Beneficial Effects of Early Enteral Nutrition After Major Rectal Surgery: A Possible Role for Conditionally Essential Amino Acids? Results of a Randomized Clinical Trial

An Elemental Diet Reduces Chylous Ascites of Patients Undergoing Pancreatoduodenectomy in the Setting of Early Enteral Feeding

OBJECTIVES

The elemental diet (ED) is a formula to support nutritional status without increasing chylous burden. This study evaluates the efficacy of early ED feeding after pancreatoduodenectomy (PD).

MATERIALS AND METHODS

A prospective phase II study of consecutive patients who underwent PD with early ED feeding was conducted. Patient backgrounds, surgical outcomes, and ED feeding tolerability were compared with a historical cohort of 74 PD patients with early enteral feeding of a low residue diet (LRD).

RESULTS

The ED group comprised 104 patients. No patient in the ED group discontinued enteral feeding because of chylous ascites (CAs), whereas 17.6% of the LRD group experienced refractory CAs that disrupted further enteral feeding. The CAs rate was significantly decreased in the ED group compared with the LRD group (3.9% and 48.7%, respectively; P < 0.001). There was no significant difference in the incidence of major complications (ED: 17.3%, LRD: 18.9%; P = 0.844). Postoperative prognostic nutritional index was similar between the 2 groups ( P = 0.764). In multivariate analysis, enteral feeding formula, and sex were independent risk factors for CAs (LRD: P < 0.001, odds ratio, 22.87; female: P = 0.019, odds ratio, 2.78).

CONCLUSIONS

An ED reduces postoperative CAs of patients undergoing PD in the setting of early enteral feeding.

Nutrition as prevention for improved cancer health outcomes: a systematic literature review

BACKGROUND

Among adults with cancer, malnutrition is associated with decreased treatment completion, more treatment harms and use of health care, and worse short-term survival. To inform the National Institutes of Health Pathways to Prevention workshop, "Nutrition as Prevention for Improved Cancer Health Outcomes," this systematic review examined the evidence for the effectiveness of providing nutrition interventions before or during cancer therapy to improve outcomes of cancer treatment.

METHODS

We identified randomized controlled trials enrolling at least 50 participants published from 2000 through July 2022. We provide a detailed evidence map for included studies and grouped studies by broad intervention and cancer types. We conducted risk of bias (RoB) and qualitative descriptions of outcomes for intervention and cancer types with a larger volume of literature.

RESULTS

From 9798 unique references, 206 randomized controlled trials from 219 publications met the inclusion criteria. Studies primarily focused on nonvitamin or mineral dietary supplements, nutrition support, and route or timing of inpatient nutrition interventions for gastrointestinal or head and neck cancers. Most studies evaluated changes in body weight or composition, adverse events from cancer treatment, length of hospital stay, or quality of life. Few studies were conducted within the United States. Among intervention and cancer types with a high volume of literature (n = 114), 49% (n = 56) were assessed as high RoB. Higher-quality studies (low or medium RoB) reported mixed results on the effect of nutrition interventions across cancer and treatment-related outcomes.

CONCLUSIONS

Methodological limitations of nutrition intervention studies surrounding cancer treatment impair translation of findings into clinical practice or guidelines.

Meta-analysis of Glutamine on Immune Function and Post-Operative Complications of Patients With Colorectal Cancer

The aim of this meta-analysis was to evaluate the clinical significance of glutamine in the management of patients with colorectal cancer (CRC) after radical operation. Electronic databases, including PubMed, EMBASE, MEDLINE, Cochrane Library, Chinese Biomedical Database (CBM), China National Knowledge Infrastructure (CNKI), VIP medicine information system (VIP), and Wanfang electronic databases were comprehensively searched from inception to 30, July 2021. Prospective randomized trials with glutamine vs. routine nutrition or blank therapy were selected. The immune function related indicators (including IgA, IgG, IgM, CD4+, CD8+, and the ratio of CD4+/CD8+), post-operative complications [including surgical site infection (SSI), anastomotic leakage, and length of hospital stay (LOS)], and corresponding 95% confidence intervals (CIs) were assessed in the pooled analysis. Subsequently, the heterogeneity between studies, sensitivity, publication bias, and meta-regression analysis were performed. Consequently, 31 studies which contained 2,201 patients (1,108 in the glutamine group and 1,093 in the control group) were included. Results of pooled analysis indicated that glutamine significantly improved the humoral immune function indicators [including IgA (SMD = 1.15, 95% CI: 0.72–1.58), IgM (SMD = 0.68, 95% CI: 0.48–0.89), and IgG (SMD = 1.10, 95% CI: 0.70–1.50)], and the T cell immune function indicators [including CD4+ (SMD = 0.76, 95% CI: 0.53–0.99) and the ratio of CD4+/CD8+ (SMD = 0.92, 95% CI: 0.57–1.28)]. Meanwhile, the content of CD8+ was decreased significantly (SMD = −0.50, 95% CI: −0.91 to −0.10) followed by glutamine intervention. Pooled analysis of SSI (RR = 0.48, 95% CI: 0.30–0.75), anastomotic leakage (RR = 0.23, 95% CI: 0.09–0.61), and LOS (SMD = −1.13, 95% CI: −1.68 to −0.58) were decreased significantly in glutamine group compared with control group. Metaregression analysis revealed that the covariate of small-sample effects influenced the robustness and reliability of IgG outcome potentially. Findings of the present work demonstrated that glutamine ought to be applied as an effective immunenutrition therapy in the treatment of patients with CRC after radical surgery. The present meta-analysis has been registered in PROSPERO (no. CRD42021243327).

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO, Identifier: CRD42021243327.

Value of nutrition support therapy in patients with gastrointestinal malignancies: a narrative review and health economic analysis of impact on clinical outcomes in the United States

Malnutrition, particularly under-nutrition, is highly prevalent among adult patients with a diagnosis of gastrointestinal (GI) cancer and negatively affects patient outcomes. Malnutrition is associated with clinical and surgical complications for patients undergoing therapy for GI cancers and the costs associated with those complications is a high burden for the US health system. Our objective was to identify high-quality evidence for nutrition support interventions associated with cost savings for patient care, followed by a complex economic value analysis to project cost savings for the US health system. A narrative literature search was conducted in which combined keywords in the areas of therapeutic nutrition (nutrition, malnutrition), a specific therapeutic area [GI cancer (esophageal, gastric, gallbladder, pancreatic, liver/hepatic, small and large intestine, colorectal)], and clinical outcomes and healthcare cost, to look for nutrition interventions that could significantly improve clinical outcomes. Medicare claims data were then analyzed using the findings of these identified studies and this modeling exercise supported identifying the cost and healthcare resource utilization implications of specific populations to determine the impact of nutrition support on reducing these costs as reflected in the summary of the evidence. Eight studies were found that provided clinical outcomes and health cost savings data, 2 of those had the strongest level of evidence and were used for Value Analysis calculations. Nutrition interventions such as oral diet modifications, enteral nutrition (EN) supplementation, and parenteral nutrition (PN) have been studied especially in the peri-operative setting. Specifically, peri-operative immunonutrition administration and utilization of enhanced recovery pathways after surgery have been associated with significant improvement in postoperative complications and decreased length of hospital stay (LOS). Utilizing economic modeling of Medicare claims data from GI cancer patients, potential annual cost savings of $242 million were projected by the widespread adoption of these interventions. Clinical outcomes can be improved with the use of nutrition interventions in patients with GI cancers. Healthcare costs can be reduced as a result of fewer in-hospital complications and shorter lengths of hospital stay. The application of nutrition intervention provides a positive clinical and economic value proposition to the healthcare system for patients with GI cancers.

Impact of Intravenous Fluids and Enteral Nutrition on the Severity of Gastrointestinal Dysfunction: A Systematic Review and Meta-analysis

Introduction

Gastrointestinal dysfunction (GDF) is one of the primary causes of morbidity and mortality in critically ill patients. Intensive care interventions, such as intravenous fluids and enteral feeding, can exacerbate GDF. There exists a paucity of high-quality literature on the interaction between these two modalities (intravenous fluids and enteral feeding) as a combined therapy on its impact on GDF.

Aim

To review the impact of intravenous fluids and enteral nutrition individually on determinants of gut function and implications in clinical practice.

Methods

Randomized controlled trials on intravenous fluids and enteral feeding on GDF were identified by a comprehensive database search of MEDLINE and EMBASE. Extraction of data was conducted for study characteristics, provision of fluids or feeding in both groups and quality of studies was assessed using the Cochrane criteria. A random-effects model was applied to estimate the impact of these interventions across the spectrum of GDF severity.

Results

Restricted/ goal-directed intravenous fluid therapy is likely to reduce ‘mild’ GDF such as vomiting (p = 0.03) compared to a standard/ liberal intravenous fluid regime. Enterally fed patients experienced increased episodes of vomiting (p = <0.01) but were less likely to develop an anastomotic leak (p = 0.03) and peritonitis (p = 0.03) compared to parenterally fed patients. Vomiting (p = <0.01) and anastomotic leak (p = 0.04) were significantly lower in the early enteral feeding group.

Conclusions

There is less emphasis on the combined approach of intravenous fluid resuscitation and enteral feeding in critically ill patients. Conservative fluid resuscitation and aggressive enteral feeding are presumably key factors contributing to severe life-threatening GDF. Future trials should evaluate the impact of cross-interaction between conservative and aggressive modes of these two interventions on the severity of GDF.

Plasma metabolomics of early parenteral nutrition followed with enteral nutrition in pancreatic surgery patients

Nutrition support is essential for surgical patients. Patients undergoing pancreaticoduodenectomy (PD) require tremendous nutrient support but also faced with risks of infection and gastrointestinal complications. Early parenteral nutrition has recently shown benefits while limited information provided about the influence on metabolism. This prospective single-center cohort study used plasma metabolomics to clarify metabolic alteration after early parenteral nutrition followed with enteral nutrition. Patients undergoing pancreaticoduodenectomy (n = 52) were enrolled. 36 patients received parenteral nutrition within 3 days postoperatively followed with EN (TPN group), 16 patients received standard fluids followed with EN (GIK group). We found that the weight loss is reduced in TPN group while the other clinical outcomes and inflammatory cytokines showed no statistical significance. The TPN group showed significance in amino acids, lipid, and phospholipids metabolism compared with the GIK group. Moreover, integration analysis indicated that early TPN could promote the metabolism of long-chain fatty acids, phospholipids, ketone bodies, and branched-chain amino acids. We conclude that early TPN support followed with EN for patients undergoing PD reduced the perioperative weight loss and promoted the metabolic transition to anabolic metabolism with the recovery of lipid metabolism, suggesting its benefits for the recovery of patients.

Enhanced recovery after surgery in pediatric gastrointestinal surgery

Objective

Enhanced recovery after surgery (ERAS) protocols help optimize inpatient care and minimize discomfort. This study was performed to explore the safety, feasibility, and clinical and social value of ERAS in pediatric gastrointestinal surgery.

Methods

This study included all children (n = 125) who underwent appendectomy, pyloromyotomy, transabdominal Soave’s procedure, Meckel’s diverticulum resection, or reduction of intussusception in our institution from January to September 2018. We compared surgical outcomes between children who underwent surgery under conventional perioperative regimens (control group, n = 57) and those who were treated with ERAS protocols (ERAS group, n = 68).

Results

There were no significant intergroup differences in demographic or surgical data. However, the bowel function recovery time, postoperative intravenous nutrition time, duration of postoperative hospital stay, and hospital costs were significantly lower in the ERAS group than control group. There was no significant intergroup difference in the complication rate.

Conclusions

Our results indicate that implementation of ERAS protocols is safe and feasible in pediatric gastrointestinal surgery. They can improve patient comfort, shorten the duration of the postoperative hospital stay, reduce hospital costs, and accelerate postoperative rehabilitation without increasing the risk of postoperative complications. Therefore, ERAS protocols deserve wider implementation and promotion.

Clinical Nutrition in Critical Care Medicine - Guideline of the German Society for Nutritional Medicine (DGEM)

PURPOSE

Enteral and parenteral nutrition of adult critically ill patients varies in terms of the route of nutrient delivery, the amount and composition of macro- and micronutrients, and the choice of specific, immune-modulating substrates. Variations of clinical nutrition may affect clinical outcomes. The present guideline provides clinicians with updated consensus-based recommendations for clinical nutrition in adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function.

METHODS

The former guidelines of the German Society for Nutritional Medicine (DGEM) were updated according to the current instructions of the Association of the Scientific Medical Societies in Germany (AWMF) valid for a S2k-guideline. According to the S2k-guideline classification, no systematic review of the available evidence was required to make recommendations, which, therefore, do not state evidence- or recommendation grades. Nevertheless, we considered and commented the evidence from randomized-controlled trials, meta-analyses and observational studies with adequate sample size and high methodological quality (until May 2018) as well as from currently valid guidelines of other societies. The liability of each recommendation was described linguistically. Each recommendation was finally validated and consented through a Delphi process.

RESULTS

In the introduction the guideline describes a) the pathophysiological consequences of critical illness possibly affecting metabolism and nutrition of critically ill patients, b) potential definitions for different disease phases during the course of illness, and c) methodological shortcomings of clinical trials on nutrition. Then, we make 69 consented recommendations for essential, practice-relevant elements of clinical nutrition in critically ill patients. Among others, recommendations include the assessment of nutrition status, the indication for clinical nutrition, the timing and route of nutrient delivery, and the amount and composition of substrates (macro- and micronutrients); furthermore, we discuss distinctive aspects of nutrition therapy in obese critically ill patients and those treated with extracorporeal support devices.

CONCLUSION

The current guideline provides clinicians with up-to-date recommendations for enteral and parenteral nutrition of adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function. The period of validity of the guideline is approximately fixed at five years (2018-2023).

Modified enhanced recovery after surgery protocols are beneficial for postoperative recovery for patients undergoing emergency surgery for obstructive colorectal cancer: A propensity score matching analysis

Enhanced recovery after surgery (ERAS) is acknowledged to reduce perioperative stress in several surgical diseases. Here, we investigated whether modified ERAS is associated with beneficial effects in the setting of emergency colorectal surgery.We retrospectively evaluated the medical records of 839 consecutive patients with obstructive colorectal cancer undergoing surgical intervention at 4 institutes. Among them, 356 cases were managed with a multidisciplinary team approach to care (modified ERAS protocols), and the remaining 483 cases were treated based on traditional protocols. According to modified ERAS or traditional care, propensity score (PS) matching was performed to adjust biases in patient selection. The primary outcome was gastrointestinal function recovery. Secondary outcomes included postoperative complications and length of hospital stay.Modified ERAS was associated with postoperative gastrointestinal function recovery, including time to first flatus (P = .002), first defecation (P = .008), and prolonged ileus (P = .016). According to the Clavien-Dindo classification, fewer total episodes of grade II or higher postoperative complications were observed in patients cared for with modified ERAS than in patients with traditional care (P = .002). Median (interquartile range) postoperative hospital stay in the modified ERAS group was 6 (3-22) days versus 9 (7-27) days in the traditional care group (P < .001). Furthermore, the interval from operation to postoperative chemotherapy (d) was significantly shorter in the modified ERAS group (35.6 ± 11.5 vs 47.6 ± 23.8, P < .001).The modified ERAS was safe and associated with clinical benefits, including fast recovery of bowel function, reduced postoperative complications, and shorter hospital stay for patients with obstructive colorectal cancer.

Nutritional interventions to improve recovery from postoperative ileus

PURPOSE OF REVIEW

Postoperative ileus (POI) is an important contributor to postoperative morbidity. However, postoperative outcomes have improved by enhanced recovery after surgery (ERAS) programs. Enteral nutrition is an essential part of ERAS and many studies suggest a therapeutic effect of nutrition on POI.

RECENT FINDINGS

Early postoperative enteral nutrition has been shown to reduce various complications, including POI, although studies are heterogeneous. Experimental studies suggest that composition and timing of the enteral feed is important for the potential beneficial effects: lipid-enriched nutrition given just before, during, and directly after surgery was most effective in reducing POI in an experimental setting. In a clinical study in patients undergoing advanced rectal cancer surgery, direct start of enteral tube feeding reduced POI. Conversely, perioperative lipid-enriched enteral nutrition did not reduce POI in patients undergoing colorectal surgery with an ERAS protocol.

SUMMARY

POI is common and remains an important determinant of postoperative recovery following colorectal surgery. Nutrition is a potential therapeutic means to reduce POI. Timing and composition of the enteral feed have been shown to be essential for the beneficial effects of enteral nutrition in an experimental setup. However perioperative lipid-enriched nutrition does not reduce POI in patients undergoing colorectal surgery with an ERAS protocol.

Enteral versus parenteral nutrition and enteral versus a combination of enteral and parenteral nutrition for adults in the intensive care unit

BACKGROUND

Critically ill people are at increased risk of malnutrition. Acute and chronic illness, trauma and inflammation induce stress-related catabolism, and drug-induced adverse effects may reduce appetite or increase nausea and vomiting. In addition, patient management in the intensive care unit (ICU) may also interrupt feeding routines. Methods to deliver nutritional requirements include provision of enteral nutrition (EN), or parenteral nutrition (PN), or a combination of both (EN and PN). However, each method is problematic. This review aimed to determine the route of delivery that optimizes uptake of nutrition.

OBJECTIVES

To compare the effects of enteral versus parenteral methods of nutrition, and the effects of enteral versus a combination of enteral and parenteral methods of nutrition, among critically ill adults, in terms of mortality, number of ICU-free days up to day 28, and adverse events.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase on 3 October 2017. We searched clinical trials registries and grey literature, and handsearched reference lists of included studies and related reviews.

SELECTION CRITERIA

We included randomized controlled studies (RCTs) and quasi-randomized studies comparing EN given to adults in the ICU versus PN or versus EN and PN. We included participants that were trauma, emergency, and postsurgical patients in the ICU.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 25 studies with 8816 participants; 23 studies were RCTs and two were quasi-randomized studies. All included participants were critically ill in the ICU with a wide range of diagnoses; mechanical ventilation status between study participants varied. We identified 11 studies awaiting classification for which we were unable to assess eligibility, and two ongoing studies.Seventeen studies compared EN versus PN, six compared EN versus EN and PN, two were multi-arm studies comparing EN versus PN versus EN and PN. Most studies reported randomization and allocation concealment inadequately. Most studies reported no methods to blind personnel or outcome assessors to nutrition groups; one study used adequate methods to reduce risk of performance bias.Enteral nutrition versus parenteral nutritionWe found that one feeding route rather than the other (EN or PN) may make little or no difference to mortality in hospital (risk ratio (RR) 1.19, 95% confidence interval (CI) 0.80 to 1.77; 361 participants; 6 studies; low-certainty evidence), or mortality within 30 days (RR 1.02, 95% CI 0.92 to 1.13; 3148 participants; 11 studies; low-certainty evidence). It is uncertain whether one feeding route rather than the other reduces mortality within 90 days because the certainty of the evidence is very low (RR 1.06, 95% CI 0.95 to 1.17; 2461 participants; 3 studies). One study reported mortality at one to four months and we did not combine this in the analysis; we reported this data as mortality within 180 days and it is uncertain whether EN or PN affects the number of deaths within 180 days because the certainty of the evidence is very low (RR 0.33, 95% CI 0.04 to 2.97; 46 participants).No studies reported number of ICU-free days up to day 28, and one study reported number of ventilator-free days up to day 28 and it is uncertain whether one feeding route rather than the other reduces the number of ventilator-free days up to day 28 because the certainty of the evidence is very low (mean difference, inverse variance, 0.00, 95% CI -0.97 to 0.97; 2388 participants).We combined data for adverse events reported by more than one study. It is uncertain whether EN or PN affects aspiration because the certainty of the evidence is very low (RR 1.53, 95% CI 0.46 to 5.03; 2437 participants; 2 studies), and we found that one feeding route rather than the other may make little or no difference to pneumonia (RR 1.10, 95% CI 0.82 to 1.48; 415 participants; 7 studies; low-certainty evidence). We found that EN may reduce sepsis (RR 0.59, 95% CI 0.37 to 0.95; 361 participants; 7 studies; low-certainty evidence), and it is uncertain whether PN reduces vomiting because the certainty of the evidence is very low (RR 3.42, 95% CI 1.15 to 10.16; 2525 participants; 3 studies).Enteral nutrition versus enteral nutrition and parenteral nutritionWe found that one feeding regimen rather than another (EN or combined EN or PN) may make little or no difference to mortality in hospital (RR 0.99, 95% CI 0.84 to 1.16; 5111 participants; 5 studies; low-certainty evidence), and at 90 days (RR 1.00, 95% CI 0.86 to 1.18; 4760 participants; 2 studies; low-certainty evidence). It is uncertain whether combined EN and PN leads to fewer deaths at 30 days because the certainty of the evidence is very low (RR 1.64, 95% CI 1.06 to 2.54; 409 participants; 3 studies). It is uncertain whether one feeding regimen rather than another reduces mortality within 180 days because the certainty of the evidence is very low (RR 1.00, 95% CI 0.65 to 1.55; 120 participants; 1 study).No studies reported number of ICU-free days or ventilator-free days up to day 28. It is uncertain whether either feeding method reduces pneumonia because the certainty of the evidence is very low (RR 1.40, 95% CI 0.91 to 2.15; 205 participants; 2 studies). No studies reported aspiration, sepsis, or vomiting.

AUTHORS' CONCLUSIONS

We found insufficient evidence to determine whether EN is better or worse than PN, or than combined EN and PN for mortality in hospital, at 90 days and at 180 days, and on the number of ventilator-free days and adverse events. We found fewer deaths at 30 days when studies gave combined EN and PN, and reduced sepsis for EN rather than PN. We found no studies that reported number of ICU-free days up to day 28. Certainty of the evidence for all outcomes is either low or very low. The 11 studies awaiting classification may alter the conclusions of the review once assessed.

Efficacy of Early Enteral Immunonutrition on Immune Function and Clinical Outcome for Postoperative Patients With Gastrointestinal Cancer

BACKGROUND

Nutrition support is crucial for patients with gastrointestinal (GI) cancer after the operation. However, the controversy over the application of parenteral nutrition (PN) and early enteral immunonutrition (EEIN) has no determinate conclusion.

MATERIALS AND METHODS

We compared the effects of PN and EEIN on the postoperative nutrition condition, immune status, inflammation level, long-term survival, and quality of life of the patients with GI cancer. Seventy-eight patients were randomly divided into the PN group (n = 44) or EEIN group (n = 34). After an 8-day nutrition treatment, clinical and immunological parameters were evaluated.

RESULTS

The EEIN group had a significantly shorter hospital stay and higher body mass index level on postoperative day 30 than those in the PN group (P < .05). However, total hospital cost and incidences of short-term postoperative complications had no significant difference (P > .05). The percentages of CD4⁺ , natural killer, and natural killer T lymphocyte cells and the ratio of CD4⁺ /CD8⁺ in peripheral blood were significantly increased. Compared with the PN group, the EEIN group had a higher expression of activated cell surface markers such as CD27 and CD28. In addition, the secretion of interleukin (IL)-2 and interferon-γ was significantly higher, and the secretion of tumor necrosis factor-α and IL-10 was lower. Complication-free survival in the EEIN group were longer than those in the PN group (P = .04).

CONCLUSION

EEIN is superior to PN in improving nutrition status, enhancing immune function, and elevating quality of life.

Effect of the route of nutrition and L-alanyl-L-glutamine supplementation in amino acids' concentration in trauma patients

PURPOSE

Our purpose was to assess the amino acids' (AAs) profile in trauma patients and to assess the effect of the route of nutrition and the exogenous ALA-GLN dipeptide supplementation on plasma AAs' concentration.

METHODS

This is a secondary analysis of a previous randomized controlled trial. On day 1 and day 6 after trauma, plasma concentration of 25 AAs was measured using reverse phase high-performance liquid chromatography. Results were analyzed in relation to the route of nutrition and supplementation of ALA-GLN dipeptide. Differences between plasma AAs' concentrations at day 1 and day 6 were evaluated using the Student's t test or Mann-Whitney-Wilcoxon test. One-way ANOVA and the Kruskal-Wallis test were used to compare groups. A two-sided p value less than 0.05 was considered statistically significant.

RESULTS

Ninety-eight patients were analyzed. Mean plasma concentrations at day 1 were close to the lower normal level for most AAs. At day 6 we found an increase in the eight essential AAs' concentrations and in 9 out of 17 measured non-essential AAs. At day 6 we found no differences in plasma concentrations for the sum of all AAs (p = .72), glutamine (p = .31) and arginine (p = .23) distributed by the route of nutrition. Administration of ALA-GLN dipeptide increased the plasma concentration of alanine (p = .004), glutamine (p < .001) and citrulline (p = .006).

CONCLUSIONS

We found an early depletion of plasma AAs' concentration which partially recovered at day 6, which was unaffected by the route of nutrition. ALA-GLN dipeptide supplementation produced a small increase in plasma levels of glutamine and citrulline.