Essential Amino Acid Deficiency Research Articles

PH shift extraction technique for plant proteins: A promising technique for sustainable development

With the recognition of animal-derived foods as unhealthy and their association with climate change, researchers are increasingly focusing on plant-based protein as a sustainable alternative. Plant proteins offer versatile functional and dietary benefits, making them suitable for various food applications. This study investigates the influence of alkaline and acidic pH conditions on the extraction yield and the functional and nutritional properties of plant-based proteins. The primary sources of plant protein include cereals, legumes, and oilseeds, which can be used to address essential amino acid deficiencies through blending. Several methods have been employed for protein extraction from plant sources, such as salt extraction, microwave-assisted extraction, ultrasound-assisted extraction, and micellar precipitation. Among these techniques, the pH shift method stands out due to its non-thermal nature, sustainability, and cost-effectiveness. In this method, proteins are solubilized at alkaline pH and then precipitated at their isoelectric point, resulting in a collection of protein precipitate. It is crucial to optimize extraction techniques based on qualitative and quantitative analysis to enhance protein yield, characteristics, and nutritional value. Most conventional protein extraction methods require a large quantity of chemicals, which imposes the issue of safe disposal, compromising environmental sustainability. Traditional methods also produce protein with non-proteinaceous constituents, adding another purification step and resulting in increased overall cost. However, the pH shift method utilizes comparatively less harsh chemicals and has a high protein extraction yield, which makes it comparatively more environmentally and economically sustainable. The sustainable extraction of plant-based proteins addresses the health and environmental concerns associated with animal-derived foods and offers a promising solution to promote sustainability in the food industry.

Metabolomic profiling of amino acid alterations in anorexia nervosa: implications for appetite regulation and therapeutic strategies.

Anorexia nervosa (AN), a severe psychiatric disorder primarily affecting adolescents and young adults, is characterized by extreme dietary restriction and distorted body image. While the psychological aspects of AN are well-documented, its intricate metabolic underpinnings remain less explored. We think that metabolomic analysis of hair samples emerges as a promising tool to unveil the complex physiological alterations in AN. This study aims to comprehensively profile amino acid concentrations in hair samples from AN patients and healthy controls. Additionally, it seeks to elucidate potential correlations between amino acid alterations and appetite dysregulation in AN, thereby shedding light on the physiological basis of this debilitating disorder. A total of 25 AN patients and 25 age-matched healthy controls were recruited for this study. Hair samples were collected, and metabolites were extracted and analyzed using high-resolution liquid chromatography-mass spectrometry. Clinical data and biochemical markers were also gathered to characterize participants' demographic and clinical profiles. Metabolomic analysis revealed significant alterations in amino acid concentrations in AN patients compared to healthy controls. Notably, deficiencies in essential amino acids (EAAs) and branched-chain amino acids (BCAAs) were observed, highlighting potential contributors to muscle wasting and appetite dysregulation. Further analysis identified specific amino acids as robust biomarkers capable of distinguishing AN patients with high sensitivity and specificity. This study unveils the complex metabolic disturbances associated with AN and underscores the role of amino acid dysregulation in the disorder's pathophysiology. The identified biomarkers hold promise for diagnostic screening and potential therapeutic interventions, opening avenues for personalized approaches in AN treatment. Ultimately, this research contributes to our understanding of chronic disorders through the lens of metabolomics and the chemosensory underpinnings of appetite regulation.

Sulfur Application Improves the Nutritional Quality of Maize by Regulating the Amino Acid Balance of Grains

As a crucial staple crop in agricultural production, maize is extensively cultivated worldwide and plays a pivotal role in ensuring global food security. However, the significant deficiency of essential amino acids (EAA) and conditionally essential amino acids (CEAA), such as lysine (Lys), tryptophan (Trp), methionine (Met), and cysteine (Cys), leads to an imbalance of amino acids in the grain. This study investigates the regulatory mechanism of sulfur (S) application for regulating the amino acid balance of maize grains. The results demonstrate that S application has substantial effects on both the maize yield and nutritional quality. The S application resulted in an increase in maize yield by simultaneously enhancing the grain number per ear (GN) and 100-grain weight (GW), while S application elevated protein concentration through the augmentation of Cys concentration in maize grains. Furthermore, the Cys in grains optimizes the amino acid balance by regulating the ratio of other amino acids, thereby enhancing the nutritional quality of maize while ensuring a steady increase in protein concentration, simultaneously. Overall, the S application at 60–90 kg ha−1 synergistically improved both the yield and nutritional quality of maize, meeting the requirements for sustainable development in maize production. The findings offer a novel theoretical foundation and nutrient management approach for achieving high-yield and superior-quality maize production.

Effects of Feed Moisture Content on the Physical and Nutritional Quality Attributes of Sunflower Meal-based High-Moisture Meat Analogues

Adding value to food industry by-products, like sunflower meal (SFM), through their utilization as ingredients in new food products can improve sustainability of food systems. This research investigated extrusion cooking to produce high-moisture meat analogues (HMMAs) made from blends of soy protein isolate and expeller-pressed SFM. The effects of feed moisture content [FMC] (60, 65, and 70%, wet basis) and SFM concentration (37.5, 50, and 62.5%, total blend weight basis) on physical and protein nutritional quality attributes of HMMAs were investigated. The processing temperatures (including cooling die), screw speed and feed rate were kept constant at 60-80-115-125-50-25 °C (from feeder to the die end), 200 rpm and 0.5 kg/h (dry basis), respectively. An increase in SFM concentration and FMC significantly (p < 0.05) reduced the mechanical energy requirements for extrusion. Cutting strength and texture profile analysis of HMMAs indicated softer texture with increases in SFM and FMC. X-ray microcomputed tomography analysis revealed that the microstructure of the HMMAs at the centre and towards the surface was different and affected by SFM concentration and FMC. The in vitro–protein digestibility corrected amino acid score of the HMMAs ranged between 85 and 91% and did not show significant (p < 0.05) changes as a function of FMC or SFM concentration. HMMAs produced from 37.5% SFM at 70% FMC showed no deficiency in essential amino acids for all age categories except for infants, suggesting the high potential of SFM and soy protein blends for creating nutritious meat alternative products. Overall, this work provided valuable insights regarding the effects of soy protein replacement by SFM on the textural, microstructural and nutritional quality of HMMA applications, paving the way for value-addition to this underutilized food industry by-product.

Temporal regulation of transgene expression controlled by amino acid availability in human T cells.

T cell therapy strategies, from allogeneic stem cell transplantation toward genetically-modified T cells infusion, develop powerful anti-tumor effects but are often accompanied by side effects and their efficacy remains sometimes to be improved. It therefore appears important to provide a flexible and easily reversible gene expression regulation system to control T cells activity. We developed a gene expression regulation technology that exploits the physiological GCN2-ATF4 pathway's ability to induce gene expression in T cells in response to one essential amino acid deficiency. We first demonstrated the functionality of NUTRIREG in human T cells by transient expression of reporter genes. We then validated that NUTRIREG can be used in human T cells to transiently express a therapeutic gene such as IL-10. Overall, our results represent a solid basis for the promising use of NUTRIREG to regulate transgene expression in human T cells in a reversible way, and more generally for numerous preventive or curative therapeutic possibilities in cellular immunotherapy strategies.

Pipecolate and Taurine are Rat Urinary Biomarkers for Lysine and Threonine Deficiencies

BackgroundThe consumption of poor-quality protein increases the risk of essential amino acid (EAA) deficiency, particularly for lysine and threonine. Thus, it is necessary to be able to detect easily EAA deficiency. ObjectivesThe purpose of this study was to develop metabolomic approaches to identify specific biomarkers for an EAA deficiency, such as lysine and threonine. MethodsThree experiments were performed on growing rats. In experiment 1, rats were fed for 3 weeks with lysine (L30), or threonine (T53)-deficient gluten diets, or nondeficient gluten diet (LT100) in comparison with the control diet (milk protein, PLT). In experiments 2a and 2b, rats were fed at different concentrations of lysine (L) or threonine (T) deficiency: L/T15, L/T25, L/T40, L/T60, L/T75, P20, L/T100 and L/T170. Twenty-four-hour urine and blood samples from portal vein and vena cava were analyzed using LC-MS. Data from experiment 1 were analyzed by untargeted metabolomic and Independent Component - Discriminant Analysis (ICDA) and data from experiments 2a and 2b by targeted metabolomic and a quantitative Partial Least- Squares (PLS) regression model. Each metabolite identified as significant by PLS or ICDA was then tested by 1-way ANOVA to evaluate the diet effect. A two-phase linear regression analysis was used to determine lysine and threonine requirements. ResultsICDA and PLS found molecules that discriminated between the different diets. A common metabolite, the pipecolate, was identified in experiments 1 and 2a, confirming that it could be specific to lysine deficiency. Another metabolite, taurine, was found in experiments 1 and 2b, so probably specific to threonine deficiency. Pipecolate or taurine breakpoints obtained give a value closed to the values obtained by growth indicators. ConclusionsOur results showed that the EAA deficiencies influenced the metabolome. Specific urinary biomarkers identified could be easily applied to detect EAA deficiency and to determine which AA is deficient.

Enriched Pea Protein Texturing: Physicochemical Characteristics and Application as a Substitute for Meat in Hamburgers.

There is currently a growing trend towards the consumption of vegetable protein, even if it shows some deficiencies in essential amino acids. It has been driven by consumer passion for health and wellness, environmental sustainability, animal welfare and the flexitarian lifestyle. However, the formulation of plant protein food analogues to meat products is complicated by the technological properties of isolated plant protein. One of the processes used to improve these properties is the texturisation of the protein by extrusion, as well as the use of other plant materials that can enrich the formulation. Therefore, the aim of this study was to evaluate the effect of pea protein (PP) enriched with lucerne (L), spinach (S) and Chlorella (C) in powdered and texturised forms on the physicochemical properties and extrusion parameters, and to evaluate its technological and sensory quality as a meat analogue in vegetal hamburgers. Texturisation reduced the number of soluble components released, thus reducing the molecular degradation in extruded material. The texturised samples were significantly (p < 0.05) less hygroscopic than the non-textured samples. Once the properties of the powder and texturised had been analysed, they were used to prepare vegetal hamburgers. The addition of vegetable-enriched texturised samples with high chlorophyll content led to more intense colour changes in the vegetal hamburgers during cooking, with PP+C providing the darkest colouring, and also resulted in a final product more similar to a traditional meat hamburger, with higher overall and meat odour/flavour intensity, hardness, juiciness and chewiness, and less legume and spice odour and flavour. Overall, texturisation improved the technological properties of the enriched protein isolate, allowing for more efficient production of vegetal hamburgers.

Lysine or Threonine Deficiency Decreases Body Weight Gain in Growing Rats despite an Increase in Food Intake without Increasing Energy Expenditure in Response to FGF21

The objective of this study is to evaluate the effects of a strictly essential amino acid (lysine or threonine; EAA) deficiency on energy metabolism in growing rats. Rats were fed for three weeks severely (15% and 25% of recommendation), moderately (40% and 60%), and adequate (75% and 100%) lysine or threonine-deficient diets. Food intake and body weight were measured daily and indirect calorimetry was performed the week three. At the end of the experimentation, body composition, gene expression, and biochemical analysis were performed. Lysine and threonine deficiency induced a lower body weight gain and an increase in relative food intake. Lysine or threonine deficiency induced liver FGF21 synthesis and plasma release. However, no changes in energy expenditure were observed for lysine deficiency, unlike threonine deficiency, which leads to a decrease in total and resting energy expenditure. Interestingly, threonine severe deficiency, but not lysine deficiency, increase orexigenic and decreases anorexigenic hypothalamic neuropeptides expression, which could explain the higher food intake. Our results show that the deficiency in one EAA, induces a decrease in body weight gain, despite an increased relative food intake, without any increase in energy expenditure despite an induction of FGF21.

The Challenge of Severe Acute Malnutrition in Inborn Errors of Metabolism: Does Medical Food Alone Suffice?

Glutaric aciduria type 1 (GA-1) is a treatable inborn error of metabolism caused by glutaryl-CoA dehydrogenase deficiency. This enzyme deficiency leads to accumulation of glutaric acid, 3-hydroxy glutaric acid, and glutaconic acid which are potentially neurotoxic. Patients with GA-1 have characteristic clinical and neuroimaging features that help us to clinch the diagnosis. Early diagnosis by newborn screening helps us to prevent the motor problems such as dystonia and spasticity. Treatment includes low-protein diet along with carnitine supplementation which may lead to deficiency of essential amino acids and hence malnutrition. Managing malnutrition in a child with inborn errors of metabolism (IEM) is challenging. Here, we describe a patient, a case of GA-1 on medical food, presenting with severe acute malnutrition, who improved with a combination of medical and home-made foods along with lysine-free, tryptophan-reduced amino acid supplements.

Perspective: Vegan Diets for Older Adults? A Perspective On the Potential Impact On Muscle Mass and Strength

ABSTRACTConsumers are increasingly encouraged to consume more plant-based foods and lower their consumption of foods from animal origin. Concurrently, older adults are recommended to consume an adequate amount of high-quality dietary protein for the prevention of age-related muscle loss. In the current Perspective article, we discuss why it may not be preferred to consume a vegan diet at an older age. Our perspective is based on the proposed lower bioavailability and functionality of proteins in a vegan diet due to the matrix of the whole-food protein sources, the lower essential amino acid (EAA) content, and specific EAA deficiencies in proteins derived from plant-based foods. We propose that a vegan diet increases the risk of an inadequate protein intake at an older age and that current strategies to improve the anabolic properties of plant-based foods are not feasible for many older adults. We provide recommendations for further research to substantiate the remaining knowledge gaps regarding the consequences of a vegan diet on skeletal muscle mass and strength at an older age.

Effects of Essential Amino Acid Deficiency on General Control Nonderepressible 2/Eukaryotic Initiation Factor 2 Signaling and Proteomic Changes in Primary Bovine Mammary Epithelial Cells.

We hypothesized that the general control nonderepressible 2 (GCN2)/eukaryotic initiation factor 2 (eIF2) signaling pathway and intracellular protein synthesis (PS) are regulated to maintain milk PS in primary bovine mammary epithelial cells (MECs) under essential amino acid (EAA) starvation conditions. We cultured MECs with 0%, 2% (depletion), and 100% (control) EAA for two exposure times (8 and 24 h), followed by three refeeding (RF) times with 100% EAA (0, 8, and 24 h). Subsequently, we measured cell viability, total protein concentration, and proliferation. Western blotting was used to quantify the levels of casein and the expression of total GCN2 and eIF2, as well as phosphorylated GCN2 (GCN2P) and eIF2 (eIF2P). The ISOQuant method was used to assess MEC proteomes, and the resultant data were analyzed using the Kruskal–Wallis test, nonpaired Wilcoxon rank post-hoc test, and ANOVA–Tukey test, as well as principal component analyses and multiple regressions models. Differences in cell viability were observed between the control versus the depleted and repleted MECs, respectively, where 97.2–99.8% viability indicated low cell death rates. Proliferation (range, 1.02–1.55 arbitrary units (AU)) was affected by starvation for 12 and 24 h and repletion for 24 h, but it was not increased compared with the control. Total protein expression was unaffected by both depletion and repletion treatments (median 3158 µg/mL). eIF2P expression was significantly increased (p < 0.05) after treatment with 2% EAA for 8 and 24 h compared with 2% EAA with 8 h + 24 h RF and 2% EAA with 24 h + 8 h RF. GCN2P also showed significantly increased expression (p < 0.05) after treatment with 2% EAA for 24 h compared with the control and 2% EAA with 24 h + 8 h RF. Intracellular casein/α-tubulin expression was unaffected by 2% EAA compared with control (0.073 ± 0.01 AU versus 0.086 ± 0.02 AU, respectively). We studied 30 of the detected 1180 proteins, 16 of which were differentially expressed in starved and refed MECs. Cells faced with EAA deficiency activated the GCN2P/eIF2P pathway, and the lack of change in the levels of casein and other milk proteins suggested that the EAA deficit was mitigated by metabolic flexibility to maintain homeostasis.

Effects of different artificial diets on commercial honey bee colony performance, health biomarkers, and gut microbiota

BackgroundHoney bee colonies managed for agricultural pollination are highly dependent on human inputs, especially for disease control and supplemental nutrition. Hives are routinely fed artificial “pollen substitute” diets to compensate for insufficient nutritional forage in the environment. The aim of this study was to investigate the effects of different artificial diets in a northern California, US commercial beekeeping operation from August through February. This time period represents an extended forage dearth when supplemental nutrition is used to stimulate late winter colony growth prior to almond pollination in the early spring. A total of 144 honey bee colonies were divided into 8 feeding groups that were replicated at three apiary sites. Feeding groups received commercial diets (Global, Ultra Bee, Bulk Soft, MegaBee, AP23, Healthy Bees), a beekeeper-formulated diet (Homebrew), or a sugar negative control. Diets were analyzed for macronutrient and amino acid content then evaluated with respect to honey bee colony population size, average bee weight, nutrition-related gene expression, gut microbiota abundance, and pathogen levels.ResultsReplicated at three apiary sites, two pollen-containing diets (Global and Homebrew) produced the largest colonies and the heaviest bees per colony. Two diets (Bulk Soft and AP23) that did not contain pollen led to significantly larger colonies than a sugar negative control diet. Diet macronutrient content was not correlated with colony size or health biomarkers. The sum of dietary essential amino acid deficiencies relative to leucine content were correlated with average bee weight in November and colony size used for almond pollination in February. Nutrition-related gene expression, gut microbiota, and pathogen levels were influenced by apiary site, which overrode some diet effects. Regarding microbiota, diet had a significant impact on the abundance of Bifidobacterium and Gilliamella and trended towards effects on other prominent bee gut taxa.ConclusionsMultiple colony and individual bee measures are necessary to test diet efficacy since honey bee nutritional responses are complex to evaluate. Balancing essential amino acid content relative to leucine instead of tryptophan may improve diet protein efficiency ratios. Optimization of bee diets could improve feed sustainability and agricultural pollination efficiency by supporting larger, healthier honey bee colonies.

Квашиоркор: патофизиологические аспекты и пути решения проблемы

Kwashiorkor is a form of severe protein-energy malnutrition known since 1995. It is observed worldwide in regions with high levels of hunger and poverty, especially where the diet consists primarily of carbohydrate-rich foods. This pathology has been reported among hundreds of thousands of children in the world. The clinical presentation of kwashiorkor resembles the symptoms of essential amino acid deficiency, which suggests that not only protein malnutrition, but also disorders of the methionine cycle take part in the pathogenesis of the disease. The study of capillary ultrastructure has shown that edema is the result of increased permeability of microvessels to protein macromolecules, including albumin. Plasma proteins are usually retained in the intravascular space by the endothelial glycocalyx, damage to which leads to edema. Oxidative stress contributes to lower levels of vitamin E and glutathione. An imbalance between the levels of reactive oxygen species and antioxidants leads to mitochondrial damage, which reduces ATP production and impairs liver function. Mitochondrial dysfunction and ATP depletion together with nutrient deficiency may contribute to the development of multiple organ dysfunction syndrome. Three clinical parameters are used to assess the severity of kwashiorkor: mid-arm muscle circumference, body mass index, and the presence of localized symmetric edema. In the absence of timely treatment in the early stages, children may have serious complications, including shock, coma, physical and mental disorders. Normalization of physiological and metabolic functions in patients with kwashiorkor is a complex task. The three-step approach to treating children with severe protein-energy malnutrition recommended by the World Health Organization includes stabilization, rehabilitation, and recurrence prevention. The prognosis in the absence of treatment is unfavorable. Key words: protein-energy malnutrition, kwashiorkor, children

Food proteins from animals and plants: Differences in the nutritional and functional properties

BackgroundAnimals and plants are the main sources of dietary proteins, and there are important differences in the type of protein that they supply. The differences include molecular structure, amino acid profile, digestibility, and technical functionality in food, i.e. the ability to gel, emulsify, bind water etc. These inherent differences influence their bioavailability from a human nutrition perspective, as well as the sensory quality of foods containing animal or plant proteins. These fundamental differences mean that designing plant-based foods to mimic animal foods requires much more than simple substitution of one ingredient with another. Scope and approachWe survey some of the nutritional and technological functionality data for animal- and plant-derived food proteins and discuss the nature and implications of the differences between them. Key findings and conclusionsPlant-based foods typically provide less complete protein nutrition because of lower digestibility and source-specific deficiencies in essential amino acids, compared with animal proteins. Such differences may not be as essential for adults as they are for infants and young children, due to their developmental requirements. Plant proteins can be subjected to various processes to bring their functionality closer to that of animal proteins (e.g. hydrolysis to improve solubility), but some processes that improve functionality also diminish amino acid bioaccessibility or bioactivity, creating negative nutritional consequences. Much more research and innovation are required to enhance the potential of plant proteins. In the short to medium term, nutritional and functional synergies between plant and animal proteins may offer a path to creating nutritious and attractive foods.

Deficiency in the Essential Amino Acids l-Isoleucine, l-Leucine and l-Histidine and Clinical Measures as Predictors of Moderate Depression in Elderly Women: A Discriminant Analysis Study.

Increases in depression are common in some elderly women. Elderly women often show moderate depressive symptoms, while others display minimal depressive symptoms. These discrepancies have produced contradictory and inconclusive outcomes, which have not been explained entirely by deficits in neurotransmitter precursors. Deficiency in some amino acids have been implicated in major depression, but its role in non-clinical elderly women is not well known. An analysis of essential amino acids, depression and the use of discriminant analysis can help to clarify the variation in depressive symptoms exhibited by some elderly women. The aim was to investigate the relationship of essential amino acids with affective, cognitive and comorbidity measures in elderly women without major depression nor severe mood disorders or psychosis, specifically thirty-six with moderate depressive symptoms and seventy-one with minimal depressive symptoms. The plasma concentrations of nineteen amino acids, Beck Depression Inventory (BDI) scores, Geriatric Depression Scale (GDS) scores, global cognitive scores and comorbidities were submitted to stepwise discriminant analysis to identify predictor variables. Seven predictors arose as important for belong to the group based on amino acid concentrations, with the moderate depressive symptoms group characterized by higher BDI, GDS and cognitive scores; fewer comorbidities; and lower levels of l-histidine, l-isoleucine and l-leucine. These findings suggest that elderly women classified as having moderate depressive symptoms displayed a deficiency in essential amino acids involved in metabolism, protein synthesis, inflammation and neurotransmission.

POST-GASTRIC BYPASS HYPERAMMONEMIC ENCEPHALOPATHY: A RARE AND POTENTIALLY FATAL CAUSE OF ENCEPHALOPATHY IN THE ICU

TOPIC: Critical Care TYPE: Fellow Case Reports INTRODUCTION: In the US the prevalence of obesity has risen to 39.8% and affected about 93.3 million of US adults in 2015. Morbidly obese patients are increasingly pursuing bariatric surgery. While the benefits of bariatric surgery are numerous, it is important to recognize and understand the short term and long term postoperative complications. Hyperammonemic syndrome is an uncommon but severe complication of gastric bypass surgery. CASE PRESENTATION: A 43 year old woman with history of non-alcoholic fatty liver disease and history of prior gastric sleeve which was followed by Roux-en-Y Gastric Bypass (RYGB) surgery was admitted for shortness of breath and altered mental status. On hospital day number 10 patient was transferred to ICU for altered mental status, worsening hypoxia, retroperitoneal bleed and septic shock. Patient was subsequently intubated, given transfusions, placed on vasopressors, and given broad-spectrum antibiotics. After 72 hours her overall shock resolved and her ventilator requirements were minimal, but she remained in a comatose state. Initial workup including CT head and brain MRI were unremarkable. Initial routine EEG was consistent with low voltage delta frequencies which could be seen in the setting of severe encephalopathy. Ammonia level had risen to 169 umol/L, which was significantly elevated from prior level of 81 umol/L on admission (Table 1). In addition to aggressive treatment with lactulose and rifaximin, multiple supplements were added, including: Zinc, multivitamin, and L-carnitine. Subsequent EEG on ICU revealed myoclonic status epilepticus for which antiepileptic drugs were given. Repeat MRI of the brain revealed increased diffusion-weighted signal intensity within the cortex and subcortical white matter of suggesting hypoxic and anoxic brain injury. DISCUSSION: Hyperammonemic syndrome related to bariatric surgery is characterized by hyperammonemia, elevated plasma glutamine, hypoalbuminemia, reactive hypoglycemia, nutritional deficiencies of essential amino acids, and low zinc levels, in the absence of overt liver fibrosis or evidence of significant hepatocellular injury (1). The mortality rate approaches 50% and it tends to occur at a high rate in women (1). Patients may present with irritability, vomiting, ataxia, mental retardation, lethargy, and eventually alteration in consciousness and coma (1). There are multiple genetic and nongenetic hypothesized mechanisms (Table 2). Treatment strategies for hyperammonemia include: lactulose, rifaximin, repletion of deficient amino acids, zinc, micro nutrients, and prevention of seizures and cerebral edema (2). CONCLUSIONS: It is important to consider hyperammonemia related to bypass as a potential etiology for neurologic changes in patients with prior bypass, especially in the ICU setting where multiple etiologies can cause encephalopathy and hyperammonemia. REFERENCE #1: Fenves, A. et al. "Hyperammonemic Syndrome After Roux-En-Y Gastric Bypass." Obesity Journal. Volume 23. Number 4. 2015. REFERENCE #2: Krishnan P, Ramdas P, Landsberg. "Bariatric Surgery causing hyperammonemia." Cureus 11 (7): e5098. DOI 10.7759/cureus.5098. July 8, 2019 DISCLOSURES: No relevant relationships by SOHAIB KHAN, source=Web Response No relevant relationships by Jessica Nash, source=Web Response No relevant relationships by Mehul Patel, source=Web Response No relevant relationships by Mena Tawfik, source=Web Response

Hepatic Manifestations of Urea Cycle Disorders.

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Gut microbiota mediate the FGF21 adaptive stress response to chronic dietary protein-restriction in mice

Chronic dietary protein-restriction can create essential amino acid deficiencies and induce metabolic adaptation through the hepatic FGF21 pathway which serves to maintain host fitness during prolonged states of nutritional imbalance. Similarly, the gut microbiome undergoes metabolic adaptations when dietary nutrients are added or withdrawn. Here we confirm previous reports that dietary protein-restriction triggers the hepatic FGF21 adaptive metabolic pathway and further demonstrate that this response is mediated by the gut microbiome and can be tuned through dietary supplementation of fibers that alter the gut microbiome. In the absence of a gut microbiome, we discover that FGF21 is de-sensitized to the effect of protein-restriction. These data suggest that host-intrinsic adaptive pathways to chronic dietary protein-restriction, such as the hepatic FGF21 pathway, may in-fact be responding first to adaptive metabolic changes in the gut microbiome.

Plasma and Urinary Amino Acid-Derived Catabolites as Potential Biomarkers of Protein and Amino Acid Deficiency in Rats.

Objective: Dietary intakes must cover protein and essential amino acid (EAA) requirements. For this purpose, different methods have been developed such as the nitrogen balance method, factorial method, or AA tracer studies. However, these methods are either invasive or imprecise, and the Food and Agriculture Organization of the United Nations (FAO, 2013) recommends new methods and, in particular, metabolomics. The aim of this study is to determine total protein/EAA requirement in the plasma and urine of growing rats. Methods: 36 weanling rats were fed with diets containing 3, 5, 8, 12, 15, and 20% protein for 3 weeks. During experimentation, urine was collected using metabolic cages, and blood from the portal vein and vena was taken at the end of the experiment. Metabolomics analyses were performed using LC-MS, and the data were analyzed with a multivariate analysis model, partial least Squares (PLS) regression, and independent component-discriminant analysis (ICDA). Each discriminant metabolite identified by PLS or ICDA was tested by one-way ANOVA to evaluate the effect of diet. Results: PLS and ICDA allowed us to identify discriminating metabolites between different diet groups. Protein deficiency led to an increase in the AA catabolism enzyme systems inducing the production of breakdown metabolites in the plasma and urine. Conclusion: These results indicate that metabolites are specific for the state of EAA deficiency and sufficiency. Some types of biomarkers such as AA degradation metabolites appear to be specific candidates for protein/EAA requirement.

Synergistic Regulation of Nitrogen and Sulfur on Redox Balance of Maize Leaves and Amino Acids Balance of Grains.

As a primary food crop, maize is widely grown around the world. However, the deficiency of essential amino acids, such as lysine, tryptophan, and methionine, results in poor nutritional quality of maize. In addition, the protein concentration of maize declines with the increase in yield, which further reduces the nutritional quality. Here, the photosynthesis of leaves, grain amino acid composition, and stoichiometry of N and S are explored. The results show that N and S maintained the redox balance by increasing the content of glutathione in maize leaves, thereby enhancing the photosynthetic rate and maize yield. Simultaneously, the synergy of N and S increased the grain protein concentration and promoted amino acid balance by increasing the cysteine concentration in maize grains. The maize yield, grain protein concentration, and concentration of essential amino acids, such as lysine, tryptophan, and methionine, could be simultaneously increased in the N:S ratio range of 11.0 to 12.0. Overall, the synergy of N and S simultaneously improved the maize yield and nutritional quality by regulating the redox balance of maize leaves and the amino acids balance of grains, which provides a new theoretical basis and practical method for sustainable production of maize.