates that do not develop NEC. Learning about the developing microbiota in neonatal gut and its immunological impacts on the host in the face of many variables will provide a leap in our pursuit to select better, if not the best candidate probiotics, and put them to work against this stubborn disease that continues to take a toll on our precious neonates and the society.

Commensal and probiotic bacteria may prevent NEC by maturing intestinal host defenses

Necrotizing enterocolitis (NEC) is a devastating disease of prematurity with significant morbidity and mortality. Immaturity of intestinal host defenses predisposes the premature infant gut to injury. An abnormal bacterial colonization pattern with a deficiency of commensal bacteria may lead to a further breakdown of these host defense mechanisms, predisposing the infant to NEC. The presence of probiotic and commensal bacteria within the gut has been shown to mature the intestinal defense system through a variety of mechanisms. We have shown that commensal and probiotic bacteria can promote intestinal host defenses by reducing apoptotic signaling, blocking inflammatory signaling, and maturing barrier function in immature intestinal epithelia. Future studies aimed at elucidating the mechanisms by which probiotic and commensal bacteria exert their effects will be critical to developing effective preventive therapies for NEC.

Probiotic effects on late-onset sepsis in very preterm infants: a randomized controlled trial

BACKGROUND AND OBJECTIVE

Late-onset sepsis frequently complicates prematurity, contributing to morbidity and mortality. Probiotics may reduce mortality and necrotizing enterocolitis (NEC) in preterm infants, with unclear effect on late-onset sepsis. This study aimed to determine the effect of administering a specific combination of probiotics to very preterm infants on culture-proven late-onset sepsis.

METHODS

A prospective multicenter, double-blinded, placebo-controlled, randomized trial compared daily administration of a probiotic combination (Bifidobacterium infantis, Streptococcus thermophilus, and Bifidobacterium lactis, containing 1 × 10(9) total organisms) with placebo (maltodextrin) in infants born before 32 completed weeks' gestation weighing <1500 g. The primary outcome was at least 1 episode of definite late-onset sepsis.

RESULTS

Between October 2007 and November 2011, 1099 very preterm infants from Australia and New Zealand were randomized. Rates of definite late-onset sepsis (16.2%), NEC of Bell stage 2 or more (4.4%), and mortality (5.1%) were low in controls, with high breast milk feeding rates (96.9%). No significant difference in definite late-onset sepsis or all-cause mortality was found, but this probiotic combination reduced NEC of Bell stage 2 or more (2.0% versus 4.4%; relative risk 0.46, 95% confidence interval 0.23 to 0.93, P = .03; number needed to treat 43, 95% confidence interval 23 to 333).

CONCLUSIONS

The probiotics B infantis, S thermophilus, and B lactis significantly reduced NEC of Bell stage 2 or more in very preterm infants, but not definite late-onset sepsis or mortality. Treatment with this combination of probiotics appears to be safe.

Efficacy of Saccharomyces boulardii on necrotizing enterocolitis or sepsis in very low birth weight infants: a randomised controlled trial

BACKGROUND

Probiotics have strain specific effects and the effects of fungi in preventing diseases in preterm infants have been investigated poorly. Saccharomyces boulardii is a yeast which acts both as a probiotic and a polyamine producer.

AIM

The objective of this study was to investigate the efficacy of S. boulardii in preventing necrotizing enterocolitis (NEC) or sepsis in very low birth weight infants.

STUDY DESIGN AND SUBJECTS

A prospective, double blind, placebo controlled trial was conducted in preterm infants (≤ 32 GWs, ≤ 1500 g birth weight). They were randomized either to receive feeding supplementation with S. boulardii 50 mg/kg every 12 h or placebo, starting with the first feed until discharged.

OUTCOME MEASURES

Necrotizing enterocolitis (NEC) or sepsis and NEC or death.

RESULTS

Birth weight and gestational age of the study (n = 104) and the control (n = 104) groups were 1126 ± 232 vs 1162 ± 216 g and 28.8 ± 2.2 vs 28.7 ± 2.1 weeks, respectively. Neither the incidence of stage ≥ 2 NEC or death nor stage ≥ 2 NEC or late onset culture proven sepsis was significantly lower in the study group when compared with the control group (9.6% vs 7.7%, p = 0.62; 28.8% vs 23%, p = 0.34). Time to reach 100 mL/kg/day of enteral feeding (11.9 ± 7 vs 12.6 ± 7 days, p = 0.37) was not different between the groups.

CONCLUSIONS

Saccharomyces boulardii did not decrease the incidence of NEC or sepsis.

Association between funding source, methodological quality and research outcomes in randomized controlled trials of synbiotics, probiotics and prebiotics added to infant formula: a systematic review

BACKGROUND

There is little or no information available on the impact of funding by the food industry on trial outcomes and methodological quality of synbiotics, probiotics and prebiotics research in infants. The objective of this study was to compare the methodological quality, outcomes of food industry sponsored trials versus non industry sponsored trials, with regards to supplementation of synbiotics, probiotics and prebiotics in infant formula.

METHODS

A comprehensive search was conducted to identify published and unpublished randomized clinical trials (RCTs). Cochrane methodology was used to assess the risk of bias of included RCTs in the following domains: 1) sequence generation; 2) allocation concealment; 3) blinding; 4) incomplete outcome data; 5) selective outcome reporting; and 6) other bias. Clinical outcomes and authors' conclusions were reported in frequencies and percentages. The association between source of funding, risk of bias, clinical outcomes and conclusions were assessed using Pearson's Chi-square test and the Fisher's exact test. A p-value < 0.05 was statistically significant.

RESULTS

Sixty seven completed and 3 on-going RCTs were included. Forty (59.7%) were funded by food industry, 11 (16.4%) by non-industry entities and 16 (23.9%) did not specify source of funding. Several risk of bias domains, especially sequence generation, allocation concealment and blinding, were not adequately reported. There was no significant association between the source of funding and sequence generation, allocation concealment, blinding and selective reporting, majority of reported clinical outcomes or authors' conclusions. On the other hand, source of funding was significantly associated with the domains of incomplete outcome data, free of other bias domains as well as reported antibiotic use and conclusions on weight gain.

CONCLUSION

In RCTs on infants fed infant formula containing probiotics, prebiotics or synbiotics, the source of funding did not influence the majority of outcomes in favour of the sponsors' products. More non-industry funded research is needed to further assess the impact of funding on methodological quality, reported clinical outcomes and authors' conclusions.

Feeding intolerance in the preterm infant

Feeding intolerance (FI), defined as the inability to digest enteral feedings associated to increased gastric residuals, abdominal distension and/or emesis, is frequently encountered in the very preterm infant and often leads to a disruption of the feeding plan. In most cases FI represents a benign condition related to the immaturity of gastrointestinal function, however its presentation may largely overlap with that of an impending necrotizing enterocolitis. As a consequence, individual interpretation of signs of FI represents one of the most uncontrollable variables in the early nutritional management of these infants, and may lead to suboptimal nutrition, delayed attainment of full enteral feeding and prolonged intravenous nutrition supply. Strategies aimed at preventing and/or treating FI are diverse, although very few have been validated in large RCT and systematic reviews. The purpose of this paper is to summarize the existing information on this topic, spanning from patho-physiological and clinical aspects to the prevention and treatment strategies tested in clinical studies, with specific attention to practical issues.

Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children

BACKGROUND

Antibiotics are widely prescribed; however they can cause disturbances in gastrointestinal flora which may lead to reduced resistance to pathogens such as Clostridium difficile (C. difficile). Probiotics are live organisms thought to balance the gastrointestinal flora.

OBJECTIVES

The primary objectives were to assess the efficacy and safety of probiotics for preventing Clostridium difficile-associated diarrhea (CDAD) or C. difficile infection in adults and children.

SEARCH METHODS

On February 21, 2013 we searched PubMed (1966-2013), EMBASE (1966-2013), Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 1), CINAHL (1982-2013), AMED (1985-2013), and ISI Web of Science. Additionally, we conducted an extensive grey literature search including contact with industry representatives.

SELECTION CRITERIA

Randomized controlled (placebo, alternative prophylaxis, or no treatment control) trials investigating probiotics (any strain, any dose) for prevention of CDAD, or C. difficile infection were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently and in duplicate extracted data and assessed risk of bias using pre-constructed, and piloted, data extraction forms. Any disagreements were resolved by a third adjudicator. For articles published in abstract form only, further information was sought by contacting principal authors. The primary outcome was the incidence of CDAD. Secondary outcomes included the incidence of C. difficile infection, adverse events, antibiotic-associated diarrhea (AAD) and length of hospital stay. Dichotomous outcomes (e.g. incidence of CDAD) were pooled using a random-effects model to calculate the relative risk and corresponding 95% confidence interval (95% CI). Continuous outcomes (e.g. length of hospital) were pooled using a random-effects model to calculate the mean difference and corresponding 95% CI. Sensitivity analyses were conducted to explore the impact of missing data on efficacy and safety outcomes. For the sensitivity analyses, we assumed that the event rate for those participants in the control group who had missing data was the same as the event rate for those participants in the control group who were successfully followed. For the probiotic group we calculated effects using the following assumed ratios of event rates in those with missing data in comparison to those successfully followed: 1.5:1, 2:1, 3:1, and 5:1. To explore possible explanations for heterogeneity, a priori subgroup analysis were conducted on probiotic species, dose, adult versus pediatric population, and risk of bias.The overall quality of the evidence supporting each outcome was assessed using the GRADE criteria.

MAIN RESULTS

A total of 1871 studies were identified with 31 (4492 participants) meeting eligibility requirements for our review. Overall 11 studies were rated as a high risk of bias due mostly to missing outcome data. A complete case analysis (i.e. participants who completed the study) of those trials investigating CDAD (23 trials, 4213 participants) suggests that probiotics significantly reduce this risk by 64%. The incidence of CDAD was 2.0% in the probiotic group compared to 5.5% in the placebo or no treatment control group (RR 0.36; 95% CI 0.26 to 0.51). Sixteen of 23 trials had missing CDAD data ranging from 5% to 45%. These results proved robust to sensitivity analyses of plausible and worst-plausible assumptions regarding missing outcome data and were similar whether considering trials in adults versus children, lower versus higher doses, different probiotic species, or higher versus lower risk of bias. Our judgment is that the overall evidence warrants moderate confidence in this large relative risk reduction. We downgraded the overall quality of evidence for CDAD to 'moderate' due to imprecision. There were few events (154) and the calculated optimal information size (n = 8218) was more than the total sample size. With respect to the incidence of C. difficile infection, a secondary outcome, pooled complete case results from 13 trials (961 participants) did not show a statistically significant reduction. The incidence of C. difficile infection was 12.6% in the probiotics group compared to 12.7% in the placebo or no treatment control group (RR 0.89; 95% CI 0.64 to 1.24). Adverse events were assessed in 26 studies (3964 participants) and our pooled complete case analysis indicates probiotics reduce the risk of adverse events by 20% (RR 0.80; 95% CI 0.68 to 0.95). In both treatment and control groups the most common adverse events included abdominal cramping, nausea, fever, soft stools, flatulence, and taste disturbance. For the short-term use of probiotics in patients that are not immunocompromised or severely debilitated, we consider the strength of this evidence to be moderate.

AUTHORS' CONCLUSIONS

Based on this systematic review and meta-analysis of 23 randomized controlled trials including 4213 patients, moderate quality evidence suggests that probiotics are both safe and effective for preventing Clostridium difficile-associated diarrhea.

Necrotizing enterocolitis: pathophysiology, platelet-activating factor, and probiotics

Although smaller and younger preterm neonates can now survive long term due to advances in neonatal medicine, necrotizing enterocolitis (NEC) continues to plague the clinicians caring for these tiny patients. Research studies have contributed to our understanding of this complex disease, including the role of platelet-activating factor (PAF), but preventative and treatment strategies remain limited. One promising preventative measure in recent years has been enteral supplementation of probiotics, but concerns remain regarding the optimal use of these organisms, and safe administration must be assured. This chapter reviews NEC pathophysiology, including the role of PAF, as well as literature on the use of probiotics in the preterm infant.

Therapeutic use of prebiotics, probiotics, and postbiotics to prevent necrotizing enterocolitis: what is the current evidence?

Necrotizing enterocolitis (NEC) is a leading cause of neonatal morbidity and mortality, and preventive therapies that are both effective and safe are urgently needed. Current evidence from therapeutic trials suggests that probiotics are effective in decreasing NEC in preterm infants, and probiotics are currently the most promising therapy for this devastating disease. However, concerns regarding safety and optimal dosing have limited the widespread adoption of routine clinical use of probiotics in preterm infants. This article summarizes the current evidence regarding the use of probiotics, prebiotics, and postbiotics in the preterm infant, including their therapeutic role in preventing NEC.

Intestinal mucosal defense system, Part 2. Probiotics and prebiotics

The interplay between microorganisms and the intestine of newborn infants is associated with diverse functional and clinical outcomes that result from the specific interactions among microbial communities, their products, and the unique characteristics of the gastrointestinal tract. Multiple mechanisms of action for infant formula ingredients with probiotic activity appear to exist. These mechanisms are thought to protect the host not only from intestinal diseases but also from systemic infection. However, questions about the safety of probiotics for preterm infants remain unanswered, particularly with regard to sepsis, immunomodulatory effects, and microbial resistance. Few well-designed studies have been conducted to evaluate the effects of probiotic, prebiotic, and synbiotic ingredients on relevant clinical outcomes in preterm infants. Although existing data are encouraging, there is insufficient evidence to recommend the routine use of these ingredients in all preterm infants.

Micronutrient supplemented probiotic yogurt for HIV-infected adults taking HAART in London, Canada

The Human Immunodeficiency Virus has devastating effects worldwide. The burden is less pronounced, but still present in Canada where approximately 64,000 men and women are HIV positive. The virus and the life-saving antiretroviral therapies often contribute to diarrhea and other gastrointestinal disturbances. Certain probiotic organisms, such as Lactobacillus rhamnosus GR-1, have been shown to alleviate diarrhea as well as delay the decline of CD4 lymphocytes in some subjects. In addition, micronutrient formulae have been used extensively among HIV positive persons as a cost-effective method for improving quality of life and immune function. The objective of the present study was to combine probiotics and micronutrients into an affordable and highly palatable nutritional supplement and assess outcomes in 21 HIV-positive participants receiving highly active antiretroviral therapy in London, Ontario, Canada. The design was a randomized, double blind, three-period, cross-over controlled trial with three different formulations of supplemented yogurt; micronutrient and probiotic (A), micronutrient alone (B) and probiotic alone (C). The period of intake for each of the types was 30 days with a 14 day wash-out period between the intervention types. The mean increase in CD4 was greatest with B (41 cells/µL, SD 221). Supplement A showed a mean change of +19 cells/µL (SD 142) and supplement C a mean change of - 7 cells/µL (SD 154). All yogurt types caused an increase in subjective energy and ability to perform daily activity scores. According to the safety measures taken to assess the tolerance of the yogurt, there were no adverse events and the yogurt was well-tolerated. These preliminary findings suggest that micronutrient supplemented probiotic yogurt may support immune function among people living with HIV.

Probiotics and prebiotics: role in prevention of nosocomial sepsis in preterm infants

Nosocomial sepsis is associated with increased mortality and morbidity including neurodevelopmental impairment and prolonged hospital stay. Prevention of sepsis especially in the preterm infants in the neonatal intensive care unit remains a major challenge. The gastrointestinal tract is an important source of potential pathogens causing nosocomial sepsis as the immature intestinal epithelium can permit translocation of bacteria and yeast. The intestinal tract and its microflora play an important role in the immunity. Altering the gut microflora has been extensively studied for immunomodulation in preterm infants. Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Probiotics have been used for prevention and treatment of various medical conditions in children and adults. Studies on probiotics in premature infants have focused on normalizing intestinal flora, improvement in feeding intolerance, prevention of necrotizing enterocolitis and sepsis. In this paper, we discuss the intestinal bacterial colonization pattern; the rational for probiotics and prebiotic therapy with special focus on the prevention of nosocomial sepsis in preterm infants.

Effectiveness of probiotics in the prophylaxis of necrotizing enterocolitis in preterm neonates: a systematic review and meta-analysis

OBJECTIVE

To elucidate the benefits of using probiotics in the prevention of necrotizing enterocolitis (NEC) and its complications in preterm newborns.

METHOD

This was a systematic review of randomized controlled trials, which included studies retrieved from three databases (MEDLINE, Embase, and LILACS), using a combination of the terms (necrotizing enterocolitis) AND (probiotics).

RESULTS

11 randomized trials were included, totaling 2,887 patients, 1,431 in the probiotic group and 1,456 in the control group. There was a reduction in the incidence of NEC (NNT=25), overall death (NNT=34), and neonatal sepsis (NNT=34) in the probiotic group compared to the control group. Patients that received probiotic supplementation had lower food reintroduction time (p<0.001) and hospitalization time (p<0.001) when compared to those not receiving probiotics. There was no difference in mortality caused by NEC.

CONCLUSION

In premature newborns, the use of probiotics is effective as a prophylaxis for NEC and its complications.

Probiotics and necrotizing enterocolitis: finding the missing pieces of the probiotic puzzle

Necrotizing enterocolitis (NEC) is one of the leading causes of death in the neonatal intensive care unit. Morbidity and mortality rates significantly increase with decreases in gestational age and birth weight. Strong evidence suggests probiotic prophylaxis may significantly decrease the incidence of NEC and should therefore be incorporated into the standard of care for preterm infants. However, debate still remains because of limitations of completed studies. The purpose of this review was to provide an overview of the controversies regarding probiotic use in preterm infants and to shed light on the practical considerations for implementation of probiotic supplementation.

A.S.P.E.N. clinical guidelines: nutrition support of neonatal patients at risk for necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is one of the most devastating diseases in the neonatal population, with extremely low birth weight and extremely preterm infants at greatest risk.

METHOD

A systematic review of the best available evidence to answer a series of questions regarding nutrition support of neonates at risk of NEC was undertaken and evaluated using concepts adopted from the Grading of Recommendations, Assessment, Development and Evaluation working group. A consensus process was used to develop the clinical guideline recommendations prior to external and internal review and approval by the A.S.P.E.N. Board of Directors. RESULTS/ CONCLUSIONS: (1) When and how should feeds be started in infants at high risk for NEC? We suggest that minimal enteral nutrition be initiated within the first 2 days of life and advanced by 30 mL/kg/d in infants ≥ 1, 000 g. (Weak) (2) Does the provision of mother's milk reduce the risk of developing NEC? We suggest the exclusive use of mother's milk rather than bovine-based products or formula in infants at risk for NEC. (Weak) (3) Do probiotics reduce the risk of developing NEC? There are insufficient data to recommend the use of probiotics in infants at risk for NEC. (Further research needed.) (4) Do nutrients either prevent or predispose to the development of NEC? We do not recommend glutamine supplementation for infants at risk for NEC (Strong). There is insufficient evidence to recommend arginine and/or long chain polyunsaturated fatty acid supplementation for infants at risk for NEC. (Further research needed.) (5) When should feeds be reintroduced to infants with NEC? There are insufficient data to make a recommendation regarding time to reintroduce feedings to infants after NEC. (Further research needed.).

Probiotic supplement reduces risk of necrotizing enterocolitis and mortality in preterm very low-birth-weight infants: an updated meta-analysis of 20 randomized, controlled trials

PURPOSE

Necrotizing enterocolitis (NEC) is the most common acquired disease of the gastrointestinal tract in preterm infants, whereas probiotic supplementation might reduce NEC risk and potentially provide benefits to preterm infants. We performed an updated meta-analysis of all relevant randomized, controlled trials to assess the benefits of probiotic supplementation for preterm very low-birth-weight (VLBW) infants.

METHODS

We searched in PubMed, Embase, and Chinese BioMedical Literature Database (CBM) databases, and 20 randomized, controlled trials (a total of 3816 preterm VLBW infants) were finally included into this meta-analysis. Incidence and relative risk (RR) were calculated using a random-effects or fixed-effects model depending on the heterogeneity of the included studies.

RESULTS

Probiotic supplement was associated with a significantly decreased risk of NEC in preterm VLBW infants (RR = 0.33; 95% confidence interval [CI], 0.24-0.46; P < .00001). Risk of death was also significantly reduced in the probiotic group (RR = 0.56; 95% CI, 0.43-0.73; P < .0001). There was no difference in the risk of sepsis between the probiotic group and placebo group (RR = 0.90; 95% CI, 0.71-1.15; P = .40).

CONCLUSIONS

Probiotic supplement can reduce risk of NEC and mortality in preterm VLBW infants. However, the optimum type of probiotic supplement and the long-term effects need further study.

Critical systematic review of the level of evidence for routine use of probiotics for reduction of mortality and prevention of necrotizing enterocolitis and sepsis in preterm infants

BACKGROUND & AIMS

Probiotics have been suggested to prevent severe necrotizing enterocolitis (NEC) and decrease mortality in preterm infants. The aim of this paper was to systematically analyze the level of evidence (LoE) of published controlled randomized trials (RCTs) on probiotics in preterm infants.

METHODS

Literature searches were made up to November 2010. LoE of recommendations based on single trials or meta-analyses were scored following the Oxford Center for Evidence based Medicine approach (1a - meta-analyses of 1b LoE studies; 1b - well designed RCT; 2a - meta-analyses which include 2b LoE studies; 2b - lesser quality RCT).

RESULTS

Fifteen trials were included (Two 1b LoE trials and thirteen 2b LoE trials). Methodological assessment revealed considerable heterogeneity. Some probiotics may be beneficial in relation to reduction of severe NEC (2b LoE) and reduction of mortality (2b LoE). Probiotics do not accelerate feeding advancement (1b and 2b LoE). There was no convincing benefit with regard to prevention of sepsis (1b and 2b LoE).

CONCLUSION

There is insufficient evidence to recommend routine probiotics. However, there is encouraging data (2b LoE) which justifies the further investigation regarding the efficacy and safety of specific probiotics in circumstances of high local incidence of severe NEC.

Myth: necrotizing enterocolitis: probiotics will end the disease, and surgical intervention improves the outcome

Necrotizing enterocolitis remains an important contributor to neonatal morbidity and mortality. Recent studies suggest that probiotic supplementation may reduce the risk of the disease in premature infants, and some authors recommend that this approach is ready to be utilized as standard-of-care. Once necrotizing enterocolitis is diagnosed and progresses toward peritonitis or perforation, surgical intervention is thought to improve the outcome, and investigators have suggested that peritoneal drainage is as effective as an exploratory laparotomy. In this chapter, we review the current state of knowledge, and suggest that additional studies are necessary to confirm that probiotics will end this disease, and that surgical intervention may not significantly improve the outcome after diagnosis in these compromised patients.

What is the power of evidence recommending routine probiotics for necrotizing enterocolitis prevention in preterm infants?

PURPOSE OF REVIEW

There is a lively discussion in literature whether routine use of probiotics should be recommended to reduce the incidence of severe necrotizing enterocolitis (NEC) and mortality in preterm infants. The aim of the present review is to analyze the level of evidence of published randomized controlled trials (RCTs) that different probiotic products reduce the incidence of severe NEC and mortality in preterm infants following Oxford Center for Evidence-based Medicine approach.

RECENT FINDINGS

Application of probiotics is not a homogeneous intervention and meta-analyses across the available trials may be misleading with the risk that generalized conclusions are erroneously extrapolated to other probiotics. Each individual probiotic intervention should be analyzed separately. Currently, there are 16 RCTs studying 12 different probiotic preparations in preterm infants which report data on clinically important outcomes such as NEC, mortality, sepsis, or feeding advancement. Certain probiotics may be beneficial in relation to severe NEC (level of evidence, LoE 2b).

SUMMARY

In circumstances of high local incidence of severe NEC, there is encouraging data (LoE 2b) for the use of probiotics. However, currently there is no level 1a evidence to recommend that all preterm infants should be fed probiotics routinely. Further, well designed RCTs on specific probiotics are required.

Effect of Bifidobacterium animalis subsp lactis supplementation in preterm infants: a systematic review of randomized controlled trials

OBJECTIVE

To systematically evaluate and update evidence on the efficacy and safety of Bifidobacterium animalis subsp lactis CNCM I-3446 supplementation in preterm infants.

MATERIALS AND METHODS

The Cochrane Library and MEDLINE databases and major pediatric conference proceedings were searched in December 2008 for randomized controlled trials (RCTs). The company that manufactures B lactis was contacted for unpublished data. The review was restricted to RCTs performed in preterm infants <37 weeks of gestation and/or with a birth weight <2500 g.

RESULTS

Four RCTs involving 324 infants met the inclusion criteria. Compared with controls, B lactis supplementation has the potential to increase fecal bifidobacteria counts and to reduce Enterobacteriaceae and Clostridium spp counts. It also can reduce stool pH and fecal calprotectin concentrations, increase fecal immunoglobulin A and short-chain fatty acid concentrations, and decrease intestinal permeability. Compared with controls, B lactis supplementation had no effect on the risk of necrotizing enterocolitis stage > or = 2 (3 RCTs, n = 293, risk ratio [RR] 0.53, 95% CI 0.16-1.83), risk of sepsis (2 RCTs, 397 cultures, RR 0.6, 95% CI 0.07-5.2), and use of antibiotics (2 RCTs, n = 255, RR 0.67, 95% CI 0.28-1.62). The power of these studies, however, does not allow for a definitive statement regarding a reduced risk of necrotizing enterocolitis. B lactis supplementation did have some effects on anthropometric parameters. No adverse events associated with B lactis supplementation were reported.

CONCLUSIONS

Evidence regarding the potential beneficial effects of B lactis supplementation in preterm infants is encouraging. Further studies to assess clinically relevant outcomes are needed.