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

Probiotic effect in preterm neonates with sepsis - A systematic review protocol

Background: The microbiota in the intestine is made up of trillions of living bacteria that coexist with the host. Administration of antibiotics during neonatal infection causes depletion of gut flora resulting in gut dysbiosis. Over the last few decades, probiotics have been created and promoted as microbiota management agents to enrich gut flora. Probiotics decrease the overgrowth of pathogenic bacteria in the gut of preterm neonates, reducing the frequency of nosocomial infections in the Neonatal Intensive Care Unit (NICUs). Methods: The systematic review will include randomized control trials (RCTs) of premier neonates with sepsis. Studies will be retrieved from global databases like Cochrane CENTRAL, CINAHL Plus via EBSCO host, MEDLINE via PubMed, EMBASE, SCOPUS, Ovid, Web of Science, ProQuest Medical Library, Microsoft academic, and DOAJ by utilizing database-specific keywords. Screening, data extraction, and critical appraisal of included research will be carried out separately by two review writers. Findings will be reported in accordance with the PRISMS-P 2020 guidelines. Conclusions: The findings of this systematic review will help to translate the evidence-based information needed to encourage the implementation of potential research output in the field of neonatal intensive care, guide best clinical practise, assist policy making and implementation to prevent gut dysbiosis in neonates with sepsis by summarising and communicating the evidence on the topic. PROSPERO registration number: This systematic review protocol has been registered in PROSPERO (Prospective Register of Systematic Reviews) on 10 th March 2022. The registration number is CRD42022315980.

[Expert consensus on enteral nutrition management of preterm infants (2024)]

Providing adequate and balanced nutrition for preterm infants, especially extremely/very preterm infants, is the material basis for promoting their normal growth and development and improving long-term prognosis. Enteral nutrition is the best way to feed preterm infants. Previous systematic reviews have shown that using evidence-based standardized feeding management strategies can effectively promote the establishment of full enteral feeding, reduce the duration of parenteral nutrition, improve the nutritional outcomes of preterm infants, and not increase the risk of necrotizing enterocolitis or death. Based on relevant research in China and overseas, the consensus working group has developed 20 recommendations in 5 aspects including the goal of enteral nutrition, transitioning to enteral nutrition, stable growth period enteral nutrition, supplementation of special nutrients, and monitoring of enteral nutrition for preterm infants, using the Grading of Recommendations Assessment, Development and Evaluation. The aim is to provide recommendations for healthcare professionals involved in the management of enteral nutrition for preterm infants, in order to improve the clinical outcomes of preterm infants.

The Potential of Fecal Volatile Organic Compound Analysis for the Early Diagnosis of Late-Onset Sepsis in Preterm Infants: A Narrative Review

Early diagnosis and treatment of late-onset sepsis (LOS) is crucial for survival, but challenging. Intestinal microbiota and metabolome alterations precede the clinical onset of LOS, and the preterm gut is considered an important source of bacterial pathogens. Fecal volatile organic compounds (VOCs), formed by physiologic and pathophysiologic metabolic processes in the preterm gut, reflect a complex interplay between the human host, the environment, and microbiota. Disease-associated fecal VOCs can be detected with an array of devices with various potential for the development of a point-of-care test (POCT) for preclinical LOS detection. While characteristic VOCs for common LOS pathogens have been described, their VOC profiles often overlap with other pathogens due to similarities in metabolic pathways, hampering the construction of species-specific profiles. Clinical studies have, however, successfully discriminated LOS patients from healthy individuals using fecal VOC analysis with the highest predictive value for Gram-negative pathogens. This review discusses the current advancements in the development of a non-invasive fecal VOC-based POCT for early diagnosis of LOS, which may potentially provide opportunities for early intervention and targeted treatment and could improve clinical neonatal outcomes. Identification of confounding variables impacting VOC synthesis, selection of an optimal detection device, and development of standardized sampling protocols will allow for the development of a novel POCT in the near future.

Probiotic formulations and gastro-intestinal diseases in the paediatric population: a narrative review

BACKGROUND/AIM

Probiotics are live microbial supplements that improve the microbial balance in the host animal when administered in adequate amounts. They play an important role in relieving symptoms of many diseases associated with gastrointestinal tract, for example, in necrotizing enterocolitis (NEC), antibiotic-associated diarrhea, relapsing Clostridium difficile colitis, Helicobacter pylori infections, and inflammatory bowel disease (IBD). In this narrative review, the authors aim to evaluate the role of different probiotic formulations in treating gastrointestinal diseases in pediatric population aged 18 years or younger and highlight the main considerations for selecting probiotic formulations for use in this population.

METHODOLOGY

The authors searched PubMed and Clinicaltrials.gov from inception to 24th July 2022, without any restrictions. Using an iterative process, the authors subsequently added papers through hand-searching citations contained within retrieved articles and relevant systematic reviews and meta-analyses.

RESULTS

The effectiveness of single-organism and composite probiotics in treating gastrointestinal disorders in pediatric patients aged 18 or under were analyzed and compared in this study. A total of 39 studies were reviewed and categorized based on positive and negative outcomes, and compared with a placebo, resulting in 25 studies for single-organism and 14 studies for composite probiotics. Gastrointestinal disorders studied included NEC, acute gastroenteritis (AGE), Acute Diarrhea, Ulcerative Colitis (UC), and others. The results show that probiotics are effective in treating various gastrointestinal disorders in children under 18, with single-organism probiotics demonstrating significant positive outcomes in most studies, and composite probiotics showing positive outcomes in all studies analyzed, with a low incidence of negative outcomes for both types.

CONCLUSION

This study concludes that single-organism and composite probiotics are effective complementary therapies for treating gastrointestinal disorders in the pediatric population. Hence, healthcare professionals should consider using probiotics in standard treatment regimens, and educating guardians can enhance the benefits of probiotic therapy. Further research is recommended to identify the optimal strains and dosages for specific conditions and demographics. The integration of probiotics in clinical practice and ongoing research can contribute to reducing the incidence and severity of gastrointestinal disorders in pediatric patients.

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.

Microbiome dysbiosis: a modifiable state and target to prevent Staphylococcus aureus infections and other diseases in neonates

Bacterial infections present a significant threat to neonates. Increasingly, studies demonstrate associations between human diseases and the microbiota, the communities of microorganisms on or in the body. A "healthy" microbiota with a great diversity and balance of microorganisms can resist harmful pathogens and protect against infections, whereas a microbiota suffering from dysbiosis, can predispose to pathogen colonization and subsequent infection. For decades, strategies such as bacterial interference, decolonization, prebiotics, and probiotics have been tested to reduce Staphylococcus aureus disease and other infections in neonates. More recently, microbiota transplant has emerged as a strategy to broadly correct dysbiosis, promote colonization resistance, and prevent infections. This paper discusses the benefits of a healthy neonate's microbiota, exposures that alter the microbiota, associations of dysbiosis and neonatal disease, strategies to prevent dysbiosis, such as microbiota transplantation, and presents a framework of microbiome manipulation to reduce Staphylococcus aureus (S. aureus) and other infections in neonates.

Using the collaborative cross to identify the role of host genetics in defining the murine gut microbiome

BACKGROUND

The human gut microbiota is a complex community comprised of trillions of bacteria and is critical for the digestion and absorption of nutrients. Bacterial communities of the intestinal microbiota influence the development of several conditions and diseases. We studied the effect of host genetics on gut microbial composition using Collaborative Cross (CC) mice. CC mice are a panel of mice that are genetically diverse across strains, but genetically identical within a given strain allowing repetition and deeper analysis than is possible with other collections of genetically diverse mice.

RESULTS

16S rRNA from the feces of 167 mice from 28 different CC strains was sequenced and analyzed using the Qiime2 pipeline. We observed a large variance in the bacterial composition across CC strains starting at the phylum level. Using bacterial composition data, we identified 17 significant Quantitative Trait Loci (QTL) linked to 14 genera on 9 different mouse chromosomes. Genes within these intervals were analyzed for significant association with pathways and the previously known human GWAS database using Enrichr analysis and Genecards database. Multiple host genes involved in obesity, glucose homeostasis, immunity, neurological diseases, and many other protein-coding genes located in these regions may play roles in determining the composition of the gut microbiota. A subset of these CC mice was infected with Salmonella Typhimurium. Using infection outcome data, an increase in abundance of genus Lachnospiraceae and decrease in genus Parasutterella correlated with positive health outcomes after infection. Machine learning classifiers accurately predicted the CC strain and the infection outcome using pre-infection bacterial composition data from the feces.

CONCLUSION

Our study supports the hypothesis that multiple host genes influence the gut microbiome composition and homeostasis, and that certain organisms may influence health outcomes after S. Typhimurium infection. Video Abstract.

Using probiotics in paediatric populations

This statement defines probiotics and reviews the most recent literature on their use in paediatrics. Many studies have examined the potential benefit of probiotics, but significant variation in the strains and doses of probiotics used, the patient populations studied, and in study design, have led to heterogeneous results. Present evidence suggests that probiotics can decrease mortality and lower incidence of necrotizing enterocolitis in preterm and low birth weight neonates. Probiotics may also be beneficial in reducing feeding intolerance. In infants, probiotics may be considered to reduce symptoms of colic. In older children, probiotics can be considered to prevent antibiotic-associated diarrhea and Clostridium difficile -associated diarrhea. Probiotic supplements used in conjunction with standard therapy can help with Helicobacter pylori eradication and decrease the side effects of treatment. Lactobacillus species can be considered to treat irritable bowel syndrome. Probiotics can also be considered to help prevent atopic dermatitis and eczema. To optimize paediatric policy and practice, large, quality studies are needed to determine what types and combinations of probiotics are most efficacious.

L’utilisation des probiotiques dans la population pédiatrique

Le présent document de principes définit les probiotiques et fournit une analyse des publications scientifiques les plus récentes sur leur utilisation en pédiatrie. De nombreuses études ont évalué les avantages potentiels des probiotiques, mais en raison des variations importantes dans les souches et les doses utilisées, des populations de patients étudiées et des méthodologies privilégiées, les résultats sont hétérogènes. Selon les données probantes à jour, les probiotiques peuvent réduire le taux de mortalité et l’incidence d’entérocolite nécrosante chez les nouveau-nés prématurés et de petit poids à la naissance. Ils peuvent également être bénéfiques pour réduire l’intolérance alimentaire. Chez les nourrissons, on peut envisager de les utiliser pour limiter les symptômes de coliques, et chez les enfants plus âgés, pour prévenir la diarrhée associée aux antibiotiques ou au Clostridium difficile . Les suppléments de probiotiques utilisés conjointement avec un traitement standard peuvent contribuer à éradiquer l’Helicobacter pylori et à atténuer les effets secondaires du traitement. On peut envisager d’utiliser des espèces de Lactobacillus pour traiter le syndrome du côlon irritable ou de recourir à des probiotiques pour contribuer à prévenir la dermatite atopique et l’eczéma. Afin d’optimiser les politiques et les pratiques en pédiatrie, de vastes études de qualité devront être réalisées pour déterminer les types et les combinaisons de probiotiques les plus efficaces.

Neonatal Sepsis-Newer Insights

Sepsis is one of the leading causes of mortality and morbidity among neonates worldwide and especially affects the preterm neonates in resource-restricted settings. The infection may be acquired in utero, from the mother's genital tract or postnatally from the community or hospital environment and personnel. Factors including the time of exposure, size of the inoculum, immunity in the host, and virulence of the infectious agent affect the severity and course of illness. Culture-independent diagnostics, sepsis prediction scores, antibiotic stewardship, and preventive strategies including hand hygiene are ongoing efforts for reducing the neonatal sepsis burden.

Look Who's Talking: Host and Pathogen Drivers of Staphylococcus epidermidis Virulence in Neonatal Sepsis

Preterm infants are at increased risk for invasive neonatal bacterial infections. S. epidermidis, a ubiquitous skin commensal, is a major cause of late-onset neonatal sepsis, particularly in high-resource settings. The vulnerability of preterm infants to serious bacterial infections is commonly attributed to their distinct and developing immune system. While developmentally immature immune defences play a large role in facilitating bacterial invasion, this fails to explain why only a subset of infants develop infections with low-virulence organisms when exposed to similar risk factors in the neonatal ICU. Experimental research has explored potential virulence mechanisms contributing to the pathogenic shift of commensal S. epidermidis strains. Furthermore, comparative genomics studies have yielded insights into the emergence and spread of nosocomial S. epidermidis strains, and their genetic and functional characteristics implicated in invasive disease in neonates. These studies have highlighted the multifactorial nature of S. epidermidis traits relating to pathogenicity and commensalism. In this review, we discuss the known host and pathogen drivers of S. epidermidis virulence in neonatal sepsis and provide future perspectives to close the gap in our understanding of S. epidermidis as a cause of neonatal morbidity and mortality.

Probiotics Regulating Inflammation via NLRP3 Inflammasome Modulation: A Potential Therapeutic Approach for COVID-19

Inflammasomes are cytoplasmic multiprotein complexes formed by the host's immune system as a response to microbial infection and cellular damage. Many studies have revealed various regulators of NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation, while it has been recently shown that NLRP3 is implicated in COVID-19 pathogenesis. At the same time, probiotics counteract the inflammatory process and modulate cytokine release, thus influencing both innate and adaptive immune systems. Herein, we review the immunomodulatory potential of probiotics on the assembly of NLRP3 inflammasome, as well as the pathophysiological mechanisms supporting the use of probiotic bacteria for SARS-CoV-2 infection management, presenting evidence from preclinical studies of the last decade: in vivo, ex vivo, and mixed trials. Data show that probiotics intake is related to NLRP3 inflammasome attenuation and lower levels of inflammation markers, highlighting the beneficial effects of probiotics on inflammatory conditions. Currently, none of the ongoing clinical trials evaluating the effectiveness of probiotics intake in humans with COVID-19 has been completed. However, evidence from preclinical studies indicates that probiotics may block virus invasion and replication through their metabolites, bacteriocins, and their ability to block Angiotensin-Converting Enzyme 2 (ACE2), and by stimulating the immune response through NLRP3 inflammasome regulation. In this review, the beneficial effects of probiotics in the inflammatory process through NLRP3 inflammasome attenuation are presented. Furthermore, probiotics may target SARS-CoV-2 both by blocking virus invasion and replication and by stimulating the immune response through NLRP3 inflammasome regulation. Heterogeneity of the results-due to, among others, different bacterial strains and their metabolites, forms, dosage, and experimental designs-indicates the need for more extensive research.

Lactiplantibacillus plantarum-Nomad and Ideal Probiotic

Probiotics are increasingly recognized as capable of positively modulating several aspects of human health. There are numerous attributes that make an ideal probiotic. Lactiplantibacillus plantarum (Lp) exhibits an ecological and metabolic flexibility that allows it to thrive in a variety of environments. The present review will highlight the genetic and functional characteristics of Lp that make it an ideal probiotic and summarizes the current knowledge about its potential application as a prophylactic or therapeutic intervention.

Association between probiotics and bronchopulmonary dysplasia in preterm infants

Bronchopulmonary dysplasia is a chronic pulmonary disease with a high incidence in premature infants, and there is still no effective treatment. The purpose of our study was to analyze the association between the use of probiotics and BPD in premature infants. We retrospectively collected clinical data of infants with gestational age < 32 weeks admitted to the NICU of The First Hospital of Jilin University from January 1, 2019 to March 31, 2020. Demographic and clinicopathological data of the inclusion population were collected. The outcome was the incidence of BPD or death. The χ² tests was used to compare the categorical variables. The t test and non-parametric Wilcoxon rank-sum test were used to compare the continuous data. Univariate and multivariate logistic regression were used to analyze the association between probiotics and BPD. A total of 318 newborns met the inclusion criteria, of which 94 received probiotics and 224 received no probiotics. There were 16 deaths and 115 newborns with BPD in the included population. The results of univariate analysis showed differences in the maternal diabetes, the proportion of systemic antibiotics given to mother within 24 h before birth, the receiving rate of invasive mechanical ventilation, the prevalence of BPD/death, PDA, RDS and Ivh between newborns with and without probiotics (p < 0.05); The results of unadjusted univariate logistic regression model showed that probiotic (OR 0.034, 95% CI 0.012-0.096) was the factor affecting BPD in preterm infants (p < 0.05). Multivariate logistic regression result (OR 0.037, 95% CI 0.013-0.105) was consistent with univariate analysis (P < 0.001). Probiotics are associated with a reduced risk of BPD in preterm infants < 32 weeks of age. More prospective studies with large samples are still needed.

Effect and Safety of Saccharomyces boulardii for Neonatal Necrotizing Enterocolitis in Pre-term Infants: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Necrotizing enterocolitis (NEC) is one of the most common and urgent neonatal emergencies in the neonatal intensive care unit. This disease leads to considerable morbidity and mortality; it also imposes a huge financial burden on patient family and society. Thus, Treatment and prevention of NEC are crucial. This meta-analysis aims to investigate the effect and safety of Saccharomyces boulardii for NEC in pre-term infants.

METHODS

A comprehensive search was retrieved in six major databases. The search included randomized controlled trials (RCTs) reporting the incidence of NEC (stage ≥ II), sepsis, mortality, feeding intolerance, full feeding days, time to regain birth weight, days of hospitalization and adverse effects. The random model was used to calculate risk ratio (RR), the standard mean difference (SMD) and its 95% confidence interval (95% CI) between the S. boulardii group and control group. Statistical analyses were conducted using Cochrane systematic review software, Rev Man (version 5.3).

RESULTS

In total, 10 RCTs involving 1264 participants met the inclusion criteria. There were significant reductions in the incidence of NEC [RR = 0.56, 95% CI (0.36-0.89)], feeding intolerance [RR = 0.52, 95% CI (0.39-0.68)], full feeding days [SMD = -1.25, 95% CI (-2.06 to -0.45)] and hospitalization days [SMD = -1.33, 95% CI (-2.64 to -0.02)] in the study group compared with the control group. However, there were no significant differences in sepsis [RR = 0.84, 95% CI (0.61-1.17)], death [RR = 1.12, 95% CI (0.46-2.70)] and the time to regain birth weight [SMD = -0.93, 95% CI (-1.88 to 0.03)] between the two groups. The adverse effect of S. boulardii was not reported. The overall methodological quality was evaluated as moderate by the Cochrane Bias Risk Assessment Tool.

CONCLUSION

According to this evidence we recommend S. boulardii to prevent NEC, reduce the feeding intolerance, shorten the full feeding days and hospitalization days. However, S. boulardii might be invalid on the incidence of sepsis, mortality and the time to regain birth weight.

REGISTRATION

This review has been registered to the PROSPERO (International prospective register of systematic reviews) on 5 December 2019 (ID: CRD42019147896).

Neonatal Sepsis: The Impact of Carbapenem-Resistant and Hypervirulent Klebsiella pneumoniae

The convergence of a vulnerable population and a notorious pathogen is devastating, as seen in the case of sepsis occurring during the first 28 days of life (neonatal period). Sepsis leads to mortality, particularly in low-income countries (LICs) and lower-middle-income countries (LMICs). Klebsiella pneumoniae, an opportunistic pathogen is a leading cause of neonatal sepsis. The success of K. pneumoniae as a pathogen can be attributed to its multidrug-resistance and hypervirulent-pathotype. Though the WHO still recommends ampicillin and gentamicin for the treatment of neonatal sepsis, K. pneumoniae is rapidly becoming untreatable in this susceptible population. With escalating rates of cephalosporin use in health-care settings, the increasing dependency on carbapenems, a "last resort antibiotic," has led to the emergence of carbapenem-resistant K. pneumoniae (CRKP). CRKP is reported from around the world causing outbreaks of neonatal infections. Carbapenem resistance in CRKP is largely mediated by highly transmissible plasmid-encoded carbapenemase enzymes, including KPC, NDM, and OXA-48-like enzymes. Further, the emergence of a more invasive and highly pathogenic hypervirulent K. pneumoniae (hvKP) pathotype in the clinical context poses an additional challenge to the clinicians. The deadly package of resistance and virulence has already limited therapeutic options in neonates with a compromised defense system. Although there are reports of CRKP infections, a review on neonatal sepsis due to CRKP/ hvKP is scarce. Here, we discuss the current understanding of neonatal sepsis with a focus on the global impact of the CRKP, provide a perspective regarding the possible acquisition and transmission of the CRKP and/or hvKP in neonates, and present strategies to effectively identify and combat these organisms.

[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.

Evaluating the efficacy of a multistrain probiotic supplementation for prevention of neonatal sepsis in 0-2-month-old low birth weight infants in India-the "ProSPoNS" Study protocol for a phase III, multicentric, randomized, double-blind, placebo-controlled trial

Background

Progress has been made in the reduction of under-five mortality in India; however, neonatal mortality is reducing at a slower rate. Efforts are required to bring down neonatal mortality in order to attain the Sustainable Development Goal-3. Prevention of sepsis among the high-risk, vulnerable low birth weight neonates by a newer intervention with probiotic supplementation is promising.

Methods

A phase III, multicenter, randomized, double-blind, placebo-controlled study is being conducted at six sites in India. A total of 6144 healthy low birth weight (LBW) infants fulfilling the eligibility criteria would be enrolled within the first week of life, after obtaining written informed consent from the parents of the infant. Randomization in 1:1 ratio, stratified by site, sex, and birth weight, would be done through an interactive web response system (IWRS) using a standard web browser and email service. Vivomixx®, a probiotic containing a mix of 8 strains of bacteria, in a suspension form standardized to deliver 10 billion CFU/ml, or an organoleptically similar placebo would be fed to enrolled infants in a 1-ml/day dose for 30 days. The follow-up of enrolled infants for 60 days would take place as per a pre-specified schedule for recording morbidities and outcome assessments at the six participating sites. Screening for morbidities would be conducted by trained field workers in the community, and sick infants would be referred to designated clinics/hospitals. A physician would examine the referred infants presenting with complaints and clinical signs, and blood samples would be collected from sick infants for diagnosis of neonatal sepsis by performing sepsis screen and blood culture. Appropriate treatment would be provided as per hospital protocol. The study would be implemented as per the MRC guideline for the management of Global Health Trials in accordance with ICH-GCP and Indian Regulatory guidelines. A contract research organization would be engaged for comprehensive monitoring and quality assurance. The final analysis would be conducted in a blinded manner as per the statistical analysis plan (SAP) to estimate the primary outcomes of sepsis, possible serious bacterial infection (PSBI), and secondary outcomes. The codes will be broken after DMC permission. The protocol has been reviewed by the Research Ethics Committee of the Liverpool School of Tropical Medicine (REC-LSTM), from Research Ethics Committees of the six subject recruitment participating sites.

Discussion

This adequately powered and well-designed trial would conclusively answer the question whether probiotics can prevent neonatal sepsis in the high-risk group of low birth weight infants as indicated by a pilot study in 1340 LBW infants, evidence from systematic reviews of hospital-based studies, and a primary study on healthy newborns in Orissa. Results of the study would be generalizable to India and other low–middle-income countries.

Trial registration

Clinical Trial Registry of India (CTRI) CTRI/2019/05/019197. Registered on 16 May 2019

NutriBrain: protocol for a randomised, double-blind, controlled trial to evaluate the effects of a nutritional product on brain integrity in preterm infants

Background

The gut microbiota and the brain are connected through different mechanisms. Bacterial colonisation of the gut plays a substantial role in normal brain development, providing opportunities for nutritional neuroprotective interventions that target the gut microbiome. Preterm infants are at risk for brain injury, especially white matter injury, mediated by inflammation and infection. Probiotics, prebiotics and L-glutamine are nutritional components that have individually already demonstrated beneficial effects in preterm infants, mostly by reducing infections or modulating the inflammatory response. The NutriBrain study aims to evaluate the benefits of a combination of probiotics, prebiotics and L-glutamine on white matter microstructure integrity (i.e., development of white matter tracts) at term equivalent age in very and extremely preterm born infants.

Methods

This study is a double-blind, randomised, controlled, parallel-group, single-center study. Eighty-eight infants born between 24 + 0 and < 30 + 0 weeks gestational age and less than 72 h old will be randomised after parental informed consent to receive either active study product or placebo. Active study product consists of a combination of Bifidobacterium breve M-16V, short-chain galacto-oligosaccharides, long-chain fructo-oligosaccharides and L-glutamine and will be given enterally in addition to regular infant feeding from 48 to 72 h after birth until 36 weeks postmenstrual age. The primary study outcome of white matter microstructure integrity will be measured as fractional anisotropy, assessed using magnetic resonance diffusion tensor imaging at term equivalent age and analysed using Tract-Based Spatial Statistics. Secondary outcomes are white matter injury, brain tissue volumes and cortical morphology, serious neonatal infections, serum inflammatory markers and neurodevelopmental outcome.

Discussion

This study will be the first to evaluate the effect of a combination of probiotics, prebiotics and L-glutamine on brain development in preterm infants. It may give new insights in the development and function of the gut microbiota and immune system in relation to brain development and provide a new, safe treatment possibility to improve brain development in the care for preterm infants.

Trial registration

ISRCTN, ISRCTN96620855. Date assigned: 10/10/2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02570-x.

Probiotic Use and Safety in the Neonatal Intensive Care Unit: A Matched Cohort Study

OBJECTIVE

To determine the prevalence of probiotic administration in infants born preterm over time, as well as the association between probiotic administration and select adverse outcomes.

STUDY DESIGN

We performed a multicenter cohort study of infants 23-29 weeks of gestational age admitted to 289 neonatal intensive care units from 1997 to 2016. We evaluated the type of probiotics given and prevalence of exposure to probiotics over time and by site. We matched infants exposed to probiotics by several factors to unexposed infants receiving enteral feeds on the same postnatal day. We performed conditional logistic regression to evaluate the association between probiotics exposure and adverse outcomes, including necrotizing enterocolitis (NEC), bloodstream infections, meningitis, and death.

RESULTS

Of 78 076 infants, 3626 (4.6%) received probiotics. Probiotic use increased over the study period and varied among neonatal intensive care units. We matched 2178 infants exposed to probiotics to 33 807 without exposure. Probiotic administration was associated with a decrease in NEC (OR 0.62, 95% CI 0.48-0.80) and death (OR 0.52, 95% CI 0.39-0.70), an increase in Candida infection (OR 2.23, 95% CI 1.29-3.85), but no increase in bloodstream infection (OR 0.86, 95% CI 0.70-1.05) or meningitis (OR 1.18, 95% CI 0.40-3.46).

CONCLUSIONS

Probiotic use increased over time and was associated with decreased odds of NEC and death. Prospective, randomized-controlled studies of specific probiotic products are needed to further investigate the safety and efficacy of probiotics in preterm infants.

Probiotics and Preterm Infants: A Position Paper by the European Society for Paediatric Gastroenterology Hepatology and Nutrition Committee on Nutrition and the European Society for Paediatric Gastroenterology Hepatology and Nutrition Working Group for Probiotics and Prebiotics

More than 10,000 preterm infants have participated in randomised controlled trials on probiotics worldwide, suggesting that probiotics in general could reduce rates of necrotising enterocolitis (NEC), sepsis, and mortality. Answers to relevant clinical questions as to which strain to use, at what dosage, and how long to supplement are, however, not available. On the other hand, an increasing number of commercial products containing probiotics are available from sometimes suboptimal quality. Also, a large number of units around the world are routinely offering probiotic supplementation as the standard of care despite lacking solid evidence. Our recent network meta-analysis identified probiotic strains with greatest efficacy regarding relevant clinical outcomes for preterm neonates. Efficacy in reducing mortality and morbidity was found for only a minority of the studied strains or combinations. In the present position paper, we aim to provide advice, which specific strains might potentially be used and which strains should not be used. In addition, we aim to address safety issues of probiotic supplementation to preterm infants, who have reduced immunological capacities and occasional indwelling catheters. For example, quality reassurance of the probiotic product is essential, probiotic strains should be devoid of transferable antibiotic resistance genes, and local microbiologists should be able to routinely detect probiotic sepsis. Provided all safety issues are met, there is currently a conditional recommendation (with low certainty of evidence) to provide either Lactobacillus rhamnosus GG ATCC53103 or the combination of Bifidobacterium infantis Bb-02, Bifidobacterium lactis Bb-12, and Streptococcus thermophilus TH-4 in order to reduce NEC rates.

Nutritional interventions to reduce rates of infection, necrotizing enterocolitis and mortality in very preterm infants

Observational studies demonstrating reduced rates of infections, necrotizing enterocolitis (NEC), and mortality in preterm infants fed their own mother's milk, as opposed to formula, have prompted endeavors to achieve similar effects with the right choice of food and food additives. In a systematic review of meta-analyses and randomized controlled trials (RCTs), we considered nutritional interventions aimed at reducing the rates of infections, NEC, or mortality in very preterm infants. The overall effects of particular interventions were presented as risk ratios with 95% confidence intervals. In RCTs, pasteurized human donor milk, as opposed to formula, reduced NEC but not infections or mortality. No differences emerged between infants receiving human or bovine milk-based fortifiers. Pooled data of small trials and a recent large RCT suggested that bovine lactoferrin reduced rates of fungal sepsis without impact on other infections, NEC, or mortality. Pooled data of RCTs assessing the use of prebiotic oligosaccharides found reduced infection but not mortality. Enteral L-glutamine (six RCTs) lowered infection rates, and enteral L-arginine (three RCTs) reduced NEC. A meta-analysis sensitivity approach found multiple-strain (but not single-strain) probiotics to be highly effective in reducing NEC and mortality. Thus, selected food components may help to improve outcomes in preterm infants.

Perspectives on Probiotics and Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic respiratory disease of preterm infants, associated with high morbidity and hospitalization expenses. With the revolutionary advances in microbiological analysis technology, increasing evidence indicates that children with BPD are affected by lung microbiota dysbiosis, which may be related to the illness occurrence and progression. However, dysbiosis treatment in BPD patients has not been fully investigated. Probiotics are living microorganisms known to improve human health for their anti-inflammatory and anti-tumor effects, and particularly by balancing gut microbiota composition, which promotes gut-lung axis recovery. The aim of the present review is to examine current evidence of lung microbiota dysbiosis and explore potential applications of probiotics in BPD, which may provide new insights into treatment strategies of this disease.

Adjunctive therapy to treat neonatal sepsis

Introduction: Neonatal sepsis (NS) is a very severe condition that causes significant morbidity and mortality.Areas covered: To overcome the limits of antibiotic therapy and improve NS outcomes, measures chosen among those theoretically able to improve host defenses or positively interfere with deleterious immune responses could be suggested. This paper discusses the mechanisms of action of these measures, whether their efficacy in prophylaxis justifies use in NS therapy and their impact.Expert opinion: NS remains a relevant problem despite the availability of antibiotics effective against the most common agents and the introduction of effective preventive measures such as group B Streptococcus prenatal screening and intrapartum antibiotic prophylaxis. This explains why attempts to introduce new prophylactic and therapeutic measures have been made. Unfortunately, none of the measures suggested and tested to date can be considered a definitive advance. It is highly likely that in the future, new measures will be proposed according to the increase in the knowledge of the characteristics of immune system function in preterm infants and the methods to modulate unproper immune responses.

Genomic and epidemiological evidence of bacterial transmission from probiotic capsule to blood in ICU patients

Probiotics are routinely administered to hospitalized patients for many potential indications1 but have been associated with adverse effects that may outweigh their potential benefits2-7. It is particularly alarming that probiotic strains can cause bacteremia8,9, yet direct evidence for an ancestral link between blood isolates and administered probiotics is lacking. Here we report a markedly higher risk of Lactobacillus bacteremia for intensive care unit (ICU) patients treated with probiotics compared to those not treated, and provide genomics data that support the idea of direct clonal transmission of probiotics to the bloodstream. Whole-genome-based phylogeny showed that Lactobacilli isolated from treated patients' blood were phylogenetically inseparable from Lactobacilli isolated from the associated probiotic product. Indeed, the minute genetic diversity among the blood isolates mostly mirrored pre-existing genetic heterogeneity found in the probiotic product. Some blood isolates also contained de novo mutations, including a non-synonymous SNP conferring antibiotic resistance in one patient. Our findings support that probiotic strains can directly cause bacteremia and adaptively evolve within ICU patients.

Neonate Bloodstream Infections in Organization for Economic Cooperation and Development Countries: An Update on Epidemiology and Prevention

The term neonatal sepsis is used to describe a generalized bloodstream infection of bacterial, viral, or fungal origin which is associated with hemodynamic changes and other clinical symptoms and signs, however, there is no unified definition. There are no basic criteria regarding differentiation of early-onset sepsis (EOS) versus late-onset sepsis (LOS). Stratification used in studies on neonatal sepsis also rarely includes the general condition of the newborn according to unambiguous assessment at birth, which hampers the establishment of a clear, uniform epidemiological description of neonatal sepsis. We aim to review the published data about the epidemiology and microbiology of sepsis in Organization for Economic Cooperation and Development (OECD) countries. Data was also collected on sepsis prevention programs that can be implemented in neonatal units. The outcomes of interest were incidence or incidence density of EOS and LOS, microbiology of EOS and LOS, and data on the methodology of the research, in particular the criteria for inclusion and exclusion of newborns from the study. Pubmed, EMBASE, LILACS Embase, Scopus, and Google Scholar were used. For the preselection step, inclusion criteria included: "bloodstream infection" or "neonatal sepsis" (MesH), "very low birth weight", and "country" full-text studies, human, and English language. Exclusion criteria included: studies published in languages other than English and studies available only as an abstracts. For proper selection, inclusion criteria included: information about epidemiology or microbiology bloodstream infection (BSI), study population and case definitions, exclusion criteria, narrative reviews, commentaries, case studies, pilot studies, study protocols, pediatric studies, and only clinical data (without microbiology or epidemiology) or studies with only one etiological factor analysis. The data review indicated the lack of an unequivocal, unified definition and no unambiguous basic criteria with regard to differentiation of EOS versus LOS. Among infants <1500 g, studies reported an EOS rate from 7% to 2%. For studies using other definitions (mostly all inborn babies), the rate of EOS ranged from 1% to 3%. The LOS incidences were much more varied among countries; the highest rates were in the multicenter studies focused on very low birth weight (VLBW) infants. The main pathogens in EOS are GBS and Gram-negative bacteria in LOS. Our review data shows that LOS microbiology is very diverse and that Gram-positive cocci, especially staphylococci, predominate versus Gram-negative rods. Unfortunately, the lack of uniform, international prevention programs results in high newborn morbidity and insufficient postnatal prevention of late-onset infections.

The good bugs: the use of probiotics in pediatrics

PURPOSE OF REVIEW

There is growing evidence encouraging the use of probiotics in many conditions in children. However, given the wide number of probiotics available and contradictory data in the literature, the health-care provider is often faced with uncertainness about whether or not to use probiotics and which one(s) to choose. We here review current hypotheses regarding the efficacy and safety of probiotics and evaluate the available data on the use of probiotics in most common diseases in children. Considering that probiotics have strain-specific effects, we will focus on individual probiotic strains rather than on probiotics in general.

RECENT FINDINGS

Strain-specific efficacy was clearly demonstrated with Lactobacillus rhamnosus GG and Saccharomyces boulardii I-745 in the treatment of acute infectious diarrhea, Lactobacillus reuteri DSM 17938 in infantile colics, Lactobacillus rhamnosus GG, and VSL#3 in irritable bowel syndrome. In addition, encouraging results are seen for use of probiotics in necrotizing enterocolitis, food allergy, and nonalcoholic fatty liver disease. However, the data available for constipation are to be considered somewhat equivocal.

SUMMARY

The clinical relevance of these findings indicates that healthcare providers need to take strain-specificity and disease specificity of probiotics into consideration when recommending probiotic for their patients.

Dysbiosis and Prematurity: Is There a Role for Probiotics?

Healthy microbiota is a critical mediator in maintaining health and it is supposed that dysbiosis could have a role in the pathogenesis of a number of diseases. Evidence supports the hypothesis that maternal dysbiosis could act as a trigger for preterm birth; aberrant colonization of preterm infant gut might have a role in feeding intolerance and pathogenesis of necrotizing enterocolitis. Despite several clinical trials and meta-analyses, it is still not clear if modulation of maternal and neonatal microbiota with probiotic supplementation decreases the risk of preterm birth and its complications.

Dose-interval study of a dual probiotic in preterm infants

OBJECTIVE

The objective of this study was to investigate the appropriate dosing interval of a probiotic (Infloran) given daily, biweekly and weekly in preterm infants <32 weeks' gestation.

METHODS

There were 8 infants in the daily group, 8 infants in the biweekly group and 10 infants in the weekly group, all born between 25 and 32 weeks' gestation. The control group consisted of 12 preterm infants who did not receive the probiotic. Infloran (250 mg/capsule), containing Bifidobacterium bifidum (1×10⁹ colony-forming unit (CFU)) and Lactobacillus acidophilus (1×10⁹ CFU), was administered in 2.5 mL of breast milk per kilogram weight of the infant (2×10⁹ CFU of bacteria in total), until 34 weeks postmenstrual age (PMA). Stool samples were collected at 31, 34, 41 and 44 weeks PMA and frozen at -20°C.

RESULTS

After administration of the probiotic at 31 weeks PMA, Bifidobacterium were significantly higher in the daily group (45%) in comparison with the biweekly (17%) and weekly (9%) groups. At 34 weeks PMA, Bifidobacterium were significantly higher again in the daily (60%) group in comparison with the biweekly (21%), weekly (23%) and control (15%) groups. At 41 weeks PMA a decrease in the relative abundances of Streptococcaceae and Enterococcaceae was found in all three probiotic groups, and by 44 weeks PMA significantly higher levels of Lactobacillus were found in the biweekly group (16.5%) in comparison with the weekly group (2.1%).

CONCLUSION

Our results indicate that a daily dose of Infloran is a suitable dosage for preterm infants in the neonatal intensive care unit, with significantly higher levels of Bifidobacterium found in the daily probiotic group up to 44 weeks PMA.

Probiotic supplements might not be universally-effective and safe: A review

Last few decades have witnessed the unprecedented growth in the application of probiotics for promoting the general gut health as well as their inception as biotherapeutics to alleviate certain clinical disorders related to dysbiosis. While numerous studies have substantiated the health-restoring potentials for a restricted group of microbial species, the marketed extrapolation of a similar probiotic label to a large number of partially characterized microbial formulations seems biased. In particular, the individuals under neonatal stages and/or those with some clinical conditions including malignancies, leaky gut, diabetes mellitus, and post-organ transplant convalescence likely fail to reap the benefits of probiotics. Further exacerbating the conditions, some probiotic strains might take advantage of the weak immunity in these vulnerable groups and turn into opportunistic pathogens engendering life-threatening pneumonia, endocarditis, and sepsis. Moreover, the unregulated and rampant use of probiotics potentially carry the risk of plasmid-mediated antibiotic resistance transfer to the gut infectious pathogens. In this review, we discuss the safety perspectives of probiotics and their therapeutic interventions in certain at-risk population groups. The embodied arguments and hypotheses certainly will shed light on the fact why probiotic usage should be treated with caution.

Probiotics in Autoimmune and Inflammatory Disorders

Probiotics have been used to ameliorate gastrointestinal symptoms since ancient times. Over the past 40 years, probiotics have been shown to impact the immune system, both in vivo and in vitro. This interaction is linked to gut microbes, their polysaccharide antigens, and key metabolites produced by these bacteria. At least four metabolic pathways have been implicated in mechanistic studies of probiotics, based on mechanistic studies in animal models. Microbial⁻immune system crosstalk has been linked to: short-chain fatty acid production and signaling, tryptophan metabolism and the activation of aryl hydrocarbon receptors, nucleoside signaling in the gut, and activation of the intestinal histamine-2 receptor. Several randomized controlled trials have now shown that microbial modification by probiotics may improve gastrointestinal symptoms and multiorgan inflammation in rheumatoid arthritis, ulcerative colitis, and multiple sclerosis. Future work will need to carefully assess safety issues, selection of optimal strains and combinations, and attempts to prolong the duration of colonization of beneficial microbes.

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 oral probiotic supplementation on gut Lactobacillus and Bifidobacterium populations and the clinical status of low-birth-weight preterm neonates: a multicenter randomized, double-blind, placebo-controlled trial

Aim

Probiotic bacteria administered directly after birth to preterm neonates may improve gastrointestinal function and may reduce the incidence of late-onset sepsis, which is a frequent complication in this group.

Purpose

The main objective of this study was to evaluate whether a new probiotic bacterial mixture of Lactobacillus rhamnosus KL53A and Bifidobacterium breve PB04 given to preterm, low-birth-weight neonates would influence composition of their gut microbiota and sepsis rates.

Patients and methods

This study was a multicenter, randomized, double-blind, placebo-controlled trial conducted in clinical centers of neonatal care in Poland. A probiotic or placebo preparation was given twice daily to 181 preterm low-birth-weight neonates who were eligible for enteral feeding between July 2012 and July 2013. The probiotic was given to 90 neonates, while placebo was given to 91 neonates. The gut microbiota was monitored by microbiological analysis of stool samples. Sepsis episodes were detected on the basis of clinical and laboratory findings and confirmed by blood cultures.

Results

Tested probiotic administration resulted in continuous increase of the Lactobacillus and Bifidobacterium counts in the gut microbiota. The applied tested strains successfully colonized the neonates gut since they were present in over 90% of stool samples, which was confirmed by molecular analysis. Regardless of the study group (probiotic or placebo), B. breve colonization correlated with lower staphylococcal sepsis incidence, which was irrespective of whether probiotics were given. No sepsis case caused by strains included in study probiotic was recorded.

Conclusion

Appropriately selected and characterized probiotic bacteria may be safely given to preterm neonates to normalize their distorted gut microbiota and may contribute to lower staphylococcal sepsis rates.

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.

Lactobacillus rhamnosus L34 Attenuates Gut Translocation-Induced Bacterial Sepsis in Murine Models of Leaky Gut

Gastrointestinal (GI) bacterial translocation in sepsis is well known, but the role of Lactobacillus species probiotics is still controversial. We evaluated the therapeutic effects of Lactobacillus rhamnosus L34 in a new sepsis model of oral administration of pathogenic bacteria with GI leakage induced by either an antibiotic cocktail (ATB) and/or dextran sulfate sodium (DSS). GI leakage with ATB, DSS, and DSS plus ATB (DSS+ATB) was demonstrated by fluorescein isothiocyanate (FITC)-dextran translocation to the circulation. The administration of pathogenic bacteria, either Klebsiella pneumoniae or Salmonella enterica serovar Typhimurium, enhanced translocation. Bacteremia was demonstrated within 24 h in 50 to 88% of mice with GI leakage plus the administration of pathogenic bacteria but not with GI leakage induction alone or bacterial gavage alone. Salmonella bacteremia was found in only 16 to 29% and 0% of mice with Salmonella and Klebsiella administrations, respectively. Klebsiella bacteremia was demonstrated in 25 to 33% and 10 to 16% of mice with Klebsiella and Salmonella administrations, respectively. Lactobacillus rhamnosus L34 attenuated GI leakage in these models, as shown by the reductions of FITC-dextran gut translocation, serum interleukin-6 (IL-6) levels, bacteremia, and sepsis mortality. The reduction in the amount of fecal Salmonella bacteria with Lactobacillus treatment was demonstrated. In addition, an anti-inflammatory effect of the conditioned medium from Lactobacillus rhamnosus L34 was also demonstrated by the attenuation of cytokine production in colonic epithelial cells in vitro In conclusion, Lactobacillus rhamnosus L34 attenuated the severity of symptoms in a murine sepsis model induced by GI leakage and the administration of pathogenic bacteria.

Probiotics and antimicrobial protein and peptide levels in preterm infants

AIM

To characterise the secreted and inducible antimicrobial protein and peptide (APP) levels in a prospective cohort of preterm infants (<30 weeks gestational age) with or without Bifidobacterium breve M16V supplementation during the first month of life.

METHODS

We analysed serial biosamples of infants who did (n = 13) or did not receive (n = 62) B. breve (3 × 10⁹ cfu/day). Peripheral blood was obtained on days 1, 14 and 28, and infant stool prior to commencement of probiotic supplementation and on day 21. Levels of APP (bactericidal/permeability inducing protein (BPI), beta defensins 1 and 2, lactoferrin, human cathelicidin, secretory phospholipase A2) in plasma and stool were determined. Further, we characterised induced APP levels in whole blood cultured with live S. epidermidis or with agonists of Toll-like receptors 2/6 and 4.

RESULTS

Stool, plasma and stimulated blood APP levels changed significantly during the first month of life. Supplementation with B. breve did not affect basal or stimulated APP levels except for a transient increase in inducible BPI.

CONCLUSION

Supplementation with B. breve does not appear to act via modulation of systemic or enteric APP expression in preterm infants although small effects cannot be excluded. Further work with other probiotic preparations is warranted.

Probiotic Supplementation in Preterm Infants Does Not Affect the Risk of Bronchopulmonary Dysplasia: A Meta-Analysis of Randomized Controlled Trials

Probiotic supplementation reduces the risk of necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) in preterm infants, but it remains to be determined whether this reduction translates into a reduction of other complications. We conducted a systematic review and meta-analysis to evaluate the possible role of probiotics in altering the risk of bronchopulmonary dysplasia (BPD). Fifteen randomized controlled trials (4782 infants; probiotics: 2406) were included. None of the included studies assessed BPD as the primary outcome. Meta-analysis confirmed a significant reduction of NEC (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.33 to 0.81, p = 0.004; random effects model), and an almost significant reduction of LOS (RR 0.82, 95% CI 0.65 to 1.03, p = 0.084). In contrast, meta-analysis could not demonstrate a significant effect of probiotics on BPD, defined either as oxygen dependency at 28 days of life (RR 1.01, 95% CI 0.91 to 1.11, p = 0.900, 6 studies) or at 36 weeks of postmenstrual age (RR 1.07, 95% CI 0.96 to 1.20, p = 0.203, 12 studies). Meta-regression did not show any significant association between the RR for NEC or LOS and the RR for BPD. In conclusion, our results suggest that NEC and LOS prevention by probiotics does not affect the risk of developing BPD in preterm infants.

Probiotic supplementation in preterm infants does not affect the risk of retinopathy of prematurity: a meta-analysis of randomized controlled trials

Retinopathy of prematurity (ROP) is a vascular disorder of the developing retina in preterm infants and is a leading cause of childhood blindness. Perinatal infection plays a pathogenic role in ROP. Probiotic supplementation reduces the risk of late onset sepsis (LOS) in preterm infants but it remains to be determined whether this reduction translates into a reduction of other complications. We conducted a systematic review and meta-analysis to evaluate the possible role of probiotics in altering the risk of ROP. Eleven randomized controlled trials (4250 infants; probiotics: 2121) were included in the meta-analysis that showed a significantly decreased rate of LOS with a risk ratio (RR) of 0.807 and a 95% confidence interval (CI) of 0.705 to 0.924 (P = 0.010; fixed effects model) but could not demonstrate a significant effect of probiotics on any stage ROP (RR 1.053, 95% CI 0.903 to 1.228, P = 0.508, 4 studies), or severe ROP (RR 0.841, 95% CI 0.666 to 1.063, P = 0.148, 9 studies). Meta-regression did not show any significant association between the RR for LOS and the RR for severe ROP. In conclusion, our results suggest that infection prevention by probiotics does not affect the risk of developing ROP in preterm infants.

Do bacteria shape our development? Crosstalk between intestinal microbiota and HPA axis

The human body contains as many bacteria in the intestine as the total number of human body cells. These bacteria have a central position in human health and disease, and would also play a role in the regulation of emotions, behavior, and even higher cognitive functions. The Hypothalamic-Pituitary-Adrenal axis (HPA axis) is a major physiological stress system that produces cortisol. This hormone is involved in responding to environmental stress and also shapes many aspects of brain development. Both the HPA axis and the intestinal microbiota show rapid and profound developmental changes during the first years of life. Early environmental disturbances can affect the development of both systems. Early adversity, for example, is known to lead to later unbalances in both, as well as to psychopathological behavior and emotions. The goal of this theoretical review is to summarize current knowledge on the developmental crosstalk between the intestinal microbiota and the HPA axis, providing a basis for understanding the development and bidirectional communication between these two essential systems in human functioning.

Probiotics Prevent Late-Onset Sepsis in Human Milk-Fed, Very Low Birth Weight Preterm Infants: Systematic Review and Meta-Analysis

Growing evidence supports the role of probiotics in reducing the risk of necrotizing enterocolitis, time to achieve full enteral feeding, and late-onset sepsis (LOS) in preterm infants. As reported for several neonatal clinical outcomes, recent data have suggested that nutrition might affect probiotics' efficacy. Nevertheless, the currently available literature does not explore the relationship between LOS prevention and type of feeding in preterm infants receiving probiotics. Thus, the aim of this systematic review and meta-analysis was to evaluate the effect of probiotics for LOS prevention in preterm infants according to type of feeding (exclusive human milk (HM) vs. exclusive formula or mixed feeding). Randomized-controlled trials involving preterm infants receiving probiotics and reporting on LOS were included in the systematic review. Only trials reporting on outcome according to feeding type were included in the meta-analysis. Fixed-effects models were used and random-effects models were used when significant heterogeneity was found. The results were expressed as risk ratio (RR) with 95% confidence interval (CI). Twenty-five studies were included in the meta-analysis. Overall, probiotic supplementation resulted in a significantly lower incidence of LOS (RR 0.79 (95% CI 0.71-0.88), p < 0.0001). According to feeding type, the beneficial effect of probiotics was confirmed only in exclusively HM-fed preterm infants (RR 0.75 (95% CI 0.65-0.86), p < 0.0001). Among HM-fed infants, only probiotic mixtures, and not single-strain products, were effective in reducing LOS incidence (RR 0.68 (95% CI 0.57-0.80) p < 0.00001). The results of the present meta-analysis show that probiotics reduce LOS incidence in exclusively HM-fed preterm infants. Further efforts are required to clarify the relationship between probiotics supplementation, HM, and feeding practices in preterm infants.

The potential role of microbiota for controlling the spread of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) in neonatal population

The spread of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) in the hospital and also the community is worrisome. Neonates particularly are exposed to the risk of ESBL-PE acquisition and, owing to the immaturity of their immune system, to a higher secondary risk of ESBL-PE-related infection. Reducing the risk of acquisition in the hospital is usually based on a bundle of measures, including screening policies at admission, improving hand hygiene compliance, and decreasing antibiotic consumption. However, recent scientific data suggest new prevention opportunities based on microbiota modifications.

Using probiotics in clinical practice: Where are we now? A review of existing meta-analyses

The scientific literature has demonstrated that probiotics have a broad spectrum of activity, although often the results are contradictory. This study provides a critical overview of the current meta-analyses that have evaluated the efficacy of probiotics in physiologic and pathological conditions, such as metabolic disease, antibiotic-associated and Clostridium difficile-associated diarrhea, IBS, constipation, IBD, chemotherapy-associated diarrhea, respiratory tract infection, ventilator-associated pneumonia, NAFLD, liver encephalopathy, periodontitis, depression, vaginosis, urinary tract infections, pancreatitis, incidence of ventilator-associated pneumonia, hospital infection and stay in ICU, mortality of post-trauma patients, necrotising enterocolitis in premature infants. Only for antibiotic- and Clostridium difficile-associated diarrhea, and respiratory tract infections the effects of probiotics are considered "evidence-based." Concerning other fields, meta-analyses lacks to define type and biologic effect of probiotic strains, as well as the outcome in a disease state. Therefore, the results presented should be a stimulus for further studies which will provide clinical recommendations.

Probiotics Prevent Candida Colonization and Invasive Fungal Sepsis in Preterm Neonates: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

To investigate whether probiotic supplementation could reduce the risk of fungal infection in preterm neonates in neonatal intensive care units (NICUs), we systematically searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials databases for randomized controlled trials (RCTs) focusing on the effect of probiotics on fungal infection in preterm neonates. The outcomes of interest were Candida colonization and invasive fungal sepsis. Seven trials involving 1371 preterm neonates were included. Meta-analysis (fixed-effects model) showed that probiotic supplementation was significantly associated with a lower risk of Candida colonization (2 RCTs, n = 329; relative risk (RR), 0.43; 95% confidence interval (CI), 0.27-0.67; p = 0.0002; I² = 0%), and invasive fungal sepsis (7 RCTs, n = 1371; RR, 0.64; 95% CI, 0.46-0.88; p = 0.006; I² = 13%). After excluding one study with a high baseline incidence (75%) of fungal sepsis, the effect of probiotics on invasive fungal sepsis became statistically insignificant (RR, 0.88; 95% CI, 0.44-1.78; p = 0.72; I² = 15%). When using the random-effects model, the effect of probiotics remained favorable for Candida colonization (RR, 0.43; 95% CI 0.27-0.68; p = 0.0002; I² = 0%) but not for fungal sepsis (RR, 0.64; 95% CI 0.38-1.08; p = 0.10; I² = 13%). Current evidence indicates that probiotics can reduce the risk of Candida colonization in preterm neonates in NICUs. Limited data support that probiotic supplementation prevents invasive fungal sepsis in preterm neonates. High-quality and adequately powered RCTs are warranted.

Gut bacteria and late-onset neonatal bloodstream infections in preterm infants

Late-onset neonatal bloodstream infections remain challenges in neonatology. Hand hygiene, line care, and judicious use of indwelling lines are welcome interventions, but might not reduce the incidence of late-onset neonatal bloodstream infections from bacteria originating in the gut. Accumulating data suggest that many pathogens causing late-onset neonatal bloodstream infections are of gut origin, including Gram-positive cocci. In addition to the host-canonical paradigm (i.e., all bacteria have equal risk of invasion and bloodstream infections are functions of variable infant susceptibility), we should now consider bacteria-canonical paradigms, whereby late-onset neonatal bloodstream infection is a function of colonization with a specific subset of bacteria with exceptional invasive potential. In either event, we can no longer be content to reactively approach late-onset neonatal bloodstream infections; instead we need to reduce the occurrences of these infections by broadening our scope of effort beyond line care, and determine the pre-invasive habitat of these pathogens.

The Significance of the Enteric Microbiome on the Development of Childhood Disease: A Review of Prebiotic and Probiotic Therapies in Disorders of Childhood

Recent studies have highlighted the fact that the enteric microbiome, the trillions of microbes that inhabit the human digestive tract, has a significant effect on health and disease. Methods for manipulating the enteric microbiome, particularly through probiotics and microbial ecosystem transplantation, have undergone some study in clinical trials. We review some of the evidence for microbiome alteration in relation to childhood disease and discuss the clinical trials that have examined the manipulation of the microbiome in an effort to prevent or treat childhood disease with a primary focus on probiotics, prebiotics, and/or synbiotics (ie, probiotics + prebiotics). Studies show that alterations in the microbiome may be a consequence of events occurring during infancy and/or childhood such as prematurity, C-sections, and nosocomial infections. In addition, certain childhood diseases have been associated with microbiome alterations, namely necrotizing enterocolitis, infantile colic, asthma, atopic disease, gastrointestinal disease, diabetes, malnutrition, mood/anxiety disorders, and autism spectrum disorders. Treatment studies suggest that probiotics are potentially protective against the development of some of these diseases. Timing and duration of treatment, the optimal probiotic strain(s), and factors that may alter the composition and function of the microbiome are still in need of further research. Other treatments such as prebiotics, fecal microbial transplantation, and antibiotics have limited evidence. Future translational work, in vitro models, long-term and follow-up studies, and guidelines for the composition and viability of probiotic and microbial therapies need to be developed. Overall, there is promising evidence that manipulating the microbiome with probiotics early in life can help prevent or reduce the severity of some childhood diseases, but further research is needed to elucidate biological mechanisms and determine optimal treatments.