Early administration of Bifidobacterium breve to preterm infants: randomised controlled trial

Probiotics may alleviate intestinal damage induced by cardiopulmonary bypass in children

OBJECTIVES

Intestinal ischaemia-reperfusion injury induced by cardiopulmonary bypass causes intestinal epithelial barrier dysfunction, leading to dysbiosis and bacterial translocation. We conducted a randomized prospective study with 2 objectives: (i) to investigate epithelial barrier dysfunction and bacterial translocation induced by cardiopulmonary bypass and changes in the gut microbiota and (ii) to verify whether probiotics can improve these conditions.

METHODS

Between 2019 and 2020, patients 0-15 years old scheduled to undergo cardiac surgery using cardiopulmonary bypass were enrolled and randomly allocated to 2 groups: the intervention group received probiotics and the control group did not receive probiotics. We analysed the microbiota in faeces and blood, organic acid concentrations in faeces, plasma intestinal fatty acid-binding protein and immunological responses.

RESULTS

Eighty-two patients were enrolled in this study. The characteristics of the patients were similar in both groups. The total number of obligate anaerobes was higher in the intervention group than in the control group after postoperative day 7. We identified 4 clusters within the perioperative gut microbiota, and cluster changes showed a corrective effect of probiotics on dysbiosis after postoperative day 7. Organic acid concentrations in faeces, incidence of bacterial translocation, intestinal fatty acid-binding protein levels and immunological responses, except for interleukin -17A, were not markedly different between the 2 groups.

CONCLUSIONS

Administration of probiotics was able to correct dysbiosis but did not sufficiently alleviate the intestinal damage induced by cardiopulmonary bypass. More effective methods should be examined to prevent disturbances induced by cardiac surgery using cardiopulmonary bypass.

CLINICAL TRIAL REGISTRATION NUMBER

https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000037174 UMIN000035556.

Bifidobacterium infantis as a probiotic in preterm infants: a systematic review and meta-analysis

BACKGROUND

Bifidobacterium infantis has special abilities to utilise human milk oligosaccharides. Hence we hypothesised that probiotic supplements containing B. infantis may confer greater benefits to preterm infants than probiotic supplements without B. infantis.

METHODS

A systematic review with meta-analysis was conducted according to standard guidelines. We selected RCTs evaluating probiotics compared to placebo or no treatment in preterm and/or low birth weight infants. Probiotic effects on Necrotizing Enterocolitis (NEC), Late Onset Sepsis (LOS) and Mortality were analysed separately for RCTs in which the supplemented probiotic product contained B. infantis and those that did not contain B. infantis.

RESULTS

67 RCTs were included (n = 14,606), of which 16 used probiotics containing B. infantis (Subgroup A) and 51 RCTs did not (Subgroup B) Meta-analysis of all RCTs indicated that probiotics reduced the risk of NEC, LOS, and mortality. The subgroup meta-analysis demonstrated greater reduction in the incidence of NEC in subgroup A than subgroup B [(relative risk in subgroup A: 0.38; 95% CI, 0.27-0.55) versus (0.67; 95% CI, 0.55-0.81) in subgroup B; p value for subgroup difference: 0.01].

CONCLUSIONS

These results provide indirect evidence that probiotic supplements that include B. infantis may be more beneficial for preterm infants. Well-designed RCTs are necessary to confirm these findings.

IMPACT

Evidence is emerging that beneficial effects of probiotics are species and strain specific. This systematic review analyses if B. infantis supplementation provides an advantage to preterm infants. This is the first systematic review evaluating the effects of probiotics containing B. infantis in preterm infants. The results of this systematic review provides indirect evidence that probiotics that include B. infantis may be more beneficial for preterm infants. These results will help in guiding future research and clinical practice for using B. infantis as a probiotic in preterm infants.

Growth and neuro-developmental outcomes of probiotic supplemented preterm infants-a systematic review and meta-analysis

Gut dysbiosis is associated with sepsis and necrotizing enterocolitis in preterm infants, which can adversely affect long-term growth and neurodevelopment. We aimed to synthesise evidence for the effect of probiotic supplementation on growth and neurodevelopmental outcomes in preterm infants. MEDLINE, EMBASE, EMCARE, Cochrane CENTRAL, and grey literature were searched in February 2022. Only randomized controlled trials (RCTs) were included. Meta-analysis was performed using random effects model. Effect sizes were expressed as standardized mean difference (SMD), mean difference (MD) or risk ratio (RR) and their corresponding 95% confidence intervals (CI). Risk of Bias (ROB) was assessed using the ROB-2 tool. Certainty of Evidence (CoE) was summarized using GRADE guidelines. Thirty RCTs (n = 4817) were included. Meta-analysis showed that probiotic supplementation was associated with better short-term weight gain [SMD 0.24 (95%CI 0.04, 0.44); 22 RCTs (n = 3721); p = 0.02; I2 = 88%; CoE: low]. However, length [SMD 0.12 (95%CI -0.13, 0.36); 7 RCTs, (n = 899); p = 0.35; I2 = 69%; CoE: low] and head circumference [SMD 0.09 (95%CI -0.15, 0.34); 8 RCTs (n = 1132); p = 0.46; I2 = 76%; CoE: low] were similar between the probiotic and placebo groups. Probiotic supplementation had no effect on neurodevelopmental impairment [RR 0.91 (95%CI 0.76, 1.08); 5 RCTs (n = 1556); p = 0.27; I2 = 0%; CoE: low]. Probiotic supplementation was associated with better short-term weight gain, but did not affect length, head circumference, long-term growth, and neurodevelopmental outcomes of preterm infants. Adequately powered RCTs are needed in this area. Prospero Registration: CRD42020064992.

A comprehensive review of Bifidobacterium spp: as a probiotic, application in the food and therapeutic, and forthcoming trends

Recently, more consumers are interested in purchasing probiotic food and beverage products that may improve their immune health. The market for functional foods and beverages that include Bifidobacterium is expanding because of their potential uses in both food and therapeutic applications. However, maintaining Bifidobacterium's viability during food processing and storage remains a challenge. Microencapsulation technique has been explored to improve the viability of Bifidobacterium. Despite the technical, microbiological, and economic challenges, the market potential for immune-supporting functional foods and beverages is significant. Additionally, there is a shift toward postbiotics as a solution for product innovation, a promising postbiotic product that can be incorporated into various food and beverage formats is also introduced in this review. As consumers become more health-conscious, future developments in the functional food and beverage market discussed in this review could serve as a reference for researchers and industrialist.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Strain-Specificity of Probiotics in Pediatrics: A Rapid Review of the Clinical Evidence

OBJECTIVE

The dogma of probiotic strain-specificity is widely accepted. However, only the genus- and species-specific effects of probiotics are supported by evidence from clinical trials. The aim of this rapid review was to assess clinical evidence supporting the claim that the efficacy of probiotics in the pediatric population is strain-specific.

METHODS

The Cochrane Library, MEDLINE, and EMBASE databases were searched (up to August 2022) for randomized controlled trials (RCTs) conducted in children aged 0-18 years evaluating the effects of prophylactic or therapeutic administration of probiotics (well-characterized at the strain level) for conditions such as antibiotic-associated diarrhea, acute diarrhea, necrotizing enterocolitis, respiratory tract infections, Helicobacter pylori infection, and atopic dermatitis. To allow evaluation of strain-specificity, a trial could only be included in the review if at least one additional RCT assessed the effect of a different strain of the same species against the same comparator. RCTs without proper strain-level data were excluded. In the absence of identifying head-to-head strain versus strain RCTs, indirect comparisons were made between interventions.

RESULTS

Twenty-three RCTs were eligible for inclusion. Out of the 11 performed comparisons, with 1 exception (two Lacticaseibacillus paracasei strains in reducing atopic dermatitis symptoms), no significant differences between the clinical effects of different strains of the same probiotic species were found.

CONCLUSIONS

Head-to-head comparison is an optimal study design to compare probiotic strains, but such comparisons are lacking. Based on indirect comparisons, this rapid review demonstrates insufficient clinical evidence to support or refute the claim that probiotic effects in children are strain-specific.

Bifidobacterium: Host-Microbiome Interaction and Mechanism of Action in Preventing Common Gut-Microbiota-Associated Complications in Preterm Infants: A Narrative Review

The development and health of infants are intertwined with the protective and regulatory functions of different microorganisms in the gut known as the gut microbiota. Preterm infants born with an imbalanced gut microbiota are at substantial risk of several diseases including inflammatory intestinal diseases, necrotizing enterocolitis, late-onset sepsis, neurodevelopmental disorders, and allergies which can potentially persist throughout adulthood. In this review, we have evaluated the role of Bifidobacterium as commonly used probiotics in the development of gut microbiota and prevention of common diseases in preterm infants which is not fully understood yet. The application of Bifidobacterium as a therapeutical approach in the re-programming of the gut microbiota in preterm infants, the mechanisms of host-microbiome interaction, and the mechanism of action of this bacterium have also been investigated, aiming to provide new insights and opportunities in microbiome-targeted interventions in personalized medicine.

Role of gut-brain axis in neurodevelopmental impairment of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a common gastrointestinal disease of preterm infants with high morbidity and mortality. In survivors of NEC, one of the leading causes of long-term morbidity is the development of severe neurocognitive injury. The exact pathogenesis of neurodevelopmental delay in NEC remains unknown, but microbiota is considered to have dramatic effects on the development and function of the host brain via the gut-brain axis. In this review, we discuss the characteristics of microbiota of NEC, the impaired neurological outcomes, and the role of the complex interplay between the intestinal microbiota and brain to influence neurodevelopment in NEC. The increasing knowledge of microbial-host interactions has the potential to generate novel therapies for manipulating brain development in the future.

Effect of Bifidobacterium on osteoclasts: TNF-α/NF-κB inflammatory signal pathway-mediated mechanism

Osteoporosis is a systemic multifactorial bone disease characterized by low bone quality and density and bone microstructure damage, increasing bone fragility and fracture vulnerability. Increased osteoclast differentiation and activity are important factors contributing to bone loss, which is a common pathological manifestation of bone diseases such as osteoporosis. TNF-a/NF-κB is an inflammatory signaling pathway with a key regulatory role in regulating osteoclast formation, and the classical pathway RANKL/RANK/OPG assists osteoclast formation. Activation of this inflammatory pathway promotes the formation of osteoclasts and accelerates the process of osteoporosis. Recent studies and emerging evidence have consistently demonstrated the potential of probiotics to modulate bone health. Secretions of Bifidobacterium, a genus of probiotic bacteria in the phylum Actinobacteria, such as short-chain fatty acids, equol, and exopolysaccharides, have indicated beneficial effects on bone health. This review discusses the molecular mechanisms of the TNF-a/NF-κB inflammatory pathway in regulating osteoclast formation and describes the secretions produced by Bifidobacterium and their potential effects on bone health through this pathway, opening up new directions for future research.

Probiotic Use in Preterm Neonates: A Review and Bibliometric Analysis

Background: Necrotizing enterocolitis (NEC) is a major health burden in peterm neonates with mortality rates between 21% and 50%. Prophylaxis is of primary importance as early diagnosis is hindered by the lack of specific signs and laboratory markers. Although probiotics have been routinely used for NEC prophylaxis in neonatal intensive care units around the world, clinical trials provide contradictory data, which fuels an ongoing debate about their efficacy and safety.

Aims: To perform a review and bibliometric analysis on available clinical trials and case reports data on the safety and efficacy of probiotics in preterm neonates and identify relevant publication trends and patterns.

Methods: A bibliometric search for publications on the topic was performed in the Web of Science Core Collection database and the resulting records analyzed in bibliometrix package in R.

Results: Trends in publication activity, historical direct citation network relationships and keyword co-ocurrences were discussed in the context of the most recent therapeutic recommendations.

Conclusion: We took a round view of the potential drawbacks to probiotic use in preterm infants and their possible solutions.

Priority effects shape the structure of infant-type Bifidobacterium communities on human milk oligosaccharides

Bifidobacteria are among the first colonizers of the infant gut, and human milk oligosaccharides (HMOs) in breastmilk are instrumental for the formation of a bifidobacteria-rich microbiota. However, little is known about the assembly of bifidobacterial communities. Here, by applying assembly theory to a community of four representative infant-gut associated Bifidobacterium species that employ varied strategies for HMO consumption, we show that arrival order and sugar consumption phenotypes significantly affected community formation. Bifidobacterium bifidum and Bifidobacterium longum subsp. infantis, two avid HMO consumers, dominate through inhibitory priority effects. On the other hand, Bifidobacterium breve, a species with limited HMO-utilization ability, can benefit from facilitative priority effects and dominates by utilizing fucose, an HMO degradant not utilized by the other bifidobacterial species. Analysis of publicly available breastfed infant faecal metagenome data showed that the observed trends for B. breve were consistent with our in vitro data, suggesting that priority effects may have contributed to its dominance. Our study highlights the importance and history dependency of initial community assembly and its implications for the maturation trajectory of the infant gut microbiota.

Highly Specialized Carbohydrate Metabolism Capability in Bifidobacterium Strains Associated with Intestinal Barrier Maturation in Early Preterm Infants

“Leaky gut,” or high intestinal barrier permeability, is common in preterm newborns. The role of the microbiota in this process remains largely uncharacterized. We employed both short- and long-read sequencing of the 16S rRNA gene and metagenomes to characterize the intestinal microbiome of a longitudinal cohort of 113 preterm infants born between 24^0/7 and 32^6/7 weeks of gestation. Enabled by enhanced taxonomic resolution, we found that a significantly increased abundance of Bifidobacterium breve and a diet rich in mother’s breastmilk were associated with intestinal barrier maturation during the first week of life. We combined these factors using genome-resolved metagenomics and identified a highly specialized genetic capability of the Bifidobacterium strains to assimilate human milk oligosaccharides and host-derived glycoproteins. Our study proposes mechanistic roles of breastmilk feeding and intestinal microbial colonization in postnatal intestinal barrier maturation; these observations are critical toward advancing therapeutics to prevent and treat hyperpermeable gut-associated conditions, including necrotizing enterocolitis (NEC).

Roles of Probiotics in Reduction of Neonatal Jaundice in Term Newborns

Objective

the primary objective was to examine the effect of Bifidobacterium on decreasing the bilirubin level in term neonates delivered by Caesarean Section (CS).

Materials and Methods

A total of 153 healthy term neonates delivered by CS were included in this study and were divided into the non-probiotic group (n=99) and probiotic group (n=54) based on the history of probiotics administration. There were no infants who underwent phototherapy. A total of 20 doses of probiotics were given orally from the first day of life. The transcutaneous bilirubin (TcB) levels were measured every day for the first 5 days of life. Data of each infant and mother were gathered from medical records.

Results

The bilirubin level per day (day-1 to day-5) in the non-probiotic group was no different from the probiotic group. Differences in bilirubin level between day-5 and day-1, and also between day-5 and day-2 were not different between the two groups. There was a significant (p = 0.03) body weight gain in the probiotic groups with a mean of 36.09 ± 8.23 gram/day. No obvious adverse reactions were seen in both the non-probiotic group and probiotic group.

Conclusions

Our findings suggest no significant effects of probiotics on lowering bilirubin levels in the first five days of life. Also, probiotics have a positive effect on body weight gain in healthy term infants, and it is safe to be given to newborns.

Clinical implications of preterm infant gut microbiome development

Perturbations to the infant gut microbiome during the first weeks to months of life affect growth, development and health. In particular, assembly of an altered intestinal microbiota during infant development results in an increased risk of immune and metabolic diseases that can persist into childhood and potentially into adulthood. Most research into gut microbiome development has focused on full-term babies, but health-related outcomes are also important for preterm babies. The systemic physiological immaturity of very preterm gestation babies (born earlier than 32 weeks gestation) results in numerous other microbiome-organ interactions, the mechanisms of which have yet to be fully elucidated or in some cases even considered. In this Perspective, we compare assembly of the intestinal microbiome in preterm and term infants. We focus in particular on the clinical implications of preterm infant gut microbiome composition and discuss the prospects for microbiome diagnostics and interventions to improve the health of preterm babies.

Role of Bifidobacteria on Infant Health

Bifidobacteria are among the predominant microorganisms during infancy, being a dominant microbial group in the healthy breastfed infant and playing a crucial role in newborns and infant development. Not only the levels of the Bifidobacterium genus but also the profile and quantity of the different bifidobacterial species have been demonstrated to be of relevance to infant health. Although no definitive proof is available on the causal association, reduced levels of bifidobacteria are perhaps the most frequently observed alteration of the intestinal microbiota in infant diseases. Moreover, Bifidobacterium strains have been extensively studied by their probiotic attributes. This review compiles the available information about bifidobacterial composition and function since the beginning of life, describing different perinatal factors affecting them, and their implications on different health alterations in infancy. In addition, this review gathers exhaustive information about pre-clinical and clinical studies with Bifidobacterium strains as probiotics in neonates.

Invasive Infections Associated with the Use of Probiotics in Children: A Systematic Review

Although the effectiveness of probiotics has only been proven in specific conditions, their use in children is massively widespread because of their perception as harmless products. Recent evidence raises concerns about probiotics' safety, especially but not only in the paediatric population due to severe opportunistic infections after their use. This review aimed at summarising available case reports on invasive infections related to probiotics' use in children. For this purpose, we assessed three electronic databases to identify papers describing paediatric patients with documented probiotic-derived invasive infections, with no language restrictions. A total of 49 case reports from 1995 to June 2021 were identified. The infections were caused by Lactobacillus spp. (35%), Saccharomyces spp. (29%), Bifidobacterium spp. (31%), Bacillus clausii (4%), and Escherichia coli (2%). Most (80%) patients were younger than 2 years old and sepsis was the most observed condition (69.4%). All the patients except one had at least one condition facilitating the development of invasive infection, with prematurity (55%) and intravenous catheter use (51%) being the most frequent. Three (6%) children died. Given the large use of probiotics, further studies aiming at evaluating the real incidence of probiotic-associated systemic infections are warranted.

The effect of probiotic supplementation on the gut microbiota of preterm infants

Introduction. Probiotic supplementation of preterm infants may prevent serious morbidities associated with prematurity.Aim. To investigate the impact of probiotic supplementation on the gut microbiota and determine factors associated with detection of probiotic species in the infant gut.Hypothesis/Gap Statement. Probiotic supplementation increases the long-term colonization of probiotic species in the gut of preterm infants.Methodology. Longitudinal stool samples were collected from a cohort of very preterm infants participating in a blinded randomized controlled trial investigating the impact of probiotic supplementation (containing Bifidobacterium longum subsp. infantis BB-02, Bifidobacterium animalis subsp. lactis BB-12 and Streptococcus thermophilus TH-4) for prevention of late-onset sepsis. The presence of B. longum subsp. infantis, B. animalis subsp. lactis and S. thermophilus was determined for up to 23 months after supplementation ended using real-time PCR. Logistic regression was used to investigate the impact of probiotic supplementation on the presence of each species.Results. Detection of B. longum subsp. infantis [odds ratio (OR): 53.1; 95 % confidence interval (CI): 35.6-79.1; P < 0.001], B. animalis subsp. lactis (OR: 89.1; 95 % CI: 59.0-134.5; P < 0.001) and S. thermophilus (OR: 5.66; 95 % CI: 4.35-7.37; P < 0.001) was increased during the supplementation period in infants receiving probiotic supplementation. Post-supplementation, probiotic-supplemented infants had increased detection of B. longum subsp. infantis (OR: 2.53; 95 % CI: 1.64-3.90; P < 0.001) and B. animalis subsp. lactis (OR: 1.59; 95 % CI: 1.05-2.41; P=0.030). Commencing probiotic supplementation before 5 days from birth was associated with increased detection of the probiotic species over the study period (B. longum subsp. infantis, OR: 1.20; B. animalis subsp. lactis, OR: 1.28; S. thermophilus, OR: 1.45).Conclusion. Probiotic supplementation with B. longum subsp. infantis BB-02, B. animalis subsp. lactis BB-12 and S. thermophilus TH-4 enhances the presence of probiotic species in the gut microbiota of very preterm infants during and after supplementation. Commencing probiotic supplementation shortly after birth may be important for improving the long-term colonization of probiotic species.

Ecological and molecular perspectives on responders and non-responders to probiotics and prebiotics

Bifidobacteria are widely used as a probiotic for their health-promoting effects. To promote their growth, bifidogenic prebiotics, including human milk oligosaccharides (HMOs), have been added to supplements and infant formula. However, the efficacy of both probiotic and prebiotic interventions is often debated, as clinical responses vary significantly by case. Here, we review clinical studies that aimed to proliferate human-residential Bifidobacterium (HRB) strains in the gut, and we highlight the difference between responders and non-responders to such interventions through an ecological, niche-based perspective and an examination of the prevalence of genes responsible for prebiotic assimilation in HRB genomes. We discuss the criteria necessary to better evaluate the efficacy of probiotic and prebiotic interventions and the recent therapeutic potential shown by synbiotics.

Does infant formula containing synbiotics support adequate growth in infants? A meta-analysis and systematic review of randomized controlled trials

In recent years, several studies have shown that formulas that contain synbiotics, i.e. composed prebiotics and probiotics have been proposed to have a beneficial effect on anthropometric indices. However, the results are inconsistent thus this meta-analysis was performed to assess this effect. PubMed/MEDLINE, Web of Science, SCOPUS, and Embase were systematically searched up to May-2020. Weight gain, length gain, head circumstance gain, weight-for-age z scores, and length-for-age z scores were considered as the outcomes. Weighted mean differences (WMD) with the 95% CI were applied for estimating the combined effect size. Subgroup analysis was performed to specify the source of heterogeneity among studies. Consumption of formulas containing synbiotics did not affect growth significantly in healthy infants (weight gain (WMD = 2.06, 95% CI: - 4.08 to 8.21; p = 0.51), length gain (WMD = - 0.05, 95% CI: - 0.70 to 0.60; p = 0.88), head circumstance (WMD = - 0.28, 95% CI: - 0.66 to 0.11; p = 0.15), on weight-for-age z-scores (WMD = - 0.05, 95% CI: - 0.23 to 0.13; p = 0.57) and length-for-age z-scores (WMD = - 0.16, 95% CI: - 0.50 to 0.19; p = 0.37)). The main results indicate a non-significant increase in infant's growth following synbiotics supplementation of infant formula. Further large-scale studies are warranted to confirm present findings.

[Efficacy of probiotics in preventing late-onset sepsis in very low birth weight infants: a Meta analysis]

OBJECTIVE

To study the efficacy of probiotics in preventing late-onset sepsis (LOS) in very low birth weight (VLBW) infants.

METHODS

Databases including PubMed, Web of Science, Cochrane Library, Wanfang Data, China National Knowledge Infrastructure, and Chinese Biomedical Literature Database were searched for randomized controlled trials (RCTs) of probiotics in preventing LOS in VLBW infants. LOS was classified as clinical LOS and confirmed LOS. RevMan 5.4 was used to perform the Meta analysis.

RESULTS

A total of 31 RCTs were included, with 3 490 VLBW infants in the probiotics group and 3 376 VLBW infants in the control group. The Meta analysis showed that compared with the control group, the probiotics group had significantly lower risks of clinical LOS (RR=0.79, 95%CI:0.66-0.94, P=0.009) and clinical/confirmed LOS (RR=0.79, 95% CI:0.67-0.94, P=0.007). In the probiotics group, the infants receiving exclusive breastfeeding had a significantly lower risk of confirmed LOS (RR=0.77, 95%CI:0.62-0.96, P=0.02).

CONCLUSIONS

Current evidence indicates that probiotics may reduce the risk of clinical LOS and clinical/confirmed LOS in VLBW infants, and the risk of confirmed LOS in VLBW infants who are exclusively breastfed.

Bifidobacterium breve BBG-001 and intestinal barrier function in preterm babies: Exploratory Studies from the PiPS Trial

BACKGROUND

Uncertainty remains about the role of probiotics to prevent necrotising enterocolitis (NEC) some of which arises from the variety of probiotic interventions used in different trials, many with no prior evidence of potential efficacy. Mechanistic studies of intestinal barrier function embedded in a large probiotic trial could provide evidence about which properties of probiotics might be important for NEC prevention thus facilitating identification of strains with therapeutic potential.

METHODS

Intestinal permeability, stool microbiota, SCFAs and mucosal inflammation were assessed from the second postnatal week in babies enrolled to a randomised controlled trial of B. breve BBG-001 (the PiPS trial). Results were compared by allocation and by stool colonisation with the probiotic.

RESULTS

Ninety-four preterm babies were recruited across six nested studies. B. breve BBG-001 content was higher by allocation and colonisation; Enterobacteriaceae and acetic acid levels were higher by colonisation. No measure of intestinal barrier function showed differences. The PiPS trial found no evidence of efficacy to reduce NEC.

CONCLUSIONS

That the negative results of the PiPS trial were associated with failure of this probiotic to modify intestinal barrier function supports the possibility that the tests described here have the potential to identify strains to progress to large clinical trials.

IMPACT

Uncertainty about the therapeutic role of probiotics to prevent necrotising enterocolitis is in part due to the wide range of bacterial strains with no previous evidence of efficacy used in clinical trials. We hypothesised that mechanistic studies embedded in a probiotic trial would provide evidence about which properties of probiotics might be important for NEC prevention. The finding that the probiotic strain tested, Bifidobacterium breve BBG-001, showed neither effects on intestinal barrier function nor clinical efficacy supports the possibility that these tests have the potential to identify strains to progress to large clinical trials.

The microbiota-gut-brain axis: A novel nutritional therapeutic target for growth retardation

Growth retardation (GR), which commonly occurs in childhood, is a major health concern globally. However, the specific mechanism remains unclear. It has been increasingly recognized that changes in the gut microbiota may lead to GR through affecting the microbiota-gut-brain axis. Microbiota interacts with multiple factors such as birth to affect the growth of individuals. Microbiota communicates with the nerve system through chemical signaling (direct entry into the circulation system or stimulation of enteroendocrine cells) and nervous signaling (interaction with enteric nerve system and vagus nerve), which modulates appetite and immune response. Besides, they may also influence the function of enteric glial cells or lymphocytes and levels of systemic inflammatory cytokines. Environmental stress may cause leaky gut through perturbing the hypothalamic-pituitary-adrenal axis to further result in GR. Nutritional therapies involving probiotics and pre-/postbiotics are being investigated for helping the patients to overcome GR. In this review, we summarize the role of microbiota in GR with human and animal models. Then, existing and potential regulatory mechanisms are reviewed, especially the effect of microbiota-gut-brain axis. Finally, we propose nutritional therapeutic strategies for GR by the intervention of microbiota-gut-brain axis, which may provide novel perspectives for the treatment of GR in humans and animals.

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.

Case Report: Treatment of Extremely Preterm Infants With Birthweight Below 300 g: Case Series

Reports on the birth of infants weighing <300 g are quite rare and little is known about the best practices in treating such micropreemies. Therefore, we report here on three cases of low birthweight infants weighing <300 g, of whom two infants survived. The birthweights and gestational ages were ranging 279-293 g and 22 + 6/7 - 23 + 6/7 weeks, respectively. All the infants had severe fetal growth restriction and prematurity. The infant in case 1 died of hepatic rupture, perhaps due to birth trauma, which emphasized the need for less invasive obstetric procedures including en caul delivery. The infant in case 2 managed to survive through severe prematurity secondary to hydrops fetalis. However, complications followed soon as tracheal granulation tissue was formed with neurodevelopmental impairment. The infant in case 3 was born recently and her clinical course was less remarkable without severe complications, despite having the least gestational age and birthweight among the three patients. The improved care protocols for extremely low birthweight infants over these years through experiential learning including that with cases 1 and 2 may have ensured the better outcome of case 3. Accumulating evidence and recording the experience of such cases with continuous constructive discussion can contribute to better outcomes and appropriate parental counseling for extremely small babies in the future.

Dynamic analysis of human small intestinal microbiota after an ingestion of fermented milk by small-intestinal fluid perfusion using an endoscopic retrograde bowel insertion technique

Probiotic products have been shown to have beneficial effects on human hosts, but what happens in the gastrointestinal tract after its ingestion remains unclear. Our aim was to investigate the changes within the small intestines after a single intake of a fermented milk product containing a probiotic. We have periodically collected the small-intestinal fluids from the terminal ileum of seven healthy subjects for up to 7 h after ingestion by small-intestinal fluid perfusion using an endoscopic retrograde bowel insertion technique. The bacterial composition of the terminal ileum clearly revealed that the ingested probiotics (Lactobacillus casei strain Shirota: LcS and Bifidobacterium breve strain Yakult: BbrY) occupied the ileal microbiota for several hours, temporarily representing over 90% of the ileal microbiota in several subjects. Cultivation of ileal fluids showed that under a dramatic pH changes before reaching the terminal ileum, a certain number of the ingested bacteria survived (8.2 ± 6.4% of LcS, 7.8 ± 11.0% of BbrY). This means that more than 1 billion LcS and BbrY cells reached the terminal ileum with their colony-forming ability intact. These results indicate that there is adequate opportunity for the ingested probiotics to continuously stimulate the host cells in the small intestines. Our data suggest that probiotic fermented milk intake affects intestinal microbes and the host, explaining part of the process from the intake of probiotics to the exertion of their beneficial effects on the host.

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

BACKGROUND

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Probiotics Reduce Mortality and Morbidity in Preterm, Low-Birth-Weight Infants: A Systematic Review and Network Meta-analysis of Randomized Trials

BACKGROUND & AIMS

We aimed to compare the effectiveness of single- vs multiple-strain probiotics in a network meta-analysis of randomized trials.

METHODS

We searched MEDLINE, Embase, Science Citation Index Expanded, CINAHL, Scopus, Cochrane CENTRAL, BIOSIS Previews, and Google Scholar through January 1, 2019, for studies of single-strain and multistrain probiotic formulations on the outcomes of preterm, low-birth-weight neonates. We used a frequentist approach for network meta-analysis and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence. Primary outcomes included all-cause mortality, severe necrotizing enterocolitis (NEC) (Bell stage II or more), and culture-proven sepsis.

RESULTS

We analyzed data from 63 trials involving 15,712 preterm infants. Compared with placebo, a combination of 1 or more Lactobacillus species (spp) and 1 or more Bifidobacterium spp was the only intervention with moderate- or high-quality evidence of reduced all-cause mortality (odds ratio [OR], 0.56; 95% confidence interval [CI], 0.39-0.80). Among interventions with moderate- or high-quality evidence for efficacy compared with placebo, combinations of 1 or more Lactobacillus spp and 1 or more Bifidobacterium spp, Bifidobacterium animalis subspecies lactis, Lactobacillus reuteri, or Lactobacillus rhamnosus significantly reduced severe NEC (OR, 0.35 [95% CI, 0.20-0.59]; OR, 0.31 [95% CI, 0.13-0.74]; OR, 0.55 [95% CI, 0.34-0.91]; and OR, 0.44 [95% CI, 0.21-0.90], respectively). There was moderate- or high-quality evidence that combinations of 1 or more Lactobacillus spp and 1 or more Bifidobacterium spp and Saccharomyces boulardii reduced the number of days to reach full feeding (mean reduction of 3.30 days [95% CI, reduction of 5.91-0.69 days]). There was moderate- or high-quality evidence that, compared with placebo, the single-species product B animalis subsp lactis or L reuteri significantly reduced duration of hospitalization (mean reduction of 13.00 days [95% CI, reduction of 22.71-3.29 days] and mean reduction of 7.89 days [95% CI, reduction of 11.60-4.17 days], respectively).

CONCLUSIONS

In a systematic review and network meta-analysis of studies to determine the effects of single-strain and multistrain probiotic formulations on outcomes of preterm, low-birth-weight neonates, we found moderate to high evidence for the superiority of combinations of 1 or more Lactobacillus spp and 1 or more Bifidobacterium spp vs single- and other multiple-strain probiotic treatments. The combinations of Bacillus spp and Enterococcus spp, and 1 or more Bifidobacterium spp and Streptococcus salivarius subsp thermophilus, might produce the largest reduction in NEC development. Further trials are needed.

Safety and efficacy of probiotic administration to preterm infants: ten common questions

In spite of a large number of randomized placebo-controlled clinical trials and observational cohort studies including >50,000 preterm infants from 29 countries that have demonstrated a decrease in the risk of necrotizing enterocolitis, death, and sepsis, routine prophylactic probiotic administration to preterm infants remains uncommon in much of the world. This manuscript reflects talks given at NEC Society Symposium in 2019 and is not intended to be a state-of-the-art review or systematic review, but a summary of the probiotic-specific aspects of the symposium with limited additions including a recent strain-specific network analysis and position statement from the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN). We address ten common questions related to the intestinal microbiome and probiotic administration to the preterm infant.

A new use of Lactobacillus rhamnosus GG administration in the NICU: colonized vancomycin-resistant enterococcus eradication in the gastrointestinal system

Introduction: Enterococci are microbiota microorganisms that normally have low virulence; however, under some conditions they may cause community-acquired urinary tract and even hospital-acquired serious infections. Vancomycin-resistant enterococci (VRE) can cause aggressive infections in immunosuppressive patients; especially in newborns in intensive care units. Asymptomatic gastrointestinal system carriers are important sources of VRE. Asymptomatic patients colonized by VRE can infect both other patients and the environment. Prevention of gastrointestinal colonization of VRE is an important issue to prevent VRE infection, and for rational use of hospital source.Method: This study was carried out at Hacettepe University, Faculty of Medicine in Newborn Intensive Care Unit between November 2015 and March 2017. The newborn infants who were find as colonized by VRE during weekly surveillance VRE rectal stool culture screening were taken into the study. A single dose of one million colonies of Lactobacillus rhamnosus GG (LGG®) was given to the study group daily. The probiotic supplement continued until consecutive three negative cultures were detected or maximum 6 months. Control group received conventional treatment.Results: In the study group, VRE eradication was successful in 21 patients out of 22 within 6 months and 1 patient was still VRE positive at 6 months. In the control group, VRE was eradicated in 12 patients out of 23 and 11 patients continued to be colonized by VRE at 6 months. There was a statistically significant difference between the groups (p <.05).Conclusion: Lactobacillus rhamnosus GG use is associated with early clearance of vancomycin-resistant enterococcus in newborn patients.

Lactobacillus Acidophilus/Bifidobacterium Infantis Probiotics Are Beneficial to Extremely Low Gestational Age Infants Fed Human Milk

Objective: To evaluate the nutrition-related effects of prophylactic Lactobacillus acidophilus/Bifidobacterium infantis probiotics on the outcomes of preterm infants <29 weeks of gestation that receive human milk and/or formula nutrition. We hypothesize that human-milk-fed infants benefit from probiotics in terms of sepsis prevention and growth. Methods: We performed an observational study of the German Neonatal Network (GNN) over a period of six years, between 1 January, 2013 and 31 December, 2018. Prophylactic probiotic use of L. acidophilus/B. infantis was evaluated in preterm infants <29 weeks of gestation (n = 7516) in subgroups stratified to feeding type: (I) Exclusively human milk (HM) of own mother and/or donors (HM group, n = 1568), (II) HM of own mother and/or donor and formula (Mix group, n = 5221), and (III) exclusive exposure to formula (F group, n = 727). The effect of probiotics on general outcomes and growth was tested in univariate models and adjusted in linear/logistic regression models. Results: 5954 (76.5%) infants received L. acidophilus/B. infantis prophylactically for the prevention of necrotizing enterocolitis (NEC). Probiotic use was associated with improved growth measures in the HM group (e.g., weight gain velocity in g/day: effect size B = 0.224; 95% CI: 2.82–4.35; p < 0.001) but not in the F group (effect size B = −0.06; 95% CI: −3.05–0.28; p = 0.103). The HM group had the lowest incidence of clinical sepsis (34.0%) as compared to the Mix group (35.5%) and the F group (40.0%). Only in the Mix group, probiotic supplementation proved to be protective against clinical sepsis (OR 0.69; 95% CI: 0.59–0.79; p < 0.001). Conclusion: Our observational data indicate that the exposure to L. acidophilus/B. infantis probiotics may promote growth in exclusively HM-fed infants as compared to formula-fed infants. To exert a sepsis-preventive effect, probiotics seem to require human milk.

Safety and efficacy of Lactobacillus for preventing necrotizing enterocolitis in preterm infants

AIM

To evaluate the safety and efficacy of Lactobacillus for preventing necrotizing enterocolitis (NEC) in preterm infants.

METHODS

We searched the Cochrane Library, PubMed, EMBASE, and Web of Science databases from inception to September 2019. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated to compare outcomes. We also performed a subgroup analysis of the incidence of NEC. Moreover, a sensitivity analysis was performed to examine the stability of the results. A Begg funnel plot was generated to detect publication bias. Two reviewers assessed trial quality and extracted data independently. This work has been reported in line with the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement and the Assessing the Methodological Quality of Systematic Reviews guidelines. Statistical analysis was performed using standard procedures in Review Manager 5.2 software.

RESULTS

Twenty-three randomized, placebo-controlled studies (N = 4686 participants) were included in this analysis. Comparing the Lactobacillus and control groups, a significant reduction was found in the incidence of NEC (RR 0.34, 95% CI 0.25-0.46; P < 0.00001) and death (RR 0.48, 95% CI 0.36-0.64; P < 0.00001). No significant difference in the incidence of sepsis was found between the Lactobacillus and placebo groups (RR 0.90, 95% CI 0.72-1.12; P = 0.34).

CONCLUSIONS

Lactobacillus is safe and can prevent necrotizing enterocolitis in preterm infants.

Gastrointestinal Helminth Infection Improves Insulin Sensitivity, Decreases Systemic Inflammation, and Alters the Composition of Gut Microbiota in Distinct Mouse Models of Type 2 Diabetes

Type 2 diabetes (T2D) is a major health problem and is considered one of the top 10 diseases leading to death globally. T2D has been widely associated with systemic and local inflammatory responses and with alterations in the gut microbiota. Microorganisms, including parasitic worms and gut microbes have exquisitely co-evolved with their hosts to establish an immunological interaction that is essential for the formation and maintenance of a balanced immune system, including suppression of excessive inflammation. Herein we show that both prophylactic and therapeutic infection of mice with the parasitic hookworm-like nematode, Nippostrongylus brasiliensis, significantly reduced fasting blood glucose, oral glucose tolerance and body weight gain in two different diet-induced mouse models of T2D. Helminth infection was associated with elevated type 2 immune responses including increased eosinophil numbers in the mesenteric lymph nodes, liver and adipose tissues, as well as increased expression of IL-4 and alternatively activated macrophage marker genes in adipose tissue, liver and gut. N. brasiliensis infection was also associated with significant compositional changes in the gut microbiota at both the phylum and order levels. Our findings show that N. brasiliensis infection drives changes in local and systemic immune cell populations, and that these changes are associated with a reduction in systemic and local inflammation and compositional changes in the gut microbiota which cumulatively might be responsible for the improved insulin sensitivity observed in infected mice. Our findings indicate that carefully controlled therapeutic hookworm infection in humans could be a novel approach for treating metabolic syndrome and thereby preventing T2D.

Probiotic strategies to prevent necrotizing enterocolitis in preterm infants: a meta-analysis

PURPOSE

We aimed to compare probiotics with placebo for necrotizing enterocolitis in preterm infants and to evaluate the safety and effect and strict effect of specific probiotic genera.

METHODS

Data recorded until January 2019 were searched, and relevant academic articles from PubMed, MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were selected by two independent reviewers. Two reviewers independently included randomized controlled trials that compared probiotics and placebo in preterm infants. The outcomes included more than one of the following outcomes: incidence of necrotizing enterocolitis, necrotizing enterocolitis-related mortality, incidence of sepsis, and all-cause mortality. Two reviewers independently extracted data and assessed the risk of bias and quality of evidence.

RESULTS

We identified 34 eligible studies of 9161 participants. This meta-analysis showed an overall advantage of probiotics to prevent the incidence of necrotizing enterocolitis (3.54%) and gut-associated sepsis (15.59%), and decrease mortality (5.23%) in preterm infants. A probiotic mixture showed a huge advantage and vitality in preventing necrotizing enterocolitis (2.48%) and gut-associated sepsis (18.39%), and in reducing mortality (5.57%) in preterm infants.

CONCLUSION

The probiotic mixture showed advantages over the single strains to decrease the incidences of necrotizing enterocolitis and gut-associated sepsis, and mortality in preterm infants.

Which is the best probiotic treatment strategy to prevent the necrotizing enterocolitis in premature infants: A network meta-analysis revealing the efficacy and safety

BACKGROUND

Previous studies have neglected to report the specific action of different probiotic genera in preterm infants. To evaluate the efficacy and safety of specific probiotic genera, we performed a network meta-analysis (NMA) to identify the best prevention strategy for necrotizing enterocolitis in preterm infants.

METHODS

MEDLINE, PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials had been searched for randomized control trials reporting the probiotics strategy for premature infants.

RESULTS

We identified 34 eligible studies of 9161 participants. The intervention in the observation group was to add probiotics for feeding: Lactobacilli in 6 studies; Bifidobacterium in 8 studies; Bacillus in 1 study; Saccharomyces in 4 studies and probiotic mixture in 15 studies. This NMA showed a significant advantage of probiotic mixture and Bifidobacterium to prevent the incidence of necrotizing enterocolitis in preterm infants. A probiotic mixture showed effectiveness in reducing mortality in preterm infants.

CONCLUSION

The recent literature has reported a total of 5 probiotic strategies, including Bacillus, Bifidobacterium, Lactobacillus, Saccharomyces, and probiotic mixture. Our thorough review and NMA provided a piece of available evidence to choose optimal probiotics prophylactic strategy for premature infants. The results indicated that probiotic mixture and Bifidobacterium showed a stronger advantage to use in preterm infants; the other probiotic genera failed to show an obvious effect to reduce the incidence of NEC, sepsis and all-cause death. More trials need to be performed to determine the optimal probiotic treatment strategy to prevent preterm related complications.

Historical aspects of probiotic use to prevent necrotising enterocolitis in preterm babies

Over the last few decades, numerous studies have evaluated probiotic use for the prevention of necrotising enterocolitis in preterm babies. Early 'proof of concept' studies evaluating whether probiotics are capable of colonising the preterm gut have translated into multiple observational studies, small and large randomised controlled trials. Some show evidence of benefit while others have produced disappointing results. In this paper, we review the history of probiotic use in preterm babies for NEC prevention in an attempt to explain why uncertainty exists and why this intervention has not been universally adopted into routine neonatal practice.

The clinical management and outcomes of extremely preterm infants in Japan: past, present, and future

There is a wide variation in neonatal mortality rates across regions and countries. Japan has one of the lowest neonatal mortality rates in the world; in particular, the mortality rate of extremely preterm infants (i.e., those born before 26 weeks of gestation) is much lower in Japan than in other developed countries. In addition, Japan has low incidences of intraventricular hemorrhage, necrotizing enterocolitis, and late-onset sepsis, a very high incidence of retinopathy of prematurity, and a relatively high incidence of chronic lung disease. In Japan, general perinatal medical centers (PMCs), which are PMCs that offer the highest levels of care, are required to have an obstetric department with maternal-fetal intensive care units as well as a neonatal or pediatric department with neonatal intensive care units (NICU), in order to promote antenatal rather than neonatal maternal transfer of high-risk cases. The limit of viability of extremely preterm infants is 22 weeks of gestation, and approximately half of them are estimated to receive active resuscitation. The clinical management of extremely preterm infants in Japan are characterized by (I) circulatory management that is guided by neonatologist-performed echocardiography, (II) relatively invasive respiratory management, (III) nutritional management, which entails the promotion of breast milk feeding, early enteral feeding, routine glycerin enema, and the administration of probiotics, (IV) neurological management by means of minimal handling, sedation of ventilated infants, and serial brain ultrasounds, and (V) infection control with the assistance of serial C-reactive protein (CRP) monitoring. Thus, this review provides a brief description of the development of neonatology in Japan, introduces the unique features of Japanese clinical management of extremely preterm infants, and overviews their outcomes.

Poor Bifidobacterial Colonization Is Associated with Late Provision of Colostrum and Improved with Probiotic Supplementation in Low Birth Weight Infants

This study aimed to evaluate the association between bifidobacterial colonization in low birth weight infants and perinatal factors, including the timing of initial colostrum and the effect of probiotics on this colonization. In this non-randomized controlled trial, we enrolled 98 low-birth-weight infants from a neonatal intensive care unit (NICU) in Japan. Infants were divided into three groups: group N (no intervention), group H (received non-live bifidobacteria), and group L (received live bifidobacteria). The number of bifidobacteria in the infants’ stools at 1 month of age was measured using real-time polymerase chain reaction (PCR). We divided infants into “rich bifidobacteria” (≥10^4.8 cells/g feces) and “poor bifidobacteria” (<10^4.8 cells/g feces) subgroups. The ratio of “rich bifidobacteria” infants was 20/31, 34/36, and 30/30 in groups N, H, and L, respectively. In group N, the “rich bifidobacteria” group received first colostrum significantly earlier than the “poor bifidobacteria” group (1 day vs. 4 days, P < 0.05). Compared with the N group, both groups H and L had a significantly high proportion of “rich bifidobacteria” infants (P < 0.05). Bifidobacterial colonization was poor in premature infants at 1 month compared with term infants, and the level of colonization was associated with the timing of initial provision of colostrum. Providing probiotics to premature infants can improve bifidobacterial colonization.

Establishment of an ideal gut microbiota to boost healthy growth of neonates

For decades, supporting the optimal growth of low birth weight (LBW) infants has been considered one of the most important paediatric challenges, despite advances in neonatal intensive care technology and nutrition interventions. Since gut microbiota affects such diverse phenotypes in adults, the difference in gut microbiota composition between normal infants and LBW infants raises the possibility of gut microbiota playing an important role in different growth rates of neonates. Based on the concept that probiotics are generally beneficial to the health, numerous studies have been made on probiotics as a supplement to the diet of the LBW infants. However, clinical results on the effects of probiotics on LBW infant growth are either inconsistent or contradictory with each other, and thus the contribution of gut microbiota in neonatal growth has remained inconclusive. In this review, recent researches on neonatal gut microbiota are discussed to develop a new strategy for targeting gut microbiota as a solution to growth retardation in LBW infants. We also discuss how to establish the ideal gut microbiota to support optimal growth of LBW infants.

Efficacy of Bifidobacterium Species in Prevention of Necrotizing Enterocolitis in Very-Low Birth Weight Infants. A Systematic Review

Necrotizing enterocolitis (NEC) is one of the most common and serious gastrointestinal diseases in preterm infants. The aim of this systematic review examines the effects of probiotics on preventing NEC in very-low birth weight (VLBW) infants with a focus on the Bifidobacterium species and its strains. A systematic review of randomized trials and retrospective studies analyzing the use of probiotics to prevent NEC in VLBW infants was conducted using PubMed, Cochrane Central Registry of Controlled Trials, and Google Scholar (1996-2016). Trials reporting NEC involving preterm infants who were given Bifidobacterium alone in the first month of life were included in the systematic review. Nine studies were suitable for inclusion. Nine studies involving VLBW infants were analyzed for strain specific effects of Bifidobacterium for the prevention of NEC ≥ Stage II. B breve showed some benefit in infants < 34 weeks GA with relative risk (RR) of 0.43 (95% confidence interval [CI]: 0.21-0.87) p = 0.019, but not in neonates < 28 weeks. B lactis greatly reduced the incidence of NEC with a RR 0.11 (95% CI: 0.03-0.47), p = < 0.001. B bifidum was not widely studied but resulted in no cases of NEC. Bifidobacterium proved to be statistically significant in reducing the incidence of NEC in preterm infants.

Effect of probiotics on C-reactive protein levels in preterm infants: Secondary analysis of a randomized controlled trial

BACKGROUND

Excessive inflammation is associated with adverse outcomes in preterm infants. C- reactive protein (CRP) is a marker of inflammation/infection. Probiotics have anti-inflammatory properties. Randomized controlled trials (RCTs) in preterm infants have not reported effect of probiotics on CRP.

AIM

To evaluate effect of probiotics on CRP in preterm infants who had participated in a RCT of Bifidobacterium breve (B. breve) m-16v.

METHODS

Data on all infants (GA <33 weeks, n = 159) enrolled in the RCT was analyzed. For study purpose, CRP <15 mg/L and ≤10 mg/L was considered normal for the first week, and thereafter respectively. Mixed logistic regression modelling was used to assess probiotic effect on CRP levels.

RESULTS

There were 1579 CRP measurements (Probiotic: 851 vs. Placebo: 728). Baseline characteristics and number [Median (IQR)] of CRP estimations per infant [l0 (5, 20) vs. 10 (6, 17), p = 0.861] were comparable between probiotic vs. placebo group. There was no significant difference in the proportion of infants with high CRP over time (treatment by weekly time points interaction, p = 0.187), and across all time points between probiotic and placebo group (adjusted OR: 1.62, 95% CI: 0.91-2.88, p = 0.102)CONCLUSION:B. breve m-16v did not decrease CRP levels in preterm infants born <33 weeks.

Bifidobacterium may benefit the prevention of necrotizing enterocolitis in preterm infants: A systematic review and meta-analysis

AIM

A systematic review and meta-analysis was designed to evaluate the efficacy and safety of Bifidobacterium for preventing necrotizing enterocolitis (NEC) in preterm infants.

METHODS

We searched the Cochrane Library, PubMed, EMBASE and Web of Science to December 2017. Risk ratio (RR) with 95% confidence intervals (CIs) were estimated to compare the outcomes of the groups. For the pooled RR estimating the incidence of NEC, we also performed subgroup analysis. Besides, sensitivity analysis was performed to examine the stability of the combined results. Two reviewers assessed trial quality and extracted data independently. The work has been reported in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and AMSTAR (Assessing the methodological quality of systematic reviews) Guidelines. All statistical analyses were performed using standard statistical procedures provided in Review Manager 5.2.

RESULTS

Twenty four randomized, placebo-controlled studies (N = 6155 participants) were included in this analysis, of which twenty two studies were used for assessing the efficacy of Bifidobacterium for preventing NEC and seventeen for assessing the safety (sepsis and death). When comparing Bifidobacterium groups with control groups, the relative risk of developing NEC (RR 0.38, 95% CI 0.25-0.58; P < 0.00001) or death (RR 0.74, 95% CI 0.60-0.92; P = 0.006) was significantly lower in the Bifidobacterium groups. No significant difference in the incidence of sepsis was found (RR 0.87, 95% CI 0.73-1.03; P = 0.11). In addition, significant results for NEC were also found in all subgroups we made.

CONCLUSIONS

Bifidobacterium may have a beneficial effect and be safe in preventing necrotizing enterocolitis in preterm infants.

Gut microbiota of preterm infants supplemented with probiotics: sub-study of the ProPrems trial

Background

The ProPrems trial, a multi-center, double-blind, placebo-controlled randomized trial, previously reported a 54% reduction in necrotizing enterocolitis (NEC) of Bell stage 2 or more from 4.4 to 2.0% in 1099 infants born before 32 completed weeks’ gestation and weighing < 1500 g, receiving probiotic supplementation (with Bifidobacterium longum subsp. infantis BB-02, Streptococcus thermophilus TH-4 and Bifidobacterium animalis subsp. lactis BB-12). This sub-study investigated the effect of probiotic supplementation on the gut microbiota in a cohort of very preterm infants in ProPrems.

Results

Bifidobacterium was found in higher abundance in infants who received the probiotics (AOR 17.22; 95% CI, 3.49–84.99, p < 0.001) as compared to the placebo group, and Enterococcus was reduced in infants receiving the probiotic during the supplementation period (AOR 0.27; 95% CI, 0.09–0.82, p = 0.02).

Conclusion

Probiotic supplementation with BB-02, TH-4 and BB-12 from soon after birth increased the abundance of Bifidobacterium in the gut microbiota of very preterm infants. Increased abundance of Bifidobacterium soon after birth may be associated with reducing the risk of NEC in very preterm infants.

Electronic supplementary material

The online version of this article (10.1186/s12866-018-1326-1) contains supplementary material, which is available to authorized users.

Therapeutic Microbiology: The Role of Bifidobacterium breve as Food Supplement for the Prevention/Treatment of Paediatric Diseases

The human intestinal microbiota, establishing a symbiotic relationship with the host, plays a significant role for human health. It is also well known that a disease status is frequently characterized by a dysbiotic condition of the gut microbiota. A probiotic treatment can represent an alternative therapy for enteric disorders and human pathologies not apparently linked to the gastrointestinal tract. Among bifidobacteria, strains of the species Bifidobacterium breve are widely used in paediatrics. B. breve is the dominant species in the gut of breast-fed infants and it has also been isolated from human milk. It has antimicrobial activity against human pathogens, it does not possess transmissible antibiotic resistance traits, it is not cytotoxic and it has immuno-stimulating abilities. This review describes the applications of B. breve strains mainly for the prevention/treatment of paediatric pathologies. The target pathologies range from widespread gut diseases, including diarrhoea and infant colics, to celiac disease, obesity, allergic and neurological disorders. Moreover, B. breve strains are used for the prevention of side infections in preterm newborns and during antibiotic treatments or chemotherapy. With this documentation, we hope to increase knowledge on this species to boost the interest in the emerging discipline known as "therapeutic microbiology".

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

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

Effects of lactoferrin on neonatal pathogens and Bifidobacterium breve in human breast milk

Supplementation with probiotics in preterm infants reduces necrotizing enterocolitis and sepsis. Bovine lactoferrin is a promising supplement that may further reduce disease burden, but its effects on probiotic bacteria in human breast milk has not been evaluated. We aimed to characterise the antimicrobial activity of bovine and human lactoferrin in human breast milk against probiotics and typical neonatal sepsis pathogens. Lactoferrin levels were determined by enzyme linked immunosorbent assay in fresh and pasteurised human breast milk. The neonatal pathogens Staphylococcus epidermidis and Escherichia coli, and the probiotic Bifidobacterium breve strain M-16V were cultured in human breast milk or infant formula in the presence or absence of clinically relevant doses of bovine or human lactoferrin. Standard microbiological methods were used to determine the effects of lactoferrin on bacterial growth. Unpasteurised human breast milk contained significantly higher lactoferrin levels and resulted in superior inhibition of pathogenic bacterial growth compared to infant formula and pasteurised human breast milk. Human lactoferrin was significantly more effective at inhibiting bacterial growth, when compared to bovine lactoferrin. Supplementation with human lactoferrin or high dose bovine lactoferrin inhibited growth of the probiotic strain B. breve M-16V in pasteurised human breast milk. Although unpasteurised human breast milk and human lactoferrin had the greatest antimicrobial activity against all bacterial species tested, higher doses of bovine lactoferrin also showed activity against B. breve and. S. epidermidis. This study suggests that simultaneous administration of lactoferrins and probiotics may affect colonisation with probiotic bacteria, warranting further investigations.

Probiotics for Preterm Infants: A Strain-Specific Systematic Review and Network Meta-analysis

OBJECTIVES

Several randomized controlled trials (RCTs) on the use of probiotics to reduce morbidity and mortality in preterm infants have provided inconsistent results. Although meta-analyses that group all of the used strains together are suggesting efficacy, it is not possible to determine the most effective strain that is more relevant to the clinician. We therefore used a network meta-analysis (NMA) approach to identify strains with greatest efficacy.

METHODS

A PubMed search identified placebo-controlled or head-to-head RCTs investigating probiotics in preterm infants. From trials that recorded mortality, necrotizing enterocolitis, late-onset sepsis, or time until full enteral feeding as outcomes, data were extracted and Bayesian hierarchical random-effects models were run to construct a NMA.

RESULTS

Fifty-one RCTs involving 11,231 preterm infants were included. Most strains or combinations of strains were only studied in one or a few RCTs. Only 3 of 25 studied probiotic treatment combinations showed significant reduction in mortality rates. Seven treatments reduced necrotizing enterocolitis incidence, 2 reduced late-onset sepsis, and 3 reduced time until full enteral feeding. There was no clear overlap of strains, which were effective on multiple outcome domains.

CONCLUSIONS

This NMA showed efficacy in reducing mortality and morbidity only in a minority of the studied strains or combinations. This may be due to an inadequate number, or size, of RCTs, or due to a true lack of effect for certain species. Further large and adequately powered RCTs using strains with the greatest apparent efficacy will be needed to more precisely define optimal treatment strategies.

Nutrition for Preterm Infants: 75 Years of History

As technology has advanced, survival rates of preterm infants have improved dramatically. Human milk was the primary source of enteral nutrition during the early days of neonatology, but the HIV/AIDS epidemic resulted in an increased use of preterm formula. More recently, the benefits of human milk were rediscovered, resulting in increased use of donor human milk as well. The awareness that human milk does not contain the amounts of nutrients to meet the high requirements of infants born premature resulted in the development of human milk fortifiers. The development of these fortifiers is still ongoing, as are alternative methods of pasteurization of donor milk. Those initiatives will increase the use of human milk with consequently short- and long-term benefits for preterm infants.