Amino Acid Supplementation Research Articles

Comparative response of casein protein hydrolysate fed young and older human serum on in vitro muscle protein metabolism and myotube size.

In this study we used an ex vivo-in vitro model to assess the effect of feeding older (50 - 70 y) adults a casein protein hydrolysate (CPH) compared with non-bioactive non-essential amino acid (NEAA) supplement on muscle protein synthesis (MPS) and markers of muscle protein breakdown (MPB). As a secondary objective, to assess any attenuation with aging, we compared the anabolic response to CPH-fed serum from older and young adults. Serum from seven healthy older and seven young men following overnight fast and 60 min postprandial ingestion of CPH or NEAA (0.33 g.kg-1 body mass) was used to condition C2C12 myotube media. Analysis by 2-way ANOVA of the fed relative to fasted MPS response revealed a main effect for protein type in pmTOR (p=0.009), p70S6K (p=0.031), p4E-BP1 (p=0.047) and MPS (p=0.041) with a greater response to CPH-fed serum, and interaction effects (AgeXProtein) between young and old serum for pmTOR (p=0.009) and p70S6K (p=0.016). In addition, significant changes in myotube diameter (p=0.049), Atrogin-1 (p=0.004) and MuRF-1 (p=0.012) in response to CPH-fed compared to fasted serum were observed with no differences between young and old serum. In conclusion, this study demonstrated that CPH-fed serum from both young and older (50 - 70 y) adults can stimulate MPS, muscle growth and suppress biomarkers of muscle protein breakdown processes.

Early Optimal Parenteral Nutrition During NICU Stay and Neurodevelopmental Outcomes in Very Preterm Infants: State of the Art

Background: Preterm infants (PIs) are more susceptible to neurodevelopmental impairment compared with term newborns. Adequate postnatal growth has been associated with improved neurocognitive outcomes; therefore, optimization of nutrition may positively impact the neurodevelopment of PIs. Objective: This study focused on macronutrient parenteral nutrition (PN) intake during the Neonatal Intensive Care Unit stay and their associations with neurodevelopmental outcomes in PIs in the first two years of life. Methods: The Embase, MEDLINE, and Cochrane Library databases were searched using the following subject headings and terms (MeSH): “premature infants”, “parenteral nutrition”, “growth”, “brain”, “neurodevelopment”, and “central nervous system diseases”. All relevant papers’ reference lists were manually searched. PN and neurodevelopment studies concerning the first two years of life were collected and analyzed. Results: 275 potential studies were retrieved, 64 were selected for full-text reading, and 22 were included (12 randomized controlled trials). While glucose intakes should be immediately provided and strictly monitored avoiding hyperglycemia, the long-term outcomes of aggressive PN caloric intakes are uncertain. Early amino acid (AA) supplementation is mandatory and improves short-term growth, though it is questionable whether increased AA and better neurodevelopment are directly related. Lipid infusion should be initiated right after birth, and further investigation will enable us to ascertain the potential impacts of lipid emulsions, particularly fish oil, on PI neurodevelopment. Conclusions: An aggressive PN and its possible metabolic complication could not favor neurodevelopment; the way forward could be a customized approach, depending on the patient’s clinical state and tolerance. Long-term follow-up studies and the search for specific markers of tolerance are warranted.

Amino Acid Supplementation May Help Prevent Muscle Wasting After Orthopedic Surgery, but Additional Studies Are Warranted: A Systematic Review of Randomized Clinical Trials.

Background: Essential amino acid (EAA) supplementation, including conditionally essential amino acid (CEAA) and branched-chain amino acids (BCAA) supplementation, has been suggested as a mechanism to optimize patient outcomes by counteracting the atrophy associated with orthopedic procedures. Purpose: We sought to investigate the effect of EAA supplementation in the perioperative period on patients undergoing orthopedic and spine surgery, specifically whether it is associated with (1) reductions in postoperative muscle atrophy and (2) improved postoperative function including range of motion, strength, and mobility. Methods: We conducted a systematic review of the literature. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used, and the protocol was registered in the Prospective Register of Systematic Reviews (PROSPERO) database (CRD42023447774). Studies of interest were prospective, placebo-controlled, randomized clinical trials (RCTs) published between 2002 and 2023 evaluating the impact of EAA supplementation on patients undergoing orthopedic and spine surgery. Results: Ten RCTs evaluating EAA supplementation in trauma, adult reconstruction, and spine surgery were identified; half of these focused on adult reconstruction. The EAA supplementation dose (3.4-20 g), frequency (daily to 3 times per day), and duration (14-49 days) varied widely across studies. Seven studies reported parameters relating to muscle size and/or composition, with 3 studies reporting superior muscle size/composition in patients receiving perioperative EAA supplementation, when compared with controls. Three studies reported favorable mobility outcomes for patients receiving EAA. Meta-analysis was prohibited by variation in measurement and outcome variables across the studies. Conclusions: Pooled data from level I studies supports the use of EAA, BCAA, and CEAA supplementations across several orthopedic subspecialties. However, significant heterogeneity exists in the quantity, duration, and content of EAA administered. Further prospective studies are needed to determine optimal/standardized parameters for supplementation.

HMB/Arg/Gln may improve short-term outcomes after esophagectomy in patients with thoracic esophageal cancer.

The wound healing effects of a specialized amino acid supplement containing calcium beta-hydroxy-beta-methylbutyrate, L-arginine, and L-glutamine (HMB/Arg/Gln) have been reported. This study aimed to investigate the effectiveness of HMB/Arg/Gln in the perioperative management of patients with thoracic esophageal cancer. This retrospective cohort study included 131 patients who underwent esophagectomy for thoracic esophageal cancer between January 2016 and November 2023. Postoperative infectious complications (PICs) were compared between patients who received HMB/Arg/Gln for 7days before surgery (n = 95) and those who did not (control group, n = 36). Among the 111 male and 20 female patients (median age 68years, range 38-84years), stage I disease was found in 37 patients, stage II in 26, stage III in 61, and stage IVa in 7. Of the 131 patients, 36 (27.5%) had PICs, with PICs occurring in 20 (21%) of the HMB/Arg/Gln group and 16 (44.4%) of the control group. The PIC rate was significantly lower in the HMB/Arg/Gln than in the control group (p = 0.007). Propensity score matching analysis showed lower rates of anastomotic leakage (5.5% vs. 22.2%; p = 0.04) and Clavien-Dindo grade III or higher PICs (5.5% vs. 27.8%; p = 0.011) in the HMB/Arg/Gln than in the control group. The healing time for anastomotic leakage was shorter in the HMB/Arg/Gln (18days, range 7-25days) than in the control group (25days, range 21-56days) (p = 0.033). HMB/Arg/Gln supplementation was associated with reduced risk of anastomotic leakage and PIC severity following esophagectomy.

Exploring the Impact of Extended Amino Acid Supplementation on Body Composition and Psychopathology in Patients with Eating Disorders Undergoing Psycho-Nutritional Rehabilitation.

Eating disorders are frequently linked to protein-energy malnutrition, resulting from chronic energy intake reduction, and leading to reduced body weight and altered body composition. A nutritional approach based on the supplementation with a mixture of essential amino acids has proven effective in conditions characterized by reduced dietary intake and increased degradation of endogenous proteins and might also contribute to correct the amino acid deficiency possibly involved in the pathogenesis of eating disorders. This study aimed to explore the effects of amino acid supplementation in conjunction with a standard psycho-nutritional rehabilitation program on body composition, symptoms and psychopathology status in 30 female patients with eating disorders hospitalized at the Residenza Palazzo Francisci in Todi, Italy. Enrolled patients were divided in two groups receiving amino acid supplementation for 45 and 90 days, respectively. Each patient underwent bioelectrical impedance analysis at baseline, after 45 days and after 90 days. Validated psychometric tests were administered at study entry and study end to all enrolled patients. Results from bioelectrical impedance analysis suggest that amino acid supplementation contributes to restoring nutritional and metabolic balance, with effects proportional to the duration of administration. Conversely, interpreting the effects on psychopathologic state and symptoms was challenging, probably due to the small sample size and short observation period. Prolonged amino acid supplementation may play a role in the management of patients with eating disorders, favoring the correction of the catabolic state and possibly contributing to improvement of the psychopathologic state.

Effects of Amino Acid Supplementation on the Growth Performance of Broiler Chicks Challenged With Coccidiosis: A Meta-Analysis.

This meta-analysis aimed to evaluate the effects of amino acid supplementation on the growth performance of broiler chicks challenged with coccidiosis. Data were collected on authorship, publication year, study sample characteristics and outcomes of interest related to growth performance. Effect sizes were calculated for both overall effects and the individual effects of each amino acid. The effects of moderator factors, such as supplementation levels and duration, were also assessed, and bias was calculated. Works were obtained from PubMed, Elsevier, ScienceDirect, Wiley, Springer Link and Scopus databases, with the help of search engines like Google Scholar and ResearchGate, covering the period from 2013 to 2023. A random-effects model was used. Thirteen works were included in the current analysis, examining the effects of arginine (n=4), methionine (n=6), threonine (n=3) and glutamine (n=3). Amino acid supplementation [0.326, CI 95% (0.297-0.355); p=0.000], arginine [0.430, CI 95% (0.293-0.568); p=0.000] and threonine [0.793, CI 95% (0.193-1.38); p=0.009] significantly increased body weight. Amino acid supplementation [0.052, CI 95% (0.022-0.081); p=0.000] and arginine [0.317, CI 95% (0.049-0.585); p=0.000] also significantly increased feed intake. Higher levels of amino acids (≥1.50%) and longer supplementation periods (≥15 days) significantly increased body weight and feed intake, while reducing the feed conversion ratio. Funnel plots, fail-safe N and Egger tests showed no evidence of bias. In conclusion, arginine supplementation has the potential to increase body weight and feed intake in poultry challenged with coccidiosis. Higher doses of amino acids and longer supplementation periods are recommended in such cases.

Unraveling the complexity: A rare case of urea cycle defect and its clinical implications

Background: Argininosuccinate lyase deficiency is a rare urea cycle disorder that leads to severe hyperammonemia, particularly in neonates. Early identification and intervention are crucial to prevent neurological damage and improve long-term outcomes. Case Presentation: This case presentation describes the clinical course of an 18-year-old male from South Africa, who was referred to the Adult Endocrine Unit for further management after being diagnosed with life-threatening hyperammonemia in the neonatal period. Presenting on the fourth day of life, the patient was ventilator-dependent and required peritoneal dialysis. Analytical results obtained during the hyperammonemia crisis showed considerable perturbements of metabolic parameters; potassium was 6.6 mmol/L, urea was <1 mmol/L and the peak ammonia level was 2590 μmol/L. The change in amino acid level showed that glutamine, alanine, and argininosuccinic acid were increased. Molecular genetic testing finally led to the diagnosis of argininosuccinate lyase deficiency, a urea cycle disorder. Mostly, dietary protein intake was restricted to about 1 g/kg/day, and the use of ammonia precursors such as sodium phenylbutyrate and sodium benzoate, L-arginine, and branched-chain amino acid supplementation. The patient was treated and developed normally up to puberty, but he had mild neurocognitive delay that affected his school attendance in the mainstream schools. He ended up experiencing multiple hyperammonemia crises in his lifespan and the last admission with crisis in September 2024 ammonia increased to 228 umol/L (11-35umol/L), treated with Dextrose 10%infusion and ammonia scavengers, and protein restriction, ammonia dropped to 93 umol/L within 24 hours. Conclusion: This case shows that urea cycle defect requires early diagnosis and continuing treatment to prevent episodes of hyperammonemia crisis. Our patient had normal physical growth but had neurocognitive dysfunction, which is why the management of this rare urea cycle disorder is challenging.

The Effects of L-Arginine Supplementation on Oxygen Saturation and Blood Lactic Acid on the Physical Fitness Level of Muaythai Athletes in West Kalimantan

This study aims to determine the extent of the effect of L-Arginine amino acid supplementation on oxygen saturation and lactic acid levels at the fitness level (VO2Max) of West Kalimantan muaythai athletes. High lactic acid levels can be an indicator of fatigue in athletes after undergoing a physical fitness test. This type of quantitative descriptive research used a randomized group pretest-posttest group design sampling method. The subjects in the study used were male athletes on the West Kalimantan Muaythai team who will be prepared for the 2024 International Student Muaythai Championship. In this study, the subjects were divided into two groups, the first group was given a placebo and the second group was given the amino acid L-arginine. Each group was given the same treatment, namely a physical fitness test to determine the VO2Max level using a bleep test. Before and after carrying out the physical fitness test, the subjects were checked for oxygen saturation, and blood lactic acid samples were taken. The results showed that L-Arginine supplementation had a positive effect in helping to maintain optimal oxygen saturation in the body and reducing the accumulation of blood lactic acid levels that can cause fatigue in Muay Thai athletes. This shows the significant role of L-arginine supplementation in helping to enhance physical endurance performance and speed up recovery during and after physical activity.

Supplementation of essential amino acids suppresses age-associated sleep loss and sleep fragmentation but not loss of rhythm strength under yeast-restricted malnutrition in Drosophila.

Sleep quality and quantity decrease with age, and sleep disturbance increases the risk of many age-associated diseases. There is a significant relationship between nutritional status and sleep outcomes, with malnutrition inducing poor sleep quality in older adults. However, it remains elusive whether, and if so how, nutritional supplementation prevents age-associated sleep problems. Here, we utilized Drosophila to investigate the effects of a malnutrition diet with restricted yeast, a primary protein source, and supplementation of ten essential amino acids (EAAs) on sleep profiles during aging. Compared with the standard diet containing 2.7% yeast, the malnutrition diet containing 0.27% yeast significantly decreased target of rapamycin (TOR) signaling and shortened the lifespan of male Canton-S flies. By contrast, age-associated sleep loss, sleep fragmentation, and loss of rhythm strength were similarly observed under both diets. Supplementation of the malnutrition diet with EAAs in restricted yeast significantly ameliorated age-associated sleep loss and sleep fragmentation without altering loss of rhythm strength. It also rescued decreased TOR signaling activity but not the shortened lifespan, suggesting that the effects of EAAs on sleep integrity are independent of TOR activity and lifespan regulation. These results may help to develop dietary interventions that improve age-related sleep problems in humans.

Optimizing Protein Bars With Whey Protein Isolate, Pea Protein Isolate, and Blue Whiting (Micromesistius poutassou) Fish Protein Hydrolysate: A Simplex-Centroid Mixture Design Study.

The aim of this study was to use blue whiting fish protein hydrolysate (BWFPH) as a novel dietary amino acid supplement in whey protein isolate (WPI) and pea protein isolate (PPI)-based protein bars. The findings indicate that incorporating BWFPH significantly influenced the nutritional profile of the protein bars, leading to a ~93% reduction in hardness compared to bars without the hydrolysate. Additionally, BWFPH effectively delayed the hardening process during storage. However, sensory evaluation revealed that the inclusion of BWFPH adversely affected the sensory characteristics, indicating a need for optimization. Using a simplex centroid mixture design, we identified an optimized protein blend compromising 76.02% WPI, 6.72% PPI, and 17.26% BWPFH, which achieved a balance of improved texture and sensory appeal. These results suggest that high-protein bars can be enhanced by integrating novel protein sources through careful formulation and optimization.

77 Essential amino acid supplementation on bovine trophectoderm: potential strategies to mitigate pregnancy loss in dairy cattle

77 Essential amino acid supplementation on bovine trophectoderm: potential strategies to mitigate pregnancy loss in dairy cattle

Reducing Dietary Protein Levels with Amino Acid Supplementation in Duroc Sire Line Finishing Pigs: Growth Performances, Carcass and Meat Traits and Nitrogen Balance in Males and Females.

Crude protein (CP) reduction and amino acid (AAs) supplementation is an interesting cost-reducing strategy for environmental compliance. The objective of this work is to study productive performances of heavy Duroc X (Landrace X Large white) male and female pigs during the finishing stage under a 2% CP reduction with crystalline AA supplementation. A total of 60 entire male and 60 female pigs (means ± standard deviations: 109 ± 4.9 days of age; 67.9 ± 7.18 kg of body weight) were distributed in split-sex pens (6 pigs/pen) and fed ad libitum. Two isoenergetic diets were provided (145 and 125 g CP/kg with AA supplementation, control and low-CP) during the final 42 days of finishing period. Growth performance, carcass and meat traits were evaluated. The fixed effects of dietary treatment, sex and their interaction were considered and simple least squares models used. Males were 7.25% heavier (p < 0.001) and had 16% higher average daily gains (p < 0.0001) than females in both treatments with no differences in feed intake or feed conversion ratio (p > 0.05). Nitrogen efficiency was 35% higher in low-CP males. Little difference was found for most carcass and meat traits between treatments. Males had 7-8% higher loin subcutaneous fat thickness in both dietary treatments (p = 0.011). Males and females of the low-CP diet showed higher fat and saturated fat contents than controls (p = 0.020). A 20 g/kg CP reduction with AA supplementation is an efficient strategy during the finishing phase without productivity losses in heavy Duroc sire line genotypes of both sexes.

Effects of Nutritional Support with a Leucine-Enriched Essential Amino Acid Supplement on Body Composition, Muscle Strength, and Physical Function in Stroke Patients Undergoing Rehabilitation.

Dietary protein intake can potentially influence renal function. This study aimed to elucidate the association between dietary protein supplementation and a decrease in the estimated glomerular filtration rate (eGFR) in Japanese stroke patients undergoing rehabilitation. From July 2017 to June 2021, 60 patients undergoing post-stroke rehabilitation were randomly assigned to a rehabilitation alone or rehabilitation nutrition group, which received 120 g Reha-Time Jelly® after each session. Both groups were followed up for 3 months. Serum nutritional markers (prealbumin and retinol-binding protein), muscle strength, body composition, renal function markers (eGFR based on creatinine [eGFR-Cr] and cystatin C [eGFR-Cys]), urinary protein-to-creatinine ratio (UPCR), and motor function (walking speed, 2-min walk distance, and chair stand test) were assessed at baseline and post-intervention. Of the 60 participants (mean age: 70.2 ± 10.0 years), 39 were men (65.0%) and 19 (31.7%) had chronic kidney disease. Initial eGFR-Cr and eGFR-Cys values were 70.5 ± 17.2 and 66.6 ± 14.8 mL/min/1.73 m2, respectively. After the intervention, the rehabilitation nutrition group demonstrated a significantly greater increase in body mass index (BMI) and a smaller decrease in bone mineral content than the rehabilitation alone group. However, no significant between-group differences were noted in serum marker levels or motor function, including grip strength and knee extensor strength, on the paralyzed and non-paralyzed sides. The change in chair stand test performance indicated a trend toward improvement in the rehabilitation nutrition group. No significant differences were observed in the changes in renal function. A 3-month nutritional supplementation intervention may help increase BMI, preserve bone mineral content, and support physical activity levels in patients undergoing post-stroke rehabilitation without negatively affecting renal function.

How does the adoption of nutritional plans influence the performance of meat quail during the growth phase in hot environments?

The present study aimed to evaluate the effects of different nutritional plans on meat quails subjected to heat stress. A total of 324 quails male European quails (Coturnix coturnix coturnix) were used, with an average initial weight of 121.48 g ± 3.1 g, distributed in a completely randomized design with nine treatments and six repetitions of six birds each. The diets were evaluated from 22 to 42 days of age, according to the following treatments: T1 - Control diet; T2 - Moderate crude protein (CP) reduction, without amino acid supplementation (AA); T3 - Moderate CP reduction with supplementation of methionine (Met) and cystine (Cys); T4 - Moderate CP reduction with Met, Cys, and lysine (Lys) supplementation; T5 - Moderate CP reduction with Met, Cys, Lys, and threonine (Thr) supplementation; T6 - Severe CP reduction, without AA supplementation; T7 - Severe CP reduction with Met and Cys supplementation; T8 - Severe CP reduction with Met, Cys, and Lys supplementation; T9 - Severe CP reduction with Met, Cys, Lys, and Thr supplementation. The room temperature was maintained at 30°C, with relative humidity at 76.42%, and a black globe humidity index (BGHI) of 82.19. No significant (p > 0.05) effect of protein reduction or amino acid supplementation was observed on live weight, feed intake, carcass weight, yield, breast, legs, heart, and gizzard. However, significant effects were observed on weight gain (p < 0.04), feed conversion (p < 0.05), liver weight (p < 0.001), and liver yield (p < 0.001). In hot environments, crude protein in the diet of meat quails can be reduced from 22 to 17.6%, with adequate methionine supplementation to achieve 0.800% digestible Met + Cys during the growth phase (22-42 days). These nutritional strategies may optimize performance, reduce costs, and provide environmental benefits by decreasing nitrogen excretion. Future research should investigate the interactions between diet, heat stress, and quail performance, focusing on different amino acid combinations and their impacts on bird health and productivity under varied thermal conditions.

Effect of amino acid supplementation on short-term complications after gastrointestinal tumor surgery: the AMIGITS randomized clinical trial.

There is a scarcity of large randomized clinical trials on the efficacy and safety of high-dose amino acid supplementation (AAS) in patients with gastrointestinal tumors undergoing surgical treatment. This pragmatic, randomized, controlled, single-center, open-label, parallel-group AMIGITS trial was performed in a tertiary care teaching hospital. Patients with gastrointestinal tumors were randomly assigned to receive either AAS or standard care (SC). Amino acid targets were 2.0g/kg per day in the AAS group and 1.2g/kg per day in the SC group. The AAS group received additional amino acids intravenously, while the SC group received an iso-energetic 5% glucose intravenously. Overall, 407 patients (AAS group, 204; SC group, 203) were included in this study. During the intervention, the actual mean daily energy intake did not differ significantly between the AAS and SC groups (25.53 vs. 25.16kcal/kg per day, P=0.493). However, the actual mean daily amino acid intake was significantly higher in the AAS group than that in the SC group (1.81 vs. 0.94g/kg per day, P<0.001). The infection incidence during hospitalization and that within 30 days of surgery was significantly lower in the AAS group than that in the SC group (P=0.031 and P=0.024, respectively). The 30-day postoperative incidence of amino acid treatment-related adverse events and other complications did not significantly differ between the two groups. The postoperative hospital stay was significantly different between the two groups (P<0.001). AAS was associated with a reduced infection incidence within 30 days of major surgery in patients with gastrointestinal tumors and can be a promising strategy.

The effect of different dietary manipulations on haematological properties in Japanese quail

Quantitative and qualitative dietary conditions are crucial for physiological functions. Blood haematology, the indicator of immune regulation, is critically affected by dietary conditions. Despite their importance, the effect of macro- and micronutrient manipulation remains unknown. We used feed restriction, energy or protein restriction, and supplementation of leucine, methionine, or both on top of restricted-feeding to study the effect on haematological properties in Japanese quail. Fifty-six birds of six weeks of age were distributed into seven treatments; control, 20% feed restriction, 20% energy restriction, 20% protein restriction, supplementing 20% leucine, 20% methionine, or both on top of restricted feeding. Haematological properties, including white blood cell count, number and percent of lymphocytes, mid-range (eosinophil + basophil), granulocytes, red blood cell count, haemoglobin levels, packed cell volume, mean corpuscular volume, and mean corpuscular haemoglobin were analysed. We found that quantitative feed restriction, energy restriction, and amino acid supplementations showed no significant effect compared to the control group. However, protein restriction reduced all indices, suggesting the importance of proteins in maintaining leukocyte and erythrocyte indices. The present study revealed that neither moderate calorie restriction nor moderate specific amino acid supplementation have an impact on blood haematology, while 20% protein restriction has a notable effect.

Impact of Amino Acid Supplementation on Aroma Development in Vidal Icewine: A Comparative Study of Saccharomyces and Non-Saccharomyces Fermentations

This study explored the effects of branched-chain amino acid (leucine, isoleucine, valine, and threonine) supplementation on the aroma development of Vidal icewine, fermented separately using commercial Saccharomyces cerevisiae (F33) and non-Saccharomyces (Hanseniaspora uvarum, Hu) yeast. The results indicated that Hu played a pivotal role in enhancing aromatic complexity by producing higher concentrations of esters, medium-chain fatty acids, and terpenes. Particularly, samples with L-isoleucine (1.0 g/L) and L-threonine (1.0 g/L) significantly increased key compounds such as beta-damascenone, isoamyl acetate, and phenethyl acetate, resulting in pronounced floral, fruity, and honey-like aromas. Conversely, during F33 fermentation, samples with added valine (1.0 g/L), threonine (1.4 g/L), and L-leucine (0.6 g/L) exhibited higher concentrations of higher alcohols and ethyl esters, crucial for delivering floral-fruity aromas. These findings suggest that precisely controlling the supply of amino acids during fermentation, through the selection of appropriate yeast strains and amino acid types, can effectively control the aromatic properties of icewine. This study offers new insights for improving icewine quality.

The Role of Amino Acid Supplementation in Orthopaedic Surgery: Erratum.

The Role of Amino Acid Supplementation in Orthopaedic Surgery: Erratum.

Nutritional Management in Stricturing Crohn's Disease: A Pilot Study.

More than half of patients with Crohn's disease develop intestinal fibrosis induced intestinal obstruction with debilitating symptoms throughout their disease course. The incidence of stricture formation in CD has remained unchanged over the last several decades. Factors promoting intestinal fibrosis are currently unclear, but diet may represent an underestimated risk factor for intestinal fibrosis by modification of both the host immune response and intestinal microbial composition. Evaluating the impact of diet on the course of IBD is very complex. Sarcopenia is a common problem in IBD patients and correlates with an increased rate of disease. Skeletal muscle index (SMI) is an important parameter to measure sarcopenia and is an easily accessible tool for evaluating the likelihood of complications in individuals with CD. Using a randomized and controlled pilot design, we aimed to investigate the efficacy of 12 months of short-term dietary intervention based on essential amino acid (EAA) and sodium butyrate (NaB) supplementation in the management of stricturing Crohn's disease patients. After the treatment in the diet EAA/NaB group, we revealed a statistically significant improvement of muscle mass (61.49 ± 5.47 vs. control 86 ± 10.70, p = 0.01) and SMI index (9.97 ± 1.79 vs. control 7.60 ± 2.29, p = 0.02). In addition, the measurement of skeletal muscle mass in CD patients has been suggested to be crucial for predicting the disease course. Indeed, after one year, surgery was required in 4/10 control group patients (40%) and 1/10 study group (10%) patients, underlining the importance of body composition alterations and adequate dietary intake in the management of these patients. Further prospective studies are needed to confirm these results; nonetheless this nutritional approach could become an integral part in the treatment of stricturing CD patients to improve disease outcomes and increase the quality of life in these patients.

Therapeutic Effects of Taurine and Histidine Supplementation in Retinal Diseases.

Amino acids are basic building blocks of structural proteins and enzymes. They also act as signaling molecules and as fuel. They are characterized as essential if sufficient quantities must be supplied exogenously or as non-essential if they can be endogenously synthesized. Appropriate intake of amino acids not only prevents the development of metabolic diseases but also can reduce the progression of some disease states. Amino acids are strongly associated with retinal metabolism in physiology and pathology. Nonetheless, there is a lack of robust clinical studies supporting the benefits of amino acid supplementation in retinopathy. In this review, we summarize preclinical evidence concerning the potential of supplementing the amino acids taurine and histidine to provide protection against diabetic retinopathy, glaucoma, and age-related macular degeneration. We suggest further directions for studying amino acid-based therapeutic interventions for eye diseases.