Glutamine supplementation to prevent morbidity and mortality in preterm infants

Targeting amino acid metabolism in cancer

Metabolic rewiring is a characteristic hallmark of cancer cells. This phenomenon sustains uncontrolled proliferation and resistance to apoptosis by increasing nutrients and energy supply. However, reprogramming comes together with vulnerabilities that can be used against tumor and can be applied in targeted therapy. In the last years, the genetic background of tumors has been identified thoroughly and new therapies targeting those mutations tested. Nevertheless, we propose that targeting the phenotype of cancer cells could be another way of treatment aiming to avoid drug resistance and non-responsiveness of cancer patients. Amino acid metabolism is part of the altered processes in cancer cells. Amino acids are building blocks and also sensors of signaling pathways regulating main biological processes. In this comprehensive review, we described four amino acids (asparagine, arginine, methionine, and cysteine) which have been actively investigated as potential targets for anti-tumor therapy. Asparagine depletion is successfully used for decades in the treatment of acute lymphoblastic leukemia and there is a strong implication to apply it to other types of tumors. Arginine auxotrophic tumors are great candidates for arginine-starvation therapy. Higher requirement for essential amino acids such as methionine and cysteine point out promising targetable weaknesses of cancer cells.

The Role of Nutrition in the Prevention and Management of Bronchopulmonary Dysplasia: A Literature Review and Clinical Approach

Bronchopulmonary dysplasia (BPD) remains the most common severe complication of preterm birth, and nutrition plays a crucial role in lung growth and repair. A practical nutritional approach for infants at risk of BPD or with established BPD is provided based on a comprehensive literature review. Ideally, infants with BPD should receive a fluid intake of not more than 135-150 mL/kg/day and an energy intake of 120-150 kcal/kg/day. Providing high energy in low volume remains a challenge and is the main cause of growth restriction in these infants. They need a nutritional strategy that encompasses early aggressive parenteral nutrition and the initiation of concentrated feedings of energy and nutrients. The order of priority is fortified mother's own milk, followed by fortified donor milk and preterm enriched formulas. Functional nutrient supplements with a potential protective role against BPD are revisited, despite the limited evidence of their efficacy. Specialized nutritional strategies may be necessary to overcome difficulties common in BPD infants, such as gastroesophageal reflux and poorly coordinated feeding. Planning nutrition support after discharge requires a multidisciplinary approach to deal with multiple potential problems. Regular monitoring based on anthropometry and biochemical markers is needed to guide the nutritional intervention.

Dietary supplementary glutamine and L-carnitine enhanced the anti-cold stress of Arbor Acres broilers

Newborn poultry in cold regions often suffer from cold stress, causing a series of changes in their physiology and metabolism, leading to slow growth and decreased production performance. However, a single anti-stress substance cannot completely or maximally eliminate or alleviate the various effects of cold stress on animals. Therefore, the effects of the supplemented glutamine and L-carnitine on broilers under low temperature were evaluated in this study. Broilers were randomly allocated into 16 groups which were respectively fed with different levels of glutamine and L-carnitine according to the L16 (45) orthogonal experimental design for 3 weeks (the first week is the adaptive feeding period; the second and third weeks are the cold exposure period). Growth performance was recorded, and blood samples were collected during cold exposure. The results showed the supplementation had altered the plasma parameters, growth performance and cold-induced oxidative stress. The increase of corticosterone and suppression of thyroid hormone was ameliorated. Supplemented groups had lower daily feed intake and feed-to-gain ratio, higher daily weight gain and better relative weights of immune organs. Plasma glucose, total protein, blood urea nitrogen and alkaline phosphatase changed as well. Oxidative stress was mollified due to the improved activities of superoxide dismutase and glutathione peroxidase, heightened total antioxidant capacity and stable malondialdehyde. Dietary glutamine and L-carnitine improve the growth performance, nutritional status and cold stress response of broilers at low temperature, and their interaction occurred.

Effect of enteral glutamine supplementation for low-birth-weight infants on weight gain patterns and levels of fecal secretory immunoglobulin A

Aim

Glutamine is needed for optimal cell growth and for the immune system, especially in the enterocytes of gut mucosal immune responses. Low birth weight makes infants susceptible to glutamine depletion because nutrition is limited in the first week of life. To determine the effect of enteral glutamine supplementation on weight gain patterns and fecal secretory immunoglobulin A.

Material and Methods

This study is a double-blind, randomized controlled trial. Infants were randomly assigned to the glutamine group and placebo group. The glutamine group was supplemented with glutamine 400 mg/kg/day for 14 days, and placebo group received glucose 400 mg/kg/day for 14 days. The infants were observed for 30 days. Return-to-birth-weight, weight gain velocity, and fecal secretory immunoglobulin A levels were monitored during the study.

Results

Thirty-seven low-birth-weight infants were randomly assigned to the glutamine and placebo groups. The glutamine group had a shorter return-to-birth-weight time than the placebo group (8.1±0.9 vs. 11.0±1.6 days) and faster weight gain velocity (20.0±1.8 vs. 15.5±2.2 g/kg/day) (p<0.001). Secretory immunoglobulin A levels after glutamine supplementation were higher than in the placebo group (0.456±0.057 vs. 0.376±0.035 mg/g) (p<0.001). Levels of secretory immunoglobulin A after treatment in each group were increased. However, there was a significant difference before and after supplementation between the glutamine and placebo groups (0.247±0.024 vs. 0.140±0.016 mg/g) (p<0.001).

Conclusion

Enteral glutamine supplementation in low-birth-weight infants accelerates return to birth weight, increases the weight gain velocity, and the levels of fecal secretory immunoglobulin A.

Comparative Effectiveness of Prophylactic Therapies for Necrotizing Enterocolitis in Preterm Infants: Protocol for a Network Meta-analysis of Randomized Trials

Necrotizing enterocolitis (NEC) is a common and devastating disease with high morbidity and mortality in premature infants. Current literature on the prevention of NEC has limitations including lack of direct and indirect comparisons of available therapies. We will search MEDLINE, EMBASE, Science Citation Index Expanded, Social Sciences Citation Index, CINAHL, Scopus, ProQuest Dissertations and Theses database, and grey literature sources to identify eligible trials evaluating NEC preventive therapies. Eligible studies will (1) enroll preterm (gestational age <37 weeks) and/or low birth weight (birth weight <2500 g) infants, (2) randomize infants to any preventive intervention or a placebo, or alternative active or nonactive intervention. Our outcomes of interest are severe NEC (stage II or more, based on Bell's criteria), all-cause mortality, NEC-related mortality, late-onset sepsis, duration of hospitalization, weight gain, time to establish full enteral feeds, and treatment-related adverse events. Two reviewers will independently screen trials for eligibility, assess risk of bias, and extract data. All discrepancies will be resolved by discussion. We will specify a priori explanations for heterogeneity between studies. For available comparisons between treatment and no treatment, and direct comparisons of treatments, we will conduct conventional meta-analysis using a random effects model. We will conduct a network meta-analysis using a random effects model within the Bayesian framework using Markov chain Monte Carlo methods to assess relative effects of eligible interventions. We will assess the certainty in direct, indirect, and network estimates using the Grading of Recommendations Assessment, Development and Evaluation approach.

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.

Infant Maturity at Birth Reveals Minor Differences in the Maternal Milk Metabolome in the First Month of Lactation

BACKGROUND

Human milk is the gold standard of nutrition for infants, providing both protective and essential nutrients. Although much is known about milk from mothers giving birth to term infants, less is known about milk from mothers giving birth to premature infants. In addition, little is known about the composition and diversity of small molecules in these milks and how they change over the first month of lactation.

OBJECTIVE

The objective was to understand how milk metabolites vary over the first month of lactation in mothers giving birth to term and preterm infants.

METHODS

(1)H nuclear magnetic resonance (NMR) metabolomics was used to characterize metabolites that were present in micromolar to molar concentrations in colostrum (day 0-5 postpartum), transition milk (day 14), and mature milk (day 28) from mothers who delivered term (n = 15) and preterm (n = 13) infants. Principal components analysis, linear mixed-effects models (LMMs), and linear models (LMs) were used to explore the relation between infant maturity and the postpartum day of collection of milk samples.

RESULTS

By using a standard NMR metabolite library, 69 metabolites were identified in the milks, including 15 sugars, 23 amino acids and derivatives, 11 energy-related metabolites, 10 fatty acid-associated metabolites, 3 nucleotides and derivatives, 2 vitamins, and 5 bacteria-associated metabolites. Many metabolite concentrations followed a similar progression over time in both term and preterm milks, with more biological variation in metabolite concentrations in preterm milk. However, although lacto-N-neotetraose (LMM, P = 4.0 × 10(-5)) and lysine (LM, P = 1.5 × 10(-4)) significantly decreased in concentration in term milk over time, they did not significantly change in preterm milk.

CONCLUSION

Overall, the metabolic profile of human milk is dynamic throughout the first month of lactation, with more variability in preterm than in term milk and subtle differences in some metabolite concentrations. This trial was registered at clinicaltrials.gov as NCT01841268.

Impact of nutrition on brain development and its neuroprotective implications following preterm birth

The impact of nutrition on brain development in preterm infants has been increasingly appreciated. Early postnatal growth and nutrient intake have been demonstrated to influence brain growth and maturation with subsequent effects on neurodevelopment that persist into childhood and adolescence. Nutrition could also potentially protect against injury. Inflammation and perinatal infection play a crucial role in the pathogenesis of white matter injury, the most common pattern of brain injury in preterm infants. Therefore, nutritional components with immunomodulatory and/or anti-inflammatory effects may serve as neuroprotective agents. Moreover, growing evidence supports the existence of a microbiome-gut-brain axis. The microbiome is thought to interact with the brain through immunological, endocrine, and neural pathways. Consequently, nutritional components that may influence gut microbiota may also exert beneficial effects on the developing brain. Based on these properties, probiotics, prebiotic oligosaccharides, and certain amino acids are potential candidates for neuroprotection. In addition, the amino acid glutamine has been associated with a decrease in infectious morbidity in preterm infants. In conclusion, early postnatal nutrition is of major importance for brain growth and maturation. Additionally, certain nutritional components might play a neuroprotective role against white matter injury, through modulation of inflammation and infection, and may influence the microbiome-gut-brain axis.

Glutamine supplementation for young infants with severe gastrointestinal disease

BACKGROUND

Endogenous glutamine biosynthesis may be insufficient to meet the needs of people with severe gastrointestinal disease. Results from studies using experimental animal models of gastrointestinal disease have suggested that glutamine supplementation improves clinical outcomes. This review examines evidence on the effect of glutamine supplementation in young infants with severe gastrointestinal disease.

OBJECTIVES

To assess the effect of supplemental glutamine on mortality and morbidity in young infants with severe gastrointestinal disease.

SEARCH METHODS

We searcheed the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2014, Issue 8), MEDLINE, EMBASE, and CINAHL (from inception to September 2014), conference proceedings, and reference lists from previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared glutamine supplementation versus no glutamine supplementation in infants up to three months old (corrected for preterm birth if necessary) with severe gastrointestinal disease defined as a congenital or acquired gastrointestinal condition that is likely to necessitate providing parenteral nutrition for at least 24 hours.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial eligibility and risk of bias and undertook data extraction independently. We analysed the treatment effects in the individual trials and reported the risk ratio (RR) and risk difference (RD) for dichotomous data and mean difference for continuous data, with 95% confidence intervals (CI). We used a fixed-effect model in meta-analyses and explored the potential causes of heterogeneity in sensitivity analyses.

MAIN RESULTS

We found three trials in which a total of 274 infants participated. The trials were of good methodological quality but were too small to detect clinically important effects of glutamine supplementation. Meta-analyses did not reveal a statistically significant difference in the risk of death before hospital discharge (typical RR 0.79, 95% CI 0.19 to 3.20; typical RD -0.01, 95% CI -0.05 to 0.03) or in the rate of invasive infection (typical RR 1.37, 95% CI 0.89 to 2.11; typical RD 0.08, 95% CI -0.03 to 0.18]).

AUTHORS' CONCLUSIONS

The available data from randomised controlled trials do not suggest that glutamine supplementation has any important benefits for young infants with severe gastrointestinal disease.

Evidence-based feeding strategies before and after the development of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a devastating disease of premature infants and is associated with significant morbidity and mortality. While the pathogenesis of NEC remains incompletely understood, it is well established that the risk of disease is increased by the administration of infant formula and decreased by the administration of breast milk. This review will focus on the mechanisms by which breast milk may serve to protect against NEC, and will review the evidence regarding various feeding strategies that may be utilized before and after an episode of NEC.

Pathophysiology and current management of necrotizing enterocolitis

Necrotizing enterocolitis (NEC), an inflammatory bowel necrosis of preterm infants, is the most common gastrointestinal emergency and a major cause of morbidity and mortality in these infants. In this article, the authors review the pathophysiology and clinical presentation of NEC and provide a critical appraisal of the evidence supporting various prophylactic and therapeutic strategies. A literature search was performed using the databases PubMed, EMBASE, and Scopus. Current pathophysiological models of NEC suggest that the disease occurs when mucosal injury in the preterm intestine results in translocation of luminal bacteria across the epithelial barrier, triggering an exaggerated and damaging local inflammatory response. Medical management of NEC is largely supportive and likely does not modify the etiopathogenesis of this disease. Antenatal steroids, human milk feedings, adoption of standardized feeding regimens, and probiotics hold promise for prevention of NEC. Future research should focus on early recognition that occurs well before the onset of intestinal necrosis, and prevention of this disease.

Glutamine supplementation for young infants with severe gastrointestinal disease

BACKGROUND

Endogenous glutamine biosynthesis may be insufficient to meet the needs of people with severe gastrointestinal disease. Studies using experimental animal models and controlled trials in adult patients with severe gastrointestinal disease have suggested that glutamine supplementation improves clinical outcomes. This review examines evidence for the effect of glutamine supplementation in young infants with severe gastrointestinal disease.

OBJECTIVES

To assess the evidence from randomised controlled trials that providing supplemental glutamine reduces mortality and morbidity in young infants with severe gastrointestinal disease.

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, 2012, Issue 1), 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 infants up to three months old (corrected for preterm birth if necessary) with severe gastrointestinal disease defined as a congenital or acquired gastrointestinal condition that is likely to necessitate providing parenteral nutrition for at least 24 hours.

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 risk ratio (RR), typical risk difference (RD), and weighted mean difference (WMD).

MAIN RESULTS

We found two trials in which a total of 100 infants participated. The trials were of good methodological quality but were too small to detect clinically important effects of glutamine supplementation. Meta-analysis did not reveal a statistically significant difference in the risk of death before hospital discharge (typical RR 1.57; 95% confidence interval (95% CI) 0.25 to 9.66; RD 0.02; 95% CI -0.06 to 0.10) or in the rate of invasive infection [typical RR 1.22; 95% CI 0.55 to 2.70; RD 0.04; 95% CI -0.12 to 0.20).

AUTHORS' CONCLUSIONS

The available data from randomised controlled trials are insufficient to determine whether glutamine supplementation has any important benefits for young infants with severe gastrointestinal disease.