Glutamine-enriched enteral nutrition in very low birth weight infants. Design of a double-blind randomised controlled trial [ISRCTN73254583]

The influence of very preterm birth on adolescent EEG connectivity, network organization and long-term outcome

OBJECTIVE

The aim of this study was to explore differences in functional connectivity and network organization between very preterm born adolescents and term born controls and to investigate if these differences might explain the relation between preterm birth and adverse long-term outcome.

METHODS

Forty-seven very preterm born adolescents (53% males) and 54 controls (54% males) with matching age, sex and parental educational levels underwent high-density electroencephalography (EEG) at 13 years of age. Long-term outcome was assessed by Intelligence Quotient (IQ), motor, attentional functioning and academic performance. Two minutes of EEG data were analysed within delta, theta, lower alpha, upper alpha and beta frequency bands. Within each frequency band, connectivity was assessed using the Phase Lag Index (PLI) and Amplitude Envelope Correlation, corrected for volume conduction (AEC-c). Brain networks were constructed using the minimum spanning tree method.

RESULTS

Very preterm born adolescents had stronger beta PLI connectivity and less differentiated network organization. Beta AEC-c and differentiation of AEC-c based networks were negatively associated with long-term outcomes. EEG measures did not mediate the relation between preterm birth and outcomes.

CONCLUSIONS

This study shows that very preterm born adolescents may have altered functional connectivity and brain network organization in the beta frequency band. Alterations in measures of functional connectivity and network topologies, especially its differentiating characteristics, were associated with neurodevelopmental functioning.

SIGNIFICANCE

The findings indicate that EEG connectivity and network analysis is a promising tool for investigating underlying mechanisms of impaired functioning.

Altered structural connectome and motor problems of very preterm born children at school-age

Infants born very preterm (<32 weeks of gestation) show distinct cognitive and motor problems throughout childhood. This study aims 1) to investigate differences in the structural connectome between very preterm born children and term born controls at school-age, and 2) to examine the relationship of the structural connectome with cognitive and motor problems. This study included 29 very preterm (12 males, mean age 8.6 years) and 52 term born peers (25 males, mean age 8.7 years). Wechsler Intelligence Scale for Children and Movement Assessment Battery for Children were used. Brain network measures of smallworldness, clustering coefficient and shortest path length based on fiber density of white matter tracts were determined from Diffusion Tensor Imaging data using probabilistic tractography. Smallworldness (F(1,79) = -2.09, p = .04, d = 0.52) and clustering coefficient (F(1,79) = -2.63, p = .01, d = 0.64) were significantly higher for very preterm children as compared to term peers. For Total Motor Impairment score and Manual Dexterity, there was a significant interaction between group and smallworldness (Beta = -10.81, p = .03 and Beta = -2.99, p = .004, respectively). Greater Total Motor Impairment and poorer Manual Dexterity were only significantly related to higher smallworldness in term controls (r = 0.35, p = .01 and r = 0.27, p = .04, respectively). Poorer Ball Skills were significantly related to higher smallworldness in both groups (Beta = -0.30, p = .03). This study clearly shows a more segregated network organization in very preterm children as compared to term peers. Importantly, motor problems go together with altered organization of the structural connectome in term born children, whereas this potential compensational process is only found for Ball Skills for very preterm children.

Social Adjustment in Adolescents Born Very Preterm: Evidence for a Cognitive Basis of Social Problems

OBJECTIVE

To increase the understanding of social adjustment and autism spectrum disorder symptoms in adolescents born very preterm by studying the role of emotion recognition and cognitive control processes in the relation between very preterm birth and social adjustment.

STUDY DESIGN

A Dutch cohort of 61 very preterm and 61 full-term adolescents aged 13 years participated. Social adjustment was rated by parents, teachers, and adolescents and autism spectrum disorder symptoms by parents. Emotion recognition was assessed with a computerized task including pictures of child faces expressing anger, fear, sadness, and happiness with varying intensity. Cognitive control was assessed using a visuospatial span, antisaccade, and sustained attention to response task. Performance measures derived from these tasks served as indicators of a latent cognitive control construct, which was tested using confirmatory factor analysis. Mediation analyses were conducted with emotion recognition and cognitive control as mediators of the relation between very preterm birth and social problems.

RESULTS

Very preterm adolescents showed more parent- and teacher-rated social problems and increased autism spectrum disorder symptomatology than controls. No difference in self-reported social problems was observed. Moreover, very preterm adolescents showed deficits in emotion recognition and cognitive control compared with full-term adolescents. The relation between very preterm birth and parent-rated social problems was significantly mediated by cognitive control but not by emotion recognition. Very preterm birth was associated with a 0.67-SD increase in parent-rated social problems through its negative effect on cognitive control.

CONCLUSIONS

The present findings provide strong evidence for a central role of impaired cognitive control in the social problems of adolescents born very preterm.

Voluntary and Involuntary Control of Attention in Adolescents Born Very Preterm: A Study of Eye Movements

Very preterm birth is associated with attention deficits that interfere with academic performance. A better understanding of attention processes is necessary to support very preterm born children. This study examined voluntary and involuntary attentional control in very preterm born adolescents by measuring saccadic eye movements. Additionally, these control processes were related to symptoms of inattention, intelligence, and academic performance. Participants included 47 very preterm and 61 full-term born 13-years-old adolescents. Oculomotor control was assessed using the antisaccade and oculomotor capture paradigm. Very preterm born adolescents showed deficits in antisaccade but not in oculomotor capture performance, indicating impairments in voluntary but not involuntary attentional control. These impairments mediated the relation between very preterm birth and inattention, intelligence, and academic performance.

Neurocognitive processes underlying academic difficulties in very preterm born adolescents

Very preterm birth is associated with academic difficulties, but the underlying neurocognitive mechanisms of these difficulties remain largely unclear. The present study aimed to assess the role of working memory (WM), attentional processes, and processing speed in academic difficulties of very preterm born adolescents at 13 years. Participants included 55 very preterm and 61 full-term adolescents. Academic performance, visuospatial WM, alerting, orienting, executive attention, sustained attention, and processing speed (simple and choice reaction time [RT]) were compared between groups. Mediation analyses with multiple, parallel mediators were performed to examine whether these functions mediate the relation between very preterm birth and academic performance. Very preterm born adolescents showed poorer reading comprehension, arithmetic, visuospatial WM, alerting, sustained attention, and choice RT than full-term controls. The relationship between very preterm birth and arithmetic was mediated by visuospatial WM, sustained attention, and choice RT. The relationship between very preterm birth and reading comprehension was mediated by visuospatial WM and choice RT. The findings indicate that very preterm birth affects arithmetic and reading comprehension through its negative effect on visuospatial WM, sustained attention, and processing speed. These neurocognitive processes may identify very preterm born children at risk for academic difficulties and could serve as targets for interventions.

Implicit Learning Abilities in Adolescents Born Very Preterm

Very preterm birth is associated with neurodevelopmental impairments and outcomes have not improved over the last decades. Insight in learning processes is important for the development of effective interventions. Implicit learning is of particular interest because of its independence from working memory processes that are affected by preterm birth. This study examined implicit learning abilities in 49 very preterm and 61 full-term 13-year-old adolescents. The degree of implicit learning was not different between groups. This indicates intact implicit learning abilities in adolescents born very preterm. Implicit learning strategies may be beneficial for skill learning in very preterm born children.

A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease

Background

Skin diseases are very common and can have a large impact on the quality of life of patients and caregivers. This programme addressed four diseases: (1) eczema, (2) vitiligo, (3) squamous cell skin cancer (SCC) and (4) pyoderma gangrenosum (PG).

Objective

To set priorities and reduce uncertainties for the treatment and prevention of skin disease in our four chosen diseases.

Design

Mixed methods including eight systematic reviews, three prioritisation exercises, two pilot randomised controlled trials (RCTs), three feasibility studies, two core outcome initiatives, four funding proposals for national RCTs and one completed national RCT.

Setting

Secondary care, primary care and the general population.

Participants

Patients (and their caregivers) with eczema, vitiligo, SCC and PG, plus health-care professionals with an interest in skin disease.

Interventions

Our three intervention studies included (1) barrier enhancement using emollients from birth to prevent eczema (pilot RCT); (2) handheld narrowband ultraviolet light B therapy for treating vitiligo (pilot RCT); and (3) oral ciclosporin (Neoral®, Novartis Pharmaceuticals) compared with oral prednisolone for managing PG (pragmatic national RCT).

Results

Systematic reviews included two overarching systematic reviews of RCTs of treatments for eczema and vitiligo, an umbrella review of systematic reviews of interventions for the prevention of eczema, two reviews of treatments for SCC (one included RCTs and the second included observational studies), and three reviews of outcome measures and outcome reporting. Three prioritisation partnership exercises identified 26 priority areas for future research in eczema, vitiligo and SCC. Two international consensus initiatives identified four core domains for future eczema trials and seven core domains for vitiligo trials. Two pilot RCTs and three feasibility studies critically informed development of four trial proposals for external funding, three of which are now funded and one is pending consideration by funders. Our pragmatic RCT tested the two commonly used systemic treatments for PG (prednisolone vs. ciclosporin) and found no difference in their clinical effectiveness or cost-effectiveness. Both drugs showed limited benefit. Only half of the participants’ ulcers had healed by 6 months. For those with healed ulcers, recurrence was common (30%). Different side effect profiles were noted for each drug, which can inform clinical decisions on an individual patient basis. Three researchers were trained to PhD level and a dermatology patient panel was established to ensure patient involvement in all aspects of the programme.

Conclusions

Findings from this programme of work have already informed clinical guidelines and patient information resources. Feasibility studies have ensured that large national pragmatic trials will now be conducted on important areas of treatment uncertainty that address the needs of patients and the NHS. There is scope for considerable improvement in terms of trial design, conduct and reporting for RCTs of skin disease, which can be improved through wider collaboration, registration of trial protocols and complete reporting and international consensus over core outcome sets. Three national trials have now been funded as a result of this work. Two international initiatives to establish how best to measure the core outcome domains for eczema and vitiligo are ongoing.

Trial registration

Current Controlled Trials Barrier Enhancement for Eczema Prevention (BEEP) (ISRCTN84854178 and NCT01142999), Study of Treatments fOr Pyoderma GAngrenosum Patients (STOP GAP) (ISRCTN35898459) and Hand Held NB-UVB for Early or Focal Vitiligo at Home (HI-Light Pilot Trial) (NCT01478945).

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 18. See the NIHR Journals Library website for further project information.

Glutamine supplementation to prevent morbidity and mortality in preterm infants

BACKGROUND

Glutamine is a conditionally essential amino acid. Endogenous biosynthesis may be insufficient for tissue needs in states of metabolic stress. Evidence exists that glutamine supplementation improves clinical outcomes in critically ill adults. It has been suggested that glutamine supplementation may also benefit preterm infants.

OBJECTIVES

To determine the effects of glutamine supplementation on mortality and morbidity in preterm infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2015, Issue 12), MEDLINE, EMBASE and Maternity and Infant Care (to December 2015), conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared glutamine supplementation versus no glutamine supplementation in preterm infants at any time from birth to discharge from hospital.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two review authors. We synthesised data using a fixed-effect model and reported typical relative risk, typical risk difference and weighted mean difference.

MAIN RESULTS

We identified 12 randomised controlled trials in which a total of 2877 preterm infants participated. Six trials assessed enteral glutamine supplementation and six trials assessed parenteral glutamine supplementation. The trials were generally of good methodological quality. Meta-analysis did not find an effect of glutamine supplementation on mortality (typical relative risk 0.97, 95% confidence interval 0.80 to 1.17; risk difference 0.00, 95% confidence interval -0.03 to 0.02) or major neonatal morbidities including the incidence of invasive infection or necrotising enterocolitis. Three trials that assessed neurodevelopmental outcomes in children aged 18 to 24 months and beyond did not find any effects.

AUTHORS' CONCLUSIONS

The available trial data do not provide evidence that glutamine supplementation confers important benefits for preterm infants.

Glutamine supplementation to prevent morbidity and mortality in preterm infants

BACKGROUND

Glutamine is a conditionally essential amino acid. Endogenous biosynthesis may be insufficient for tissue needs in states of metabolic stress. Evidence exists that glutamine supplementation improves clinical outcomes in critically ill adults. It has been suggested that glutamine supplementation may also benefit preterm infants.

OBJECTIVES

To determine the effects of glutamine supplementation on mortality and morbidity in preterm infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2015, Issue 12), MEDLINE, EMBASE and Maternity and Infant Care (to December 2015), conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared glutamine supplementation versus no glutamine supplementation in preterm infants at any time from birth to discharge from hospital.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two review authors. We synthesised data using a fixed-effect model and reported typical relative risk, typical risk difference and weighted mean difference.

MAIN RESULTS

We identified 12 randomised controlled trials in which a total of 2877 preterm infants participated. Six trials assessed enteral glutamine supplementation and six trials assessed parenteral glutamine supplementation. The trials were generally of good methodological quality. Meta-analysis did not find an effect of glutamine supplementation on mortality (typical relative risk 0.97, 95% confidence interval 0.80 to 1.17; risk difference 0.00, 95% confidence interval -0.03 to 0.02) or major neonatal morbidities including the incidence of invasive infection or necrotising enterocolitis. Three trials that assessed neurodevelopmental outcomes in children aged 18 to 24 months and beyond did not find any effects.

AUTHORS' CONCLUSIONS

The available trial data do not provide evidence that glutamine supplementation confers important benefits for preterm infants.

Effects of oral glutamine supplementation on exercise-induced gastrointestinal permeability and tight junction protein expression

The objectives of this study are threefold: 1) to assess whether 7 days of oral glutamine (GLN) supplementation reduces exercise-induced intestinal permeability; 2) whether supplementation prevents the proinflammatory response; and 3) whether these changes are associated with upregulation of the heat shock response. On separate occasions, eight human subjects participated in baseline testing and in GLN and placebo (PLA) supplementation trials, followed by a 60-min treadmill run. Intestinal permeability was higher in the PLA trial compared with baseline and GLN trials (0.0604 ± 0.047 vs. 0.0218 ± 0.008 and 0.0272 ± 0.007, respectively; P < 0.05). IκBα expression in peripheral blood mononuclear cells was higher 240 min after exercise in the GLN trial compared with the PLA trial (1.411 ± 0.523 vs. 0.9839 ± 0.343, respectively; P < 0.05). In vitro using the intestinal epithelial cell line Caco-2, we measured effects of GLN supplementation (0, 4, and 6 mM) on heat-induced (37° or 41.8°C) heat shock protein 70 (HSP70), heat shock factor-1 (HSF-1), and occludin expression. HSF-1 and HSP70 levels increased in 6 mM supplementation at 41°C compared with 0 mM at 41°C (1.785 ± 0.495 vs. 0.6681 ± 0.290, and 1.973 ± 0.325 vs. 1.133 ± 0.129, respectively; P < 0.05). Occludin levels increased after 4 mM supplementation at 41°C and 6 mM at 41°C compared with 0 mM at 41°C (1.236 ± 0.219 and 1.849 ± 0.564 vs. 0.7434 ± 0.027, respectively; P < 0.001). GLN supplementation prevented exercise-induced permeability, possibly through HSF-1 activation.

Prebiotics in infants for prevention of allergy

BACKGROUND

Prebiotics (commonly oligosaccharides) added to infant feeds have the potential to prevent sensitisation of infants to dietary allergens.

OBJECTIVES

To determine the effect of prebiotic given to infants for the prevention of allergy.

SEARCH METHODS

We performed an updated search in August 2012 of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 8), MEDLINE, EMBASE, conference proceedings, citations, expert informants and clinical trials registries.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared the use of a prebiotic to no prebiotic, or a specific prebiotic compared to a different prebiotic in infants for prevention of allergy.

DATA COLLECTION AND ANALYSIS

Assessment of trial quality, data extraction and synthesis of data were performed using the standard methods of The Cochrane Collaboration.

MAIN RESULTS

The 2012 update identified 13 studies classified as ongoing or awaiting classification (yet to report allergy outcomes). Forty-three studies were excluded, primarily as no allergy data were reported, although none of these enrolled infants were at high risk of allergy. Four studies enrolling 1428 infants were eligible for inclusion. All studies were at high risk of attrition bias. Allergy outcomes were reported from four months to two years of age.Meta-analysis of two studies (226 infants) found no significant difference in infant asthma although significant heterogeneity was found between studies. Meta-analysis of four studies found a significant reduction in eczema (1218 infants, typical risk ratio 0.68, 95% CI 0.48 to 0.97; typical risk difference -0.04, 95% CI -0.07 to -0.00; number needed to treat to benefit (NNTB) 25, 95% CI 14 to > 100; P = 0.03). No statistically significant heterogeneity was found between studies. One study reported no significant difference in urticaria.No statistically significant subgroup differences were found according to infant risk of allergy or type of infant feed. However, individual studies reported a significant reduction in asthma and eczema from supplementation with a mixture of galacto- and fructo-oligosaccharide (GOS/FOS 9:1 ratio) (8 g/L) in infants at high risk of allergy; and in eczema from supplementation with GOS/FOS (9:1) (6.8 g/L) and acidic oligosacccharide (1.2 g/L) in infants not selected for allergy risk.

AUTHORS' CONCLUSIONS

Further research is needed before routine use of prebiotics can be recommended for prevention of allergy in formula fed infants. There is some evidence that a prebiotic supplement added to infant feeds may prevent eczema. It is unclear whether the use of prebiotic should be restricted to infants at high risk of allergy or may have an effect in low risk populations; or whether it may have an effect on other allergic diseases including asthma.

How should an incident case of atopic dermatitis be defined? A systematic review of primary prevention studies

BACKGROUND

Eczema prevention is now an active area of dermatologic and allergy research. Defining an incident case is therefore a prerequisite for such a study.

OBJECTIVE

We sought to examine how an incident case of atopic dermatitis was defined in previous atopic dermatitis prevention studies in order to make recommendations on a standard definition of new atopic dermatitis cases for use in future prevention trials.

METHODS

We conducted a systematic review of controlled interventional atopic dermatitis prevention studies by using searches of MEDLINE and Cochrane databases for studies published from 1980 to the end of January 2011. Studies that included atopic dermatitis as a secondary outcome, such as asthma prevention trials, were included.

RESULTS

One hundred two studies were included in the final analysis, of which 27 (26.5%) did not describe any criteria for defining an incident case of atopic dermatitis. Of the remaining 75 studies with reported disease criteria, the Hanifin-Rajka criteria were the most commonly used (28 studies). A disease definition unique to that particular study (21 studies) was the second most commonly used disease definition, although the sources for such novel definitions were not cited.

CONCLUSIONS

The results from this systematic review highlight the need for improved reporting and standardization of the definition used for an incident case in atopic dermatitis prevention studies. Most prevention studies have used disease definitions such as the Hanifin-Rajka criteria that include disease chronicity. While acceptable for cumulative incidence outcomes, inclusion of disease chronicity precludes the precise measurement of disease onset. We propose a definition based on existing scientific studies that could be used in future prospective studies.

Glutamine supplementation to prevent morbidity and mortality in preterm infants

BACKGROUND

Glutamine is a conditionally essential amino acid. Endogenous biosynthesis may be insufficient for tissue needs in states of metabolic stress. Evidence exists that glutamine supplementation improves clinical outcomes in critically ill adults. It has been suggested that glutamine supplementation may also benefit preterm infants.

OBJECTIVES

To determine the effects of glutamine supplementation on mortality and morbidity in preterm infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2011, Issue 4), MEDLINE, EMBASE and CINAHL (to November 2011), conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared glutamine supplementation versus no glutamine supplementation in preterm infants at any time from birth to discharge from hospital.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two review authors. We synthesised data using a fixed-effect model and reported typical relative risk, typical risk difference and weighted mean difference.

MAIN RESULTS

We identified 11 randomised controlled trials in which a total of 2771 preterm infants participated. Five trials assessed enteral glutamine supplementation and six trials assessed parenteral glutamine supplementation. The trials were generally of good methodological quality. Meta-analysis did not detect a statistically significant effect of glutamine supplementation on mortality [typical relative risk 0.98 (95% confidence interval 0.80 to 1.18); risk difference 0.00 (95% confidence interval -0.03 to 0.02)] or major neonatal morbidities including the incidence of invasive infection or necrotising enterocolitis. Two trials that assessed neurodevelopmental outcomes at 18 to 24 months did not find any statistically significant differences in various assessments.

AUTHORS' CONCLUSIONS

The available trial data do not provide evidence that glutamine supplementation confers important benefits for preterm infants.

Intestinal microbiota in allergic and nonallergic 1-year-old very low birth weight infants after neonatal glutamine supplementation

AIM

Previously, glutamine-enriched enteral nutrition in very low birth weight infants (VLBW) decreased the incidence of atopic dermatitis at age 1 year. The aim of this study was to determine whether this effect is related to changes in intestinal bacterial species that are associated with allergy, such as bifidobacteria, clostridium histolyticum, clostridium lituseburense (Chis/lit group) and Escherichia coli at age 1 year.

METHODS

  Eighty-nine infants were eligible for this follow-up study, conducted at a Tertiary care hospital. Bifidobacteria, Chis/lit group and E. coli were measured by fluorescent in situ hybridization in faecal samples collected at age 1 year. Information on allergic and infectious diseases was previously determined by questionnaire.

RESULTS

 Seventy-two of 89 (81%) infants were participated. Prevalence of all studied species was not different between glutamine-supplemented and control groups. Allergic infants were less frequently colonized with bifidobacteria than nonallergic infants (p =0.04). Between neonatal period and 1 year, prevalence of bifidobacteria was increased (p < 0.001), of Chis/lit group was unchanged (p=0.84), and of E. coli was decreased (p < 0.001).

CONCLUSION

 The beneficial effect of glutamine-enriched enteral nutrition on the incidence of atopic dermatitis in the first year of life in VLBW infants is not related to changes in bifidobacteria, Chis/lit group or E. coli. Allergic VLBW infants are less frequently colonized with bifidobacteria compared to nonallergic VLBW infants.

Cytokine profiles in 1-yr-old very low-birth-weight infants after enteral glutamine supplementation in the neonatal period

In a previous study, we found that glutamine-enriched enteral nutrition in 102 very low-birth-weight (VLBW) infants decreased both the incidence of serious neonatal infections and atopic dermatitis during the first year of life. The aims of this follow-up study were to determine whether these beneficial effects are attended by changes in Th(1) and Th(2) cytokine profiles at age 1 yr. Furthermore, we studied changes in cytokine profiles during the first year of life in these VLBW infants. In total, 89 infants were eligible for the follow-up study (12 died, 1 exclusion due to a chromosomal abnormality). Th(1) (IFN-gamma, TNF- alpha and IL-2) and Th(2) cytokine (IL-10, IL-5, and IL-4) profiles following in vitro whole blood stimulation were measured at 1 yr. Cytokine profiles were measured in 59/89 (66%) infants. Glutamine-enriched enteral nutrition in neonatal period did not influence cytokine profiles at 1 yr. Cytokine profiles were not different in infants with and without allergic or infectious diseases. The beneficial effect of glutamine-enriched enteral nutrition on the incidence of serious neonatal infections and atopic dermatitis during the first year of life is not related to changes in the Th(1) and Th(2) cytokine profiles. Both Th(1) and Th(2) cytokine profiles increased during the first year of life in this cohort of VLBW infants.

Design of a randomised controlled trial on immune effects of acidic and neutral oligosaccharides in the nutrition of preterm infants: carrot study

Background

Prevention of serious infections in preterm infants is a challenge, since prematurity and low birth weight often requires many interventions and high utility of devices. Furthermore, the possibility to administer enteral nutrition is limited due to immaturity of the gastrointestinal tract in the presence of a developing immune system. In combination with delayed intestinal bacterial colonisation compared with term infants, this may increase the risk for serious infections. Acidic and neutral oligosaccharides play an important role in the development of the immune system, intestinal bacterial colonisation and functional integrity of the gut. This trial aims to determine the effect of enteral supplementation of acidic and neutral oligosaccharides on infectious morbidity (primary outcome), immune response to immunizations, feeding tolerance and short-term and long-term outcome in preterm infants. In addition, an attempt is made to elucidate the role of acidic and neutral oligosaccharides in postnatal modulation of the immune response and postnatal adaptation of the gut.

Methods/Design

In a double-blind placebo controlled randomised trial, 120 preterm infants (gestational age <32 weeks and/or birth weight <1500 gram) are randomly allocated to receive enteral acidic and neutral oligosaccharides supplementation (20%/80%) or placebo supplementation (maltodextrin) between day 3 and 30 of life. Primary outcome is infectious morbidity (defined as the incidence of serious infections). The role of acidic and neutral oligosaccharides in modulation of the immune response is investigated by determining the immune response to DTaP-IPV-Hib(-HBV)+PCV7 immunizations, plasma cytokine concentrations, faecal Calprotectin and IL-8. The effect of enteral acidic and neutral oligosaccharides supplementation on postnatal adaptation of the gut is investigated by measuring feeding tolerance, intestinal permeability, intestinal viscosity, and determining intestinal microflora. Furthermore, short-term and long-term outcome are evaluated.

Discussion

Especially preterm infants, who are at increased risk for serious infections, may benefit from supplementation of prebiotics. Most studies with prebiotics only focus on the colonisation of the intestinal microflora. However, the pathways how prebiotics may influence the immune system are not yet fully understood. Studying the immune modulatory effects is complex because of the multicausal risk of infections in preterm infants. The combination of neutral oligosaccharides with acidic oligosaccharides may have an increased beneficial effect on the immune system. Increased insight in the effects of prebiotics on the developing immune system may help to decrease the (infectious) morbidity and mortality in preterm infants.

Trial registration

Current Controlled Trials ISRCTN16211826.

Neurodevelopmental outcomes of very low-birth-weight infants after enteral glutamine supplementation in the neonatal period

AIM

To determine the effect of neonatal glutamine-enriched enteral nutrition in very low birth weight (VLBW) infants on neurodevelopmental outcome at 2 years of age.

METHODS

Eighty-eight out of one hundred two infants participating in the initial study were eligible for the follow-up study (13 died, one exclusion due to a chromosomal abnormality). Neurodevelopmental outcome (neurologic status, vision, hearing and Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) of the Bayley Scales of Infant Development II) was evaluated at the corrected age of 2 years. To adjust for potential confounders, data were analyzed by multiple linear or logistic regression (for continuous and dichotomous variables, respectively)

RESULTS

Seventy-two out of eighty-eight (82%) infants participated in the follow-up study: 40 and 32 infants in glutamine-supplemented and control groups, respectively. The incidence of neither an MDI nor a PDI <or= 85 was different in glutamine-supplemented and control groups (MDI <or= 85: 27 and 19%, p = 0.17; PDI <or= 85: 28 and 16% p = 0.16, respectively). The incidence of neurodevelopmental impairment was not different between both groups (OR: 2.16, 95% CI: 0.64-7.28).

CONCLUSIONS

A positive effect of neonatal glutamine-enriched enteral nutrition in VLBW infants on neurodevelopmental outcome at 2 years of age was not found in this study.

Glutamine supplementation to prevent morbidity and mortality in preterm infants

BACKGROUND

Glutamine endogenous biosynthesis may be insufficient for tissue needs in states of metabolic stress. Trials in adults have suggested that glutamine supplementation improves clinical outcomes in critically ill adults. It has been suggested that glutamine supplementation may benefit preterm infants, particularly very low birth weight infants.

OBJECTIVES

To determine the effects of glutamine supplementation on mortality and morbidity in preterm infants.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2007), MEDLINE (1966 - July 2007), EMBASE (1980 - July 2007), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared glutamine supplementation versus no glutamine supplementation in preterm infants at any time from birth to discharge from hospital.

DATA COLLECTION AND ANALYSIS

The standard methods of the Cochrane Neonatal Review Group were used, with separate evaluation of trial quality and data extraction by two authors. Data were synthesised using a fixed effects model and reported using typical relative risk, typical risk difference and weighted mean difference.

MAIN RESULTS

2365 preterm infants have participated in seven randomised controlled trials. All of the participating infants were of very low birth weight. Three trials assessed enteral glutamine supplementation and four trials assessed parenteral glutamine supplementation. The trials were generally of good methodological quality with adequate allocation concealment, blinding of caregivers and assessors to the intervention, and complete or near-complete follow-up of recruited infants. Glutamine supplementation does not have a statistically significant effect on mortality: typical relative risk 0.98 (95% confidence interval 0.80 to 1.20); typical risk difference 0.00 (95% confidence interval -0.03 to 0.02). The only trial that assessed long-term outcomes did not find any statistically significant differences in various assessments of neurodevelopment at 18 months corrected age. Glutamine supplementation does not have a statistically significant effect on other neonatal morbidities including invasive infection, necrotising enterocolitis, time to achieve full enteral nutrition, or duration of hospital stay.

AUTHORS' CONCLUSIONS

The available data from good quality randomised controlled trials indicate that glutamine supplementation does not confer benefits for preterm infants. The narrow confidence intervals for the effect size estimates suggest that a further trial of this intervention is not a research priority.

The effect of glutamine-enriched enteral nutrition on intestinal microflora in very low birth weight infants: A randomized controlled trial

BACKGROUND & AIMS

In a previous study, we have found that glutamine supplementation decreased the infection rate in very low birth weight (VLBW) infants. In this study, we investigated whether this beneficial effect originated from increased number of bifidobacteria and lactobacilli in the intestinal microflora of these infants.

METHODS

In a randomized controlled trial, VLBW infants (gestational age <32 weeks and/or birth weight <1500g) received enteral glutamine supplementation (0.3g/kg/day) or isonitrogenous placebo supplementation between d3 and d30 of life. Faecal microflora was determined by fluorescent in situ hybridization <48h, at d7, d14 and d30 of life.

RESULTS

In 43/52 (glutamine group) and 43/50 (control group) infants, > or = 2 samples were analyzed. Baseline characteristics were not different between groups. The prevalence of bifidobacteria, lactobacilli, Escheria coIi, streptococci and clostridia was not different between groups (p>0.05). In both groups, colonization with bifidobacteria was delayed, whereas potentially pathogenic bacteria such as E. coli, appeared rapidly after birth. Antibiotic treatment decreased the prevalence of all faecal bacteria (p<0.05).

CONCLUSIONS

Decreased infectious morbidity in VLBW infants that received glutamine supplementation was not associated with alterations in the prevalence of bifidobacteria, lactobacilli, E. coIi, streptococci and clostridia. In general, colonization with health-promoting bacteria was delayed, whereas potentially pathogenic bacteria appeared rapidly after birth. Antibiotic treatment delayed the bacterial colonization.