Single strain versus multispecies probiotic on necrotizing enterocolitis and faecal IgA levels in very low birth weight preterm neonates: A randomized clinical trial

No differences were observed in the prevention of necrotizing enterocolitis and late-onset sepsis among preterm infants who received either single-species or multi-species probiotics

BACKGROUND

Probiotic prophylaxis has been suggested to reduce the incidence of necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) in very preterm newborns. However, choosing the optimal probiotic is difficult due to variations in strain-specific effects and interactions facilitated by the use of combination species.

AIMS

To compare clinical outcomes of very preterm infants receiving multi or single-species probiotics.

STUDY DESIGN

Retrospective, single-center, cohort study.

SUBJECTS

Very preterm infants (<32 weeks' gestation) born between 2019 and 2022 at a tertiary perinatal center received either a multi-species (Lactobacillus rhamnosus 45 %, Lactobacillus casei 15 %, Lactobacillus acidophilus 15 %, Bifidobacterium infantis 15 %, Bifidobacterium bifidum 10 %; n = 228) or a single-species (Bifidobacterium breve BR03 and B632; n = 227) probiotic formulation.

MAIN OUTCOME MEASURES

NEC, LOS, and mortality.

RESULTS

The overall incidence of NEC and LOS was 3.1 % and 13.8 %, respectively. There were no differences between the multi-species and single-species probiotic groups in the rate of NEC (3.5 % vs 2.6 %; p = 0.787), LOS (15.4 % vs 12.3 %; p = 0.416), mortality (0.9 % vs 1.8 %; p = 0.449), or composite outcome (NEC, LOS and/or death; 16.7 % vs 12.8 %; p = 0.290).

CONCLUSION

The clinical outcomes of very preterm newborns receiving multi vs. single-species probiotic formulations were similar in our study. In view of the sample size and low baseline rate of NEC in our unit, further trials are warranted to investigate the effects of specific probiotics for prevention of serious neonatal morbidities.

Safety and Effectiveness of Probiotics in Preterm Infants with Necrotizing Enterocolitis

Although necrotizing enterocolitis is a leading cause of morbidity and mortality among preterm infants, its underlying pathophysiology is not fully understood. Gut dysbiosis, an imbalance between commensal and pathogenic microbes, in the preterm infant is likely a major contributor to the development of necrotizing enterocolitis. In this review, we will discuss the increasing use of probiotics in the NICU, an intervention aimed to mitigate alterations in the gut microbiome. We will review the existing evidence regarding the safety and effectiveness of probiotics, and their potential to reduce rates of necrotizing enterocolitis in preterm infants.

Safety and Effectiveness of Probiotics in Preterm Infants with Necrotizing Enterocolitis

Although necrotizing enterocolitis is a leading cause of morbidity and mortality among preterm infants, its underlying pathophysiology is not fully understood. Gut dysbiosis, an imbalance between commensal and pathogenic microbes, in the preterm infant is likely a major contributor to the development of necrotizing enterocolitis. In this review, we will discuss the increasing use of probiotics in the NICU, an intervention aimed to mitigate alterations in the gut microbiome. We will review the existing evidence regarding the safety and effectiveness of probiotics, and their potential to reduce rates of necrotizing enterocolitis in preterm infants.

Listeria monocytogenes infection in pregnant macaques alters the maternal gut microbiome†

OBJECTIVES

The bacterium Listeria monocytogenes (Lm) is associated with adverse pregnancy outcomes. Infection occurs through consumption of contaminated food that is disseminated to the maternal-fetal interface. The influence on the gastrointestinal microbiome during Lm infection remains unexplored in pregnancy. The objective of this study was to determine the impact of listeriosis on the gut microbiota of pregnant macaques.

METHODS

A non-human primate model of listeriosis in pregnancy has been previously described. Both pregnant and non-pregnant cynomolgus macaques were inoculated with Lm and bacteremia and fecal shedding were monitored for 14 days. Non-pregnant animal tissues were collected at necropsy to determine bacterial burden, and fecal samples from both pregnant and non-pregnant animals were evaluated by 16S rRNA next-generation sequencing.

RESULTS

Unlike pregnant macaques, non-pregnant macaques did not exhibit bacteremia, fecal shedding, or tissue colonization by Lm. Dispersion of Lm during pregnancy was associated with a significant decrease in alpha diversity of the host gut microbiome, compared to non-pregnant counterparts. The combined effects of pregnancy and listeriosis were associated with a significant loss in microbial richness, although there were increases in some genera and decreases in others.

CONCLUSIONS

Although pregnancy alone is not associated with gut microbiome disruption, we observed dysbiosis with listeriosis during pregnancy. The macaque model may provide an understanding of the roles that pregnancy and the gut microbiota play in the ability of Lm to establish intestinal infection and disseminate throughout the host, thereby contributing to adverse pregnancy outcomes and risk to the developing fetus.

A prediction model for neonatal necrotizing enterocolitis in preterm and very low birth weight infants

Objectives

Neonatal necrotizing enterocolitis (NEC) is a severe gastrointestinal disease that primarily affects preterm and very low birth weight infants, with high morbidity and mortality. We aim to build a reliable prediction model to predict the risk of NEC in preterm and very low birth weight infants.

Methods

We conducted a retrospective analysis of medical data from infants (gestational age <32 weeks, birth weight <1,500 g) admitted to Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region. We collected clinical data, randomly dividing it into an 8:2 ratio for training and testing. Multivariate logistic regression was employed to identify significant predictors for NEC. Principal component analysis was used for dimensionality reduction of numerical variables. The prediction model was constructed through logistic regression, incorporating all relevant variables. Subsequently, we calculated performance evaluation metrics, including Receiver Operating Characteristic (ROC) curves and confusion matrices. Additionally, we conducted model performance comparisons with common machine learning models to establish its superiority.

Results

A total of 292 infants were included, with 20% (n = 58) randomly selected for external validation. Multivariate logistic regression revealed the significance of four predictors for NEC in preterm and very low birth weight infants: temperature (P = 0.003), Apgar score at 5 min (P = 0.004), formula feeding (P = 0.007), and gestational diabetes mellitus (GDM, P = 0.033). The model achieved an accuracy of 82.46% in the test set with an F1 score of 0.90, outperforming other machine learning models (support vector machine, random forest).

Conclusions

Our logistic regression model effectively predicts NEC risk in preterm and very low birth weight infants, as confirmed by external validation. Key predictors include temperature, Apgar score at 5 min, formula feeding, and GDM. This study provides a vital tool for NEC risk assessment in this population, potentially improving early interventions and child survival. However, clinical validation and further research are necessary for practical application.

Non-human primate models for understanding the impact of the microbiome on pregnancy and the female reproductive tract†

The microbiome has been shown, or implicated to be involved, in multiple facets of human health and disease, including not only gastrointestinal health but also metabolism, immunity, and neurology. Although the predominant focus of microbiome research has been on the gut, other microbial communities such as the vaginal or cervical microbiome are likely involved in physiological homeostasis. Emerging studies also aim to understand the role of different microbial niches, such as the endometrial or placental microbial communities, on the physiology and pathophysiology of reproduction, including their impact on reproductive success and the etiology of adverse pregnancy outcomes (APOs). The study of the microbiome during pregnancy, specifically how changes in maternal microbial communities can lead to dysfunction and disease, can advance the understanding of reproductive health and the etiology of APOs. In this review, we will discuss the current state of non-human primate (NHP) reproductive microbiome research, highlight the progress with NHP models of reproduction, and the diagnostic potential of microbial alterations in a clinical setting to promote pregnancy health. NHP reproductive biology studies have the potential to expand the knowledge and understanding of female reproductive tract microbial communities and host-microbe or microbe-microbe interactions associated with reproductive health through sequencing and analysis. Furthermore, in this review, we aim to demonstrate that macaques are uniquely suited as high-fidelity models of human female reproductive pathology.

Probiotics for the prevention of mortality and sepsis in preterm very low birth weight neonates from low- and middle-income countries: a Bayesian network meta-analysis

Background

Probiotics have been shown to reduce the risk of mortality and necrotizing enterocolitis (NEC) in very low birth weight (VLBW) neonates. The probiotic species with the maximal benefits in neonates from low- and middle-income countries are unknown.

Objective

To identify the strain of probiotics with the maximum benefit in preventing neonatal mortality, sepsis, and NEC using the Bayesian network meta-analysis.

Search methods

We searched Medline via PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL). We also hand-searched reference lists of previous systematic reviews to identify eligible studies.

Selection criteria

Randomized controlled trials (RCTs) from LMICs comparing enteral supplementation of one or more probiotics with another probiotic species or placebo were included.

Data collection and analysis

Two authors screened the studies, extracted the data, and examined the risk of bias using the Cochrane risk of bias 2 (RoB 2) tools. Bayesian network meta-analysis was performed using the "BUGSnet" package in R and RStudio (version 1.4.1103). The confidence in the findings was assessed using the Confidence in Network Meta-analysis (CINeMA) web application.

Results

Twenty-nine RCTs enrolling 4,906 neonates and evaluating 24 probiotics were included. Only 11 (38%) studies had a low risk of bias. All the studies compared the probiotics with a placebo; none had a head-to-head comparison of different probiotic species. Also, only one study each had evaluated most probiotic regimens. When compared to placebo, the combination of B longum, B bifidum, B infantis, and L acidophilus may reduce the risk of mortality (relative risk [RR] 0.26; 95% credible interval [CrI] 0.07 to 0.72), sepsis (RR 0.47; 95% CrI 0.25 to 0.83), and NEC (RR 0.31; 95% CrI 0.10 to 0.78) but the evidence is very uncertain. There is low certainty evidence that the single probiotic species, B lactis, could reduce the risk of mortality (RR 0.21; 0.05 to 0.66) and NEC (RR 0.09; 0.01 to 0.32).

Conclusion

Given the low to very low certainty of evidence for the efficacy of the two probiotics found to reduce mortality and necrotizing enterocolitis, no firm conclusions can be made on the optimal probiotics for use in preterm neonates in low- and middle-income countries.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022353242, identifier: CRD42022353242.

Probiotics to prevent necrotizing enterocolitis and reduce mortality in neonates: A meta-analysis

BACKGROUND

Probiotics are gradually being used as a supplementation to prevent necrotizing enterocolitis (NEC) and reduce mortality in neonates. We performed an updated meta-analysis to systematically evaluate the efficacy and safety of prophylactic probiotic supplementation for preventing NEC.

METHODS

The databases including PubMed, Embase, Scopus, Web of Science, and China National Knowledge Infrastructure were used to search the relevant articles. The latest retrieval date was up to December 2021. The meta-analysis was performed using Stata version 10.0. Finally, a total of 70 studies containing 8319 cases and 9283 controls were included. The strength of the association between the supplementation of probiotics and NEC was measured by risk ratios (RRs) with 95% confidence intervals (CIs). Pooled effect sizes across studies were performed by a random effect model.

RESULTS

The results showed that the probiotics could significantly reduce the incidence of NEC (stage II or more) (RR = 0.436, 95% CI = 0.357-0.531, P < .001), the overall mortality (RR = 0.651, 95% CI = 0.506-0.836, P < .001), and NEC-related mortality (RR = 0.639, 95% CI = 0.423-0.966, P = .034). Due to the lack of sufficient sample size, we did not perform the subgroup analysis by types of probiotic strain.

CONCLUSION

This meta-analysis indicates that the use of probiotics can effectively reduce the occurrence of NEC and mortality in neonates.

Probiotics for the Management of Pediatric Gastrointestinal Disorders: Position Paper of the ESPGHAN Special Interest Group on Gut Microbiota and Modifications

BACKGROUND

Probiotics, defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host, are widely used despite uncertainty regarding their efficacy and discordant recommendations about their use. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Special Interest Group on Gut Microbiota and Modifications provides updated recommendations for the use of probiotics for the management of selected pediatric gastrointestinal disorders.

METHODS

All systematic reviews and/or meta-analyses, as well as subsequently published randomized controlled trials (RCTs) (until December 2021), that compared the use of probiotics in all delivery vehicles and formulations, at any dose, with no probiotic (ie, placebo or no treatment), were eligible for inclusion. The recommendations were formulated only if at least 2 RCTs on a similar well-defined probiotic strain were available. The modified Delphi process was used to establish consensus on the recommendations.

RESULTS

Recommendations for the use of specific probiotic strains were made for the management of acute gastroenteritis, prevention of antibiotic-associated diarrhea, nosocomial diarrhea and necrotizing enterocolitis, management of Helicobacter pylori infection, and management of functional abdominal pain disorders and infant colic.

CONCLUSIONS

Despite evidence to support the use of specific probiotics in some clinical situations, further studies confirming the effect(s) and defining the type, dose, and timing of probiotics are still often required. The use of probiotics with no documented health benefits should be discouraged.

Current and future methods of probiotic therapy for necrotizing enterocolitis

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

Lactate acid level and prognosis of neonatal necrotizing enterocolitis: a retrospective cohort study based on pediatric-specific critical care database

OBJECTIVE

To investigate the relationship between lactate acid level and hospitalization mortality in neonatal necrotizing enterocolitis (NEC).

METHOD

Paediatric-specific critical care database collected clinical data from the intensive care unit of Children's Hospital Affiliated to Zhejiang University Medical College from 2010 to 2018. Clinical and laboratory examination information of NEC patients was collected and divided into the death group and discharge group to find out the risk factors affecting the prognosis through univariate and multivariate analysis.

RESULTS

Among 104 NEC neonates, the admission age was 7.5 days and the weight was 2.03 kg. Comparing the death group with the discharge group, there were significant differences in therapeutic regimen, pH, serum albumin, total protein, creatinine and lactate acid. Multivariate and threshold effect analysis showed that lactate acid had a linear correlation with hospital mortality, and newborns who died in the hospital had much higher lactate levels than those who were discharged. The mortality of NEC newborns increased by 40-45% for every 1 mmol/L increase in lactate acid level.

CONCLUSIONS

There was a correlation between lactate acid level and hospital mortality in newborns with NEC, and lactate acid level was an important index to evaluate the prognosis of NEC.

Perinatal transmission of a probiotic Bifidobacterium strain protects against early life stress-induced mood and gastrointestinal motility disorders

Early life stress can considerably interfere in gut microbiome formation and nervous system development. Specific probiotic strains have been proved to exert anti-stress effects by modulating the gut-brain axis. However, little is known about whether probiotic treatment during pregnancy can protect the offspring from early life stress. In this study, Bifidobacterium breve CCFM1025, previously proven to exert microbial and neurobiological regulation effects, was given to pregnant mice. The offspring's gut and brain functions were evaluated when challenged with maternal separation. Intriguingly, treatment with probiotics during pregnancy protected the offspring from maternal separation-induced neurobiological and gastrointestinal disorders such as depression-like behaviour and delayed defecation. Quantification of CCFM1025 was performed, and perinatal transmission of CCFM1025 was further validated, which also explained the reason for increased levels of colonic 5-hydroxytryptamine and caecal short-chain fatty acids in the offspring. Our findings indicated that the effects of probiotics can be perinatally transmitted through gut microbes and that probiotic treatment during pregnancy may have great potential in managing health risks in early life.

Randomized, Double-Blind, Placebo-Controlled Study to Assess the Effect of Two Probiotics on the Preterms' Gut Microbiota

OBJECTIVE

To evaluate the effect of a new probiotic strain combination, Ligilactobacillus salivarius subsp infantis PS11603 and Bifidobacterium longum PS10402, on gut bacterial colonization of preterm infants.

METHODS

A randomized, double-blind, placebo-controlled study was conducted in preterm infants from 28 weeks + 0days to 30 weeks + 6days of gestation. Thirty preterm infants were randomly selected after birth to receive either probiotics or placebo. Stool samples were collected before product intake and then sequentially during the first weeks of their admission. Classical microbiological, metagenomics and multiplex immunological analyses were performed to assess the bacterial and immune profile of the samples.

RESULTS

Twenty-seven infants completed the study (14 vs 13, probiotic and placebo groups). A higher number of participants were colonized by Lactobacilli in the probiotic group than in the placebo group (93% vs 46%; P  = 0.013). Similar results were obtained when analysing bifidobacterial colonization (100% vs 69%; P  = 0.041). Earlier colonization was observed in the probiotics group versus the placebo group, specifically 5 weeks for Lactobacillus and 1 week for Bifidobacterium. Although no effect was observed in the faecal immunological profile, a decreasing trend could be observed in Th17 response during the first week of probiotic treatment. None of the adverse events (AEs) registered were related to product intake.

CONCLUSION

Probiotic supplementation with L salivarius PS11603 and B longum subsp. infantis PS10402 enhanced an earlier colonization of Lactobacillus and Bifidobacterium in preterm infants' guts in 5 and 1 week, respectively. A higher number of infants were colonized by Lactobacilli with the probiotics' intake at the end of the study.

Effect of single versus multistrain probiotic in extremely preterm infants: a randomised trial

OBJECTIVE

Evidence indicates that multistrain probiotics benefit preterm infants more than single-strain (SS) probiotics. We assessed the effects of SS versus triple-strain (TS) probiotic supplementation (PS) in extremely preterm (EP) infants.

DESIGN

EP infants (gestational age (GA) <28 weeks) were randomly allocated to TS or SS probiotic, assuring blinding. Reference (REF) group was EP infants in the placebo arm of our previous probiotic trial. PS was commenced with feeds and continued until 37 weeks' corrected GA. Primary outcome was time to full feed (TFF: 150 mL/kg/day). Secondary outcomes included short-chain fatty acids and faecal microbiota collected at T1 (first week) and T2 (after 3 weeks of PS) using 16S ribosomal RNA gene sequencing.

RESULTS

173 EP (SS: 86, TS: 87) neonates with similar GA and birth weight (BW) were randomised. Median TFF was comparable (11 (IQR 8-16) vs 10 (IQR 8-16) days, p=0.92). Faecal propionate (SS, p<0.001, and TS, p=0.0009) and butyrate levels (TS, p=0.029) were significantly raised in T2 versus T1 samples. Secondary clinical outcomes were comparable. At T2, alpha diversity was comparable (p>0.05) between groups, whereas beta-diversity analysis revealed significant differences between PS and REF groups (both p=0.001). Actinobacteria were higher (both p<0.01), and Proteobacteria, Firmicutes and Bacteroidetes were lower in PS versus REF. Gammaproteobacteria, Clostridia and Negativicutes were lower in both PS versus REF.

CONCLUSION

TFF in EP infants was similar between SS and TS probiotics. Both probiotics were effective in reducing dysbiosis (higher bifidobacteria and lower Gammaproteobacteria). Long-term significance of increased propionate and butyrate needs further studies.

TRIAL REGISTRATION NUMBER

ACTRN 12615000940572.

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

Necrotizing enterocolitis (NEC) is a major cause of morbidity and mortality in preterm infants. The exact mechanism by which NEC develops is poorly understood however there is growing evidence to suggest that perturbations in the early-life gut microbiota composition increase the risk for NEC. Modulation of the gut microbiota with probiotics, prebiotics, or in combination (synbiotics) is an area which has attracted intense interest in recent years. In this narrative review, we present an overview of the role of the gut microbiota in the pathogenesis of NEC. We also examine the evidence currently available from randomized controlled trials, observational studies, systematic reviews, and meta-analysis examining the role of probiotics, prebiotics, and synbiotics in reducing the risk of or preventing NEC. Current clinical practice guidelines with recommendations on the routine administration of probiotics to preterm infants for NEC are also explored.

Enteral Feeding Interventions in the Prevention of Necrotizing Enterocolitis: A Systematic Review of Experimental and Clinical Studies

Necrotizing enterocolitis (NEC), which is characterized by severe intestinal inflammation and in advanced stages necrosis, is a gastrointestinal emergency in the neonate with high mortality and morbidity. Despite advancing medical care, effective prevention strategies remain sparse. Factors contributing to the complex pathogenesis of NEC include immaturity of the intestinal immune defense, barrier function, motility and local circulatory regulation and abnormal microbial colonization. Interestingly, enteral feeding is regarded as an important modifiable factor influencing NEC pathogenesis. Moreover, breast milk, which forms the currently most effective prevention strategy, contains many bioactive components that are known to support neonatal immune development and promote healthy gut colonization. This systematic review describes the effect of different enteral feeding interventions on the prevention of NEC incidence and severity and the effect on pathophysiological mechanisms of NEC, in both experimental NEC models and clinical NEC. Besides, pathophysiological mechanisms involved in human NEC development are briefly described to give context for the findings of altered pathophysiological mechanisms of NEC by enteral feeding interventions.

Evaluation of Growth, Viability, Lactic Acid Production and Anti-Infective Effects of Lacticaseibacillus rhamnosus ATCC 9595 in Bacuri Juice (Platonia insignis)

Fruit juices have been emerging as excellent vehicles for development of probiotic products due to their nutritional properties and presence of bioactive compounds. This work evaluated the growth and viability of Limosilactobacillus fermentum ATCC 23271 and Lacticaseibacillus rhamnosus ATCC 9595 in bacuri juice (Platonia insignis Mart., Clusiaceae). Both strains were able to grow in bacuri juice, without any supplementation. Viability was kept after 28 days of storage; however, growth was significantly higher for L. rhamnosus ATCC 9595 (7.40 ± 0.04 Log CFU/mL). Following this, the effects of bacterial inoculum and pulp concentration on growth and lactic acid production by L. rhamnosus ATCC 9595 were investigated using a central composite rotational design. The inoculum concentration was the main factor for obtaining the most favorable relation between growth and organic acid production (G/pH ratio). Among the tested conditions, those used in assay 6 allowed the best G/pH ratio (2.13) and higher lactic acid production (4.14 g/L). In these conditions, L. rhamnosus ATCC 9595 grown in bacuri juice showed the same resistance towards acidification or addition of lysozyme than when cultivated in MRS. Finally, the anti-infective effects of fermented and non-fermented juices were analyzed using Tenebrio molitor larvae infected by enteroaggregative Escherichia coli 042. The pre-treatment with supernatants of both fermented and non-fermented juices significantly increased the survival of E. coli-infected larvae. However, only the L. rhamnosus-fermented juice had protective effects when inoculated 2 h after infection. Collectively, the results obtained in this research allowed the basis for the development of a non-dairy probiotic product from bacuri juice.

Effects of neonatal nutrition interventions on neonatal mortality and child health and development outcomes: A systematic review

Background

The last two decades have seen a significant decrease in mortality for children <5 years of age in low and middle-income countries (LMICs); however, neonatal (age, 0-28 days) mortality has not decreased at the same rate. We assessed three neonatal nutritional interventions that have the potential of reducing morbidity and mortality during infancy in LMICs.

Objectives

To determine the efficacy and effectiveness of synthetic vitamin A, dextrose oral gel, and probiotic supplementation during the neonatal period.

Search Methods

We conducted electronic searches for relevant studies on the following databases: PubMed, CINAHL, LILACS, SCOPUS, and CENTRAL, Cochrane Central Register for Controlled Trials, up to November 27, 2019.

Selection Criteria

We aimed to include randomized and quasi-experimental studies. The target population was neonates in LMICs. The interventions included synthetic vitamin A supplementation, oral dextrose gel supplementation, and probiotic supplementation during the neonatal period. We included studies from the community and hospital settings irrespective of the gestational age or birth weight of the neonate.

Data Collection and Analysis

Two authors screened the titles and extracted the data from selected studies. The risk of bias (ROB) in the included studies was assessed according to the Cochrane Handbook of Systematic Reviews. The primary outcome was all-cause mortality. The secondary outcomes were neonatal sepsis, necrotizing enterocolitis (NEC), prevention and treatment of neonatal hypoglycaemia, adverse events, and neurodevelopmental outcomes. Data were meta-analyzed by random effect models to obtain relative risk (RR) and 95% confidence interval (CI) for dichotomous outcomes and mean difference with 95% CI for continuous outcomes. The overall rating of evidence was determined by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

Main Results

Sixteen randomized studies (total participants 169,366) assessed the effect of vitamin A supplementation during the neonatal period. All studies were conducted in low- and middle-income (LMIC) countries. Thirteen studies were conducted in the community setting and three studies were conducted in the hospital setting, specifically in neonatal intensive care units. Studies were conducted in 10 different countries including India (four studies), Guinea-Bissau (three studies), Bangladesh (two studies), and one study each in China, Ghana, Indonesia, Nepal, Pakistan, Tanzania, and Zimbabwe. The overall ROB was low in most of the included studies for neonatal vitamin A supplementation. The pooled results from the community based randomized studies showed that there was no significant difference in all-cause mortality in the vitamin A (intervention) group compared to controls at 1 month (RR, 0.99; 95% CI, 0.90-1.08; six studies with 126,548 participants, statistical heterogeneity I 2 0%, funnel plot symmetrical, grade rating high), 6 months (RR, 0.98; 95% CI, 0.89-1.07; 12 studies with 154,940 participants, statistical heterogeneity I 2 43%, funnel plot symmetrical, GRADE quality high) and 12 months of age (RR, 1.04; 95% CI, 0.94-1.14; eight studies with 118,376 participants, statistical heterogeneity I 2 46%, funnel plot symmetrical, GRADE quality high). Neonatal vitamin A supplementation increased the incidence of bulging fontanelle by 53% compared to control (RR, 1.53; 95% CI, 1.12-2.09; six studies with 100,256 participants, statistical heterogeneity I 2 65%, funnel plot symmetrical, GRADE quality high). We did not identify any experimental study that addressed the use of dextrose gel for the prevention and/or treatment of neonatal hypoglycaemia in LMIC. Thirty-three studies assessed the effect of probiotic supplementation during the neonatal period (total participants 11,595; probiotics: 5854 and controls: 5741). All of the included studies were conducted in LMIC and were randomized. Most of the studies were done in the hospital setting and included participants who were preterm (born < 37 weeks gestation) and/or low birth weight (<2500 g birth weight). Studies were conducted in 13 different countries with 10 studies conducted in India, six studies in Turkey, three studies each in China and Iran, two each in Mexico and South Africa, and one each in Bangladesh, Brazil, Colombia, Indonesia, Nepal, Pakistan, and Thailand. Three studies were at high ROB due to lack of appropriate randomization sequence or allocation concealment. Combined data from 25 studies showed that probiotic supplementation reduced all-cause mortality by 20% compared to controls (RR, 0.80; 95% CI, 0.66-0.96; total number of participants 10,998, number needed to treat 100, statistical heterogeneity I 2 0%, funnel plot symmetrical, GRADE quality high). Twenty-nine studies reported the effect of probiotics on the incidence of NEC, and the combined results showed a relative reduction of 54% in the intervention group compared to controls (RR, 0.46; 95% CI, 0.35-0.59; total number of participants 5574, number needed to treat 17, statistical heterogeneity I 2 24%, funnel plot symmetrical, GRADE quality high). Twenty-one studies assessed the effect of probiotic supplementation during the neonatal period on neonatal sepsis, and the combined results showed a relative reduction of 22% in the intervention group compared to controls (RR, 0.78; 95% CI, 0.70-0.86; total number of participants 9105, number needed to treat 14, statistical heterogeneity I 2 23%, funnel plot symmetrical, GRADE quality high).

Authors' Conclusions

Vitamin A supplementation during the neonatal period does not reduce all-cause neonatal or infant mortality in LMICs in the community setting. However, neonatal vitamin A supplementation increases the risk of Bulging Fontanelle. No experimental or quasi-experimental studies were available from LMICs to assess the effect of dextrose gel supplementation for the prevention or treatment of neonatal hypoglycaemia. Probiotic supplementation during the neonatal period seems to reduce all-cause mortality, NEC, and sepsis in babies born with low birth weight and/or preterm in the hospital setting. There was clinical heterogeneity in the use of probiotics, and we could not recommend any single strain of probiotics for wider use based on these results. There was a lack of studies on probiotic supplementation in the community setting. More research is needed to assess the effect of probiotics administered to neonates in-home/community setting in LMICs.

Probiotics for Preventing Necrotizing Enterocolitis in Preterm Infants: A Network Meta-Analysis

BACKGROUND

Recent evidence supports a role of probiotics in preventing necrotizing enterocolitis (NEC) in preterm infants.

METHODS

A systematic review and network meta-analysis of randomized controlled trials (RCTs) on the role of probiotics in preventing NEC in preterm infants, focusing on the differential effect of type of feeding, was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A random-effects model was used; a subgroup analysis on exclusively human milk (HM)-fed infants vs. infants receiving formula (alone or with HM) was performed.

RESULTS

Fifty-one trials were included (10,664 infants, 29 probiotic interventions); 31 studies (19 different probiotic regimens) were suitable for subgroup analysis according to feeding. In the overall analysis, Lactobacillus acidophilus LB revealed the most promising effect for reducing NEC risk (odds ratio (OR), 0.03; 95% credible intervals (CrIs), 0.00-0.21). The subgroup analysis showed that Bifidobacterium lactis Bb-12/B94 was associated with a reduced risk of NEC stage ≥2 in both feeding type populations, with a discrepancy in the relative effect size in favour of exclusively HM-fed infants (OR 0.04; 95% CrIs <0.01-0.49 vs. OR 0.32; 95% CrIs 0.10-0.36).

CONCLUSIONS

B. lactis Bb-12/B94 could reduce NEC risk with a different size effect according to feeding type. Of note, most probiotic strains are evaluated in few trials and relatively small populations, and outcome data according to feeding type are not available for all RCTs. Further trials are needed to confirm the present findings.