Difficulties in developmental follow-up of preterm neonates in a randomised-controlled trial of Bifidobacterium breve M16-V - Experience from Western Australia

Impact of maternal Bifidobacterium breve M-16V and scGOS/lcFOS supplementation during pregnancy and lactation on the maternal immune system and milk composition

Introduction

Maternal synbiotic supplementation during pregnancy and lactation can significantly influence the immune system. Prebiotics and probiotics have a positive impact on the immune system by preventing or ameliorating among others intestinal disorders. This study focused on the immunomodulatory effects of B. breve M-16V and short chain galacto-oligosaccharides (scGOS)/long chain fructo-oligosachairdes (lcFOS), including systemic and mucosal compartments and milk composition.

Methods

Lewis rats were orally administered with the synbiotic or vehicle during pregnancy (21 days) and lactation (21 days). At the weaning day, small intestine (SI), mammary gland (MG), adipose tissue, milk, mesenteric lymph nodes (MLN), salivary gland (SG), feces and cecal content were collected from the mothers.

Results

The immunoglobulinome profile showed increased IgG2c in plasma and milk, as well as elevated sIgA in feces at weaning. The supplementation improved lipid metabolism through enhanced brown adipose tissue activity and reinforced the intestinal barrier by increasing the expression of Muc3, Cldn4, and Ocln. The higher production of short chain fatty acids in the cecum and increased Bifidobacterium counts suggest a potential positive impact on the gastrointestinal tract.

Discussion

These findings indicate that maternal synbiotic supplementation during gestation and lactation improves their immunological status and improved milk composition.

Effects of probiotics on neurocognitive outcomes in infants and young children: a meta-analysis

Background

Therapeutic efficacies of probiotics in improving neurocognitive functions in infants and young children remained unclear. This meta-analysis focused on different cognitive outcomes in this population.

Methods

Major databases were searched electronically from inception to October 2023 to identify randomized controlled trials (RCTs) that investigated the therapeutic efficacy of probiotics in enhancing cognitive functions assessed by standardized tasks. The overall effect size was calculated as standardized mean difference (SMD) based on a random effects model.

Results

Nine RCTs with 3,026 participants were identified. Both our primary and secondary results demonstrated no significant difference in neurocognitive outcomes between infants/children treated with probiotics and those receiving placebos. However, our subgroup analysis of studies that offered a probiotics treatment course of over six months demonstrated a significantly better neurocognitive outcome than placebos (SMD = 0.21, p = 0.03, two studies with 451 participants), but this finding was based on only two RCTs.

Conclusion

Despite lack of significant therapeutic effects of probiotics on neurocognitive outcomes, our finding of a positive impact of probiotics on neurocognitive development in those undergoing treatment for over six months may provide an important direction for further investigations into the enhancement of therapeutic effects of probiotics on neurocognitive development in infants and young children.

Systematic review registration

PROSPERO CRD42023463412.

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.

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.

Effectiveness of a probiotic combination on the neurodevelopment of the very premature infant

Probiotics have shown a benefit in reducing necrotising enterocolitis in the premature infant, however the study of their effect on premature neonates' neurodevelopment is limited. The aim of our study was to elucidate whether the effect of Bifidobacterium bifidum NCDO 2203 combined with Lactobacillus acidophilus NCDO 1748 could positively impact the neurodevelopment of the preterm neonates. Quasi-experimental comparative study with a combined treatment of probiotics in premature infants < 32 weeks and < 1500 g birth weight, cared for at a level III neonatal unit. The probiotic combination was administered orally to neonates surviving beyond 7 days of life, until 34 weeks postmenstrual age or discharge. Globally, neurodevelopment was evaluated at 24 months corrected age. A total of 233 neonates were recruited, 109 in the probiotic group and 124 in the non-probiotic group. In those neonates receiving probiotics, there was a significant reduction in neurodevelopment impairment at 2 years of age RR 0.30 [0.16-0.58], and a reduction in the degree of impairment (normal-mild vs moderate-severe, RR 0.22 [0.07-0.73]). Additionally, there was a significant reduction in late-onset sepsis (RR 0.45 [0.21-0.99]). The prophylactic use of this probiotic combination contributed to improving neurodevelopmental outcome and reduced sepsis in neonates born at < 32 weeks and < 1500 g.Per style, a structured abstract is not allowed so we have changed the structured abstract to an unstructured abstract. Please check and confirm.Accepted.

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.

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.