L-Glutamine (Gut Repair)

Under stress conditions, the metabolic demand for nutrients increases, which, if not met, may slow down or indeed stop the wound from healing, thus, becoming chronic wounds. This study aims to perform a systematic review and meta-analysis of the effect of arginine and glutamine supplementation on wound healing. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed for the systematic review and ten electronic databases were used. Five and 39 human studies met the inclusion criteria for arginine and glutamine, respectively. The overall meta-analysis demonstrated a significant effect of arginine supplementation on hydroxyproline content (MD: 4.49, 95% CI: 3.54, 4.45, p < 0.00001). Regarding glutamine supplementation, there was significant effect on nitrogen balance levels (MD: 0.39, 95% CI: 0.21, 0.58, p < 0.0001), IL-6 levels (MD: -5.78, 95% CI: -8.71, -2.86, p = 0.0001), TNFα levels (MD: -8.15, 95% CI: -9.34, -6.96, p < 0.00001), lactulose/mannitol (L/M) ratio (MD: -0.01, 95% CI: -0.02, -0.01, p < 0.00001), patient mortality (OR: 0.48, 95% CI: 0.32, 0.72, p = 0.0004), C-reactive protein (CRP) levels (MD: -1.10, 95% CI: -1.26, -0.93, p < 0.00001) and length of hospital stay (LOS) (MD: -2.65, 95% CI: -3.10, -2.21, p < 0.00001). Regarding T-cell lymphocytes, a slight decrease was observed, although it failed to reach significance (MD: -0.16, 95% CI: -0.33, 0.01, p = 0.07). Conclusion: The wound healing might be enhanced in one or at various stages by nutritional supplementation in the right dose.

Some amino acids and their derivatives, such as arginine (ARG), glutamine (GLN) in free form or as dipeptides, and ornithine-ketoglutarate (OKG), have specific pharmacological properties concerning namely immunomodulation, control of protein turn-over, maintenance of gut trophicity. In the context of the postoperative nutrition in the adult, supplementation of enteral nutrition with ARG and of parental nutrition with GLN and OKG has improved nutritional and biochemical markers such as nitrogen balance, muscle protein synthesis and glutamine content. However, only few studies have tried to demonstrate a clinical benefit with such a supplementation. At present only the beneficial effect of OKG on postoperative wound healing has been recognized.

PURPOSE OF REVIEW: Glutamine and arginine are conditionally essential amino acids because depletion occurs in stressed conditions. Intravenous glutamine supplementation reduces morbidity and mortality in critically ill patients fed parenterally. In surgical patients, arginine-enriched diets have beneficial effects, but the use of supplemental arginine in critically ill patients should be avoided in most cases. RECENT FINDINGS: In addition to its role as a fuel, glutamine regulates gut barrier function, immuno-inflammatory response and antioxidant status. Arginine metabolism leads to nitric oxide and/or polyamines and thus modulates the immuno-inflammatory response and wound healing. Glutamine and arginine metabolism are closely related, and therefore may give additive or antagonist effects on several pathways. The effects of combined arginine and glutamine are still poorly documented. Combined administration of arginine and glutamine resulted in additive or synergistic effects on gut barrier function and inflammatory response but arginine reduced glutamine protection against oxidative stress. Preliminary data indicate that the combination may be beneficial during intestinal inflammation, whereas data in surgical or critically ill patients are still lacking. SUMMARY: Mostly speculative effects of combined infusion of arginine and glutamine are discussed. Future studies are needed in specific pathophysiological conditions to assess whether this combination is beneficial or detrimental.

Several lines of evidence demonstrate that general nutritional status, specific nutrients (eg, zinc, glutamine), and certain trophic growth factors (eg, growth hormone, insulin-like growth factor I, keratinocyte growth factor, and glucagon-like peptide-2) have important interactions relevant for intestinal growth and function. Adequate nutritional status is critical for endogenous growth factor synthesis in the gut and other tissues and is an important mediator of organ responsiveness to exogenous growth factor administration. Both endogenously synthesized and exogenously administered growth factors upregulate nutrient uptake and utilization by gut mucosa, skeletal muscle, and other organs. Emerging data from both animal and human studies indicate that combinations of selected growth factors and specific nutrients may improve the growth, adaptation, and repair of the intestinal mucosa. Additional studies to determine basic mechanisms of nutrient-growth factor interactions and the safety and efficacy of treatment with combinations of specific nutrients and recombinant growth factors are needed. Results of these investigations should define new methods for support of the intestinal tract during short bowel syndrome (SBS), catabolic illness, and malnutrition.

BACKGROUND: Female athletes who experience menstrual disorders have an energy imbalance due to dietary restrictions and training. A significant problem arising from the daily training of such athletes is the imbalance between energy intake and energy expenditure, leading to fractures due to osteoporosis, amenorrhea, diabetes, and cardiovascular disease. The purpose of this study was to investigate and compare the complementary effect of calcium (Ca), Glutamine (Gln), and Ca+Gln supplements on bone mineral density (BMD), body composition, and physiological and biochemical symptoms of young female athletes with menstrual disorders during 90 days of the training program. METHODS: In this randomized clinical trial (RCT), participants were classified into four groups: Ca supplementation group (Ca), Gln supplementation group (Gln), Ca+Gln supplementation group, and placebo group. Ca supplement containing 500 mg elemental Ca was given to the recipient groups daily. Gln supplement was given at the dose of 10,000 mg. The control group received maltodextrin (similar to Gln powder) as a placebo. BMD, serum Ca and vitamin D3, mid-arm upper circumference (MUAC), weight, and body mass index (BMI) were recorded in the four groups pre and post intervention. RESULTS: Our study found that BMD differences in the three intervention groups were significant (P < 0.05). Results showed that Ca+Gln and Ca supplementation significantly improved BMD. This effect was observed in the Gln supplementation group too; however, it was lower than that of the Ca and Ca+Gln groups. Serum Ca was significantly elevated in the Ca group (P < 0.05). CONCLUSIONS: Ca+Glu supplement improves BMD in female athletes. Copyright: © 2026 International Journal of Preventive Medicine.

Hypothalamic inflammation plays a key pathophysiological mechanism linking chronic consumption of a high fat diet (HFD) to the development of obesity and associated metabolic complications. Pilot studies report that oral glutamine (Gln) supplementation might reduce waist circumference and improve metabolic and inflammatory status in obesity patients. Although Gln metabolism plays a key role in intercellular communication in the central nervous system, its potential beneficial effects remain unexplored in these contexts. Here, we aimed to evaluate how stress and glutamine supplementation can modulate the hypothalamic response to HFD in mice using a chronic-restraint stress (CRS) model, which mimics IBS symptoms. From week 12 to week 14, mice received or not Gln diluted in drinking water (2 g/kg/day) and were placed in restraint tubes (2 h/day) for the last four consecutive days of protocol. Male and female obese mice showed a difference in vulnerability to CRS-induced effects. Moreover, mice responded to Gln supplementation in a sex-dependent manner, especially in stress conditions. Hypothalamic pathways regulating energy homeostasis were more impacted in male mice, whereas factors involved in neuroinflammation were more affected in female mice. Gln supplementation led to an increase in Mc4r and Bdnf mRNA levels and GFAP expression in male mice, while upregulated Iba1 and Il6 mRNA levels as well as signs of microgliosis were observed in stressed females. In conclusion, mice with obesity showed sex-specific hypothalamic response to glutamine supplementation and stress. Further investigations should be done to decipher underlying mechanisms. © 2026. The Author(s).

Background: Oral mucositis (OM) is a frequent complication of anticancer therapy which arises from cytotoxic injury, having significant clinical implications. Nutritional and supplement-based interventions have been proposed as adjunctive strategies to improve outcomes. Objectives: This systematic review aimed to identify and synthesize evidence from randomized controlled trials (RCTs) evaluating nutritional or natural supplement interventions for prevention or management of OM in pediatric oncology. Methods: We conducted a systematic search (17 August 2025) of Scopus, PubMed/MEDLINE, and Google Scholar (1 January 2000-1 June 2025) following PRISMA guidelines and registered in PROSPERO (CRD420251134454). The review included randomized controlled trials in pediatric cancer patients (≤18 years; up to 25 years for follow-up) receiving chemo-/radiotherapy, assessing nutritional, dietary, or natural product interventions for oral mucositis prevention or treatment. Non-randomized, adult, non-English, non-peer-reviewed, or inaccessible studies were excluded. Outcomes included incidence, severity, duration of OM, and mucositis-associated pain. Risk of bias was assessed using the NIH Study Quality Assessment Tools and the Cochrane RoB 2 tool. Results were qualitatively summarized. Results: Of 5870 records identified, 20 RCTs met inclusion criteria resulting in 1430 total included patients. Interventions tested included systemic supplements (e.g., glutamine, zinc, and bovine colostrum), topically applied agents (e.g., honey, vitamin E, Aloe vera, and olive oil), and nutrient-containing rinses (e.g., chamomile, Caphosol, and Traumeel S). Honey-based interventions showed promising outcomes. Discussion: Study designs and sample sizes varied considerably, and outcome measures were heterogeneous. Challenges with blinding, variable compliance, and inconsistent reporting reduce confidence and precision in the findings. Conclusions: Evidence from pediatric RCTs remains limited but highlights nutritional and natural products as promising supportive care options for OM. Findings suggest potential for practical, low-cost adjuncts to established oral care protocols, warranting furthe

BACKGROUND/OBJECTIVES: Fatigue is closely associated with an impaired mitochondrial function, oxidative stress, and inefficient energy metabolism, all contributing to reduced physical performance. Nutritional strategies targeting mitochondrial biogenesis and antioxidant defense may help alleviate fatigue and enhance endurance. This study examined the anti-fatigue and antioxidant effects of an amino acid (AA)-epigallocatechin gallate (EGCG) mixture comprised of 3 AAs (cysteine [Cys], glutamine [Gln], and leucine [Leu]) and EGCG on mitochondrial biogenesis, oxidative stress mitigation, and physical performance enhancement. MATERIALS/METHODS: C2C12 myoblasts were treated to assess mitochondrial biogenesis-related gene expression and oxidative stress markers. Animal studies measured the swimming endurance, glycogen, adenosine triphosphate (ATP), and serum parameters. A pilot clinical trial evaluated the blood glucose, lactate, and serum enzyme levels post-exercise. RESULTS: In cellular experiments, a 1:1:3 ratio of the AA mixture (Cys, Gln, and Leu) with EGCG enhanced mitochondrial biogenesis-related gene expression (AMP-activated protein kinase, sirtuin 1, and peroxisome proliferator-activated receptor gamma coactivator 1α [PGC-1α]) and reduced the oxidative stress markers (reactive oxygen species and malondialdehyde [MDA]). Animal studies revealed significant increases in swimming endurance, elevated glycogen and ATP levels, and reduced serum fatigue markers (creatine phosphokinase, lactate dehydrogenase, and blood nitrogen). Furthermore, nuclear factor erythroid 2-related factor 2 (NRF2) and PGC-1α expression was significantly upregulated in the gastrocnemius muscle, supporting enhanced mitochondrial function. In addition, the antioxidant effects were observed with reduced MDA levels in liver tissue. Clinical trial data showed improved blood lactate clearance and higher post-exercise blood glucose levels in the AA-EGCG group compared to the placebo group. CONCLUSION: The AA-EGCG mixture enhances mitochondrial biogenesis and antioxidant capacity by activating the NRF2 and PGC-1α pathways, improving physical performance and reducing fatigue. This study highlights i

OBJECTIVE: To assess the efficacy of glutamine in preventing diarrhea associated with chemotherapy or chemoradiotherapy in colorectal cancer. METHODS: Randomized controlled trials of glutamine in the prevention of chemotherapy-associated diarrhea of colorectal cancer were retrieved from the Cochrane Library, Pubmed, EMBASE, CNKI, and Wanfang by computer up to August 1, 2024. Results were presented using relative risk (RR) or mean difference (MD) with a 95% confidence interval (CI). Publications were reviewed in accordance with the Cochrane Handbook and the guidelines of the Preferred Reporting Project for Systematic Review and Meta-Analysis (PRISMA2020). This study has been registered with INPLASY (registration number: INPLASY202490057). RESULTS: A total of 5 studies were included, and the total number of patients was 311. Meta-analysis showed that compared with the control group, glutamine supplementation significantly reduced the incidence of chemoradiation-induced diarrhea in colorectal cancer patients (RR = 0.72, 95%CI: 0.60-0.87, P < 0.01, I²=37%). Subgroup analysis found that glutamine was more effective in reducing diarrhea in patients receiving chemotherapy alone than in those undergoing chemoradiotherapy (RR = 0.65, 95%CI: 0.43-0.98, P < 0.05, I²=35%). By tumor location, glutamine reduced diarrhea in the colorectal cancer subgroup (RR = 0.65, 95%CI: 0.44-0.97, P < 0.05, I²=30%) but not in the rectal cancer subgroup (P > 0.05). D-xylose levels were significantly higher in the glutamine group (MD = 0.32, 95%CI: 0.14-0.51, P < 0.01, I²=0%), while C-reactive protein levels were significantly lower (MD = 0.52, 95%CI: 0.32-0.72, P < 0.01, I²=0%). The certainty of evidence for diarrhea was rated as low. CONCLUSION: Glutamine supplementation is associated with a reduced incidence of diarrhea in patients with colorectal cancer, with a more pronounced efficacy observed in those receiving chemotherapy alone. © 2025. The Author(s).

BACKGROUND: Preoperative physical frailty is a significant predictor of adverse postoperative outcomes in older patients undergoing cardiac surgery. Inflammation plays a crucial role in the development of frailty and contributes to postoperative complications. This study investigated the effects of preoperative beta-hydroxy-beta-methylbutyrate (HMB), arginine, and glutamine supplementation on inflammatory markers, nutritional status, and renal function in older patients undergoing cardiac surgery. METHODS: This was a secondary analysis of a single-center, open-label, randomized controlled trial. Patients aged ≥65 years scheduled for elective cardiac surgery were randomized to receive either HMB supplementation (1200 mg HMB, 7000 mg l-glutamine, and 7000 mg L-arginine, twice daily) or routine care for at least two weeks before surgery. Serum levels of tumor necrosis factor-alpha (TNF-α), and other biochemical markers were measured at baseline, pre-surgery, and two weeks post-surgery. RESULTS: Forty-four patients (mean age 72.5 years, 36 % women) were analyzed. Preoperative HMB supplementation significantly reduced pre-surgery serum TNF-α levels compared to the control group (0.85 ± 0.28 pg/mL vs. 1.10 ± 0.44 pg/mL, p = 0.039). However, this difference was not observed two weeks post-surgery. No significant differences were observed in C-reactive protein levels or other nutritional markers between the two groups at any time point. CONCLUSIONS: Preoperative supplementation with a combination of HMB, glutamine, and arginine was effective in reducing preoperative TNF-α levels in older patients undergoing cardiac surgery, suggesting a potential anti-inflammatory effect. This anti-inflammatory effect suggests a potential mechanism for improving postoperative outcomes and warrants further investigation. Registration number of Clinical Trial: UMIN000030490 (https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000034773).

INTRODUCTION: Elevated total homocysteine (tHcy) is a major predictor of brain atrophy, cognitive decline, and Alzheimer's disease (AD) progression. The VITACOG trial, a randomized, placebo-controlled study in mild cognitive impairment (MCI), previously showed that B vitamin supplementation lowered tHcy, slowing brain atrophy and cognitive decline; however, the underlying mechanisms remained unclear. METHODS: We used untargeted, multi-platform metabolomics, with nuclear magnetic resonance and liquid chromatography-mass spectrometry to analyze serum samples from 89 B vitamin-treated and 84 placebo-treated MCI participants over a 2 year follow-up period. RESULTS: Multivariate modeling distinguished treated from placebo groups with 91.2 ± 1.8% accuracy. B vitamin supplementation induced significant metabolic reprogramming, lowering quinolinic acid, α-ketoglutarate, α-ketobutyrate, glucose, and glutamate. DISCUSSION: These findings reveal that B vitamins influence metabolic pathways beyond tHcy reduction, particularly the tricarboxylic acid cycle and glutamine-glutamate cycling, critical for brain energy homeostasis and neurotransmission. This metabolic signature supports B vitamin supplementation as a strategy for slowing MCI progression. HIGHLIGHTS: Nuclear magnetic resonance and multi-platform liquid chromatography tandem mass spectrometry metabolomics were performed on serum samples from 89 B vitamin-treated and 84 placebo participants in the VITACOG trial. Multi-platform metabolomics revealed B vitamin-driven metabolic reprogramming, achieving 91% classification accuracy. B vitamin supplementation modulates key neuroprotective metabolic pathways. Regulation of energy metabolism and neurotransmission by B vitamins contributes to brain health in elderly individuals. B vitamins demonstrate potential as an adjunct therapy in mild cognitive impairment, potentially mitigating progression to Alzheimer's disease. © 2025 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.

PURPOSE: Radiation-induced oral mucositis (RIOM) severely impacts patients with head and neck cancer (HNC) undergoing radiotherapy, often leading to pain and malnutrition. L-arginine and glutamine are immune-enhancing amino acids with potential benefits in wound healing and inflammation control. This study evaluated the efficacy of L-arginine versus L-glutamine oral suspensions in managing RIOM. METHODS: In this triple-blind, randomized controlled trial, 69 HNC patients with RIOM were allocated to three groups (n = 23 each): Group I (L-arginine 5 g + maltodextrin 5 g), Group II (glutamine 5 g + maltodextrin 5 g), or Group III (maltodextrin 10 g). Outcomes, assessed at weeks 2, 5, and 7 of radiotherapy, included the WHO oral mucositis scale, Pain Visual Analogue Scale (Pain-VAS), body mass index (BMI), and Oral Health Impact Profile (OHIP-14) questionnaire. RESULTS: By week 5, WHO scale scores differed significantly among groups (p < 0.001), with arginine and glutamine groups exhibiting lower mucositis severity than the maltodextrin group. Pain-VAS scores at weeks 5 and 7 were significantly lower in the arginine and glutamine groups compared to maltodextrin (p = 0.004 and p < 0.001, respectively). By 7th week of radiotherapy, BMI was significantly decreased in the maltodextrin group than in either the arginine (p = 0.028) or glutamine (p = 0.001) groups, indicative of treatment-mediated weight loss. In contrast, the BMI over time in the arginine (p = 0.87) and glutamine (p = 0.170) groups were almost constant. This indicates that compared to maltodextrin alone, both amino acid supplements prevented a decline in BMI during radiotherapy. OHIP-14 scores improved significantly in the arginine and glutamine groups at weeks 5 and 7 (p < 0.001), indicating better quality of life. CONCLUSIONS: Both L-arginine and glutamine significantly reduced RIOM severity, pain, and weight loss compared to maltodextrin, while improving quality of life in patients with head and neck cancer. Although no statistically significant difference was found between the two, a higher proportion of patients receiving L-arginine achieved complete healing by week 7, suggesting a potential late adva

INTRODUCTION: Acute kidney injury (AKI) is a frequent complication of cardiac surgery, contributing to increased morbidity, longer hospital stays, and higher mortality. Evidence suggests amino acid (AA) supplementation may enhance renal blood flow and glomerular filtration rate (GFR), potentially reducing AKI risk; however, findings remain inconclusive. This study evaluated the efficacy of perioperative AA supplementation in preventing AKI and related complications post-cardiac surgery. METHODS: PubMed, Embase, and Cochrane databases were searched for randomized controlled trials (RCTs) comparing AA supplementation versus standard care in preventing cardiac surgery-associated AKI. Main outcomes included AKI incidence (defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria), 30-day mortality, and renal replacement therapy (RRT) requirement. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using random-effects models. Statistical significance was set at p < 0.05. The certainty of the evidence (CoE) was assessed using the GRADE approach. RESULTS: Six RCTs involving 4501 cardiac surgery patients were included. AA mixture interventions significantly reduced the risk of AKI stage 1 (RR: 0.56; 95% CI: 0.77-0.96; p = .009; CoE: Moderate) and Stage 3 (RR: 0.53; 95% CI: 0.34-0.83; p = .005; CoE: Moderate), but not stage 2 (RR: 1.24; 95% CI: 0.60-2.55; p = .568; CoE: Low). Preliminary findings from glutamic acid and glutamine (single AA interventions) showed potential benefits in reducing AKI incidence (CoE: Very low) and improving surrogate biomarkers, respectively. No significant effects were observed on mortality or RRT incidence for any intervention. CONCLUSION: AA mixtures likely reduce AKI incidence following cardiac surgery but show limited effects on mortality and RRT. Further trials are needed to confirm the benefits of glutamic acid and glutamine supplementation. EDITORIAL COMMENT: Use of amino acid supplementation for the prevention of acute kidney injury after cardiac surgery may be effective, but more trial data and confidence in a beneficial effect is needed for this to be implemented in everyday clinical practice

BACKGROUND & AIMS: In older patients undergoing cardiac surgery, physical function is a critical determinant of postoperative outcomes. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation has been shown to promote muscle protein anabolism and inhibit catabolism, thereby preventing muscle weakness. However, its efficacy in older patients undergoing cardiac surgery remains unknown. This study aimed to examine the effects of preoperative HMB supplementation on postoperative physical function and complications in this population. METHODS: In this single-center, open-label, randomized controlled trial, patients aged ≥65 years scheduled for cardiac surgery were randomized to receive HMB supplementation or no nutritional intervention. The HMB group received HMB 1200 mg, l-glutamine 7000 mg, and l-arginine 7000 mg, once or twice daily, for at least 2 weeks before surgery. Evaluations were performed at baseline and before and after surgery. The primary outcome was the 6-min walking distance (6MWD) before and after surgery. Secondary outcomes included the incidence of complications, muscle mass and strength, physical performance, and length of hospital stay. RESULTS: Forty-four patients with a mean age of 72.5 years (women, 38 %) were randomized to the HMB (n = 22) or control (n = 22) group. Compared with the control group, the HMB group demonstrated a statistically significant improvement in the 6MWD both at the pre-surgery (448.0 ± 73.5 m vs. 375.5 ± 58.8 m; P = 0.01) and post-surgery time points (428.9 ± 76.4 m vs. 304.5 ± 52.3 m; P = 0.001). Muscle strength and physical performance also showed significant improvements in the HMB group. However, no significant difference in muscle mass was observed between the groups at any time point. The HMB group had a shorter hospital length of stay compared with that of the control group (16.1 ± 3.8 days vs. 20.4 ± 7.6 days, P = 0.03), and no adverse events were observed with the intervention. CONCLUSIONS: Preoperative HMB supplementation in older adults undergoing cardiac surgery resulted in significant improvements in postoperative exercise capacity and physical function, along with a reduction in the length of hospital stay,

BACKGROUND: Diabetes is a significant risk factor for sarcopenia, a muscle dystrophy affecting older individuals. Sarcopenia management typically involves resistance exercise and oral supplements. Given the limitations of resistance training for many elderly individuals, oral supplements play a crucial role in treatment. This study is a protocol for evaluating the efficacy of the Sarcomeal® supplement, a mixture of whey protein, creatine, branch-chained amino acids (BCAAs), glutamine, and hydroxyl-methyl-butyrate (HMB) in diabetic people who also have sarcopenia. METHODS AND ANALYSIS: This study is a randomized clinical trial, in which sixty diabetic sarcopenia patients who meet the inclusion criteria will be randomly assigned to the control or the intervention group with a 1:1 allocation. The intervention group will receive one Sarcomeal® supplement sachet plus 1000 IU of vitamin D daily and both groups will be recommended to consume protein-rich food, be educated about the disease, and perform light exercises for 12 weeks. Anthropometric measurements, body composition analysis, muscle strength assessments, and blood tests will be conducted at the trial's start and end. DISCUSSION: It is hypothesized that the Sarcomeal® supplement plus vitamin D may be beneficial for the management of diabetic sarcopenia by reducing inflammation, oxidative stress, and glucose metabolism. The outcome of this trial will provide a basis for prescribing sarcomeal to patients with diabetic sarcopenia. ETHICS AND DISSEMINATION: This protocol is registered at the Iranian Registry of Clinical Trials (IRCT20230831059311N1) and also is approved by the ethics committee of Tehran University of Medical Sciences (September 2023, IR.TUMS.EMRI.REC.1402.071). TRIAL REGISTRATION: Iranian Registry of Clinical Trials (ID: IRCT20230831059311N1). © 2024. The Author(s).

Multiple reviews have examined the impact of nutritional interventions in patients with burn injuries; however, discrepancies among results cast doubt about their validity. We implemented this review to assess the impact of various nutritional interventions in adult patients with burn injuries. We conducted a thorough search of PubMed, Scopus and Web of Science databases until 1 August 2024, to identify relevant meta-analyses of intervention trials, examining the impact of nutritional interventions on burn patients. We adopted the random-effect models to determine the pooled effect sizes while employing the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to examine evidence certainty. Thirty-three original intervention trials from eleven meta-analyses were entered in our review. Early enteral nutrition could substantially reduce overall mortality (relative risk (RR): 0·36, 95 % CI: 0·19, 0·68, GRADE = moderate certainty), hospital stay (mean difference (MD): -15·3, 95 % CI: -20·4, -10·2, GRADE = moderate certainty) and sepsis risk (RR: 0·23, 95 % CI: 0·11, 0·45, GRADE = moderate certainty). Glutamine showed a notable decrease in the length of hospital stay (MD: -6·23, 95 % CI: -9·53, -2·94, GRADE = low certainty). However, other nutritional interventions, including combined immunonutrition, branched-chain amino acids, fish oil, ornithine α-ketoglutarate and trace elements, did not significantly affect the assessed clinical outcomes. Early enteral nutrition might impose a beneficial effect on mortality, hospital stay length and incidence of sepsis with moderate evidence. Lower length of hospital stay was also seen in burn patients supplemented with glutamine, although the evidence was weak.

The gastrointestinal tract's epithelial barrier plays a crucial role in maintaining health. This study aims to investigate the impact of glutamine supplementation on intestinal permeability, considering its importance for immune function and nutrient absorption. The study adhered to the PRISMA protocol for systematic reviews and meta-analyses. A systematic search was performed in four databases (PubMed, Scopus, Web of Science, and Google Scholar) until April 2023 to identify clinical trials on glutamine supplementation and gastrointestinal permeability. Eligibility criteria included randomized placebo-controlled trials measuring gut permeability post-glutamine supplementation. Studies were included regardless of language or publication date. Data extraction involved study characteristics, intervention details, and outcomes. Quality assessment was performed using the Cochrane tool, and statistical analysis utilized mean differences and standard deviations with a random effects model. Subgroup analysis was conducted to explore heterogeneity. The systematic review and meta-analysis included 10 studies from 1998 to 2014 with 352 participants. A total of 216 patients were enrolled in the intervention group, and 212 in the control group. The mean participant age was 46.52 years. The participants had different types of diseases in terms of their health status. Overall, glutamine supplementation did not significantly affect intestinal permeability (WMD: -0.00, 95% CI -0.04, 0.03). Subgroup analysis showed a significant reduction in intestinal permeability with doses over 30g/day (WMD: -0.01, 95% CI -0.10, -0.08). The glutamine supplements were administered orally in all included studies. The meta-analysis demonstrated a significant reduction in intestinal permeability with glutamine supplementation exceeding 30 mg/day for durations of less than 2 weeks. Further investigations with varying dosages and patient populations are warranted to enhance understanding and recommendations regarding glutamine supplementation's effects on gut permeability. © 2024. The Author(s).

BACKGROUND: It is plausible that supplementation with specific amino acids or metabolites could attenuate skeletal muscle wasting during critical illness. The aim of this systematic review was to explore if amino acids or their derivatives impact skeletal muscle wastage in critically ill adults. METHODS: Four databases were systematically searched to identify randomised control trials which delivered enteral supplemental amino acids, or their metabolites compared with placebo, standard care or no intervention, to critically ill patients and reported outcomes of skeletal muscle mass, plasma amino acids, nitrogen balance, or muscle strength. Two authors independently completed screening, data extraction, and risk of bias assessment using the Cochrane Risk of Bias 2 Tool. A meta-analysis was planned but heterogeneity in the type of intervention used and outcome assessment precluded this. Therefore, data were synthesised using vote counting. RESULTS: Thirty randomised control trials, comprising 1976 patients were included. The most frequently studied interventional amino acid or metabolite was glutamine (n = 12 trials), a combination (n = 9), arginine (n = 6), β-hydroxy β-methylbutyrate (HMB) (n = 2) or ornithine (n = 1). Six trials (including 284 participants) measured skeletal muscle following supplementation, four of which used HMB alone or in combination as the intervention. Of these, one trial observed an attenuation of muscle wasting with a combination of amino acids, one observed an exacerbation of muscle wasting with HMB, three trials observed no impact on muscle wasting with HMB or a combination of amino acids and one trial reported no information. CONCLUSION: Six trials have investigated the effect of enteral amino acid or amino acid metabolite supplementation on muscle mass in critically ill. Heterogeneity of interventions, outcome assessments and direction of effects limits the certainty regarding the effect of supplemental amino acids, or their metabolites, on skeletal muscle wasting during critical illness. The trial protocol is registered on PROSPERO (CRD42021275989).

BACKGROUND: Analyse the effects of Bifidobacterium BB-12 on intestinal metabolites and serum inflammatory factors in premature infants. METHODS: 71 premature infants at gestational age of ≤32 weeks were randomly divided into the probiotic (n = 36) and control (n = 35) groups. Faecal and blood samples were collected from the two groups of premature infants at the 2nd and 4th week of life for intestinal metabolite detection and assessment of the level of the serum inflammatory markers TLR4, NF- κ B, IL-1β, and TNF- α. RESULTS: Compared to the control group, the probiotic group contained more amino acids, these elements were enriched on multiple amino acid metabolic pathways, and the probiotic group showed significantly lower levels of the serum inflammatory markers TLR4, NF-κB, IL-1β, and TNF-α. Finally, the probiotic group showed a lower incidence of feeding intolerance. CONCLUSIONS: The administration of Bifidobacterium BB-12 is associated with increasing the levels of glutamine, glutamic acid, and kynurenine in the gut of premature infants, and associated with reducing the levels of TLR4 and NF-κB in the serum, further decreasing the secretion of the pro-inflammatory factors IL-1β and TNF-α, and alleviating systemic inflammatory reactions, thereby reducing the incidence of feeding intolerance. IMPACT: 1. The use of Bifidobacterium BB-12 in premature infants can increase the levels of amino acids in the intestine. 2. Increases in Bifidobacterium BB-12 may decrease the serum levels of TLR4, NF-κB, IL-1β, and TNF-α. 3. Kynurenine may improve the prognosis of preterm infants by reducing inflammation. 4. Bifidobacterium BB-12 may improve the feeding tolerance of premature infants, thus reducing the incidence of feeding intolerance. © 2024. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.