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On the basis of research presented during the 9th Amino Acid Assessment Workshop, a No Observed Adverse Effect Level (NOAEL) for diet-added arginine (added mostly in the form of dietary supplements) of 30 g/d and an upper limit of safe intake (ULSI) for diet-added tryptophan (added mostly in the form of dietary supplements) of 4.5 g/d have been proposed. Both recommendations apply to healthy young adults. The total dietary leucine ULSI proposed for elderly individuals is 500 mg · kg-1 · d-1 All 3 recommendations are relevant only to high-quality amino acid-containing products with specifications corresponding to those listed in the US Pharmacopeia Because the above amino acids are extensively utilized as dietary supplements for various real or perceived benefits, such as vasodilation, spermatogenesis, sleep, mood regulation, or muscle recovery, the above safety recommendations will have an important impact on regulatory and nutritional practices. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Assessment of protein requirement in octogenarian women with use of the indicator amino acid oxidation technique" by M. Tang and colleagues in a 2014 issue of the journal.

Background: Data on the protein requirements of elderly adults are limited, because it is impractical to conduct repeated nitrogen balance protocols in these vulnerable humans. Objective: This study was designed to determine the dietary protein requirement of elderly women by using the recently developed minimally invasive indicator amino acid oxidation (IAAO) technique. Design: Six white women aged 80-87 y [mean ± SEM: 82 ± 1 y and body mass index (in kg/m²) 26 ± 2] completed a 3-d protocol 7 times. Each woman consumed an adaptation diet for 2 d and on day 3 consumed a complete test diet with a crystalline amino acid mixture containing 1 of 7 protein intakes (0.1, 0.3, 0.6, 0.9, 1.2, 1.5, or 1.8 g ⋅ kg-1 ⋅ d-1) tested randomly. A group-based protein requirement was assessed by using a nonlinear mixed model of protein intake and L-[1-13C]phenylalanine oxidation. The breakpoint, at which there was no further decline in the rate of appearance of 13C in the breath, was used as an index of the mean protein requirement. Results: The mean protein requirement (95% CI) was 0.85 (0.60, 1.09) g ⋅ kg-1 ⋅ d-1. This requirement is 29% higher than the current Estimated Average Requirement (EAR) for adults of 0.66 g ⋅ kg-1 ⋅ d-1 based on the nitrogen balance technique, although the 95% CI includes the current EAR. The corresponding adequate protein allowance of 1.15 (0.77, 1.54) g ⋅ kg-1 ⋅ d-1 is 44% higher, although the 95% CI includes the Recommended Dietary Allowance (RDA) of 0.80 g ⋅ kg-1 ⋅ d-1. Conclusions: Notwithstanding uncertainty about the validity of the use of the IAAO technique to assess protein requirements, the results of this study with octogenarian women suggest that the current EAR and RDA for elderly women may be underestimated. The limitations of this short-term, noninvasive method underscore the need for new research that uses alternative experimental designs and measuring physiologic, morphologic, and health-related outcomes. This trial was registered at clinicaltrials.gov as NCT01193946. [ABSTRACT FROM AUTHOR]

Background: Leucine has been suggested to improve athletic performance. Therefore, the branched-chain amino acids (BCAAs), especially leucine, are popular as dietary supplements in strength- training athletes; however, the intake of leucine in excess of requirements raises concerns regarding adverse effects. Currently, the tolerable upper intake level (UL) for leucine is unknown. Objective: The objective of the current study was to determine the UL for leucine in adult men under acute dietary conditions. Design: Five healthy adults (20-35 y) each received graded step- wise increases in leucine intakes of 50, 150, 250, 500, 750, 1000, and 1250 mg • kg-1 d-1, which corresponded to the Estimated Average Requirement (EAR) and the EAR X3, X5, X10, X15, X20, and X25 in a total of 29 studies. The UL of leucine was identified by the measurement of plasma and urinary biochemical variables and changes in leucine oxidation by using L-[l-l3C]-leucine. Results: A significant increase in blood ammonia concentrations above normal values, plasma leucine concentrations, and urinary leucine excretion were observed with leucine intakes >500 mg •-1 d-1. The oxidation of L-[l-13C]-leucine expressed as label tracer oxidation in breath (F13CO2), leucine oxidation, and a-ketoisocaproic acid (KIC) oxidation led to different results: a plateau in (F13CO2) observed after 500 mg • kg-1 d-1, no clear plateau observed in leucine oxidation, and KIC oxidation appearing to plateau after 750 mg • kg-1 d-1. Conclusion: On the basis of plasma and urinary variables, the UL for leucine in healthy adult men can be suggested at 500 mg • kg-1 d-1' or ~35 g/d as a cautious estimate under acute dietary conditions. This trial was registered at clinicaltrials.gov as NCT00972582. [ABSTRACT FROM AUTHOR]

A letter to the editor and a reply are presented in response to the article "Protein requirement of healthy school-age children determined by the indicator amino acid oxidation method," R. Elango amd colleagues in the 2011 issue.

We recently reported the lysine requirement of school-aged children living in Canada consuming a mixed diet to be 35 mg.kg-1∙d-1. Because the majority of children in the world live on cereal-based diets in developing countries, we measured the daily lysine requirement in healthy children living in India and consuming a mostly cereal-based diet. Our objective in this study was to determine the lysine requirement in healthy, school-aged children in the developing world by using the indicator amino acid oxidation method with L-[1-13C] phenylalanine. Six healthy, school-aged children consumed 7 levels of lysine (5, 15, 25, 35, 50, 65, and 80 mgkg-1d-1) each in a random order along with an amino acid mixture providing energy and protein intakes of 1.7 x resting energy expenditure and 1.5 gkg-1d-1, respectively. The mean lysine requirement was determined by applying a 2-phase linear regression crossover analysis on tracer oxidation (F13CO2) data, which identified a breakpoint (requirementl at minimal F13CO2 in response to the graded lysine intakes. The mean lysine requirements with the upper 95% Cl for children were determined to be 33.5 and 46.6 mgkg-1∙d-1, respectively, by breakpoint analysis of the F13CO2 data. The mean lysine requirements of Indian children were almost identical to that of Canadian children (35 mg∙kg-1∙d-1). There is no evidence for any adaptation in lysine requirements in children from developing countries such as India [ABSTRACT FROM AUTHOR]

We recently reported the lysine requirement of school-aged children living in Canada consuming a mixed diet to be 35 mg.kg-1∙d-1. Because the majority of children in the world live on cereal-based diets in developing countries, we measured the daily lysine requirement in healthy children living in India and consuming a mostly cereal-based diet. Our objective in this study was to determine the lysine requirement in healthy, school-aged children in the developing world by using the indicator amino acid oxidation method with L-[1-13C] phenylalanine. Six healthy, school-aged children consumed 7 levels of lysine (5, 15, 25, 35, 50, 65, and 80 mgkg-1d-1) each in a random order along with an amino acid mixture providing energy and protein intakes of 1.7 x resting energy expenditure and 1.5 gkg-1d-1, respectively. The mean lysine requirement was determined by applying a 2-phase linear regression crossover analysis on tracer oxidation (F13CO2) data, which identified a breakpoint (requirementl at minimal F13CO2 in response to the graded lysine intakes. The mean lysine requirements with the upper 95% Cl for children were determined to be 33.5 and 46.6 mgkg-1∙d-1, respectively, by breakpoint analysis of the F13CO2 data. The mean lysine requirements of Indian children were almost identical to that of Canadian children (35 mg∙kg-1∙d-1). There is no evidence for any adaptation in lysine requirements in children from developing countries such as India [ABSTRACT FROM AUTHOR]

Abstract: The sulfur amino acids, methionine and cysteine play crucial roles in cells as a substrate for protein synthesis, as a methyl donor, and for the synthesis of sulfur-containing compounds, including the key intracellular tripeptide, glutathione. Homocysteine is an intermediary metabolite formed during the metabolism of methionine to cysteine. Dysregulation of homocysteine metabolism is implicated in adverse clinical outcomes such as increased risk of cardiovascular disease, stroke, Alzheimer''s disease dementia and osteoporosis. While hyperhomocysteinemia is commonly observed in those conditions, the impact on other related metabolites is condition-specific. Therefore, there exists a need to establish precise and sensitive analytical techniques that allow for the simultaneous measurement of homocysteine and related metabolites in biological samples. The current review outlines the development and use of liquid chromatography electrospray tandem mass spectrometry (LC–MS/MS) to simultaneously measure metabolites involved in sulfur amino acid metabolism. Additionally, extensions of the technique in relation to the measurement of sulfur amino acid and one-carbon kinetics in vivo are discussed. The LC–MS/MS technique has the capacity for unambiguous analyte identification and confirmation, due to its high specificity and sensitivity. It has the greatest potential of being accepted and utilized as a dedicated homocysteine and its related metabolite Standard reference method (SRM). [Copyright &y& Elsevier]

Objectives The pregnancy-induced alterations in 1-carbon (1C) metabolism, effects of advancing gestation on maternal plasma concentrations of methyl nutrients, and potential implications for maternal dietary intake and infant clinical outcomes are summarized in this narrative review. Background 1C metabolism encompasses a series of pathways where 1C units are transferred among nutrients such as B vitamins, choline, and amino acids (the methyl nutrients). Use of isotopic tracers and measuring methyl nutrients in maternal plasma and infant cord blood has advanced the understanding of 1C flux in pregnancy and kinetics of maternal-placental-fetal transfer. Methyl nutrients are supplied from maternal plasma to the placenta and fetus to support growth and 1C metabolism in these compartments. Methods A literature review was completed in MEDLINE and Google Scholar using search terms related to 1C metabolism, methyl nutrients, and nutrition requirements in pregnancy. English-language articles were reviewed in which 1C metabolism in pregnancy, maternal-placental-fetal transfer of methyl nutrients, and determinants of maternal plasma concentrations of methyl nutrients among healthy pregnant women were assessed. Discussion Adaptations in 1C metabolism occur throughout a healthy pregnancy to support this unique period of accelerated growth. Studies report similar temporal changes in plasma concentrations of many methyl nutrients, including B vitamins, choline, betaine, methionine, and cysteine, among healthy pregnant women from diverse geographic regions. Other key findings discussed in this review include an apparent high degree of B vitamin transfer to the placenta and fetus, influence of choline supplementation on 1C flux and possible benefit of supplementation for infant cognitive development, and that glycine may be conditionally essential in pregnancy. Conclusion Understanding the flux of 1C metabolism in pregnancy and methyl nutrient transfer from maternal plasma is needed to establish appropriate plasma references ranges and, ultimately, dietary recommendations that aim to prevent deficiency and associated adverse health outcomes for mother and baby. [ABSTRACT FROM AUTHOR]

Background Early childhood is a period of rapid brain development, with increases in synapses rich in the omega-3 (ω-3) fatty acid, DHA (22:6ω-3) continuing well beyond infancy. Despite the importance of DHA to neural phospholipids, the requirement of dietary DHA for neurodevelopment remains unclear. Objectives The aim was to assess the dietary DHA and DHA status of young children, and determine the association with cognitive performance. Methods This was a cross-sectional study of healthy children (5–6 y), some of whom were enrolled in a follow-up of a clinical trial (NCT00620672). Dietary intake data (n  = 285) were assessed with a food-frequency questionnaire (FFQ) and three 24-h recalls. Family characteristics were collected by questionnaire, and anthropometric data measured. Venous blood was collected, cognitive performance assessed using several age-appropriate tools including the Kaufman Assessment Battery for Children. The relation between dietary DHA, RBC DHA, and child neurodevelopment test scores was determined using Pearson's correlation or Spearman's rho, and quintiles of test scores compared by Mann–Whitney U test. Results Child DHA intakes were highly variable, with a stronger association between RBC DHA and DHA intake assessed by FFQ (rho = 0.383, P  < 0.001) compared with one or three 24-h recalls. Observed ethnic differences in DHA intake status as well as neurodevelopmental test scores led to analysis of the association between DHA intake and status with neurodevelopment test scores for White children only (n  = 190). Child RBC DHA status was associated with neurodevelopment test scores, including language (rho = 0.211, P  = 0.009) and short-term memory (rho = 0.187, P  = 0.019), but only short-term memory was associated with dietary DHA (rho = 0.221, P  = 0.003). Conclusions Child RBC DHA but not dietary DHA was associated with multiple tests of cognitive performance. In addition, DHA intake was only moderately associated with RBC DHA, raising complex questions on the relation between diet, DHA transfer to membrane lipids, and neural function. [ABSTRACT FROM AUTHOR]

Methionine is a nutritionally indispensable amino acid, and is unique among indispensable amino acids due to its sulfur atom. Methionine is involved in cysteine synthesis via the transsulfuration pathway, which is rate limiting for the key antioxidant molecule, glutathione. Methionine is also the primary methyl donor in the body through S-adenosylmethionine via the transmethylation pathway, which is involved in the synthesis of several key metabolites including creatine and phosphatidylcholine. Methionine can also be remethylated from homocysteine, in the presence of betaine via choline and/or folate. Thus methionine demands from a dietary perspective are regulated not only by the presence of cysteine in the body, but also by the demands in vivo for the various metabolites formed from it, and also by the presence of these compounds in foods. Indeed, methionine, cysteine, and the various methyl donors/acceptors vary in human foods, and thus regulate methionine availability, especially under conditions of growth and development. Much of our understanding of methionine nutrition and metabolism arises from experiments in animal models. This is because most animal feed formulations are plant-based and plant sources are relatively low in methionine and cysteine amounts. Thus, this brief review will touch on some broad aspects of human methionine nutrition, including requirements in different life stages, disease, and bioavailability, with some examples from the insights/lessons learned from experiments initially conducted in animals. [ABSTRACT FROM AUTHOR]

Amino acid supplementation may be indicated to correct for insufficient amino acid intake in healthy individuals, and in specific physiological or pathophysiological situations. However, there is a concern to not supplement beyond the tolerable upper intake level (UL) by determining parameters of no-observed-adverse-effect level (NOAEL) or lowest-observed-adverse-effect level (LOAEL) for each amino acid. Since the NOAEL and LOAEL values are at least one order of magnitude different when comparing the values obtained in rats and humans, the aim of this review is to evaluate to what extent the amino acid UL measured in the rat model, when referenced to the dietary usual consumption (UC) and dietary requirement (RQ) for indispensable amino acids, may be used as an approximation of the UL in humans. This review then compares the ratios of the NOAEL or LOAEL over UC and RQ in the rat model with the same ratios calculated in humans for the nine amino acids (arginine, serine, glycine, histidine, leucine, lysine, methionine, phenylalanine, and tryptophan) for which this comparison can be done. From the calculations made, it appears that for these 9 amino acids, the calculated ratios for rats and humans, although rather different for several amino acids, remains for all of them in the same order of magnitude. For tryptophan, tyrosine, and valine, the ratios calculated in rats are markedly different according to the sex of animals, raising the view that it may be also the case in humans. [ABSTRACT FROM AUTHOR]

Human milk contains nutritional, immunoprotective and developmental components that support optimal infant growth and development. The milk fat globule membrane (MFGM) is one unique component, comprised of a tri-layer of polar lipids, glycolipids, and proteins, that may be important for brain development. MFGM is not present in most infant formulas. We tested the effects of bovine MFGM supplementation on reflex development and on brain lipid and metabolite composition in rats using the “pup in a cup” model. From postnatal d5 to d18, rats received either formula supplemented with MFGM or a standard formula without MFGM; a group of mother-reared animals was used as reference/control condition. Body and brain weights did not differ between groups. MFGM supplementation reduced the gap in maturation age between mother-reared and standard formula-fed groups for the ear and eyelid twitch, negative geotaxis and cliff avoidance reflexes. Statistically significant differences in brain phospholipid and metabolite composition were found at d13 and/or d18 between mother-reared and standard formula-fed groups, including a higher phosphatidylcholine:phosphatidylethanolamine ratio, and higher phosphatidylserine, glycerol-3 phosphate, and glutamine in mother-reared compared to formula-fed pups. Adding MFGM to formula narrowed these differences. Our study demonstrates that addition of bovine MFGM to formula promotes reflex development and alters brain phospholipid and metabolite composition. Changes in brain lipid metabolism and their potential functional implications for neurodevelopment need to be further investigated in future studies. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Protein requirement of healthy school-age children determined by the indicator amino acid oxidation method," by R. Elango and colleagues in the 2011 issue, which discusses protein requirements in school-age children.

Background: Calcium supplementation reduces the risk of pre-eclampsia, but questions remain about the dosage to prescribe and who would benefit most.Objectives: To evaluate the effectiveness of high (≥1 g/day) and low (<1 g/day) calcium dosing for pre-eclampsia prevention, according to baseline dietary calcium, pre-eclampsia risk and co-interventions, and intervention timing.Search Strategy: CENTRAL, PubMed, Global Index Medicus and CINAHL, from inception to 2 February 2021, clinical trial registries, reference lists and expert input (CRD42018111239).Selection Criteria: Randomised controlled trials of calcium supplementation for pre-eclampsia prevention, for women before or during pregnancy. Network meta-analysis (NMA) also included trials of different calcium doses.Data Collection and Analysis: Two independent reviewers extracted published data. The meta-analysis employed random-effects models and the NMA, a Bayesian random-effects model, to obtain direct and indirect effect estimates.Main Results: The meta-analysis included 30 trials (N = 20 445 women), and the NMA to evaluate calcium dosage included 25 trials (N = 15 038). Calcium supplementation prevented pre-eclampsia similarly with a high dose (RR 0.49, 95% CI 0.36-0.66) or a low dose (RR 0.49, 95% CI 0.36-0.65). By NMA, high-dose (vs low-dose) calcium did not differ in effect (RR 0.79, 95% CI 0.43-1.40). Calcium was similarly effective regardless of baseline pre-eclampsia risk, vitamin D co-administration or timing of calcium initiation, but calcium was ineffective among women with adequate average baseline calcium intake.Conclusions: Low- and high-dose calcium supplementation are effective for pre-eclampsia prevention in women with low calcium intake. This has implications for population-level implementation where dietary calcium is low, and targeted implementation where average intake is adequate.Tweetable Abstract: A network meta-analysis of 25 trials found that low-dose calcium supplementation (<1 g/day) is as effective as high-dose calcium supplementation (≥1 g/day) in halving the risk of pre-eclampsia when baseline calcium intake is low. [ABSTRACT FROM AUTHOR]

Background: Pre-eclampsia is a leading cause of maternal mortality and morbidity that involves pregnancy-related stressors on the maternal cardiovascular and metabolic systems. As nutrition is important to support optimal development of the placenta and for the developing fetus, maternal diets may play a role in preventing pre-eclampsia. The purpose of this scoping review is to map the maternal nutritional deficiencies and imbalances associated with pre-eclampsia incidence and discuss evidence consistency and linkages with current understandings of the etiology of pre-eclampsia. Methods: A narrative scoping review was conducted to provide a descriptive account of available research, summarize research findings and identify gaps in the evidence base. Relevant observational studies and reviews of observational studies were identified in an iterative two-stage process first involving electronic database searches then more sensitive searches as familiarity with the literature increased. Results were considered in terms of their consistency of evidence, effect sizes and biological plausibility. Results: The review found evidence for associations between nutritional inadequacies and a greater risk of pre-eclampsia. These associations were most likely mediated through oxidative stress, inflammation, maternal endothelial dysfunction and blood pressure in the pathophysiology of pre-eclampsia. Maternal nutritional risk factors for pre-eclampsia incidence with the strongest consistency, effect and biological plausibility include vitamin C and its potential relationship with iron status, vitamin D (both on its own and combined with calcium and magnesium), and healthy dietary patterns featuring high consumption of fruits, vegetables, whole grains, fish, seafood and monounsaturated vegetable oils. Foods high in added sugar, such as sugary drinks, were associated with increased risk of pre-eclampsia incidence. Conclusion: A growing body of literature highlights the involvement of maternal dietary factors in the development of pre-eclampsia. Our review findings support the need for further investigation into potential interactions between dietary factors and consideration of nutritional homeostasis and healthy dietary patterns. Further research is recommended to explore gestational age, potential non-linear relationships, dietary diversity and social, cultural contexts of food and meals. Plain language summary: Pre-eclampsia is a condition of high blood pressure during the second half of pregnancy with signs of damage to another organ system, often the liver and kidneys. It is a serious and potentially deadly disease and is the second top cause of deaths related to pregnancy and childbirth globally. Though the exact cause of pre-eclampsia is unclear, researchers have discovered that pre-eclampsia develops through abnormal development of the placenta, which is the interface between the growing baby and the mother in the womb. The placenta helps to transfer nutrients, oxygen and waste between the mother and fetus. Nutrition has important roles to play in the development of the placenta and certain vitamins and minerals have clinical properties that may help prevent pre-eclampsia. We conducted a review to summarize observational studies on maternal nutritional risk factors associated with the development of pre-eclampsia. Promising maternal dietary factors that fit with current understandings of how pre-eclampsia develops include vitamin C and its potential relationship with iron, calcium and vitamin D. Healthy dietary patterns with high consumption of fruits, vegetables, whole grains, fish and seafood and monounsaturated vegetable oils are likely beneficial. Foods high in added sugar, such as sugary drinks, may be linked to higher rates of developing pre-eclampsia. Instead of focusing on single nutrient deficiencies, our findings support a broader approach to explore interrelationships between dietary factors and balanced healthy dietary intake for the prevention of pre-eclampsia. [ABSTRACT FROM AUTHOR]

Background: Lentil is considered a high protein source. However, it is low in sulphur amino acids (SAA) and their metabolic availability (MA) is further affected by antinutritional factors in lentils. The combination of lentils with grains such as rice can enhance the protein quality of a lentil-based meal but the MA of SAA in lentils must first be known.Objectives: The objectives of the current study were to assess the MA of methionine in lentils and to test the effects of consumption of complementing lentils with rice in young adults.Methods: Five healthy young men [age <30 y, BMI <25 (in kg/m2)] were each studied at 8 or 10 intake amounts of methionine in random order; 4 daily intake amounts of l-methionine: 0.5, 1, 2, and 3 mg.kg-1.d-1 (reference diet), 3 daily intake amounts of methionine from lentils, and 3 daily intake amounts of the mixed meal of lentils + rice (test diets). The MA of methionine and the effects of complementation were assessed by comparing the indicator amino acid oxidation (IAAO) response to varying intakes of methionine in cooked Canadian lentils, and in rice + lentils combined, compared with the IAAO response to l-methionine intakes in the reference protein (crystalline AA mixture patterned after egg protein) using the slope ratio method. l-[1-13C] phenylalanine was used as the indicator. Data were analyzed using the procedure "MIXED" with subject as a random variable, and oxidation day as repeated measure.Results: The MA of methionine from lentils was 69%. Complementation of cooked lentils with rice decreased the oxidation of l-[1-13C] phenylalanine by up to 16% (P < 0.05).Conclusions: The content and MA of methionine are low in lentils. However, combination of lentils with rice in a 1:1 ratio can improve the protein quality of lentil-based diets, resulting in increased protein synthesis in young healthy adults. This trial was registered at www.clinical trials.gov as NCT03110913. [ABSTRACT FROM AUTHOR]

Background: Sorghum is the fifth most consumed cereal grain but limiting in the indispensable amino acid lysine. Complementing sorghum with lentils can improve the quality of sorghum-based diets. However, knowledge of lysine bioavailability in sorghum is lacking.Objectives: The study objectives were to determine the bioavailability of lysine in sorghum and to assess the effect of complementation of sorghum and lentils in a mixed-meal format.Methods: We studied 5 healthy young men (≤30 years; BMI <25 kg/m2) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject participated in 8 determinations in random order. On the reference diet, subjects received 4 amounts of L-lysine (5, 8, 12, and 15 mg. kg-1 . d-1) from a crystalline amino acid mixture patterned after egg protein. On the test diet, they received 3 levels of lysine (8.2, 12.5, and 15.7 mg. kg-1 . d-1) from sorghum, and on the complementation diet they received 1 level of lysine from a mixed meal of sorghum and lentils. The bioavailability of lysine in sorghum was estimated by comparing the IAAO response to the test diet with the IAAO response to the reference diet using the slope-ratio method. Effectiveness of complementation was assessed by comparing the IAAO response to the mixed meal to the IAAO response to the test protein.Results: The bioavailability of lysine from sorghum was 94%. Upon complementation with lentils, there was a decline in the oxidation of L-[1-13C] phenylalanine by 19% (P < 0.0495), reflecting an improvement in available lysine in the mixed meal due to increased lysine intake.Conclusions: Although the bioavailability of lysine in sorghum is high, its lysine content is limiting. Complementation with lentils in a 1:1 ratio is recommended to achieve the lysine requirement for adult men consuming a sorghum-based diet. This trial was registered at clinicaltrials.gov as NCT03411005. [ABSTRACT FROM AUTHOR]

Propionic Acidemia (PROP) is an inherited metabolic disorder, with defect in the enzyme propionyl-CoA carboxylase (PCC) which catalyzes catabolism of two of the branched-chain amino acids (BCAA), valine, isoleucine. Nutritional management in PROP depends on dietary protein restriction and consumption of medical formula depleted of the offending amino acids. Recently, concerns have been raised about medical formula due to imbalanced content of BCAA (high leucine – another BCAA, and no valine/isoleucine), which negatively impacts plasma concentrations of BCAA, and growth in children with PROP. To determine an optimal BCAA ratio at which total body protein synthesis is optimized in healthy children using the indicator amino acid oxidation method (oxidation of L-13C-Phenylalanine to 13CO 2). This was accomplished by reducing leucine intake gradually from the current high dose in medical formula, in order to compare protein synthesis, under different BCAA ratios. A total of 8 healthy children were studied, completing 42 study days. Significant differences in F13CO 2 with different BCAA ratios were found. BCAA ratio (leucine: isoleucine: valine) 1:0:0 was associated with the highest F13CO 2 (low protein synthesis) compared to other ratios. By reducing leucine intake, and isoleucine and valine at minimum PROP recommendations, BCAA ratio between1:0.26:0.28 to 1:0.35:0.4 was associated with optimal protein synthesis. BCAA ratio of 1:0:0, present in medical formula limited total body protein synthesis. A balanced BCAA ratio was found between 1:0.26:0.28 and 1:0.35:0.4 (leucine:isoleucine:valine). Future research is needed to test this optimal BCAA ratio for optimizing protein synthesis in patients with PROP. The article describes a proof-of-concept study done on healthy school-aged children testing different ratios of branched chain amino acid (BCAA, leucine:isoleucine:valine), in order to determine an optimal ratio at which total body protein synthesis is improved and has implications for dietary management of children with Propionic Acidemia (PROP). [ABSTRACT FROM AUTHOR]

The article focuses on DNA methylation at a nutritionally sensitive region of the PAX8 gene is associated with thyroid volume and function in Gambian children. Topics include PAX8 is a key thyroid transcription factor implicated in thyroid gland differentiation and function, PAX8 gene methylation is reported to be sensitive to the periconceptional environment, and Free T4 was associated with a decrease in DXA-derived body fat and bone mineral density.

Background: North American health authorities recommend 0.4 mg/day folic acid before conception and throughout pregnancy to reduce the risk of neural tube defects. Folic acid is a synthetic form of folate that must be reduced by dihydrofolate reductase and then further metabolized. Recent evidence suggests that the maximal capacity for this process is limited and unmetabolized folic acid has been detected in the circulation. The biological effects of unmetabolized folic acid are unknown. A natural form of folate, (6S)-5-methyltetrahydrofolic acid (Metafolin®), may be a superior alternative because it does not need to be reduced in the small intestine. Metafolin® is currently used in some prenatal multivitamins; however, it has yet to be evaluated during pregnancy.Methods/design: This double-blind, randomized trial will recruit 60 pregnant women aged 19-42 years. The women will receive either 0.6 mg/day folic acid or an equimolar dose (0.625 mg/day) of (6S)-5-methyltetrahydrofolic acid for 16 weeks. The trial will be initiated at 8-21 weeks' gestation (after neural tube closure) to reduce the risk of harm should (6S)-5-methyltetrahydrofolic acid prove less effective. All women will also receive a prenatal multivitamin (not containing folate) to ensure adequacy of other nutrients. Baseline and endline blood samples will be collected to assess primary outcome measures, including serum folate, red blood cell folate and unmetabolized folic acid. The extent to which the change in primary outcomes from baseline to endline differs between treatment groups, controlling for baseline level, will be estimated using linear regression. Participants will have the option to continue supplementing until 1 week postpartum to provide a breastmilk and blood sample. Exploratory analyses will be completed to evaluate breastmilk and postpartum blood folate concentrations.Discussion: This proof-of-concept trial is needed to obtain estimates of the effect of (6S)-5-methyltetrahydrofolic acid compared to folic acid on circulating biomarkers of folate status during pregnancy. These estimates will inform the design of a definitive trial which will be powered to assess whether (6S)-5-methyltetrahydrofolic acid is as effective as folic acid in raising blood folate concentrations during pregnancy. Ultimately, these findings will inform folate supplementation policies for pregnant women.Trial Registration: ClinicalTrials.gov, ID: NCT04022135. Registered on 14 July 2019. [ABSTRACT FROM AUTHOR]

Background: The phenylalanine requirement of the elderly is not known. Current recommendations are based on studies in young adults and are derived from a combined estimate of the total aromatic amino acids, phenylalanine, and tyrosine.Objectives: The purpose of this study was to determine the dietary phenylalanine requirement of adults aged >65 y, using the direct amino acid oxidation method, by measuring the oxidation of l-[1-13C]phenylalanine to 13CO2 in response to graded phenylalanine intakes in the presence of excess tyrosine.Methods: Twelve subjects (6 men, 6 women), aged 73.8 ± 6.7 y (mean ± SD) and with a BMI (in kg/m2) of 26.4 ± 4.8 and 25.2 ± 4.4 for men and women, respectively, were randomized to phenylalanine intakes ranging from 7.20 to 40.0 mg .kg-1 .d-1 for a total of 66 studies. Study diets were isocaloric and isonitrogenous, providing protein and energy at 1.0 g .kg-1 .d-1 and 1.5 × resting energy expenditure (REE), respectively. Protein was provided as an amino acid mixture patterned after egg protein, with an excess of tyrosine and alanine to balance the nitrogen as phenylalanine intakes were varied. Two days prior to the study day, subjects were adapted to a milkshake diet providing protein at 1.0 g.kg-1 .d-1 and energy at 1.7 × REE. The mean phenylalanine requirement was determined using biphase linear regression analysis, which identified a breakpoint in the F13CO2 in response to graded phenylalanine intakes.Results: The mean and upper 95% CIs (approximating the recommended dietary allowance) of phenylalanine requirements were estimated to be 9.03 and 15.9 mg.kg-1 .d-1, respectively.Conclusion: These results are similar to previously derived estimates of 9.1 and 13.6 mg.kg-1 .d-1 in young adult men and suggest that higher protein needs of the elderly to stimulate similar muscle protein synthesis rates as young adults are not driven by an increased requirement for phenylalanine. This trial was registered at clinicaltrials.gov as NCT02971059. [ABSTRACT FROM AUTHOR]

Leucine, a branched-chain amino acid (BCAA), has been shown to stimulate muscle protein synthesis, and thus has been proposed to prevent age-related muscle atrophy (sarcopenia). Therefore, leucine supplementation may have potential benefits in elderly populations to preserve muscle mass. The tolerable upper intake level (UL) for leucine intake in young men has recently been determined to be 500 mg kg day, and increases in blood ammonia concentrations were seen at intake levels above 500 mg kg day; the UL for leucine in elderly is unknown. The objective of the current study was to determine the safety of leucine supplementation in healthy elderly men. Six healthy elderly men (72.2 ± 3.5 years) received graded stepwise increases in leucine intakes ranging from 50 to 750 mg kg day, on eight separate study days. Plasma and urinary biochemical variables, including blood ammonia, and an oral primed-continuous protocol of L-1-C-Leucine was performed. Blood ammonia concentrations above normal values (35 µmol/L) were observed at leucine intakes >550 mg kg day. Leucine oxidation measured as a FCO (rate of label tracer oxidation) increased with increasing leucine intakes and started to plateau after 450 mg kg day. Two-phased linear regression analysis of the FCO data revealed a breakpoint of 431 mg kg day ( R = 0.73), suggesting that the upper limit to oxidize leucine was reached at that point. Taking the data together the upper limit for leucine intake in healthy elderly could be set similar to young men at 500 mg kg day or ~35 g/day for an individual weighing 70 kg. [ABSTRACT FROM AUTHOR]

Adequate dietary protein intake throughout pregnancy is essential to ensure healthy fetal development. Insufficient and excessive maternal dietary protein intakes are both associated with intrauterine growth restriction, resulting in low birth weight infants. The aim of this study was to analyze the dietary protein intake patterns of healthy pregnant women in Vancouver, British Columbia, during early and late gestation. We hypothesized that women would be consuming higher protein during late stages of pregnancy compared with early stages of pregnancy. Interviewer-administered food frequency questionnaires were collected prospectively from 270 women at 16- and 36-week gestation; food frequency questionnaires from 212 women met study criteria. Maternal anthropometrics at both stages and infant weight at birth were collected. Wilcoxon signed rank tests were used to determine significant gestational differences in protein intakes. Spearman correlation was used to determine the influence of protein intakes and maternal anthropometrics on pregnancy outcomes. Median (25th and 75th percentiles) protein intakes adjusted for body weight were 1.5 (1.18 and 1.79) and 1.3 (1.04 and 1.60) g/kg per day at 16- than 36-week gestation, respectively. Primary protein sources were identified as dairy products. Protein intakes were negatively correlated with birth weight (P < .05), whereas maternal height, weight, body mass index, and weight gain to 36-week gestation were positively correlated with birth weight (P < .05). This study provides current dietary protein intake patterns among healthy Canadian women during pregnancy and indicates higher intakes than current Dietary Reference Intakes recommended dietary allowance of 1.1 g/kg per day, especially during early gestation. [ABSTRACT FROM AUTHOR]

Background: Previous studies proposed varying leucine requirements for adults ranging from 25 to 40 mg⋅kg -1 ⋅d -1 , but often these studies did not test intakes exceeding 40 mg⋅kg -1 ⋅d -1 . Data using the indicator amino acid oxidation (IAAO) method suggest a higher requirement of 55 mg⋅kg -1 ⋅d -1 on the basis of the total branched-chain amino acids requirement, but not leucine independently., Objectives: The IAAO method was used to determine the leucine requirement in healthy young adult males., Methods: Ten healthy adult males (26.9 ± 1.87 y, mean ± SEM) were studied at 7 leucine intakes; each studied over a 3-d period. Following 2-d of preadaptation to adequate protein intake (1.0 g⋅kg -1 ⋅d -1 ), subjects received experimental diets containing the randomly assigned test leucine intake (10, 20, 30, 40, 50, 65, and 75 mg⋅kg -1 ⋅d -1 ) for 8 h. The rate of the release of 13 CO 2 from the oxidation of L-[1- 13 C]phenylalanine (F 13 CO 2 ) was measured on the third day, and the leucine requirement was determined using mixed-effect change-point regression and the F 13 CO 2 data in R. The 95% confidence interval was calculated using parametric bootstrap. The effect of leucine intake on the concentration of plasma amino acids, insulin, and glucose were assessed using repeated measures analysis of variance and linear mixed effects., Results: The mean leucine requirement was 33.6 mg⋅kg -1 ⋅d -1 with a lower and upper 95% confidence of 26.16, 41.04 mg⋅kg -1 ⋅d -1 . Higher leucine intakes were associated with increased plasma leucine, and decreased valine, isoleucine, and serine concentrations., Conclusions: The leucine requirement of young adult males is ∼34 mg⋅kg -1 ⋅d -1 , which aligns with previously published tracer balance experiments. This trial was registered at http://clinicaltrials.gov (https://clinicaltrials.gov/study/NCT05394155?term=leucine%20young%20adult&rank=1) as NCT05394155., (Copyright © 2024 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Objective: Preterm infants need enrichment of human milk (HM) for optimal growth. This study evaluated a novel, point-of-care human milk concentration (HMC) process for water removal from fresh HM samples by passive osmotic concentration., Study Design: Nineteen fresh HM samples were concentrated by incubation with the HMC devices for 3 h at 4 °C. Pre- and post-concentration HM samples were compared by HM properties for: pH, osmolality, macronutrients, enzyme activity, bioactive, and total cell viability., Results: Passive osmotic concentration reduced HM volume by an average of 16.3% ± 3.8% without a significant effect on pH or cell viability. Ten of the 41 HM components did not differ significantly (p > 0.05) between pre- and post-concentration samples. Twenty-three increased within the expected range by volume reduction. Six increased more than expected, two less than expected, and none decreased significantly., Conclusion: Passive osmotic concentration of fresh HM can concentrate HM components by selective removal of water. HM osmolality and pH remained within neonatal feeding parameters., (© 2024. The Author(s).)

Background: Phenylketonuria (PKU) is caused by phenylalanine hydroxylase deficiency. Treatment is primarily a low-Phe diet combined with l-amino acid-based products (l-AA). Protein requirements in adults with PKU have not been directly determined. A formula with glycomacropeptide (GMP) and low phenylalanine is available, yet untested for optimal protein synthesis., Objectives: To determine the protein requirements in adults with PKU and the bioavailability of GMP-AA in the same patients using the indicator amino acid oxidation (IAAO) technique., Methods: Each participant was allocated to 7 separate l-AA intakes (range: 0.1-1.8 g/kg/day) in Experiment 1. In Experiment 2, the same patients participated in 4 GMP-AA intakes (range: 0.1-0.9 g/kg/day). The IAAO method with l-[1- 13 C]-lysine as the indicator amino acid and its oxidation to 13 CO 2 was used as the primary indicator of protein synthesis. Protein requirements were identified with a breakpoint, and bioavailability was determined by comparing 13 CO 2 slope from GMP-AA versus l-AA., Results: Six adults with PKU (4 M: 2F) completed a total of 54 study days over the 2 experiments. The estimated average requirement (EAR) for protein was determined to be 1.11 g/kg/day (R 2  = 0.20). The bioavailability of protein from GMP-AA was determined to be 99.98%, which was high and near to 100% comparable to l-AA; although, the results apply only to the tested GMP-AA blend., Conclusions: To our knowledge, this is the first study to directly define a quantitative protein requirement and indicates that current PKU protein recommendations for adults with PKU may be underestimated. The bioavailability of protein in the GMP-AA blend was high and optimal for protein synthesis in adults with PKU., (© 2024 The Author(s). Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.)

Background: Dietary Reference Intake (DRI) Recommendations for total sulfur amino acids (TSAAs; methionine + cysteine) during pregnancy are based on factorial calculations using data from adult males. To date, no data exist on TSAA requirements obtained directly during pregnancy., Objectives: The objective of this study was to examine whether TSAA requirements during early (11-20 wk) and late (31-40 wk) gestation in healthy females with singleton pregnancies are different than current recommendations, and different between early and late gestation using the indicator amino acid oxidation (IAAO) technique., Methods: Twenty-five females 20-40 y with a healthy singleton pregnancy were studied using the IAAO technique in a repeated measures design for a total of 70, 8-h d. On each study day a methionine test intake (range: 0-40 mg⋅kg -1 ⋅d -1 ) was provided in 8 hourly, isonitrogenous and isocaloric meals with cysteine excluded from the diet. Breath samples were collected at baseline and isotopic steady state of orally provided L-1- 13 C-Phenylalanine for measurement of phenylalanine oxidation. The requirement was determined using biphasic linear regression crossover analysis to identify a breakpoint in 13 CO 2 production, representing the estimated average requirement (EAR)., Results: The TSAA requirement in healthy pregnant participants in early gestation was 11.1 mg⋅kg -1 ⋅d -1 {R 2 m = 0.79, R 2 c = 0.79; 95% confidence interval [CI] (8.9, 13.3 mg⋅kg -1 ⋅d -1 )} and 15.0 mg⋅kg -1 ⋅d -1 (R 2 m = 0.72, R 2 c = 0.79; 95% CI [13.0, 17.0 mg⋅kg -1 ⋅d -1 ]) in late gestation. The difference between confidence intervals of the 2 breakpoints was = -3.9 ± 3.0, and statistically different., Conclusions: We directly measured TSAA requirements in healthy pregnant mothers, and our findings suggest that requirements are lower than current DRI recommendations of 20 and 25 mg⋅kg -1 ⋅d -1 , as the EAR, and Recommended Dietary Allowance, respectively. Late gestation TSAA needs are significantly different and increased 35% compared with early gestation. Recommendations for TSAA intake need to be tailored for gestational stage. This clinical trial was registered at clinicaltrials.gov as NCT04326322., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: The protein quality of wheat is limited by its low content of the indispensable amino acid (AA) lysine and the metabolic availability (MA) of lysine in wheat bread for humans is unknown., Objective: The study objective was to determine the MA of lysine in whole wheat bread., Methods: Five healthy young men (≤30 y, BMI <25) were studied in a repeated measures design using the indicator amino acid oxidation (IAAO) method, with L-[1- 13 C] phenylalanine as the indicator. Each received 7 levels of lysine intakes in random order; 4 levels of L-lysine; 5, 8, 12 and 15 mg . kg -1. d -1 (reference diet), and 3 intakes of lysine from whole wheat bread (test diet).The MA of lysine in whole wheat bread were assessed by comparing the IAAO response to the test diet (whole wheat bread) with the IAAO response to the reference diet using the slope ratio method., Results: The MA of lysine from whole wheat bread was 90%., Conclusions: Lysine has high metabolic availability but it is still limiting in whole wheat bread due to its low concentration. A combination of wheat with a complementary protein source (i.e. lentils which are sufficient in lysine) is recommended to meet the lysine requirement in a wheat-based diet for healthy young males. This trial was registered at clinicaltrials.gov as NCT03674736 and NCT03200652., Competing Interests: Declaration of Competing Interest ☒ The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Glenda Courtney-Martin reports financial support was provided by Canadian Institutes of Health Research. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Amino acids form the building blocks of body protein. Dietary protein sources provide the amino acids needed, but protein sources vary widely in amio acid composition. To ensure humans can meet body demands for amino acids, amino acid intake recommendations are provided by the Dietary Reference Intakes (DRI) and by Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU). Current amino acid intake recommendations, however, are based on data collected predominantly from young adult males. The development of the minimally invasive indicator amino acid oxidation (IAAO) method has permitted the evaluation of amino acid requirements in various vulnerable populations. The purpose of this review is to discuss recent amino acid requirement studies in school-age children, pregnant females and the elderly determined using the IAAO technique. These requirements will help to inform evidence-based recommendations that will help to guide dietary guidelines., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Paoletti, Courtney-Martin and Elango.)

Background: Current recommendation for lysine in older adults, 30 mg/kg/d, is based on young adult data. Evidence suggests that amino acid requirements may differ between young and old adults with both sex and age having an effect in the elderly., Objectives: This study aimed to define the lysine requirements in healthy older adults using the indicator amino acid oxidation (IAAO) method with L-[1- 13 C] phenylalanine as the indicator and to compare the derived estimates based on age: 60-69 y and >70 y., Methods: Fourteen healthy males and 16 healthy females [>60 y, body mass index (BMI) = 26.3 kg/m 2 ] were randomly assigned to receive 3-7 lysine intakes from 10 to 80 mg/kg/d. Subjects were adapted to a standard liquid diet providing 1.0 g/kg/d protein and adequate energy, for 2 d, with indicator oxidation measurements performed on day 3. The rate of release of 13 CO 2 from the oxidation of L-[1- 13 C] phenylalanine was measured in breath. A 2-phase linear mixed-effect model, and parametric bootstrap were used to determine mean lysine requirements and the 95% confidence intervals (CIs). The overlap of the 95% CI between the 2 age groups were used to compare the requirement estimates. The null hypothesis was accepted if the interval contained zero., Results: The mean and upper 95% CI of the lysine requirement for females were 32.9 and 40.9 and 46.2 and 53.7 mg/kg/d for those aged 60-69 y and >70 y, respectively. The mean and upper 95% CI of the lysine requirement for the 2 groups of males were not different so was combined to yield a mean and 95% CI of 32.2 and 38.2 mg/kg/d., Conclusions: To our knowledge, this is the first study to report on the lysine requirement in adults aged >60 y. These results provide a basis from which the adequacy of diets to meet lysine needs of older adults can be assessed. The trial was registered at clinicaltrials.gov as NCT02008955 (https://clinicaltrials.gov/study/NCT02008955)., (Copyright © 2024 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Knowledge of amino acid bioavailability and the effect of combining complementary protein sources are required to determine how to best meet an individual's protein and indispensable amino acid needs. Traditionally, protein quality of foods has been assessed using digestibility data. Digestibility may overestimate bioavailability of some amino acids particularly those more susceptible to heat and processing. The indicator amino acid oxidation (IAAO) method has been validated and applied to determine amino acid bioavailability termed metabolic availability of the first limiting amino acid of a proteinaceous food. The metabolic availability of the limiting amino acid in the test protein is determined as a ratio of the indicator amino acid oxidation response to graded intakes of the test protein compared to the indicator response to a reference protein (crystalline amino acid patterned after egg protein). The IAAO method has also been applied to assess the effect of protein complementation directly in humans on the overall protein quality of the diet. The results demonstrate that protein complementation augments the limiting amino acid supply and increases protein synthesis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Paoletti, Elango and Courtney-Martin.)

Background: Protein recommendations for older adults are based on nitrogen balance data from young adults. Physiological studies using the indicator amino acid oxidation method suggest they need 30% to 50% more protein than current recommendations. We herein present glutathione (GSH) as a physiological estimate of protein adequacy in older adults., Objectives: The objective was to measure GSH kinetics in response to varying protein intakes in a repeated-measures design in healthy adults aged ≥60 y using the precursor-product method., Methods: Sixteen healthy older adults (n = 8 male and n = 8 female; body mass index ≤30 kg/m 2 ) were studied. Each received 4 of 6 protein intakes in random order (0.66, 0.8, 0.9, 1.1, 1.3 and 1.5 g⋅kg -1 ⋅d -1 ). At each intake level, participants underwent isotope infusion studies of 7 h duration following a 3-d adaptation to the test level of protein. On the fourth day, GSH fractional (FSR) and absolute synthesis (ASR) rates were quantified by measuring the incorporation of U-[ 13 C 2 - 15 N]glycine into GSH at isotopic steady state. A mixed-effect change-point regression model was used to determine a breakpoint in FSR and ASR. Secondary outcomes included plasma concentrations of oxidative stress markers, homocysteine, 5-L-oxoproline (5-OP), and urinary sulfate. The effect of secondary outcomes on GSH kinetics was analyzed using a joint linear mixed-effect model and Tukey's post hoc test., Results: A protein intake of 1.08 g⋅kg -1 ⋅d -1 (95% confidence interval [CI]: 0.83, 1.32; R m 2 = 0.207; R c 2 = 0.671; P < 0.001) maximized GSH FSR. There was no effect of protein intake on concentrations of erythrocyte GSH, plasma homocysteine, oxidative stress markers, or 5-OP (P > 0.05). Protein intake had a positive effect on urinary sulfate excretion (P < 0.0001)., Conclusion: A protein intake of 1.08 g⋅kg -1 ⋅d -1 from a high-quality protein maximized GSH synthesis in adults ≥60 y. This lends support to data suggesting a requirement higher than the current recommendation. This study was registered at clinicaltrials.gov as NCT02971046., (Copyright © 2024 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Background: In 2005, the Institute of Medicine advised using methods other than nitrogen balance (NB) for determining protein requirements. Since then, protein requirements using indicator amino acid oxidation (IAAO) have been published and are higher than NB. Glutathione (GSH), a tripeptide of cysteine, glutamate, and glycine, is a principal antioxidant that can be used as a functional indicator of protein adequacy., Objectives: The aim of this study was to measure changes in erythrocyte GSH kinetics [fractional synthesis rate (FSR) and absolute synthesis rate (ASR)] in healthy adults following a range of protein intakes at and above the current recommendations., Methods: Sixteen healthy adults [8 males and 8 females, aged 25.6 ± 0.9 y (mean ± SEM)] were studied at 4 of 6 protein intakes ranging from 0.6 to 1.5 g⋅kg -1 ⋅d -1 . Erythrocyte GSH kinetics were assessed during a 7-h infusion of [U- 13 C 2 - 15 N]glycine following 2 d of adaptation to each protein intake. Blood and urine tests were performed to measure oxidative stress markers, plasma homocysteine, triglycerides, plasma amino acid concentrations, 5-L-oxoproline (5-OP), and urinary sulfate. The protein intake that maximized GSH synthesis was determined using mixed-effect change-point regression in R. Primary and secondary outcomes were analyzed using linear mixed-effects and repeated-measures analysis of variance with Tukey's post hoc test., Results: The protein intake that maximized GSH FSR at 78%⋅d -1 was 1.0 g⋅kg -1 ⋅d -1 (95% confidence interval: 0.63, 1.39). GSH ASR was significantly lower at 0.6 and 0.8 g⋅kg -1 ⋅d -1 than at 1.5 g⋅kg -1 ⋅d -1 (2.03 and 2.17, respectively, compared with 3.71 mmol⋅L -1 ⋅d -1 ). Increasing the protein intake led to increased urinary sulfate but did not affect erythrocyte GSH concentration, plasma oxidative stress markers, triglycerides, homocysteine, or 5-OP., Conclusions: A protein intake of 1.0 g⋅kg -1 ⋅d -1 maximized GSH synthesis, which is in agreement with earlier IAAO-derived protein requirements of 0.93 to 1.2 g⋅kg -1 ⋅d -1 . These findings suggest that recommendations based on NB (0.66 g⋅kg -1 ⋅d -1 ) may underestimate protein needs for adequate health. This trial was registered at clinicaltrials.gov as NCT02971046., (Copyright © 2023 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Folic acid supplementation is recommended during pregnancy to support healthy fetal development; (6 S )-5-methyltetrahydrofolic acid ((6 S )-5-MTHF) is available in some commercial prenatal vitamins as an alternative to folic acid, but its effect on blood folate status during pregnancy is unknown. To address this, we randomised sixty pregnant individuals at 8-21 weeks' gestation to 0·6 mg/d folic acid or (6 S )-5-MTHF × 16 weeks. Fasting blood specimens were collected at baseline and after 16 weeks (endline). Erythrocyte and serum folate were quantified via microbiological assay (as globally recommended) and plasma unmetabolised folic acid (UMFA) via LC-MS/MS. Differences in biochemical folate markers between groups were explored using multivariable linear/quantile regression, adjusting for baseline concentrations, dietary folate intake and gestational weeks. At endline ( n 54), the mean values and standard deviations (or median, inter-quartile range) of erythrocyte folate, serum folate and plasma UMFA (nmol/l) in those supplemented with (6 S )-5-MTHF v . folic acid, respectively, were 1826 (sd 471) and 1998 (sd 421); 70 (sd 13) and 78 (sd 17); 0·5 (0·4, 0·8) and 1·3 (0·9, 2·1). In regression analyses, erythrocyte and serum folate did not differ by treatment group; however, concentrations of plasma UMFA in pregnancy were 0·6 nmol/l higher (95 % CI 0·2, 1·1) in those supplementing with folic acid as compared with (6 S )-5-MTHF. In conclusion, supplementation with (6 S )-5-MTHF may reduce plasma UMFA by ∼50 % as compared with supplementation with folic acid, the biological relevance of which is unclear. As folate is currently available for purchase in both forms, the impact of circulating maternal UMFA on perinatal outcomes needs to be determined.

This study reveals that Tenebrio molitor larvae are fed with two different feeds i.e., barley bran along with Styrofoam, and barley bran without Styrofoam, the survival percentage of mealworms shows 86 and 89%, respectively. Five isolates namely S1, S2, S3, S4, and S5 were isolated from the gut of Styrofoam-feeding Tenebrio molitor larvae and tested for Hydrophobicity percentage, clear zone assay and turbidity measurement. S1 isolate showed best (turbidity percentage of 19.65%, 13.54% hydrophobicity percentage, and 37% zone of clearance) when compared to other isolates, respectively. 16S rRNA characterization of S1 isolate revealed that the isolate belongs to Priestia megaterium S1(ON024787). Biodegradation of PE and PS beads by Priestia megaterium S1 makes physical and structural changes over 180 days, after microbial adhesion to the beads. Growth parameters have shown that the Priestia megaterium S1 thrives more effectively in the pH (6.5), temperature (28 °C) and at 1.5% LDPE/HDPE/PS concentration there is maximum utilization of carbon and a high percentage survival rate. Significant colonization of the isolate after 30 days over beads of LDPE (52.47%), HDPE (49.26%), and PS (48.11%), respectively. Experimental data revealed that Priestia megaterium S1 have PE and PS beads degradation capacity, proven by weight loss studies, at 6th-month percentage weight loss of LDPE (36.1%), HDPE (31.9%), and PS (28.6%), the percentage loss of carbon and hydrogen shows higher when compared to control. One month Biological Oxygen Demand (BOD) showed that LDPE (7.4 mg/l), HDPE (7.2 mg/l), PS (6.7 mg/l), and simultaneous studies on CO 2 evolution over LDPE treatment is 5.05 g/l, HDPE (4.26 g/l), and PS (3.91 g/l), respectively. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) prove the occurrence of biodegradation on the surface of beads. This work highlights that Priestia megaterium S1 plays a vital role in effectively degrading PE and PS beads., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)