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

Milk microbiome transplantation: recolonizing donor milk with mother's own milk microbiota

Donor human milk (DHM) provides myriad nutritional and immunological benefits for preterm and low birthweight infants. However, pasteurization leaves DHM devoid of potentially beneficial milk microbiota. In the present study, we performed milk microbiome transplantation from freshly collected mother's own milk (MOM) into pasteurized DHM. Small volumes of MOM (5%, 10%, or 30% v/v) were inoculated into pasteurized DHM and incubated at 37 °C for up to 8 h. Further, we compared microbiome recolonization in UV-C-treated and Holder-pasteurized DHM, as UV-C treatment has been shown to conserve important biochemical components of DHM that are lost during Holder pasteurization. Bacterial culture and viability-coupled metataxonomic sequencing were employed to assess the effectiveness of milk microbiome transplantation. Growth of transplanted MOM bacteria occurred rapidly in recolonized DHM samples; however, a greater level of growth was observed in Holder-pasteurized DHM compared to UV-C-treated DHM, potentially due to the conserved antimicrobial properties in UV-C-treated DHM. Viability-coupled metataxonomic analysis demonstrated similarity between recolonized DHM samples and fresh MOM samples, suggesting that the milk microbiome can be successfully transplanted into pasteurized DHM. These results highlight the potential of MOM microbiota transplantation to restore the microbial composition of UV-C-treated and Holder-pasteurized DHM and enhance the nutritional and immunological benefits of DHM for preterm and vulnerable infants. KEY POINTS: • Mother's own milk microbiome can be successfully transplanted into donor human milk. • Recolonization is equally successful in UV-C-treated and Holder-pasteurized milk. • Recolonization time should be restricted due to rapid bacterial growth.

The importance of gut microbiome in the perinatal period

This narrative review describes the settlement of the neonatal microbiome during the perinatal period and its importance on human health in the long term. Delivery methods, maternal diet, antibiotic exposure, feeding practices, and early infant contact significantly shape microbial colonization, influencing the infant's immune system, metabolism, and neurodevelopment. By summarizing two decades of research, this review highlights the microbiome's role in disease predisposition and explores interventions like maternal vaginal seeding and probiotic and prebiotic supplementation that may influence microbiome development.

CONCLUSION

The perinatal period is a pivotal phase for the formation and growth of the neonatal microbiome, profoundly impacting long-term health outcomes.

WHAT IS KNOWN

• The perinatal period is a critical phase for the development of the neonatal microbiome, with factors such as mode of delivery, maternal diet, antibiotic exposure, and feeding practices influencing its composition and diversity, which has significant implications for long-term health. • The neonatal microbiome plays a vital role in shaping the immune system, metabolism, and neurodevelopment of infants.

WHAT IS NEW

• Recent studies have highlighted the potential of targeted interventions, such as probiotic and prebiotic supplementation, and innovative practices like maternal vaginal seeding, to optimize microbiome development during the perinatal period. • Emerging evidence suggests that specific bacterial genera and species within the neonatal microbiome are associated with reduced risks of developing chronic conditions, indicating new avenues for promoting long-term health starting from early life.

Comparative efficacy of different single drugs to prevent necrotizing enterocolitis in preterm infants: an update systematic review and network meta-analysis

Objective

To investigate an optimal regimen of six drugs, including lactoferrin, probiotics, prebiotics, glutamine, arginine and erythropoietin (EPO), for the prevention of necrotizing enterocolitis (NEC) in preterm infants.

Methods

PubMed, Embase, Ovid, The Cochrane Library, and Web of Science databases were searched for randomized controlled trials (RCTs) investigating the efficacy of lactoferrin, probiotics, prebiotics, glutamine, arginine, and EPO in preventing NEC in preterm infants, with a cutoff date of June 20, 2024. Two authors independently screened studies and extracted all the data. Network meta-analysis (NMA) was conducted to compare the outcomes of different interventions, and group rankings were determined using the surface under the cumulative ranking curve (SUCRA).

Results

A total of 89 RCTs with 26,861 preterm infants were included. Arginine demonstrated the highest clinical efficacy in reducing the incidence of NEC, with probiotics being the next most effective and the placebo being the least effective. Lactoferrin was identified as the most effective intervention for reducing the incidence of NEC-associated sepsis. Prebiotics showed the highest effect on overall mortality, reducing the beginning of enteral feeding, and were associated with the shortest hospital stay. Glutamine significantly decreased the time to full enteral feeding.

Conclusion

Existing literature highlights arginine as the most efficacious pharmacological agent in preventing NEC in preterm infants. It has been shown to effectively lower the rates of NEC, septicemia, and mortality, warranting its recommendation as the first-line clinical intervention. Following this, probiotics are recommended as a second option.

Probiotics vs. Placebo: Preventing Necrotizing Enterocolitis in a Premature Infant

BACKGROUND

Necrotizing enterocolitis (NEC) is a severe gastrointestinal condition primarily affecting preterm newborns, leading to significant morbidity and mortality.

OBJECTIVE

This prospective cohort study aimed to evaluate the effectiveness of probiotics in preventing NEC in premature infants. Secondary objectives included assessing the impact on mortality, late-onset sepsis, duration of hospital stay, and weight gain.

METHODS

The study was conducted at Lady Reading Hospital Medical Teaching Institute, Peshawar, from April 1, 2023, to March 31, 2024, involving 102 preterm infants. Participants were randomly assigned to receive daily oral probiotics (Lactobacillus and Bifidobacterium species) or a placebo.

RESULTS

The incidence of NEC was significantly lower in the probiotic group (7.8%) compared to the placebo group (21.6%; p = 0.04). The probiotic group also showed significant reductions in late-onset sepsis (13.7% vs. 29.4%; p = 0.03), shorter hospital stays (42.5 vs. 48.1 days; p = 0.02), and greater weight gain (15.3 vs. 13.4 grams/day; p = 0.01).

CONCLUSION

These findings support the integration of probiotics into neonatal care, particularly in resource-limited settings.

Invasive Candida Infections in Neonatal Intensive Care Units: Risk Factors and New Insights in Prevention

Invasive Candida infections represent a significant cause of morbidity and mortality in neonatal intensive care units (NICUs), with a particular impact on preterm and low-birth-weight neonates. In addition to prematurity, several predisposing factors for Candida colonization and dissemination during NICU hospitalization have been identified, including prolonged exposure to broad-spectrum antibiotics, central venous catheters, parenteral nutrition, corticosteroids, H2 antagonist administration, and poor adherence to infection control measures. According to the literature, the implementation of antifungal prophylaxis, mainly fluconazole, in high-risk populations has proven to be an effective strategy in reducing the incidence of fungal infections. This review aims to provide an overview of risk factors for invasive Candida infections and current perspectives regarding antifungal prophylaxis use. Recognizing and reducing people's exposure to these modifiable risk factors, in conjunction with the administration of antifungal prophylaxis, has been demonstrated to be an effective method for preventing invasive candidiasis in susceptible neonatal populations.

Neonatal Necrotizing Enterocolitis: An Update on Pathophysiology, Treatment, and Prevention

Necrotizing enterocolitis (NEC) is a life-threatening disease predominantly affecting premature and very low birth weight infants resulting in inflammation and necrosis of the small bowel and colon and potentially leading to sepsis, peritonitis, perforation, and death. Numerous research efforts have been made to better understand, treat, and prevent NEC. This review explores a variety of factors involved in the pathogenesis of NEC (prematurity, low birth weight, lack of human breast milk exposure, alterations to the microbiota, maternal and environmental factors, and intestinal ischemia) and reports treatment modalities surrounding NEC, including pain medications and common antibiotic combinations, the rationale for these combinations, and recent antibiotic stewardship approaches surrounding NEC treatment. This review also highlights the effect of early antibiotic exposure, infections, proton pump inhibitors (PPIs), and H2 receptor antagonists on the microbiota and how these risk factors can increase the chances of NEC. Finally, modern prevention strategies including the use of human breast milk and standardized feeding regimens are discussed, as well as promising new preventative and treatment options for NEC including probiotics and stem cell therapy.

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

KEY POINTS

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

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.

Factors influencing necrotizing enterocolitis in premature infants in China: a systematic review and meta-analysis

BACKGROUND

Necrotizing enterocolitis (NEC) is a multifactorial gastrointestinal disease with high morbidity and mortality among premature infants. However, studies with large samples on the factors of NEC in China have not been reported. This meta-analysis aims to systematically review the literature to explore the influencing factors of necrotizing enterocolitis in premature infants in China and provide a reference for the prevention of NEC.

METHODS

PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM), Wanfang and VIP databases were systematically searched from inception to February 2023. We used Stata14.0 software to perform the systematic review and meta-analysis. We used fixed or random effects models with combined odds ratios (ORs) and 95% confidence intervals (CIs), and quality was evaluated using the Newcastle‒Ottawa Scale (NOS).

RESULTS

The total sample was 8616 cases, including 2456 cases in the intervention group and 6160 cases in the control group. It was found that 16 risk factors and 3 protective factors were related to necrotizing enterocolitis in premature infants. Septicemia (OR = 3.91), blood transfusion (OR = 2.41), neonatal asphyxia (OR = 2.46), pneumonia (OR = 6.17), infection (OR = 5.99), congenital heart disease (OR = 4.80), intrahepatic cholestasis of pregnancy (ICP) (OR = 2.71), mechanical ventilation (OR = 1.44), gestational diabetes mellitus (GDM) (OR = 3.08), respiratory distress syndrome (RDS) (OR = 3.28), hypoalbuminemia (OR = 2.80), patent ductus arteriosus (PDA) (OR = 3.10), respiratory failure (OR = 7.51), severe anemia (OR = 2.86), history of antibiotic use (OR = 2.12), and meconium-stained amniotic fluid (MSAF) (OR = 3.14) were risk factors for NEC in preterm infants in China. Breastfeeding (OR = 0.31), oral probiotics (OR = 0.36), and prenatal use of glucocorticoids (OR = 0.38) were protective factors for NEC in preterm infants.

CONCLUSIONS

Septicemia, blood transfusion, neonatal asphyxia, pneumonia, infection, congenital heart disease, ICP, GDM, RDS, hypoproteinemia, PDA, respiratory failure, severe anemia, history of antibiotic use and MSAF will increase the risk of NEC in premature infants, whereas breastfeeding, oral probiotics and prenatal use of glucocorticoids reduce the risk. Due to the quantity and quality of the included literature, the above findings need to be further validated by more high-quality studies.

Metabolic and fecal microbial changes in adult fetal growth restricted mice

BACKGROUND

Fetal growth restriction (FGR) increases risk for development of obesity and type 2 diabetes. Using a mouse model of FGR, we tested whether metabolic outcomes were exacerbated by high-fat diet challenge or associated with fecal microbial taxa.

METHODS

FGR was induced by maternal calorie restriction from gestation day 9 to 19. Control and FGR offspring were weaned to control (CON) or 45% fat diet (HFD). At age 16 weeks, offspring underwent intraperitoneal glucose tolerance testing, quantitative MRI body composition assessment, and energy balance studies. Total microbial DNA was used for amplification of the V4 variable region of the 16 S rRNA gene. Multivariable associations between groups and genera abundance were assessed using MaAsLin2.

RESULTS

Adult male FGR mice fed HFD gained weight faster and had impaired glucose tolerance compared to control HFD males, without differences among females. Irrespective of weaning diet, adult FGR males had depletion of Akkermansia, a mucin-residing genus known to be associated with weight gain and glucose handling. FGR females had diminished Bifidobacterium. Metabolic changes in FGR offspring were associated with persistent gut microbial changes.

CONCLUSION

FGR results in persistent gut microbial dysbiosis that may be a therapeutic target to improve metabolic outcomes.

IMPACT

Fetal growth restriction increases risk for metabolic syndrome later in life, especially if followed by rapid postnatal weight gain. We report that a high fat diet impacts weight and glucose handling in a mouse model of fetal growth restriction in a sexually dimorphic manner. Adult growth-restricted offspring had persistent changes in fecal microbial taxa known to be associated with weight, glucose homeostasis, and bile acid metabolism, particularly Akkermansia, Bilophilia and Bifidobacteria. The gut microbiome may represent a therapeutic target to improve long-term metabolic outcomes related to fetal growth restriction.

The Role of Diet and Nutritional Interventions for the Infant Gut Microbiome

The infant gut microbiome plays a key role in the healthy development of the human organism and appears to be influenced by dietary practices through multiple pathways. First, maternal diet during pregnancy and infant nutrition significantly influence the infant gut microbiota. Moreover, breastfeeding fosters the proliferation of beneficial bacteria, while formula feeding increases microbial diversity. The timing of introducing solid foods also influences gut microbiota composition. In preterm infants the gut microbiota development is influenced by multiple factors, including the time since birth and the intake of breast milk, and interventions such as probiotics and prebiotics supplementation show promising results in reducing morbidity and mortality in this population. These findings underscore the need for future research to understand the long-term health impacts of these interventions and for further strategies to enrich the gut microbiome of formula-fed and preterm infants.

Epidemiology, risk factors, clinical presentation and complications of late-onset neonatal sepsis among preterm neonates in Cyprus: a prospective case-control study

BACKGROUND

Late-onset neonatal sepsis (LOS) is common in preterm neonates, with increasing incidence in recent years. In the present study, we examined the epidemiology, clinical presentation, and complications of LOS in Cyprus and quantified possible risk factors for the development of this condition.

METHODS

The study subjects were preterm neonates admitted in the Neonatal Intensive Care Unit (NICU) of Archbishop Makarios III Hospital, the only neonatal tertiary centre in Cyprus. A prospective, case-control study was designed, and carried out between April 2017-October 2018. Depending on blood culture results, preterm neonates were classified as "Confirmed LOS": positive blood culture - microorganism isolated and LOS symptoms, "Unconfirmed LOS": negative blood culture and LOS symptoms, and "Controls" group: negative blood culture and absence of LOS symptoms. Comparisons between the 3 groups were performed and the associations between demographic, clinical and treatment characteristics with the likelihood of LOS were assessed using univariate and multivariate logistic regression.

RESULTS

A total of 350 preterm neonates were included in the study and the incidence of LOS was 41.1%. 79 (22.6%) and 65 (18.6%) neonates were classified as "Confirmed LOS", and "unconfirmed LOS" cases respectively while 206 (58.9%) served as controls. The rate of confirmed LOS ranged from 12.2% in moderate to late preterm neonates to 78.6% in extremely preterm neonates. In the multivariate model, we demonstrated an independent association between LOS and duration of hospitalization (OR: 1.06, 95%CI: 1.01-1.10), duration of ventilation (OR: 1.23, 95%CI: 1.07-1.43) and necrotising enterocolitis (OR: 3.41, 95%CI: 1.13-10.25).

CONCLUSIONS

The present study highlights the epidemiology of LOS in preterm neonates in Cyprus and its association with the duration of ventilation and hospitalization as well as with necrotizing enterocolitis. Establishment of protocols for the prevention of nosocomial infections during hospitalization in the NICUs and mechanical ventilation of preterm neonates is recommended.

Probiotic supplementation modifies the gut microbiota profile of very low birth weight preterm infants during hospitalization

BACKGROUND

Probiotic supplementation is increasingly being given to very low birth weight (VLBW) preterm infants. This preliminary observational study aimed to investigate the effects of multiple-strain probiotics on the gut microbiota of VLBW preterm infants.

METHODS

We collected meconium and stool samples on days 14, 30, and 60 after birth from 49 VLBW infants with a gestational age of <32 weeks. The infants were divided into the probiotics (n = 24) and control (n = 25) groups. The microbial composition and diversity in the gut of the two groups were analyzed using 16 S rRNA gene sequencing.

RESULTS

The relative abundance of Bifidobacterium and Lactobacillus was significantly higher in the probiotics group than in the control group on days 14, 30, and 60 (Bifidobacterium: p = 0.002, p < 0.0001, and p < 0.0001, respectively; Lactobacillus: p = 0.012, p < 0.0001, and p < 0.0001, respectively). The control group exhibited a significantly higher proportion of participants with a low abundance (<1%) of Bifidobacterium or Lactobacillus on days 14, 30, and 60 than those in the probiotic group. Moreover, the probiotics group exhibited a significantly lower abundance of Klebsiella on days 14 and 30 (2.4% vs. 11.6%, p = 0.037; and 7.9% vs. 16.6%, p = 0.032, respectively) and of Escherichia-Shigella on day 60 than the control group (6.1% vs. 12.3%, p = 0.013). Beta diversity analysis revealed that the microbiota profile was clearly divided into two groups on days 30 and 60 (p = 0.001).

CONCLUSION

Probiotic supplementation significantly increased the relative abundance of Bifidobacterium and Lactobacillus and inhibited the growth of potential pathogens. Furthermore, probiotic supplementation led to a distinct gut microbiota profile. Further research is needed to identify probiotic strains that exert significant influence on the gut microbiome and their long-term health implications in preterm infants.

Efficacy and Safety of Bifidobacterium longum Supplementation in Infants: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Strategies to stabilize and support overall infant health by increasing the number of Bifidobacterium longum in the infant gut are of interest, but few studies have systematically addressed this issue. We aimed to evaluate the efficacy and safety of Bifidobacterium longum use in infants using meta-analysis.

METHODS

We searched PubMed, EMBASE, Cochrane Library of Systematic Reviews, and SinoMed for publications until 27 July 2022. The main outcomes of interest were weight gain, risk of necrotizing enterocolitis (NEC), and adverse events. Two authors independently performed study screening, risk of bias assessment, and data extraction. Outcome data were extracted from each included study and combined using mean difference (MD) or risk ratio (RR) and finally combined using a fixed-effect model or random-effect model.

RESULTS

A total of 4481 relevant studies were identified, of which 15 were found to be eligible for randomized controlled trials and were included in the meta-analysis. The combined extracted data showed that the intervention group containing Bifidobacterium longum had a significantly lower risk of NEC (RR = 0.539, 95% CI: 0.333, 0.874) compared to the control group. There was no statistical difference between the intervention and control groups regarding weight gain (MD = 0.029, 95% CI: -0.032, 0.090), the occurrence of adverse events (RR = 0.986, 95% CI: 0.843, 1.153), and serious adverse events (RR = 0.881, 95% CI: 0.493, 1.573).

CONCLUSIONS

Bifidobacterium longum may significantly reduce the risk of NEC in infants as well as being safe; thus, further research evidence is needed on whether there is a benefit on weight gain.

Assessment of food supplements for the prevention of necrotizing enterocolitis in preterm neonates: A systematic review and network meta-analysis

BACKGROUND

The network meta-analysis (NMA) investigated the efficacy of six food supplements, namely glutamine, arginine, lactoferrin, prebiotics, synbiotics, and probiotics, in preventing necrotizing enterocolitis in premature infants.

METHODS

MEDLINE, Embase, and Cochrane Library were searched. Randomized controlled trials comparing different food supplements for premature infants were included.

RESULTS

Probiotics (OR, 0.47; 95% CrI, 0.33-0.63), arginine (OR, 0.38; 95% CrI, 0.14-0.98), glutamine (OR, 0.30; 95% CrI, 0.079-0.90), and synbiotics (OR, 0.13; 95% CrI, 0.037-0.37). were associated with a decreased incidence of NEC. Only probiotics (OR, 0.81; 95% CrI, 0.69-0.95) and lactoferrin (OR, 0.74; 95% CrI, 0.54-0.92) achieved lower risk of sepsis. Probiotics (OR, 0.58; 95% CrI, 0.40-0.79), prebiotics (OR, 0.23; 95% CrI, 0.043-0.86), and synbiotics (OR, 0.15; 95% CrI, 0.035-0.50) were associated with lower odds of mortality. Probiotics (MD, -2.3; 95% CrI: -3.7- -0.63) appeared to have earlier age of attainment of full feeding.

CONCLUSIONS

Based on this NMA, probiotics and synbiotics had the potential to be the top two preferable food supplements.

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

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

Probiotics, Prebiotics, Lactoferrin, and Combination Products for Prevention of Mortality and Morbidity in Preterm Infants: A Systematic Review and Network Meta-Analysis

Importance

Modulation of intestinal microbiome by administering probiotics, prebiotics, or both may prevent morbidity and mortality in premature infants.

Objective

To assess the comparative effectiveness of alternative prophylactic strategies through a network meta-analysis (NMA) of randomized clinical trials.

Data Sources

MEDLINE, EMBASE, Science Citation Index Expanded, CINAHL, Scopus, Cochrane CENTRAL, and Google Scholar from inception until May 10, 2023.

Study Selection

Eligible trials tested probiotics, prebiotics, lactoferrin, and combination products for prevention of morbidity or mortality in preterm infants.

Data Extraction and Synthesis

A frequentist random-effects model was used for the NMA, and the certainty of evidence and inferences regarding relative effectiveness were assessed using the GRADE approach.

Main Outcomes and Measures

All-cause mortality, severe necrotizing enterocolitis, culture-proven sepsis, feeding intolerance, time to reach full enteral feeding, and duration of hospitalization.

Results

A total of 106 trials involving 25 840 preterm infants were included. Only multiple-strain probiotics were associated with reduced all-cause mortality compared with placebo (risk ratio [RR], 0.69; 95% CI, 0.56 to 0.86; risk difference [RD], -1.7%; 95% CI, -2.4% to -0.8%). Multiple-strain probiotics alone (vs placebo: RR, 0.38; 95% CI, 0.30 to 0.50; RD, -3.7%; 95% CI, -4.1% to -2.9%) or in combination with oligosaccharides (vs placebo: RR, 0.13; 95% CI, 0.05 to 0.37; RD, -5.1%; 95% CI, -5.6% to -3.7%) were among the most effective interventions reducing severe necrotizing enterocolitis. Single-strain probiotics in combination with lactoferrin (vs placebo RR, 0.33; 95% CI, 0.14 to 0.78; RD, -10.7%; 95% CI, -13.7% to -3.5%) were the most effective intervention for reducing sepsis. Multiple-strain probiotics alone (RR, 0.61; 95% CI, 0.46 to 0.80; RD, -10.0%; 95% CI, -13.9% to -5.1%) or in combination with oligosaccharides (RR, 0.45; 95% CI, 0.29 to 0.67; RD, -14.1%; 95% CI, -18.3% to -8.5%) and single-strain probiotics (RR, 0.61; 95% CI, 0.51 to 0.72; RD, -10.0%; 95% CI, -12.6% to -7.2%) proved of best effectiveness in reduction of feeding intolerance vs placebo. Single-strain probiotics (MD, -1.94 days; 95% CI, -2.96 to -0.92) and multistrain probiotics (MD, -2.03 days; 95% CI, -3.04 to -1.02) proved the most effective in reducing the time to reach full enteral feeding compared with placebo. Only single-strain and multistrain probiotics were associated with greater effectiveness compared with placebo in reducing duration of hospitalization (MD, -3.31 days; 95% CI, -5.05 to -1.58; and MD, -2.20 days; 95% CI, -4.08 to -0.31, respectively).

Conclusions and Relevance

In this systematic review and NMA, moderate- to high-certainty evidence demonstrated an association between multistrain probiotics and reduction in all-cause mortality; these interventions were also associated with the best effectiveness for other key outcomes. Combination products, including single- and multiple-strain probiotics combined with prebiotics or lactoferrin, were associated with the largest reduction in morbidity and mortality.

Microencapsulation of Limosilactobacillus reuteri (DSM 23878) for application in infant formula: Heat resistance and bacterial viability during long-time storage

This study aimed to evaluate the survival capacity of the probiotic culture Limosilactobacillus reuteri (DSM 23878) to microencapsulation by spray drying, and its potential as component of an infant formula. Preliminary tests were performed between skim milk (SM) and infant formula (IF) as wall material and two inlet temperatures, evaluating the encapsulation efficiency, moisture content, water activity and stability, to choose the drying parameters. After drying in optimized conditions, the powder of microencapsulated L. reuteri was characterized and the viability after dilution in an infant formula at 70 °C was determined. In addition, the survival rate throughout 360 days of storage was assessed. As results, encapsulation efficiency was superior to 90 % in both wall materials. However, the use of IF as for microencapsulation produced microparticles with lower water activity (Aw) and moisture, as compared with the SM. Final microparticles produced with IF as wall material presented values of Aw, moisture content, and particle diameter averaged 0.11 ± 0.02, 2.10 ± 0.35 % and 10.30 ± 0.12 μm, respectively. The viability of microencapsulated L.reuteri decreased 1 Log CFU/mL after dilution at 70 °C and the powder maintained a survivor of 73.5 % after 365 days of storage at 4 °C. Thus, the microencapsulation by spray drying under the conditions of this study proved to be an effective technique to protect the probiotic L. reuteri for application in infant formulas, obtaining an adequate number of viable cells after reconstitution at 70 °C and during long time the storage.

Role of the microbiome in pathophysiology of necrotising enterocolitis in preterm neonates

Although necrotising enterocolitis (NEC) is a serious, life-threatening disease, improved neonatal care is increasing the number of survivors with NEC among extremely preterm neonates. Therapy is nevertheless mostly symptomatic and the mortality rate remains high, especially among neonates requiring surgery. Therefore, it is important to focus on preventing the disease and modifiable risk factors. NEC's pathophysiology is multifaceted, with key factors being immaturity of the immune and barrier protective mechanisms of the premature gut and exaggerated proinflammatory reaction to insults like gut hypoxia, enteral nutrition or microbial dysbiosis. The role of the intestinal microbiome in the pathophysiology of NEC has been a subject of research for many years, but to date no specific pathogen or type of dysbiosis has been connected with NEC development. This review assesses current knowledge as to the role of the intestinal microbiota in the pathophysiology of NEC and the possibilities for positively influencing it.

Limosilactobacillus reuteri DSM 17938 as a probiotic in preterm infants: An updated systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Our previous strain-specific systematic review (SR) showed that Lactobacillus reuteri (LR) DSM 17938 reduces necrotizing enterocolitis (NEC), late-onset sepsis (LOS), and time to full feeds (TFF) in preterm infants. Considering progress in the field over the past 6 years, we aimed to update our SR.

METHODS

SR of randomized controlled trials (RCTs) and non-RCTs was conducted. MEDLINE, Embase, Emcare, Cochrane CENTRAL, and gray literature were searched in June 2023. Primary outcomes were TFF, NEC stage ≥II, LOS, and all-cause mortality. Meta-analysis was performed using random-effects model. Certainty of evidence (CoE) was summarized using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) guidelines. Trial sequential analysis (TSA) was applied for outcome of NEC in RCTs.

RESULTS

Twelve RCTs (n = 2284) and four non-RCTs (n = 1616) were included. Six RCTs and three non-RCTs were new. Meta-analysis of RCTs showed LR significantly reduced TFF (mean difference, -2.70 [95% CI, -4.90 to -1.31] days; P = 0.0001), NEC stage ≥II (risk ratio [RR], 0.57 [95% CI, 0.37-0.87]; P = 0.009; eight RCTs), and LOS (RR, 0.72 [95% CI, 0.54-0.97]; P = 0.03); but not mortality (RR, 0.76 [95% CI, 0.54-1.06]; P = 0.10). TSA showed diversity-adjusted required information size (DARIS) as 3624 for NEC. Overall CoE was "very low." Meta-analysis of non-RCTs showed LR reduced NEC (odds ratio, 0.34 [95% CI, 0.15-0.77]; P = 0.01) but not LOS. LR had no adverse effects.

CONCLUSIONS

Very low CoE suggests that LR DSM 17938 may reduce NEC and LOS and shorten TFF in preterm infants. Additional RCTs are required to confirm our findings.

Probiotics in the Neonatal Intensive Care Unit-A Framework for Optimizing Product Standards

This Viewpoint outlines a framework for optimizing probiotic product stringency and use in the neonatal intensive care unit.

Impact of Probiotics on the Prevention and Treatment of Gastrointestinal Diseases in the Pediatric Population

Despite the high prevalence of gastrointestinal disorders (GIDs) in infants and children, especially those categorized as functional GIDs (FGIDs), insufficient knowledge about their pathophysiology has limited both symptomatic diagnosis and the development of optimal therapies. Recent advances in the field of probiotics have made their potential use as an interesting therapeutic and preventive strategy against these disorders possible, but further efforts are still needed. In fact, there is great controversy surrounding this topic, generated by the high variety of potential probiotics strains with plausible therapeutic utility, the lack of consensus in their use as well as the few comparative studies available on probiotics that record their efficacy. Taking into account these limitations, and in the absence of clear guidelines about the dose and timeframe for successful probiotic therapy, our review aimed to evaluate current studies on potential use of probiotics for the prevention and treatment of the most common FGIDs and GIDs in the pediatric population. Furthermore, matters referring to know major action pathways and key safety recommendations for probiotic administration proposed by major pediatric health agencies shall also be discussed.

The Impact of Maternal Probiotics on Intestinal Vitamin D Receptor Expression in Early Life

Vitamin D signaling via the Vitamin D Receptor (VDR) has been shown to protect against intestinal inflammation. Previous studies have also reported the mutual interactions of intestinal VDR and the microbiome, indicating a potential role of probiotics in modulating VDR expression. In preterm infants, although probiotics have been shown to reduce the incidence of necrotizing enterocolitis (NEC), they are not currently recommended by the FDA due to potential risks in this population. No previous studies have delved into the effect of maternally administered probiotics on intestinal VDR expression in early life. Using an infancy mouse model, we found that young mice exposed to maternally administered probiotics (SPF/LB) maintained higher colonic VDR expression than our unexposed mice (SPF) in the face of a systemic inflammatory stimulus. These findings indicate a potential role for microbiome-modulating therapies in preventing diseases such as NEC through the enhancement of VDR signaling.

Maternal provisions in type 1 diabetes: Evidence for both protective & pathogenic potential

Maternal influences on the immune health and development of an infant begin in utero and continue well into the postnatal period, shaping and educating the child's maturing immune system. Two maternal provisions include early microbial colonizers to initiate microbiota establishment and the transfer of antibodies from mother to baby. Maternal antibodies are a result of a lifetime of antigenic experience, reflecting the infection history, health and environmental exposure of the mother. These same factors are strong influencers of the microbiota, inexorably linking the two. Together, these provisions help to educate the developing neonatal immune system and shape lymphocyte repertoires, establishing a role for external environmental influences even before birth. In the context of autoimmunity, the transfer of maternal autoantibodies has the potential to be harmful for the child, sometimes targeting tissues and cells with devastating consequences. Curiously, this does not seem to apply to maternal autoantibody transfer in type 1 diabetes (T1D). Moreover, despite the rising prevalence of the disease, little research has been conducted on the effects of maternal dysbiosis or antibody transfer from an affected mother to her offspring and thus their relevance to disease development in the offspring remains unclear. This review seeks to provide a thorough evaluation of the role of maternal microorganisms and antibodies within the context of T1D, exploring both their pathogenic and protective potential. Although a definitive understanding of their significance in infant T1D development remains elusive at present, we endeavor to present what has been learned with the goal of spurring further interest in this important and intriguing question.

Pathogenesis from the microbial-gut-brain axis in white matter injury in preterm infants: A review

White matter injury (WMI) in premature infants is a unique form of brain injury and a common cause of chronic nervous system conditions such as cerebral palsy and neurobehavioral disorders. Very preterm infants who survive are at high risk of WMI. With developing research regarding the pathogenesis of premature WMI, the role of gut microbiota has attracted increasing attention in this field. As premature infants are a special group, early microbial colonization of the microbiome can affect brain development, and microbiome optimization can improve outcomes regarding nervous system development. As an important communication medium between the gut and the nervous system, intestinal microbes form a microbial-gut-brain axis. This axis affects the occurrence of WMI in premature infants via the metabolites produced by intestinal microorganisms, while also regulating cytokines and mediating oxidative stress. At the same time, deficiencies in the microbiota and their metabolites may exacerbate WMI in premature infants. This confers promise for probiotics and prebiotics as treatments for improving neurodevelopmental outcomes. Therefore, this review attempted to elucidate the potential mechanisms behind the communication of gut bacteria and the immature brain through the gut-brain axis, so as to provide a reference for further prevention and treatment of premature WMI.

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.

Probiotics to improve the gut microbiome in premature infants: are we there yet?

Gut microbiome maturation in infants born prematurely is uniquely influenced by the physiological, clinical, and environmental factors surrounding preterm birth and early life, leading to altered patterns of microbial succession relative to term infants during the first months of life. These differences in microbiome composition are implicated in acute clinical conditions that disproportionately affect preterm infants, including necrotizing enterocolitis (NEC) and late-onset sepsis (LOS). Probiotic supplementation initiated early in life is an effective prophylactic measure for preventing NEC, LOS, and other clinical concerns relevant to preterm infants. In parallel, reported benefits of probiotics on the preterm gut microbiome, metabolome, and immune function are beginning to emerge. This review summarizes the current literature on the influence of probiotics on the gut microbiome of preterm infants, outlines potential mechanisms by which these effects are exerted, and highlights important clinical considerations for determining the best practices for probiotic use in premature infants.

Biotics in neonatal period: what's the evidence?

Breastfeeding is considered the gold standard for infants' nutrition and provides unique benefits for infants' health. Great research interest has been raised about the use of bioactive components in neonatal medicine, both as standalone products and as addition to infant formula, in the attempt to reproduce human milk beneficial effects. Thus, the aim of this narrative review is to summarize most recent evidence on biotics' use in the neonatal period, with a focus on infant formula (IF) supplemented with probiotics, prebiotics, synbiotics and postbiotics. Growing data indicate overall positive effects of biotic supplemented formula on microbiome composition and metabolic activity. Furthermore, some benefits are also emerging from randomized controlled trials evaluating the clinical impact these enriched formulas may have on the health of formula fed infants. However, clear evidence still lacks and none of this supplemented IF has demonstrated conclusive superiority. To date, whereas no routine recommendations can be done, biotics supplemented IF have generally proven to be well-tolerated and safe in ensuring infants' normal growth, paving the way for future IF alternatives for those infants who are not able to be (fully) breastfed. More RCTs, with adequate design and statistical power, are still needed to better clarify, if present, which benefits the supplementation of IF may confer to infants' short and long-term outcomes.

The Microbiota-Gut-Brain Axis in Psychiatric Disorders

Modulating the gut microbiome and its influence on human health is the subject of intense research. The gut microbiota could be associated not only with gastroenterological diseases but also with psychiatric disorders. The importance of factors such as stress, mode of delivery, the role of probiotics, circadian clock system, diet, and occupational and environmental exposure in the relationship between the gut microbiota and brain function through bidirectional communication, described as "the microbiome-gut-brain axis", is especially underlined. In this review, we discuss the link between the intestinal microbiome and the brain and host response involving different pathways between the intestinal microbiota and the nervous system (e.g., neurotransmitters, endocrine system, immunological mechanisms, or bacterial metabolites). We review the microbiota alterations and their results in the development of psychiatric disorders, including major depressive disorder (MDD), schizophrenia (SCZ), bipolar disorder (BD), autism spectrum disorder (ASD), and attention-deficit hyperactivity disorder (ADHD).

Regulatory T Cells in Development and Prediction of Necrotizing Enterocolitis in Preterm Neonates: A Scoping Review

Necrotizing enterocolitis (NEC) is a leading cause of mortality in premature infants. However, the pathophysiology and influence of regulatory T cells (Tregs) have not been sufficiently elucidated. We performed a scoping review to investigate current knowledge on the influence of Tregs in NEC, and to investigate the predictive value of Treg number in NEC development. Pubmed, Embase, Prospero and Cochrane Library were searched during December 2020. Primary research articles discussing Tregs and NEC development written in English were selected. Two reviewers screened title and abstract for relevance, after which full-text screening was performed. A total of 20 articles were selected-13 of the articles discussed studies performed in animal models, while 8 used human neonate data. One study discussed both animal and human data. It was shown that after NEC diagnosis or induction, Treg levels were decreased while Th17 levels were increased. No studies were found which investigated the predictive value of Treg number in NEC development. A reduced Treg level is found in animals and neonates with NEC. The question remains whether this effect is a factor on the causal pathway of NEC development or a bystander effect. Future research focusing on the pathophysiological timeline of NEC and the involvement of Tregs is required for better understanding of this disease.

Neonatal Morbidities and Feeding Tolerance Outcomes in Very Preterm Infants, before and after Introduction of Probiotic Supplementation

While probiotics are reported to reduce the risks of neonatal morbidities, less is known about probiotics and feeding tolerance. With this retrospective cohort study, we investigate whether introduction of probiotic supplementation as the standard of care was associated with fewer neonatal morbidities and improved feeding tolerance in very preterm infants. Using the Swedish Neonatal Quality Register, 345 live-born very preterm infants (28–31 weeks’ gestation), from January 2019–August 2021, in NICUs in Stockholm, Sweden, either received probiotic supplementation (Bifidobacterium infantis, Bifidobacterium lactis, Streptococcusthermophilus) (139) or no supplementation (206); they were compared regarding a primary composite outcome of death, sepsis, and/or necrotising enterocolitis and secondary outcomes: time to full enteral feeding and antibiotics use. Probiotics seemed associated with a reduced risk of the composite outcome (4.3% versus 9.2%, p = 0.08). In the subgroup of 320 infants without the primary outcome, probiotics were associated with shorter time to full enteral feeding (6.6 days versus 7.2 days) and less use of antibiotics (5.2 days versus 6.1 days). Our findings suggest that probiotics improve feeding tolerance and further support that very preterm infants may benefit from probiotic supplementation.

Effects of Probiotics on Gut Microbiomes of Extremely Preterm Infants in the Neonatal Intensive Care Unit: A Prospective Cohort Study

Background: Probiotics have been previously reported to reduce the incidence of necrotizing enterocolitis (NEC) in extremely preterm infants, but the mechanisms by which the probiotics work remain unknown. We aimed to investigate the effects of probiotics on the gut microbiota of extremely preterm infants. Methods: A prospective cohort study was conducted on 120 extremely preterm neonates (gestational age ≤ 28 weeks) between August 2019 and December 2021. All neonates were divided into the study (receiving probiotics) and the control (no probiotics) groups. Multivariate logistic regression analysis was performed to investigate the significantly different compositions of gut microbiota between these two groups. The effects of probiotics on the occurrence of NEC and late-onset sepsis were also investigated. Results: An increased abundance of Lactobacillus was noted in neonates who received the probiotics (AOR 4.33; 95% CI, 1.89-9.96, p = 0.009) when compared with the control group. Subjects in the probiotic group had significantly fewer days of total parenteral nutrition (median [interquartile range, IQR]) 29.0 (26.8-35.0) versus 35.5 (27.8-45.0), p = 0.004) than those in the control group. The probiotic group had a significantly lower rate of late-onset sepsis than the control group (47.1% versus 70.0%, p = 0.015), but the rate of NEC, duration of hospitalization and the final in-hospital mortality rates were comparable between these two groups. Conclusions: Probiotic supplementation of extremely preterm infants soon after the initiation of feeding increased the abundance of Lactobacillus. Probiotics may reduce the risk of late-onset sepsis, but further randomized controlled trials are warranted in the future.

Adenosine Alleviates Necrotizing Enterocolitis by Enhancing the Immunosuppressive Function of Myeloid-Derived Suppressor Cells in Newborns

Necrotizing enterocolitis (NEC) is a common disorder in premature infants that is characterized by hyperinflammation and severe necrosis in the intestine. The pathogenesis of NEC remains to be elucidated. In this study, we demonstrate that adenosine, a metabolite more abundant in infants than in adults, plays an important role in the prevention of NEC. Administration of adenosine or its analog, adenosine-5'-N-ethyluronamide (NECA), dramatically relieved the severity of NEC in neonatal mice. Meanwhile, adenosine treatment significantly enhanced the immunosuppressive function, antibacterial activity, and migration of myeloid-derived suppressor cells (MDSCs). However, depletion of MDSCs or inhibition of their migration using the CXCR2 inhibitor SB225002 almost completely abrogated the protective effect of adenosine on NEC. Mechanistic studies showed that MDSCs in newborns expressed abundant adenosine receptor A2B (A2BR) that elicits intracellular cAMP signaling and its downstream target NF-κB. Importantly, intestinal tissues from patients with NEC showed significantly lower infiltration of A2BR-positive MDSCs than those from healthy donors. These observations revealed that adenosine-induced MDSCs represent an essential immune axis for intestinal homeostasis in newborns.

Gut immune homeostasis: the immunomodulatory role of Bacillus clausii, from basic to clinical evidence

INTRODUCTION

The gut microbiota affects the development of the gut immune system in early life. Perturbations to microbiota structure and composition during this period can have long-term consequences on the health of the individual, through its effects on the immune system. Research in the last few decades has shown that probiotic administration can reverse these effects in strain- and environment-specific ways. Bacillus clausii (B. clausii) has been in use for many decades as a safe and efficacious probiotic, but its mode of action has not yet been completely elucidated.

AREAS COVERED

In this review, we discuss how the gut immune system works, the factors that affect its functioning, and the plethora of research highlighting its role in various diseases. We also discuss the known modes of action of Bacillus probiotics, and highlight the preclinical and clinical evidence that reveal how B. clausii acts to bolster gut defense.

EXPERT OPINION

We anticipate that the treatment and/or prevention of dysbiosis will be central to managing human health and disease in the future. Discovering the pathophysiology of autoimmune diseases, infections, allergies, and some cancers will aid our understanding of the key role played by microbial communities in these diseases.

First encounters of the microbial kind: perinatal factors direct infant gut microbiome establishment

The human gut microbiome harbors a diverse range of microbes that play a fundamental role in the health and well-being of their host. The early-life microbiome has a major influence on human development and long-term health. Perinatal factors such as maternal nutrition, antibiotic use, gestational age and mode of delivery influence the initial colonization, development, and function of the neonatal gut microbiome. The perturbed early-life gut microbiome predisposes infants to diseases in early and later life. Understanding how perinatal factors guide and shape the composition of the early-life microbiome is essential to improving infant health. The following review provides a synopsis of perinatal factors with the most decisive influences on initial microbial colonization of the infant gut.

Safety and efficacy of probiotics in the prevention of necrotizing enterocolitis in premature and/or low-birthweight infants: a systematic review and meta-analysis

BACKGROUND

Neonatal necrotizing enterocolitis (NEC) is a serious pediatric gastrointestinal disease and a cause of death in neonates, especially in premature infants. The addition of probiotics to the diet can reduce the incidence and severity of neonatal NEC. This meta-analysis explored the preventive effect of probiotics on NEC.

METHODS

Endnote X9 software was used to search for relevant studies in the Ovid, Embase, PubMed, and Web of Science databases. The search terms were "probiotics" and "necrotizing enterocolitis". After retrieval, screening, and quality evaluation of the studies, Stata 16.0 software was used to analyze the data.

RESULTS

A total of 10 studies, which collectively included 3,227 patients, were selected for analysis. Of them, 5 used a multiple-strain probiotics, and 5 used single-strain probiotic. Meta-analysis showed that treatment with probiotics could reduce the incidence of severe NEC [risk ratio (RR) =0.66; 95% confidence interval (CI): (0.50, 0.87); Z=-2.978; P=0.003], reduce mortality in underweight premature children [RR =0.81; 95% CI: (0.70, 0.94); Z=-2.864; P=0.004], and reduce the incidence of feeding intolerance [RR =0.78; 95% CI: (0.67, 0.90); Z=-3.280; P=0.001].

DISCUSSION

The addition of probiotics to the diet of low-birthweight and premature infants can reduce the incidence of severe NEC and reduce related mortality rates.

Evaluation of Risk and Preventive Factors for Necrotizing Enterocolitis in Premature Newborns. A Systematic Review of the Literature

Necrotizing enterocolitis (NEC) is a serious condition related to prematurity and the initiation of enteral feeding. In this article, we review the evidence published in recent years on necrotizing enterocolitis risk factors (prematurity, feeding with low-weight formula, existence of intestinal dysbiosis) and protective factors (human milk or donated milk supply, supplementation of human milk with oligosaccharides, probiotics administration, and the determination of disease predictive biomarkers). A systematic review was conducted of preventive, risk and predictive factors for necrotizing enterocolitis in neonates prior to 37 weeks' gestational age, based on a literature search for clinical trials, meta-analyses, randomized controlled trials and systematic reviews published between January 2018 and October 2021. For this purpose, the PubMed, MEDLINE, and Cochrane Library databases were consulted. The literature search obtained 113 articles, of which 19 were selected for further analysis after applying the inclusion and exclusion criteria. The conclusions drawn from this analysis were that adequate knowledge of risk factors that can be prevented or modified (such as alteration of the intestinal microbiota, oxidative stress, metabolic dysfunction at birth, or alteration of the immunity modulation) can reduce the incidence of NEC in premature infants. These factors include the supplementation of enteral nutrition with human milk oligosaccharides (with prebiotic and immunomodulatory effects), the combined administration of probiotics (especially the Lactobacillus spp and Bifidobacterium spp combination, which inhibits bacterial adhesion effects, improves the intestinal mucosa barrier function, strengthens the innate and adaptive immune system and increases the secretion of bioactive metabolites), the supplementation of human milk with lactoferrin and the use of donated milk fortified in accordance with the characteristics of the premature newborn. The determination of factors that can predict the existence of NEC, such as fecal calprotectin, increased TLR4 activity, and IL6 receptor, can lead to an early diagnosis of NEC. Although further studies should be conducted to determine the values of predictive biomarkers of NEC, and/or the recommended doses and strains of probiotics, lactoferrin or oligosaccharides, the knowledge acquired in recent years is encouraging.

The Role of Dietary Fats in the Development and Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a significant cause of mortality and morbidity in preterm infants. The pathogenesis of NEC is not completely understood; however, intestinal immaturity and excessive immunoreactivity of intestinal mucosa to intraluminal microbes and nutrients appear to have critical roles. Dietary fats are not only the main source of energy for preterm infants, but also exert potent effects on intestinal development, intestinal microbial colonization, immune function, and inflammatory response. Preterm infants have a relatively low capacity to digest and absorb triglyceride fat. Fat may thereby accumulate in the ileum and contribute to the development of NEC by inducing oxidative stress and inflammation. Some fat components, such as long-chain polyunsaturated fatty acids (LC-PUFAs), also exert immunomodulatory roles during the early postnatal period when the immune system is rapidly developing. LC-PUFAs may have the ability to modulate the inflammatory process of NEC, particularly when the balance between n3 and n6 LC-PUFAs derivatives is maintained. Supplementation with n3 LC-PUFAs alone may have limited effect on NEC prevention. In this review, we describe how various fatty acids play different roles in the pathogenesis of NEC in preterm infants.

Short- and Long-Term Implications of Human Milk Microbiota on Maternal and Child Health

Human milk (HM) is considered the most complete food for infants as its nutritional composition is specifically designed to meet infant nutritional requirements during early life. HM also provides numerous biologically active components, such as polyunsaturated fatty acids, milk fat globules, IgA, gangliosides or polyamines, among others; in addition, HM has a “bifidogenic effect”, a prebiotic effect, as a result of the low concentration of proteins and phosphates, as well as the presence of lactoferrin, lactose, nucleotides and oligosaccharides. Recently, has been a growing interest in HM as a potential source of probiotics and commensal bacteria to the infant gut, which might, in turn, influence both the gut colonization and maturation of infant immune system. Our review aims to address practical approaches to the detection of microbial communities in human breast milk samples, delving into their origin, composition and functions. Furthermore, we will summarize the current knowledge of how HM microbiota dysbiosis acts as a short- and long-term predictor of maternal and infant health. Finally, we also provide a critical view of the role of breast milk-related bacteria as a novel probiotic strategy in the prevention and treatment of maternal and offspring diseases.

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.

Microbiome First Medicine in Health and Safety

Microbiome First Medicine is a suggested 21st century healthcare paradigm that prioritizes the entire human, the human superorganism, beginning with the microbiome. To date, much of medicine has protected and treated patients as if they were a single species. This has resulted in unintended damage to the microbiome and an epidemic of chronic disorders [e.g., noncommunicable diseases and conditions (NCDs)]. Along with NCDs came loss of colonization resistance, increased susceptibility to infectious diseases, and increasing multimorbidity and polypharmacy over the life course. To move toward sustainable healthcare, the human microbiome needs to be front and center. This paper presents microbiome-human physiology from the view of systems biology regulation. It also details the ongoing NCD epidemic including the role of existing drugs and other factors that damage the human microbiome. Examples are provided for two entryway NCDs, asthma and obesity, regarding their extensive network of comorbid NCDs. Finally, the challenges of ensuring safety for the microbiome are detailed. Under Microbiome-First Medicine and considering the importance of keystone bacteria and critical windows of development, changes in even a few microbiota-prioritized medical decisions could make a significant difference in health across the life course.

Current Status of Probiotics for Preterm Infants

Probiotics have been shown to reduce the risk of all-cause mortality, necrotizing enterocolitis (NEC ≥ stage II), late onset sepsis (LOS), and feeding intolerance in preterm infants. Considering the substantial health burden imposed by these conditions, the importance of probiotics in preterm infants cannot be overemphasized. Based on the data from experimental studies, and systematic reviews of randomized controlled trials (RCTs) and non-RCTs, the uptake of this intervention in neonatal medicine has been increasing over the last few years. However, many are still hesitating to adopt this intervention for various reasons, including concerns about probiotic sepsis, product quality, and lack of clarity on optimal strain/s or their combinations. Some question the validity of meta-analyses of studies involving different probiotic strains or their combinations because probiotics effects are considered to be strain-specific. Some of the early concerns about probiotics in preterm infants have been shown to be unjustified. However, the resistance to probiotics continues in many neonatal units around the world. The future of probiotics for preterm infants depends on continued efforts to develop high-quality probiotic products using stringent quality control, improving access to such products, and robust head-to-head comparisons to know the optimal strains or their combinations. Monitoring for adverse effects such as probiotic sepsis and development of antibiotic resistance is crucial. The authors review the current status of probiotics in preterm infants and discuss the scope for further research in this field.

Gastrointestinal microbiome, what is behind faecal microbiota transplantation?

The intestinal microbiota is made up of billions of microorganisms that coexist in an organised ecosystem, where strict and facultative anaerobic bacteria predominate. The alteration or imbalance of these microorganisms, known as dysbiosis, can be associated with both gastrointestinal and extraintestinal diseases. Based on a review of the literature, the intestinal microbiota is described in its state of health, the changes associated with some gastrointestinal diseases and the potential role that faecal microbiota transplantation has in the reestablishment of an altered ecosystem. Undoubtedly, the information revealed makes us reflect on the indication of faecal microbiota transplantation in various pathologies of intestinal origin. However, to ensure the efficacy and safety of this therapy, more studies are needed to obtain more evidence.