Functional amino acids in growth, reproduction, and health

Distinct maternal amino acids and oxylipins predict infant fat mass and fat-free mass indices

Interested in maternal determinants of infant fat mass index (FMI) and fat-free mass index (FFMI), considered as predictors for later development of obesity, we analysed amino acids (AA) and oxylipins in maternal serum and breast milk (BM). FMI and FFMI were calculated in 47 term infants aged 4 months (T4). Serum AA were analysed in pregnancy (T1, T2) and 6-8 weeks postpartum (T3). At T3, AA and oxylipins were analysed in BM. Biomarker-index-associations were identified by regression analysis. Infant FMI (4.1 ± 1.31 kg/m²; MW ± SD) was predicted by T2 proline (R² adj.: 7.6%, p = .036) and T3 BM 11-hydroxy-eicosatetraenoic-acid (11-HETE) and 13-hydroxy-docosahexaenoic-acid (13-HDHA; together:35.5% R² adj., p < .001). Maternal peripartum antibiotics (AB) emerged as confounders (+AB: 23.5% higher FMI; p = .025). Infant FFMI (12.1 ± 1.19 kg/m²; MW ± SD) was predicted by histidine (R² adj.: 14.5%, p < .001) and 17-HDHA (BM, R² adj.:19.3%, p < .001), determined at T3. Confirmed in a larger cohort, the parameters could elucidate connections between maternal metabolic status, nutrition, and infant body development.

One Carbon Metabolism and Mammalian Pregnancy Outcomes

One-carbon metabolism is involved in varieties of physiological processes in mammals, including nucleic acid synthesis, amino acid homeostasis, epigenetic regulation, redox balance and neurodevelopment. The current evidence linking levels of one-carbon nutrients during pregnancy to the development of oocytes, embryos, and placentas, as well as maternal and offspring health, is reviewed. The sources of mammalian one-carbon units, the pathways active in mammalian one-carbon metabolism, the maternal and fetal needs for one-carbon units and their functions during pregnancy are described. The demand for one-carbon metabolism is highest during pregnancy compared to the entire lifetime of a mammal. The primary types of one-carbon metabolism in mammals are the folate cycle, methionine cycle and transsulfuration pathway, which varies at different pregnancy stages (e.g., methylation programming of embryo, neural development of fetus, fetal growth and placenta development). Therefore, an overall consideration of one-carbon metabolism requirements for different pregnancy stages, is called for, specifically, the balance of all nutrients involved, not just one single nutrient in one-carbon metabolism. Moreover, the establishment of an ideal one-carbon metabolism requirement model is suggested according to the requirements for different pregnancy stages to support optimal pregnancy outcomes and maternal and offspring health.

The effects of amino acids and fatty acids on the disease resistance of Epinephelus fuscoguttatus in response to Vibrio vulnificus infection

Mass mortality resulting from bacterial infection poses a major problem in the grouper aquaculture industry. The purpose of this study was to profile the metabolites released in challenged fish and to reconstruct the metabolic pathways of brown marble grouper (Epinephelus fuscoguttatus) in response to Vibrio vulnificus infection. Metabolite profiles from control and challenged treatment groups after feeding were determined using gas chromatography-mass spectrometry (GC-MS). Forty metabolites were identified from the GC-MS analysis. These metabolites comprised of amino acids, fatty acids, organic acids and carbohydrates. The profiles showed the highest percent area (33.1%) for leucine from the amino acid class in infected fish compared to the control treatment group (12.3%). Regarding the fatty acid class, a higher percent area of the metabolite 8,11-eicosadienoic acid (27.04%) was observed in fish infected with V. vulnificus than in the control treatment group (22.5%). Meanwhile, in the carbohydrate class, glucose (47.0%) was the metabolite in the carbohydrate class present at highest percentage in the control treatment group compared to infected fish (30.0%). Our findings highlight the importance of a metabolic analysis for understanding the changes of metabolites in E. fuscoguttatus in response to bacterial infections.

Effect of dietary arginine-to-lysine ratio in lactation on biochemical indices and performance of lactating sows

The present study investigated the effect of optimizing the total dietary arginine (Arg)-to-lysine (Lys) ratios on the metabolism of lactating sows and piglet performance by supplementation with l- Arg during lactation. A total of 200 multiparous sows (three to six parities, Yorkshire × Landrace) were selected and randomly and equally assigned to five groups in lactation, and finally, 36, 34, 35, 36, and 33 dams completed the study in the dietary treatments, respectively, where the diets consisted of five step-up Arg-to-Lys ratios (0.9, 1.0, 1.1, 1.2, and 1.3) by the addition of 0%, 0.10%, 0.20%, 0.30%, and 0.40% Arg. The diets contained 3.37 to 3.38 Mcal of digestible energy/kg energy, 17.73% to 17.75% crude protein, and 0.98% to 1.01% Lys and were fed ad libitum during lactation. The performance of sows and suckling piglets was measured, and plasma and milk samples were collected for analysis. The feed intake of sows as well as litter weight gain during lactation increased linearly (P ≤ 0.05), while maternal backfat and milk composition were not affected (P > 0.05) as the dietary Arg-to-Lys ratios increased. Analyzed plasma biochemical indices, including concentrations of free Arg, Orn, and Glu, and prolactin, insulin, and follicle-stimulating hormone, responded linearly (P ≤ 0.05) to increases in dietary Arg-to-Lys ratios. The dietary Arg-to-Lys ratios of 1.01 and 1.02 were optimal for maternal feed intake and litter weight gain, based on broken-line models. Collectively, the results of this study indicate that increasing total dietary Arg-to-Lys ratios in lactation was beneficial for the performance of lactating sows and suckling piglets, and dietary Arg-to-Lys ratios of 1.01 and 1.02 were optimal, from regression analyses, for the practical feeding of lactating sows.

Protein intakes of pregnant women and children in India-protein quality implications

The recent National Family Health Survey (NFHS-4, 2016) reports a national average of 18% for low birthweight (LBW) and 38% for stunting in children <5 years. Nutrition and environmental influences (chronic enteric pathogenic exposure through poor water, sanitation, and hygiene) are two critical factors that impact the health outcomes of the populxation. This is particularly relevant for vulnerable age groups such as pregnant women and children <5 years, who bear long-lasting and intergenerational consequences of impoverished nutrition and suboptimal living conditions. The present review provides, for the first time, an analysis of indispensable amino acid (IAA) requirements for pregnant women, separately for the second and third trimesters, using protein accretion data from a recent Indian study. Furthermore, using these estimates for pregnancy, and the current IAA requirements for young children, the quality of protein was assessed in Indian diets consumed by pregnant women and children (1-3 and 4-6 years) from national representative rural National Nutrition Monitoring Bureau survey. The assessment was considered in the context of an adverse environment and in relation to outcomes such as LBW, stunting, and underweight. Finally, an assessment was made of the proportion of the surveyed population at risk of dietary quality protein inadequacy and implications for planning nutrition intervention programmes. Specifically, state-wise estimates of the risk of quality protein inadequacy are provided, in addition to evaluations of additional dietary supplementation, which could inform the policy of supplementary nutrition programmes to improve health outcomes.

IN VITRO ASSESSMENT OF THE BIOLOGICAL ACTIVITY OF A NEW REGENERATIVE AGENT PREPARED FROM THE CONCENTRATE OF DEPROTEINIZED DERMAL LAYER OF PORCINE SKIN

Background. Presently, a prospective direction for the development of regenerative medicine in the world is the search for regulatory molecules and the identification of molecular targets to stimulate the body's endogenous regenerative potential. The concentrate of the deproteinized dermal layer of porcine skin (СDDLPS) is a new therapeutic agent with restorative properties, the action of which is directed on the induction of the self resources of cells. Aim. The assessment of the effect of СDDLPS on the proliferative activity of mammalian cells of different histogenesis in vitro. Materials and Methods. To determine the amino acid composition of the СDDLPS liquid chromatography and biochemical methods were used. The biological effects and mechanisms of action of the drug were investigated by cell culture and molecular biological methods. The research was carried out using stable cell lines: human keratinocytes (HaCaT cell line), porcine endothelial cells (PAE cell line), bovine kidney cells (MDBK cell line) and mouse fibroblasts (3T3A31 cell line). Results. The cells of the bovine kidney MDBK cell line were the most sensitive to the effect of the CDDLPS. Also, the obtained results suggest that, depending on the concentration, the drug not only stimulates cell proliferation by 10–30 %, but also significantly enhances biosynthetic processes in cells, in particular, protein synthesis by 20–40 %. Conclusions. CDDLPS is an effective and affordable therapeutic agent with restorative properties, the biological activity of which manifests itself in the activation of cell biosynthetic and proliferative potentials and is comparable to effects of some growth factors, in particular epidermal growth factor

Modulation of Crustacean Innate Immune Response by Amino Acids and Their Metabolites: Inferences From Other Species

Aquaculture production of crustaceans (mainly shrimp and crabs) has expanded globally, but disease outbreaks and pathogenic infections have hampered production in the last two decades. As invertebrates, crustaceans lack an adaptive immune system and mainly defend and protect themselves using their innate immune system. The immune system derives energy and metabolites from nutrients, with amino acids constituting one such source. A growing number of studies have shown that amino acids and their metabolites are involved in the activation, synthesis, proliferation, and differentiation of immune cells, as well as in the activation of immune related signaling pathways, reduction of inflammatory response and regulation of oxidative stress. Key enzymes in amino acid metabolism have also been implicated in the regulation of the immune system. Here, we reviewed the role played by amino acids and their metabolites in immune-modulation in crustaceans. Information is inferred from mammals and fish where none exists for crustaceans. Research themes are identified and the relevant research gaps highlighted for further studies.

Transcriptomic and metabolomic landscape of the molecular effects of glyphosate commercial formulation on Apis mellifera ligustica and Apis cerana cerana

Understanding the causes of the decline in bee population has attracted intensive attention worldwide. The indiscriminate use of agrochemicals is a persistent problem due to their physiological and behavioural damage to bees. Glyphosate and its commercial formulation stand out due to their wide use in agricultural areas and non-crop areas, such as parks, railroads, roadsides, industrial sites, and recreational and residential areas, but the mode of action of glyphosate on bees at the molecular level remains largely unelucidated. Here, we found that the numbers of differentially expressed genes and metabolites under glyphosate commercial formulation (GCF) stress were significantly higher in Apis cerana cerana than in Apis mellifera ligustica. Despite these differences, the number of differentially expressed transcripts increased following an increase in the GCF treatment time in both A. cerana cerana and A. mellifera ligustica. GCF exerted adverse impacts on the immune system, digestive system, nervous system, amino acid metabolism, carbohydrate metabolism, growth and development of both bee species by influencing their key genes and metabolites to some extent. The expression of many genes involved in immunity, agrochemical detoxification and resistance, such as antimicrobial peptides, cuticle proteins and cytochrome P450 families, was upregulated by GCF in both bee species. Collectively, our results indicate that both A. cerana cerana and A. mellifera ligustica strive to mitigate the pernicious effects caused by GCF by regulating detoxification and immune systems. Moreover, A. cerana cerana might be better able to withstand the toxic effects of GCF with lower fitness costs than A. mellifera ligustica. Our work will contribute to elucidating the deleterious physiological and behavioural impacts of GCF on bees.

Secondary Functions of Arginine and Sulfur Amino Acids in Poultry Health: Review

Simple Summary

Historically, studies with amino acids have focused on protein synthesis and accretion, especially with eggs and meat, whereas less importance has been given to their secondary functions on the metabolism. However, certain amino acids, such as arginine, methionine, and cysteine are precursors for other essential molecules in the immune defense, antioxidant system, cell signaling, and gene expression, and can act as regulators in the growth and development of the animals. Because poultry are subjected to stressful conditions throughout their lives, the use of these amino acids and their secondary functions could beneficiate their general health. This review describes the metabolism of arginine, methionine, and cysteine and how they modulate different tissues, especially during challenging conditions. Arginine supplementation has been shown to modulate musculoskeletal health development, reduce fat accretion, and improve the antioxidant system. Moreover, methionine and cysteine could improve the bone development and have a potential in mitigating the negative effects caused by heat stress. Understanding how these amino acids can ameliorate stressful conditions may provide novel insights about their use as nutritional strategies to modulate the health status of chickens.

Abstract

Amino acids such as arginine, methionine, and cysteine are the precursors of essential molecules that regulate growth and health, being classified as functional amino acids. This review describes the metabolism of arginine and the sulfur amino acids and how they modulate, directly or indirectly, different tissues. Emphasis is placed on their effects in supporting health during challenging conditions, such as heat stress and Eimeria infection. The use of arginine has been shown to reduce abdominal fat pad in ducks and increase lean tissue and bone mineral density in broilers. Additionally, the sulfur amino acids have been shown to improve bone development and are beneficial during heat stress. The use of L-methionine increased the cortical and trabecular bone mineral densities, in laying hens. Moreover, the dietary inclusion of these amino acids could reduce the damage caused by Eimeria spp. infection by regulating the antioxidant system and cell repair. Understanding how these amino acids can mitigate stressful conditions may provide us novel insights of their use as nutritional strategies to modulate the health status of chickens.

Metabolomic modulations in a freshwater microbial community exposed to the fungicide azoxystrobin

An effective broad-spectrum fungicide, azoxystrobin (AZ), has been widely detected in aquatic ecosystems, potentially affecting the growth of aquatic microorganisms. In the present study, the eukaryotic alga Monoraphidium sp. and the cyanobacterium Pseudanabaena sp. were exposed to AZ for 7 days. Our results showed that 0.2-0.5 mg/L concentrations of AZ slightly inhibited the growth of Monoraphidium sp. but stimulated Pseudanabaena sp. growth. Meanwhile, AZ treatment effectively increased the secretion of total organic carbon (TOC) in the culture media of the two species, and this phenomenon was also found in a freshwater microcosm experiment (containing the natural microbial community). We attempted to assess the effect of AZ on the function of aquatic microbial communities through metabolomic analysis and further explore the potential risks of this compound. The metabonomic profiles of the microcosm indicated that the most varied metabolites after AZ treatment were related to the citrate cycle (TCA), fatty acid biosynthesis and purine metabolism. We thereby inferred that the microbial community increased extracellular secretions by adjusting metabolic pathways, which might be a stress response to reduce AZ toxicity. Our results provide an important theoretical basis for further study of fungicide stress responses in aquatic microcosm microbial communities, as well as a good start for further explorations of AZ detoxification mechanisms, which will be valuable for the evaluation of AZ environmental risk.

Comparative study of innovative blends prepared by fortification of date powder to alleviate child malnutrition

Child malnutrition is one of the biggest problems in developing countries with higher level of food insecurity. Pakistan is 5th largest producer of date fruit; therefore, its processing and products should be explored in various dimensions. Being rich source of minerals and sugars, it can contribute in weaning foods in a good manner. In current study, three blends were prepared with specific proportions of spray-dried date powder and rich in specific proportions. They were compared with each other and control (free of date powder). The nutritional profile of the formulations revealed that 100 g of each formulation included all macronutrients in compliance with the requirements of Food and Agriculture Organization for weaning formulations; moreover, they are enriched with minerals due to presence of date powder. The iron contents reached up to 12.74 ± 0.16 mg/100 g. The phosphorus, zinc, and potassium contents also increased with the increase in date powder subsequently. Physicochemical properties exhibited in compliance with the requirement of the weaning foods. The protein quality was assessed both in vivo and in vitro. Amino acid profiling indicated that the limiting amino acid in F1 and control were lysine but in F2 and F3 were threonine. This is suggested that date powder might contain good quality protein that was further explained in biological studies, the formulations that contained higher amount of date powder reveled better PDCAAS score 86.76 ± 4.5, true digestibility 84 ± 4.36, biological value 69.45 ± 0.69, net protein utilization 73.82 ± 1.46, and protein efficiency score 1.18 ± 0.07. The sensory evaluation revealed that F2 showed better result in overall acceptability. Thus, date powder is suggested to be used as good constituent that can fortify mineral contents and sugar contents of the weaning foods.

Effect of supplementation of unprotected or protected arginine to prolific ewes on maternal amino acids profile, lamb survival at birth, and pre- and post-weaning lamb growth

This research determined the effects of dietary supplementation with rumen-protected arginine (Pro-Arg) on metabolites and amino acids in maternal plasma and lamb survival rate at birth (LSRAB) in prolific Afec-Assaf ewes. The hypothesis was that Pro-Arg, the precursor for nitric oxide and polyamines, would increase placental development and vascularity, uteroplacental blood flow, and nutrient transport and reduce oxidative stress to increase LSRAB. Ewes were fed either their basal diet, basal diet with Pro-Arg, or basal diet with unprotected arginine (Unp-Arg; 18 g/head/d). The supplemental arginine was about 1% of the dry matter intake from day 40 or 60 of gestation until parturition. Ninety-two of 98 ewes produced live lambs. Ewes fed Pro-Arg had greater (P = 0.002) concentrations of arginine and other amino acids in plasma, whereas Unp-Arg did not affect concentrations of arginine, but decreased (P < 0.05) concentrations of some amino acids. There was no effect of treatments on gestation length (144 ± 2 d), prolificacy (2.65 lambs born per ewe), LSRAB (0.80), body weight (88.8 ± 10.8 kg), and body condition score (2.8 ± 0.6) of ewes, or birth weight and crown-rump length of lambs. The GI (BW/CRL1.5) was affected by sex of lamb (P = 0.008), parity of ewe (P = 0.002), litter size (P = 0.0001), and lamb status (P = 0.003). Of 229 lambs born, 32 were dead and 16 died before 5 mo of age, leaving 181 lambs with records on weights at birth and 5 mo of age. Interestingly, lambs born to ewes fed the Unp-Arg and Pro-Arg weighed 3.6 kg less at postnatal day 150 than lambs from control ewes.

Insights into the Function and Evolution of Taste 1 Receptor Gene Family in the Carnivore Fish Gilthead Seabream (Sparus aurata)

A plethora of molecular and functional studies in tetrapods has led to the discovery of multiple taste 1 receptor (T1R) genes encoding G-protein coupled receptors (GPCRs) responsible for sweet (T1R2 + T1R3) and umami (T1R1 + T1R3) taste. In fish, the T1R gene family repertoires greatly expanded because of several T1R2 gene duplications, and recent studies have shown T1R2 functional divergence from canonical mammalian sweet taste perceptions, putatively as an adaptive mechanism to develop distinct feeding strategies in highly diverse aquatic habitats. We addressed this question in the carnivore fish gilthead seabream (Sparus aurata), a model species of aquaculture interest, and found that the saT1R gene repertoire consists of eight members including saT1R1, saT1R3 and six saT1R2a-f gene duplicates, adding further evidence to the evolutionary complexity of fishT1Rs families. To analyze saT1R taste functions, we first developed a stable gene reporter system based on Ca²⁺-dependent calcineurin/NFAT signaling to examine specifically in vitro the responses of a subset of saT1R heterodimers to L-amino acids (L-AAs) and sweet ligands. We show that although differentially tuned in sensitivity and magnitude of responses, saT1R1/R3, saT1R2a/R3 and saT1R2b/R3 may equally serve to transduce amino acid taste sensations. Furthermore, we present preliminary information on the potential involvement of the Gi protein alpha subunits saGαi1 and saGαi2 in taste signal transduction.

Recent Techniques in Nutrient Analysis for Food Composition Database

Food composition database (FCD) provides the nutritional composition of foods. Reliable and up-to date FCD is important in many aspects of nutrition, dietetics, health, food science, biodiversity, plant breeding, food industry, trade and food regulation. FCD has been used extensively in nutrition labelling, nutritional analysis, research, regulation, national food and nutrition policy. The choice of method for the analysis of samples for FCD often depends on detection capability, along with ease of use, speed of analysis and low cost. Sample preparation is the most critical stage in analytical method development. Samples can be prepared using numerous techniques; however it should be applicable for a wide range of analytes and sample matrices. There are quite a number of significant improvements on sample preparation techniques in various food matrices for specific analytes highlighted in the literatures. Improvements on the technology used for the analysis of samples by specific instrumentation could provide an alternative to the analyst to choose for their laboratory requirement. This review provides the reader with an overview of recent techniques that can be used for sample preparation and instrumentation for food analysis which can provide wide options to the analysts in providing data to their FCD.

Nutritional Analysis and Overall Diet Quality of Fresh and Sun-dried Mystus bleekeri

Background:

Mystus bleekeri (M. bleekeri) is a small, freshwater catfish, with a maximum length of 15.5cm, which belongs to family Bagridae and order Siluriformes. It can be consumed both in fresh and processed form. Sun-drying is one of the most important traditional methods for processing M. bleekeri. However, neither fresh nor sun-dried M. bleekeri is normally consumed in raw form. Various cooking methods are applied to prepare them.

Objective:

The objective of the present study is to estimate the nutritional values of fresh and sundried Mystus bleekeri and evaluate the effect of different cooking methods on their nutrient contents.

Methods:

Proximate Analysis of minerals, amino acids, and fatty acids was performed using sophisticated analytical instruments.

Results:

Changes in various micronutrients and macronutrients were observed in the present study. The total amount of fat and ash content was found to be higher after frying in a fresh sample of M. bleekeri. Mineral content was found to be higher in sun-dried fish whereas that was reduced after boiling. Aspartic acid was the major component of fish protein. Saturated fatty acids were the most abundant in both fresh and sun-dried M. bleekeri which were increased through frying.

Conclusion:

The present experiment showed that after frying, minerals and fatty acids content exhibited higher concentration in both fresh and sun-dried M. bleekeri which is good for human health.

The effects of total sulfur amino acids on the intestinal health status of broilers challenged with Eimeria spp

This study evaluated the effects of total sulfur amino acid (TSAA) levels on the performance and intestinal health of broilers challenged with Eimeria spp. A total of 432 one-day-old off-sex Cobb 500 male chicks were randomly assigned to a 3 × 2 factorial arrangement (6 replicates/12 birds), with diets and Eimeria challenge as the main factors. The diets were as follows: 70% (no methionine [Met] supplementation), 85, and 100% TSAA, supplemented with L-Met. At day 14, the challenged birds (n = 216) were orally gavaged with a pool of Eimeria acervulina, Eimeria maxima, and Eimeria tenella sporulated oocysts, and the unchallenged birds (n = 216) received water. At 6 and 12 D post inoculation (dpi), performance and intestinal health were evaluated. The challenge, regardless of diets, significantly impaired the performance, intestinal villi height, villus-to-crypt ratio, and ileal digestibility of dry matter, energy, and crude protein (CP) and modulated the tight junction protein (TJP) expression throughout the experiment. Moreover, the superoxide dismutase activity was increased, whereas the reduced glutathione (GSH)-to-oxidized glutathione (GSSG) ratio was decreased by the challenge at 6 dpi. Regardless of the challenge, the 70% TSAA diet reduced the body weight and feed intake in all phases, whereas the ileal digestibility of CP was higher in birds fed with the 70% TSAA diet than in those fed with the 100% TSAA diet at 6 dpi. No major differences were observed among the diets with regard to the intestinal histomorphology and TJP expression, and birds fed with the 100% TSAA diet had the highest GSH concentration at 12 dpi. Few interactions were observed, and the Met supplementation counteracted the negative effects of the Eimeria challenge on GSH concentration when 85 and 100% of TSAA levels were reached. Overall, the Eimeria challenge had a negative impact on growth and intestinal health. Moreover, the supplementation of L-Met until either 85 or 100% of TSAA levels were reached was enough to assure good performance and intestinal health in birds challenged or not challenged with Eimeria spp.

Impacts of Amino Acids on the Intestinal Defensive System

The intestine interacts with a diverse community of antigens and bacteria. To keep its homeostasis, the gut has evolved with a complex defense system, including intestinal microbiota, epithelial layer and lamina propria. Various factors (e.g., nutrients) affect the intestinal defensive system and progression of intestinal diseases. This review highlights the current understanding about the role of amino acids (AAs) in protecting the intestine from harm. Amino acids (e.g., arginine, glutamine and tryptophan) are essential for the function of intestinal microbiota, epithelial cells, tight junction, goblet cells, Paneth cells and immune cells (e.g., macrophages, B cells and T cells). Through the modulation of the intestinal defensive system, AAs maintain the integrity and function of the intestinal mucosa and inhibit the progression of various intestinal diseases (e.g., intestinal infection and intestinal colitis). Thus, adequate intake of functional AAs is crucial for intestinal and whole-body health in humans and other animals.

Dispensable Amino Acids, except Glutamine and Proline, Are Ideal Nitrogen Sources for Protein Synthesis in the Presence of Adequate Indispensable Amino Acids in Adult Men

BACKGROUND

Nutritionally, there is a dietary requirement for indispensable amino acids (IAAs) but also a requirement for nitrogen (N) intake for the de novo synthesis of the dispensable amino acids (DAAs). It has been suggested that there might be a dietary requirement for specific DAAs.

OBJECTIVES

Experiment 1 tested whether 9 of the DAAs (Ala, Arg, Asn, Asp, Gln, Glu, Gly, Pro, Ser) are ideal N sources using the indicator amino acid oxidation (IAAO) technique. Experiment 2 examined whether there is a dietary requirement for Glu in adult men.

METHODS

Seven healthy men (aged 20-24 y) participated in 11 or 2 test diet intakes, in experiment 1 and 2, respectively, in a repeated measures design. In experiment 1, a base diet consisting of the IAA provided at the RDA was compared with test intakes with the base diet plus addition of individual DAAs to meet a 50:50 ratio of IAA:DAA on an N basis. In experiment 2, the diets corresponded to the amino acid pattern present in egg protein, in which all Glu and Gln was present as Glu, or removed, with Ser used to make the diets isonitrogenous. On each study day the IAAO protocol with l-[1-13C]phenylalanine was used to measure whole-body protein synthesis.

RESULTS

In experiment 1, repeated measures ANOVA with post hoc multiple comparisons showed that 7 of the 9 DAAs (Ala, Arg, Asn, Asp, Glu, Gly, Ser) decreased IAAO significantly (P < 0.05) compared with base IAA diet, the exceptions being Gln and Pro. In experiment 2, a paired t test did not find significant (P > 0.05) differences in the IAAO in response to removal and replacement of Glu intake.

CONCLUSIONS

The results suggest that in healthy men most DAAs are ideal N sources for protein synthesis, in the presence of adequate IAAs, and that endogenous synthesis of Glu is sufficient.Registered clinicaltrials.gov identifier: NCT02009917.

The effects of L-Arginine supplementation on growth performance and intestinal health of broiler chickens challenged with Eimeria spp

This study evaluated the effects of varying levels of L-arginine (Arg) on performance and intestinal health of broilers challenged with Eimeria. Cobb 500 male chicks (n = 720) were randomly distributed in a 5 × 2 factorial arrangement (6 replicates/12 birds). The main factors were Arg levels (1.04, 1.14, 1.24, 1.34, 1.44%) and challenge or non-challenge with Eimeria. At day 12, in the challenge group, each bird received orally 12,500 Eimeria maxima, 12,500 Eimeria tenella, and 62,500 Eimeria acervulina sporulated oocysts. At 5 d postinfection (dpi), intestinal permeability was measured. At 6 and 14 dpi, performance, intestinal histomorphology, nutrient digestibility, tight junction protein (TJP) gene expression, and antioxidant markers were evaluated. Few interactions were found, and when significant, the supplementation of Arg did not counteract the negative effects of Eimeria challenge. Challenge, regardless of Arg level, increased intestinal permeability, although the expression of Claudin-1, a TJP, was upregulated. At 6 dpi, the antioxidant system was impaired by the challenge. Moreover, growth performance, intestinal histomorphology, and nutrient digestibility were negatively affected by challenge at 6 and 14 dpi. Regardless of challenge, from 0 to 14 dpi, birds fed 1.44% showed higher weight gain than 1.04% of Arg, and birds fed 1.34% showed lower feed conversion than 1.04% of Arg. At 5 dpi, intestinal permeability was improved in birds fed 1.34% than 1.04% of Arg. Moreover, 1.34% of Arg upregulated the expression of the TJP Zonula occludens-1 (ZO-1) as compared with 1.24 and 1.44% of Arg at 6 dpi. At 14 dpi, 1.44% of Arg upregulated the expression of ZO-1 and ZO-2 compared with 1.24 and 1.34% of Arg. The nutrient digestibility was quadratically influenced by Arg, whereas the antioxidant markers were unaffected. Thus, the challenge with Eimeria had a negative impact on growth and intestinal health. The dietary supplementation of levels ranging from 1.24 to 1.44% of Arg showed promising results, improving overall growth, intestinal integrity, and morphology in broilers subjected or not to Eimeria challenge.

Metabolomic Signature of Amino Acids, Biogenic Amines and Lipids in Blood Serum of Patients with Severe Osteoarthritis

Metabolomic analysis is an emerging new diagnostic tool, which holds great potential for improving the understanding of osteoarthritis (OA)-caused metabolomic shifts associated with systemic inflammation and oxidative stress. The main aim of the study was to map the changes of amino acid, biogenic amine and complex lipid profiles in severe OA, where the shifts should be more eminent compared with early stages. The fasting serum of 70 knee and hip OA patients and 82 controls was assessed via a targeted approach using the AbsoluteIDQ™ p180 kit. Changes in the serum levels of amino acids, sphingomyelins, phoshatidylcholines and lysophosphatidylcholines of the OA patients compared with controls suggest systemic inflammation in severe OA patients. Furthermore, the decreased spermine to spermidine ratio indicates excessive oxidative stress to be associated with OA. Serum arginine level was positively correlated with radiographic severity of OA, potentially linking inflammation through NO synthesis to OA. Further, the level of glycine was negatively associated with the severity of OA, which might refer to glycine deficiency in severe OA. The current study demonstrates significant changes in the amino acid, biogenic amine and low-molecular weight lipid profiles of severe OA and provides new insights into the complex interplay between chronic inflammation, oxidative stress and OA.

The influence of the intestinal microbiota and its modifications on the well-being of patients with depression

Depression is an increasingly common disease that significantly reduces quality of life. The number of patients with depression is constantly increasing, especially among younger people. There are many likely causes of depression related to internal as well as environmental factors. It is possible that the intestinal microbiota may play an important role in the development of depressive symptoms. Its diversity is important for the proper development and functioning of the nervous system, in which an important role is played by the gut brain axis, which is the path-way of communication of intestinal microorganisms with the central nervous system. Changes in the number and diversity of the intestinal microbiota affect many pathways potentially related to mood, including hypothalamic-pituitary-adrenal axis, tryptophan metabolism, as well as the synthesis of neurotransmitters, short-chain fatty acids and brainderived neurotrophic factor. These changes can also affect the response of the immune system and inflammatory processes. Therefore, it seems that modulation of the intestinal microbiota through diet components and probiotic supplementation may be extremely important in the treatment of depression, also as one of the methods of treating this pharmacotherapyresistant condition. This work focuses on the effects of intestinal microbiota and its changes on the well-being of patients with depression.

Why Not Glycine Electrochemical Biosensors?

Glycine monitoring is gaining importance as a biomarker in clinical analysis due to its involvement in multiple physiological functions, which results in glycine being one of the most analyzed biomolecules for diagnostics. This growing demand requires faster and more reliable, while affordable, analytical methods that can replace the current gold standard for glycine detection, which is based on sample extraction with subsequent use of liquid chromatography or fluorometric kits for its quantification in centralized laboratories. This work discusses electrochemical sensors and biosensors as an alternative option, focusing on their potential application for glycine determination in blood, urine, and cerebrospinal fluid, the three most widely used matrices for glycine analysis with clinical meaning. For electrochemical sensors, voltammetry/amperometry is the preferred readout (10 of the 13 papers collected in this review) and metal-based redox mediator modification is the predominant approach for electrode fabrication (11 of the 13 papers). However, none of the reported electrochemical sensors fulfill the requirements for direct analysis of biological fluids, most of them lacking appropriate selectivity, linear range of response, and/or capability of measuring at physiological conditions. Enhanced selectivity has been recently reported using biosensors (with an enzyme element in the electrode design), although this is still a very incipient approach. Currently, despite the benefits of electrochemistry, only optical biosensors have been successfully reported for glycine detection and, from all the inspected works, it is clear that bioengineering efforts will play a key role in the embellishment of selectivity and storage stability of the sensing element in the sensor.

Metabolomic characterization of colorectal cancer cell lines highlighting stage-specific alterations during cancer progression

Introduction: Metabolomic studies on various colorectal cancer (CRC) cell lines have improved our understanding of the biochemical events underlying the disease. However, the metabolic profile dynamics associated with different stages of CRC progression is still lacking. Such information can provide further insights into the pathophysiology and progression of the disease that will prove useful in identifying specific targets for drug designing and therapeutics. Thus, our study aims to characterize the metabolite profiles in the established cell lines corresponding to different stages of CRC. Methods: Metabolite profiling of normal colon cell lines (CCD 841 CoN) and CRC cell lines corresponding to different stages, i.e., SW 1116 (stage A), HT 29 and SW 480 (stage B), HCT 15 and DLD-1 (stage C), and HCT 116 (stage D), was carried out using liquid chromatography-mass spectrometry (LC-MS). Mass Profiler Professional and Metaboanalyst 4.0 software were used for statistical and pathway analysis. METLIN database was used for the identification of metabolites. Results: We identified 72 differential metabolites compared between CRC cell lines of all the stages and normal colon cells. Principle component analysis and partial least squares discriminant analysis score plot were used to segregate normal and CRC cells, as well as CRC cells in different stages of the disease. Variable importance in projection score identified unique differential metabolites in CRC cells of the different stages. We identified 7 differential metabolites unique to stage A, 3 in stage B, 5 in stage C, and 5 in stage D. Conclusion: This study highlights the differential metabolite profiling in CRC cell lines corresponding to different stages. The identification of the differential metabolites in CRC cells at individual stages will lead to a better understanding of the pathophysiology of CRC development and progression and, hence, its application in treatment strategies.

Dietary glutamine, glutamate, and aspartate supplementation improves hepatic lipid metabolism in post-weaning piglets

A previous study has demonstrated that early weaning significantly suppressed hepatic glucose metabolism in piglets. Glutamate (Glu), aspartate (Asp) and glutamine (Gln) are major metabolic fuels for the small intestine and can alleviate weaning stress, and therefore might improve hepatic energy metabolism. The objective of this study was to investigate the effects of administration of Glu, Asp and Gln on the expression of hepatic genes and proteins involved in lipid metabolism in post-weaning piglets. Thirty-six weaned piglets were assigned to the following treatments: control diet (Control; basal diet + 15.90 g/kg alanine); Asp, Gln and Glu-supplemented diet (Control + AA; basal diet + 1.00 g/kg Asp + 5.00 g/kg Glu + 10.00 g/kg Gln); and the energy-restricted diet supplemented with Asp, Gln and Glu (Energy⁻ + AA; energy deficient diet + 1.00 g/kg Asp + 5.00 g/kg Glu + 10.00 g/kg Gln). Liver samples were obtained on d 5 and 21 post-weaning. Piglets fed Energy⁻ + AA diet had higher liver mRNA abundances of acyl-CoA oxidase 1 (ACOX1), succinate dehydrogenase (SDH), mitochondrial transcription factor A (TFAM) and sirtuin 1 (SIRT1), as well as higher protein expression of serine/threonine protein kinase 11 (LKB1), phosphor-acetyl-CoA carboxylase (P-ACC) and SIRT1 compared with piglets fed control diet (P < 0.05) on d 5 post-weaning. Control + AA diet increased liver malic enzyme 1 (ME1) and SIRT1 mRNA levels, as well as protein expression of LKB1 and P-ACC on d 5 post-weaning (P < 0.05). On d 21 post-weaning, compared to control group, Glu, Gln and Asp supplementation up-regulated the mRNA levels of ACOX1, ME1 and SIRT1 (P < 0.05). These findings indicated that dietary Glu, Gln and Asp supplementation could improve hepatic lipid metabolism to some extent, which may provide nutritional intervention for the insufficient energy intake after weaning in piglets.

Dietary methionine supplementation improves the European seabass (Dicentrarchus labrax) immune status following long-term feeding on fishmeal-free diets

Methionine is a limiting amino acid (AA) in fish diets, particularly in those containing high levels of plant protein (PP), and is key in the immune system. Accordingly, outcome on the fish immune mechanisms of methionine-deficient and methionine-supplemented diets within the context of 0 % fishmeal formulation, after a short and prolonged feeding period, was studied in European seabass (Dicentrarchus labrax). For this, seabass juveniles were fed a (i) fishmeal-free diet, meeting AA requirements, but deficient in methionine (MET0·65); (ii) as control, the MET0·65 supplemented with l-methionine at 0·22 % of feed weight (CTRL); (iii) two diets, identical to MET0·65 but supplemented at 0·63 and 0·88 % of feed weight of l-methionine (MET1·25 and MET1·5, respectively); and (iv) a fishmeal-based diet (FM), as positive control. After 2 and 12 weeks of feeding, blood and plasma were sampled for leucocyte counting and humoral parameter assays and head-kidney collected for gene expression. After 2 weeks of feeding, a fishmeal-free diet supplemented with methionine led to changes in the expression of methionine- and leucocyte-related genes. A methionine immune-enhancer role was more evident after 12 weeks with an increased neutrophil percentage and a decreased expression of apoptotic genes, possibly indicating an enhancement of fish immunity by methionine dietary supplementation. Furthermore, even though CTRL and FM present similar methionine content, CTRL presented a reduced expression of several immune-related genes indicating that in a practical PP-based diet scenario, the requirement level of methionine for an optimal immune status could be higher.

Free Amino Acids in Human Milk: A Potential Role for Glutamine and Glutamate in the Protection Against Neonatal Allergies and Infections

Breastfeeding is indicated to support neonatal immune development and to protect against neonatal infections and allergies. Human milk composition is widely studied in relation to these unique abilities, which has led to the identification of various immunomodulating components in human milk, including various bioactive proteins. In addition to proteins, human milk contains free amino acids (FAAs), which have not been well-studied. Of those, the FAAs glutamate and glutamine are by far the most abundant. Levels of these FAAs in human milk sharply increase during the first months of lactation, in contrast to most other FAAs. These unique dynamics are globally consistent, suggesting that their levels in human milk are tightly regulated throughout lactation and, consequently, that they might have specific roles in the developing neonate. Interestingly, free glutamine and glutamate are reported to exhibit immunomodulating capacities, indicating that these FAAs could contribute to neonatal immune development and to the unique protective effects of breastfeeding. This review describes the current understanding of the FAA composition in human milk. Moreover, it provides an overview of the effects of free glutamine and glutamate on immune parameters relevant for allergic sensitization and infections in early life. The data reviewed provide rationale to study the role of free glutamine and glutamate in human milk in the protection against neonatal allergies and infections.

Biochemical characterization of progesterone-induced alterations in bovine uterine fluid amino acid and carbohydrate composition during the conceptus elongation window†

Pregnancy establishment in cattle is contingent on conceptus elongation-a fundamental developmental event coinciding with the time during which most pregnancies fail. Elongation in vivo is directly driven by uterine secretions, indirectly influenced by systemic progesterone concentrations, and has yet to be recapitulated in vitro. To better understand the microenvironment evolved to facilitate this phenomenon, the amino acid and carbohydrate composition of uterine fluid was interrogated using high-throughput metabolomics on days 12, 13, and 14 of the estrous cycle from heifers with normal and high circulating progesterone. A total of 99 biochemicals (79 amino acids and 20 carbohydrates) were consistently identified, of which 31 showed a day by progesterone interaction. Fructose and mannitol/sorbitol did not exhibit a day by progesterone interaction, but displayed the greatest individual fluctuations (P ≤ 0.05) with respective fold increases of 18.39 and 28.53 in high vs normal progesterone heifers on day 12, and increases by 10.70-fold and 14.85-fold in the uterine fluid of normal progesterone animals on day 14 vs day 12. Moreover, enrichment analyses revealed that the phenylalanine, glutathione, polyamine, and arginine metabolic pathways were among the most affected by day and progesterone. In conclusion, progesterone had a largely stabilizing effect on amino acid flux, and identified biochemicals of likely importance to conceptus elongation initiation include arginine, fructose, glutamate, and mannitol/sorbitol.

Non-invasive Amino Acid Profiling of Embryo Culture Medium Using HPLC Correlates With Embryo Implantation Potential in Women Undergoing in vitro Fertilization

This study aimed to determine the correlation between amino acid profiling of a 3-day-old embryo culture medium and embryo implantation potential in women undergoing in vitro fertilization (IVF). The data of 98 patients who received IVF treatment in our hospital from December 2015 to February 2017 were retrospectively analyzed. The 98 patients were grouped into a pregnant group (gemellary pregnancy), a non-pregnant group (non-pregnancy), and a blank control group. The amino acids from a 3-day-old embryo culture medium and blank control medium were collected and were analyzed using high performance liquid chromatography (HPLC). The HPLC results showed that amino acids including aspartate (ASP), serine (SER), glycine (GLY), histidine (HIS), taurine (TAU), arginine (ARG), threonine (THR), alanine (ALA), and proline (PRO) were detected in the 3-day-old embryo culture medium and blank control medium. There are significant differences between the pregnant group and non-pregnant group in peak height (H)-SER, surface area (S)-ASP, S-SER, S-HIS, and S-ALA. The discrimination analysis according to the peak height and peak area of amino acids revealed that the prediction rate of the pregnant group, non-pregnant group, and blank control group were 82.7, 95.7, and 100%. Further, by using the principal component analysis, we found that the prediction rate in these three groups were 90.4, 91.3, and 100%. Our data may suggest that using amino acid concentrations for principal component analysis and discriminant analysis has high accuracy in predicting the relationship between amino acid fingerprint and embryo implantation potential.

1H NMR-Based Urine Metabolomics Reveals Signs of Enhanced Carbon and Nitrogen Recycling in Prostate Cancer

Prostate cancer is the second most common tumor and the fifth cause of cancer-related death among men worldwide. PC cells exhibit profound signaling and metabolic reprogramming that account for the acquisition of aggressive features. Although the metabolic understanding of this disease has increased in recent years, the analysis of such alterations through noninvasive methodologies in biofluids remains limited. Here, we used NMR-based metabolomics on a large cohort of urine samples (more than 650) from PC and benign prostate hyperplasia (BPH) patients to investigate the molecular basis of this disease. Multivariate analysis failed to distinguish between the two classes, highlighting the modest impact of prostate alterations on urine composition and the multifactorial nature of PC. However, univariate analysis of urine metabolites unveiled significant changes, discriminating PC from BPH. Metabolites with altered abundance in urine from PC patients revealed changes in pathways related to cancer biology, including glycolysis and the urea cycle. We found out that metabolites from such pathways were diminished in the urine from PC individuals, strongly supporting the notion that PC reduces nitrogen and carbon waste in order to maximize their usage in anabolic processes that support cancer cell growth.

Nutrition and metabolism of glutamate and glutamine in fish

Glutamate (Glu) and glutamine (Gln) comprise a large proportion of total amino acids (AAs) in fish in the free and protein-bound forms. Both Glu and Gln are synthesized de novo from other α-amino acids and ammonia. Although these two AAs had long been considered as nutritionally non-essential AAs for an aquatic animal, they must be included adequately in its diet to support optimal health (particularly intestinal health) and maximal growth. In research on fish nutrition, Glu has been used frequently as an isonitrogenous control on the basis of the assumption that this AA has no nutritional or physiological function. In addition, purified diets used for feeding fish generally lack glutamine. As functional AAs, Glu and Gln are major metabolic fuels for tissues of fish (including the intestine, liver, kidneys, and skeletal muscle), and play important roles not only in protein synthesis but also in glutathione synthesis and anti-oxidative reactions. The universality of Glu and Gln as abundant intracellular AAs depends on their enormous versatility in metabolism. Dietary supplementation with Glu and Gln to farmed fish can improve their growth performance, intestinal development, innate and adaptive immune responses, skeletal muscle development and fillet quality, ammonia removal, and the endocrine status. Glu (mainly as monosodium glutamate), glutamine, or AminoGut (a mixture of Glu and Gln) is a promising feed additive to reduce the use of fishmeal, while gaining the profitability of global aquaculture production. Thus, the concept of dietary requirements of fish for Glu and Gln is a paradigm shift in the nutrition of aquatic animals (including fish).

Foraging strategy of a carnivorous-insectivorous raptor species based on prey size, capturability and nutritional components

Optimal foraging theory has typically paid little attention to species feeding on mobile prey and has emphasised energy intake rather than the nutritional contribution of food. The difficulty of capturing food has rarely been included in foraging models, even when it is a potentially important modulator of time devoted to foraging. From the central place foraging and provisioning perspectives, it is posited that at high levels of prey selectivity, the time spent to capture prey is longer than at low levels of prey selectivity. Furthermore, in the case of carnivorous predators, it is thought that nutritional composition does not influence foraging strategies. To explore these issues, we investigated the influence of abundance, size, difficulty of capture, gross energy and nutritional composition (fat, protein, protein-fat ratio and amino acid contents) of prey species on the foraging behaviour of a predator species, the common kestrel Falco tinnunculus, in a region of high diversity of prey species. Our results show that capturability index and load-size explain the foraging behaviour of kestrels. Preferred prey take longer to be provisioned, both selectivity and capturability might explain this result. It is also shown that specific nutritional components, such as protein and amino acid contents, are likely to explain food preference in this carnivorous-insectivorous species.

Glycine Attenuates LPS-Induced Apoptosis and Inflammatory Cell Infiltration in Mouse Liver

BACKGROUND

Liver dysfunction impairs immunological homeostasis. Glycine (Gly) has been reported to have antioxidative and anti-inflammatory effects and to regulate apoptosis in various models.

OBJECTIVES

The aim of the present study was to determine whether Gly could attenuate LPS-induced liver injury.

METHODS

In Experiment 1, 48 6-week-old male C57BL/6 mice were randomly assigned into one of 4 groups: CON (control), GLY [orally administered Gly, 5 g · kg body weight (BW)-1 · d-1 for 6 d], LPS (5 mg/kg BW, intraperitoneally administered), and GLY + LPS (Gly supplementation, and on day 7 LPS treatment). In Experiment 2, mice were untreated, pretreated with Gly as above, or pretreated with Gly + l-buthionine sulfoximine (BSO) (0.5 g/kg BW, intraperitoneally administered every other day) for 6 d. On day 7, mice were injected with LPS as above. Histological alterations, activities of antioxidative enzymes, apoptosis, and immune cell infiltration were analyzed.

RESULTS

In Experiment 1, compared with CON, LPS administration resulted in increased karyolysis and karyopyknosis in the liver by 8- to 10-fold, enhanced serum activities of alanine transaminase (ALT), aspartate transaminase (AST), and lactate dehydrogenase (LDH) by 1- to 1.8-fold, and increased hepatic apoptosis by 5.5-fold. Furthermore, LPS exposure resulted in increased infiltration of macrophages and neutrophils in the liver by 3.2- to 7.5-fold, elevated hepatic concentrations of malondialdehyde and hydrogen peroxide (H2O2), and elevated myeloperoxidase (MPO) activity by 1.5- to 6.3-fold. In Experiment 2, compared with the LPS group, mice in the GLY + LPS group had fewer histological alterations (68.5%-75.9%); lower serum ALT, AST, and LDH activities (24.3%-64.7%); and lower hepatic malondialdehyde and H2O2 concentrations (46.1%-80.2%), lower MPO activity (39.2%), immune cell infiltration (52.3%-85.3%), and apoptosis (69.6%), which were abrogated by BSO. Compared with the GLY + LPS group, mice in the GLY + BSO + LPS group had lower hepatic activities of catalase, superoxide dismutase, and glutathione peroxidase by 33.5%-48.5%; increased activation of NF-κB by 2.3-fold; and impaired nuclear factor (erythroid-derived 2)-like 2 signaling by 38.9%.

CONCLUSIONS

Gly is a functional amino acid with an ability to protect the liver against LPS-induced injury in mice.

The Urinary Metabolome of Healthy Newborns

The knowledge of normal metabolite values for neonates is key to establishing robust cut-off values to diagnose diseases, to predict the occurrence of new diseases, to monitor a neonate's metabolism, or to assess their general health status. For full term-newborns, many reference biochemical values are available for blood, serum, plasma and cerebrospinal fluid. However, there is a surprising lack of information about normal urine concentration values for a large number of important metabolites in neonates. In the present work, we used targeted tandem mass spectrometry (MS/MS)-based metabolomic assays to identify and quantify 136 metabolites of biomedical interest in the urine from 48 healthy, full-term term neonates, collected in the first 24 h of life. In addition to this experimental study, we performed a literature review (covering the past eight years and over 500 papers) to update the references values in the Human Metabolome Database/Urine Metabolome Database (HMDB/UMDB). Notably, 86 of the experimentally measured urinary metabolites are being reported in neonates/infants for the first time and another 20 metabolites are being reported in human urine for the first time ever. Sex differences were found for 15 metabolites. The literature review allowed us to identify another 78 urinary metabolites with concentration data. As a result, reference concentration values and ranges for 378 neonatal urinary metabolites are now publicly accessible via the HMDB.

Effect of dietary fiber and threonine content on intestinal barrier function in pigs challenged with either systemic E. coli lipopolysaccharide or enteric Salmonella Typhimurium

Background

The independent and interactive effects of dietary fiber (DF) and threonine (Thr) were investigated in growing pigs challenged with either systemic E. coli lipopolysaccharide (LPS) or enteric Salmonella Typhimurium (ST) to characterise their effect on intestinal barrier function.

Results

In experiment 1, intestinal barrier function was assessed via oral lactulose and mannitol (L:M) gavage and fecal mucin analysis in pigs challenged with E. coli LPS and fed low fiber (LF) or high fiber (HF) diets with graded dietary Thr. Urinary lactulose recovery and L:M ratio increased (P < 0.05) during the LPS inoculation period in LF fed pigs but not in HF fed pigs. Fecal mucin output was increased (P < 0.05) in pigs fed HF compared to LF fed pigs. In experiment 2, RT-qPCR, ileal morphology, digesta volatile fatty acid (VFA) content, and fecal mucin output were measured in Salmonella Typhimurium challenged pigs, fed LF or HF diets with standard or supplemented dietary Thr. Salmonella inoculation increased (P < 0.05) fecal mucin output compared to the unchallenged period. Supplemental Thr increased fecal mucin output in the HF-fed pigs (Fib × Thr; P < 0.05). Feeding HF increased (P < 0.05) VFA concentration in cecum and colon. No effect of either Thr or fiber on expression of gene markers was observed except a tendency (P = 0.06) for increased MUC2 expression with the HF diet. Feeding HF increased goblet cell numbers (P < 0.05).

Conclusion

Dietary fiber appears to improve barrier function through increased mucin production capacity (i.e., goblet cell numbers, MUC2 gene expression) and secretion (i.e., fecal mucin output). The lack of effect of dietary Thr in Salmonella-challenged pigs provides further evidence that mucin secretion in the gut is conserved and, therefore, Thr may be limiting for growth under conditions of increased mucin production.

Metabolites and metabolic pathways associated with glucocorticoid resistance in pregnant African-American women

Glucocorticoid resistance (GR) is associated with exposure to chronic stress and an increased risk of metabolic and inflammatory disorders in both animal and human populations. Studies on ethnic disparities highlight the African-American (AA) population as having a high propensity to both GR and chronic stress exposure. Glucocorticoids and inflammation play a very important role in pregnancy outcome and fetal development. To date, however, the metabolites and metabolic pathways associated with GR during pregnancy have not been identified, obscuring the mechanisms by which adverse health consequences arise, and thus impeding targeted therapeutic intervention. The objective of this study was to perform untargeted high-resolution metabolomics (HRM) profiling on 273 pregnant AA women, to identify metabolites and metabolic pathways associated with GR during the first trimester of pregnancy and to evaluate their cross-sectional association with birth outcomes and psychosocial variables related to chronic stress exposure. For this study, GR was determined by the concentration of dexamethasone required for 50% inhibition (Dex IC50) of the cytokine tumor-necrosis factor alpha (TNF-alpha) release in vitro in response to a standard dose of lipopolysaccharide. The results for Metabolome-Wide Association Studies (MWAS) and pathway enrichment analysis for serum metabolic associations with Dex IC50, showed energy (nicotinamide and TCA cycle), amino acid, and glycosphingolipid metabolism as top altered pathways. Bioinformatic analysis showed that GR, as indicated by elevated Dex IC50 in the pregnant women, was associated with increased inflammatory metabolites, oxidative stress related metabolites, increased demand for functional amino acids to support growth and development, and disruption in energy-related metabolites. If confirmed in future studies, targeting these physiologically significant metabolites and metabolic pathways may lead to future assessment and intervention strategies to prevent inflammatory and metabolic complications observed in pregnant populations.

•

GR is associated with chronic stress and is a risk factor for adverse health outcomes, especially among African Americans.

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Metabolites and metabolic pathways associated with GR relate to energy production, amino acid metabolism, and inflammation.

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Findings provide a foundation for future studies investigating risk factors in this health disparity population.

Metabolite profiling and mechanisms of bioactivity of snake autolysate - A traditional Uzbek medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Aqueous autolysate from the snake Eryx miliaris (SNA) has been used in traditional medicine of Uzbekistan as anti-inflammatory, hepatoprotective and immunomodulatory agent. However, little is known about the chemical composition and its mechanisms of activity.

AIM OF THE STUDY

This is our first attempt to analyse the composition of snake autolysate using gas chromatography with mass spectrometry (GC-MS) and to investigate the mechanisms of anti-inflammatory and hyaluronidase activity of fingerprinted E. miliaris autolysate to support their use in the traditional Uzbek medicine.

MATERIALS AND METHODS

Aqueous autolysate was evaporated and derivatised for GC-MS analysis of metabolites. For quantification, lipids were extracted from autolysate by solvent extraction and derivatised by esterification and silylation. Biological activity was evaluated with lipid peroxidation, cyclooxygenase (COX) inhibition and antihyaluronidase activity tests.

RESULTS

GC-MS analysis of SNA enabled the identification of 27 compounds. Short chain fatty acids (SCFA, 21%), amino acid/derivatives 39% (incl. 2-piperidinone 19%), phenyl (7%), and OH-Phenyl (10%) derivatives covered 77%. Other derivatives (9%) included succinic acid and 3-indole acetic acid). Long chain fatty acids (C₁₆-C₁₈) accounted for 3%. The lipid concentration of SNA was 1.2 mg/mL (0.12%). Three concentration levels (1.0-20.0 μg/mL) did not inhibit COX-1 and COX-2 in vitro and malondialdehyde level was not decreased by SNA in lipid peroxidation model. However, SNA was a potent inhibitor of the hyaluronidase enzyme activity in a dose dependent manner with IC₅₀ = 0.086 mL/mL.

CONCLUSION

The results from GC-MS analyses of SNA lead us to the identification of a wide range of major chemical structures of the metabolites and their derivatives with several categories. Pharmacological studies support the traditional use of SNA and show one of its possible mechanisms of activity via inhibition of hyaluronidase.

Beyond Heat Stress: Intestinal Integrity Disruption and Mechanism-Based Intervention Strategies

The current climate changes have increased the prevalence and intensity of heat stress (HS) conditions. One of the initial consequences of HS is the impairment of the intestinal epithelial barrier integrity due to hyperthermia and hypoxia following blood repartition, which often results in a leaky gut followed by penetration and transfer of luminal antigens, endotoxins, and pathogenic bacteria. Under extreme conditions, HS may culminate in the onset of “heat stroke”, a potential lethal condition if remaining untreated. HS-induced alterations of the gastrointestinal epithelium, which is associated with a leaky gut, are due to cellular oxidative stress, disruption of intestinal integrity, and increased production of pro-inflammatory cytokines. This review summarizes the possible resilience mechanisms based on in vitro and in vivo data and the potential interventions with a group of nutritional supplements, which may increase the resilience to HS-induced intestinal integrity disruption and maintain intestinal homeostasis.

Fast quantification of free amino acids in food by microfluidic voltage-assisted liquid desorption electrospray ionization-tandem mass spectrometry

A method based on microfluidic voltage-assisted liquid desorption electrospray ionization-tandem mass spectrometry (VAL-DESI-MS/MS) has been developed for fast quantification of free amino acids in food. Food extracts were transferred to the microfluidic platform and analyzed by liquid desorption ESI-MS/MS. Deuterated aspartic acid (i.e., 2,2,3-d3-Asp) was used as internal standard for analysis. The method had linear calibration curves with r2 values > 0.998. Limits of detection were at the level of sub μM for the amino acids tested, i.e., glutamic acid (Glu), arginine (Arg), tyrosine (Tyr), tryptophan (Trp), and phenylalanine (Phe). To validate the proposed method in food analysis, extracts of Cordyceps fungi were analyzed. Amino acid contents were found in the range from 0.63 mg/g (Tyr in Cordyceps sinensis) to 4.44 mg/g (Glu in Cordyceps militaris). Assay repeatability (RSD) was ≤ 5.2% for all the five amino acids measured in all the samples analyzed. Recovery was found in the range from 95.8 to 105.1% at two spiking concentrations of 0.250 mg/g and 1.00 mg/g. These results prove that the proposed microfluidic VAL-DESI-MS/MS method offers a quick and convenient means of quantifying free amino acids with accuracy and repeatability. Therefore, it may have potential in food analysis for nutritional and quality assessment purposes. Graphical abstract.

Probiotic, Bacillus subtilis E20 alters the immunity of white shrimp, Litopenaeus vannamei via glutamine metabolism and hexosamine biosynthetic pathway

The purpose of this study was to profile the mechanisms of action of probiotic, Bacillus subtilis E20 in activating the immunity of white shrimp, Litopenaeus vannamei. Two groups of shrimp were studied. One group was fed a control diet without probiotic supplementation and the other was fed a probiotic-containing diet at a level of 10⁹ cfu kg diet^-1. After the 8-week feeding regimen, the metabolite composition in the hepatopancreas of shrimp were investigated using ¹H nuclear magnetic resonance (¹H NMR) based metabolomic analysis. Results from the ¹H NMR analysis revealed that 16 hepatopancreatic metabolites were matched and identified among groups, of which 2 metabolites, creatinine and glutamine were significantly higher in probiotic group than in the control group. This result was confirmed by the reverse-phase high-performance liquid chromatography (RP-HPLC) and spectrophotometric analysis. Transcriptome analysis indicated the expressions of 10 genes associated with antioxidant enzymes, pattern recognition proteins and antimicrobial molecules, more active expression in the shrimp fed a diet supplemented with probiotic as compared to that of shrimp in control. In addition, the expressions of 4 genes involved with hexosamine biosynthesis pathway (HBP) and UDP-N-acetylglucosamine-peptide N-acetylglucosaminyltransferase for protein O-glycosylation were also higher in hepatopancreas of probiotic-treated shrimp than in shrimp fed a control diet. Western blot and enzyme-linked immunosorbent assay showed that heat shock factor 1, heat shock protein 70, and protein O-glycosylation in hepatopancreas were higher in probiotic group than the control group. These findings suggest that probiotic, B. subtilis E20 promotes the digestibility of glutamine in the diet, and that the increased glutamine in shrimp can be used as fuel for immune cells or may be used to regulate immune molecule expressions and protein O-glycosylation via the HBP to increase protein O-glycosylation, thereby improving the health of shrimp.

Decreased amylolytic microbes of the hindgut and increased blood glucose implied improved starch utilization in the small intestine by feeding rumen-protected leucine in dairy calves

Starch digestion in the small intestine in ruminants is relatively lower compared with that in monogastric animals, likely due to low pancreatic α-amylase secretion. Previous studies suggested that leucine could increase pancreatic α-amylase secretion in the small intestine of heifers cannulated with abomasal, duodenal, and ileal catheters. However, the surgical procedures probably have an effect on pancreatic function. Thus, we used rumen-protected leucine (RP-Leu) to explore its effect on small intestinal digestion of starch in calves without any surgery in 3 experiments. The first experiment was to explore whether RP-Leu could improve post-ruminal starch digestion in 5-mo-old calves (158 ± 19 kg body weight ± standard deviation). We found that RP-Leu did not affect rumen fermentation profile or whole-tract starch digestibility, but it increased blood glucose concentration and fecal pH and decreased fecal propionate molar proportion. Additionally, RP-Leu increased fibrolytic genera Ruminiclostridium and Pseudobutyrivibrio and decreased the amylolytic genus of Faecalibacterium. The second experiment compared RP-Leu and rumen-protected lysine (RP-Lys) for their effects on post-ruminal starch digestion in 6-mo-old calves (201 ± 24 kg body weight). The responses of blood glucose concentration, fecal pH, fecal propionate proportion, and starch digestibility to RP-Leu supplementation were similar to those observed in experiment 1. Cellulolytic family Ruminococcaceae and Bacteroidales BS11 gut group tended to be increased by RP-Leu. In contrast, RP-Lys showed no significant influence on the above measurements. The third experiment determined the interaction between RP-Leu and rumen-escape starch (RES) on the small intestinal digestion of starch in 8-mo-old calves (289 ± 26 kg body weight). An interaction between RP-Leu and RES levels was observed in fecal butyrate concentration and the relative abundance of family Bacteroidaceae, and genera Ruminococcaceae UCG-005 and Bacteroides. We found that RP-Leu tended to increase the abundance of fecal Firmicutes and decrease Spirochaetae. In conclusion, RP-Leu, but not RP-Lys, increased blood glucose concentration and decreased the amount of starch fermented in the hindgut in a RES dose-dependent manner, suggesting that RP-Leu might stimulate starch digestion in the small intestine.

Glycine supplementation during six months does not alter insulin, glucose or triglycerides plasma levels in healthy rats

Nowadays, glycine is used in nutritional supplements and to attenuate chronic complications of diabetes and obesity; however, its use has side effects as insulin resistance. Our aim was to evaluate the effect of chronic glycine supplementation on insulin, glucose and triglyceride levels in healthy Wistar rats. Groups were: Control (C), that received sterilized water only, glycine (GG), that received 1% glycine and taurine (TG), that received 0.5% taurine during 6 months (n = 10). Our results showed no differences in plasma insulin levels after six months of supplementation (C: 13.22 ± 2.0; GG: 11.4 ± 2.0; TG: 11.13 ± 2.0 ng/ml; p = 0.64). Likewise, neither glucose plasma concentration (C: 99.9 ± 3.9 mg/dl; GG: 104.3 ± 4.3 mg/dl; TG: 104.5 ± 4.8 mg/dl) (p = 0.88) nor triglyceride levels (C: 58.4 ± 5.6 mg/dl; GG: 46.9 ± 2.3 mg/dl; TG: 50.68 ± 3.3 mg/dl), showed differences after six months supplementation (p = 0.22). Furthermore, the analysis of glycine (C: 80 ± 24.6; GG: 83.9 ± 25.9; TG: 90.7 ± 13.5 nmol/ml) (p = 0.19) and taurine (C: 169 ± 15.17; GG: 148.7 ± 23.9; TG: 165.8 ± 22.5 nmol/ml) (p = 0.4) in the plasma of animals with supplementation showed no significant changes. Additionally, general urine tests and histological analysis of liver or kidneys showed no alterations. In conclusion, chronic supplementation with 1% glycine did not have any significant detrimental side effects in our model. However, more studies are still necessary to evaluate the effect of 1% glycine supplementation in humans.

L-arginine supplementation during the final third of gestation improves litter uniformity and physical characteristics of neonatal piglet thermoregulation

The study assessed the effects of dietary L-arginine supplementation from days 85 to 115 of gestation on sow performance, litter quality, piglet physiology and survival variables in the first 24 hr of life. Twenty multiparous sows, with a history of hyperprolificacy (more than 14 piglets per litter), were used. A completely randomized experimental design was used, consisting of two treatments: feed supplemented or not with 1% L-arginine from days 85 to 115 of gestation. The experimental unit consisted of the sow and its respective litter, using 10 replicates per treatment. The sows were distributed into the treatments based on body condition and parity. Supplementation with L-arginine reduced the within-litter standard deviation and the within-litter coefficient of variation of piglet weight at 24 hr by 54 g and 4.14 percentage points respectively (p = .029; p = .035). Supplementation with 1.0% L-arginine decreased the percentages of piglets weighing less than 800 g by 5.60 and 5.08 points at birth and at 24 hr of life respectively. Piglets from sows supplemented with L-arginine had higher (p = .088) average rectal temperatures at birth and lower (p = .030) rectal temperature at 24 hr of life in comparison with control piglets. No significant differences in placental weight or estimated colostrum production and intake were observed in the first 24 hr of life. At 24 hr of life, piglets weighing less than 1,000 g and from supplemented sows had lower (p = .048) surface/mass ratios and higher body mass index (p = .070). Piglets from supplemented sows and who weighed 1601 to 1,800 g had lower body mass index and ponderal index (p = .002; p = .003). Supplementation with L-arginine during the final third of gestation reduces the incidence of unviable piglets (<800 g) and improved litter uniformity and piglets' body conformation within the first 24 hr of life.