Functional amino acids in growth, reproduction, and health

The Serum Metabolomics Study of Liver Failure and Artificial Liver Therapy Intervention

Background

This study was designed to study the serum metabolites of patients with liver failure.

Material/Methods

The study included 50 patients with liver failure, 30 patients with chronic hepatitis B treated with an artificial liver, 11 patients with an artificial liver, and 32 healthy controls. Clinical data were recorded, and blood samples were analyzed by gas chromatography–mass spectrometry (GC-MS). The random forest algorithm was used to construct a multidimensional scale map to preliminarily reflect the differences between samples. The data were then analyzed to obtain the correlation of different variables among samples, from which the differential metabolites were screened.

Results

Thirty-five metabolites were identified by GC-MS. There were significant differences in serum metabolites levels before and after treatment in the liver failure group and in the chronic hepatitis group, healthy control group, and artificial liver group. Different metabolites were screened according to the importance of different variables among samples. Significant differences were found between the liver failure group, the chronic hepatitis group, and the healthy control group. In addition, there were significant differences in the liver group before and after treatment with an artificial liver, including differences in boric acid, 2-(methoxyamino)-propionic acid, glycine, l-methionine, aminopropionic acid, glyceryl monostearate, cholesterol, and other substances.

Conclusions

A variety of differences in metabolites were found in each group, some of which revealed possible metabolic pathways leading to differences between groups. Blood metabolomics analysis has great potential in real-time dynamic monitoring of liver failure and evaluation of artificial liver therapy.

A mix of functional amino acids and grape polyphenols promotes the growth of piglets, modulates the gut microbiota in vivo and regulates epithelial homeostasis in intestinal organoids

Weaning is a challenging period for gut health in piglets. Previous studies showed that dietary supplementations with either amino acids or polyphenols promote piglet growth and intestinal functions, when administered separately. Thus, we hypothesized that a combination of amino acids and polyphenols could facilitate the weaning transition. Piglets received during the first two weeks after weaning a diet supplemented or not with a mix of a low dose (0.1%) of functional amino acids (L-arginine, L-leucine, L-valine, L-isoleucine, L-cystine) and 100 ppm of a polyphenol-rich extract from grape seeds and skins. The mix of amino acids and polyphenols improved growth and feed efficiency. These beneficial effects were associated with a lower microbiota diversity and a bloom of Lactobacillaceae in the jejunum content while the abundance of Proteobacteria was reduced in the caecum content. The mix of amino acids and polyphenols also increased the production by the caecum microbiota of short-chain fatty acids (butyrate, propionate) and of metabolites derived from amino acids (branched-chain fatty acids, valerate, putrescine) and from polyphenols (3-phenylpropionate). Experiments in piglet jejunum organoids revealed that the mix of amino acids and polyphenols upregulated the gene expression of epithelial differentiation markers while it reduced the gene expression of proliferation and innate immunity markers. In conclusion, the supplementation of a mix of amino acids and polyphenols is a promising nutritional strategy to manage gut health in piglets through the modulation of the gut microbiota and of the epithelial barrier.

Microalgae for high-value products: A way towards green nutraceutical and pharmaceutical compounds

Microalgae is a renewable bioresource with the potential to replace the conventional fossil-based industrial production of organic chemicals and pharmaceuticals. Moreover, the microalgal biomass contains carotenoids, vitamins, and other biomolecules that are widely used as food supplements. However, the microalgal biomass production, their composition variations, energy-intensive harvesting methods, optimized bio-refinery routes, and lack of techno-economic analysis are the major bottleneck for the life-sized commercialization of this nascent bio-industry. This review discusses the microalgae-derived key bioactive compounds and their applications in different sectors for human health. Furthermore, this review proposes advanced strategies to enhance the productivity of bioactive compounds and highlight the key challenges associated with a safety issue for use of microalgae biomass. It also provides a detailed global scenario and market demand of microalgal bioproducts. In conclusion, this review will provide the concept of microalgal biorefinery to produce bioactive compounds at industrial scale platform for their application in the nutraceutical and pharmaceutical sector considering their current and future market trends.

Arginine Regulates TOR Signaling Pathway through SLC38A9 in Abalone Haliotis discus hannai

Arginine plays an important role in the regulation of the target of the rapamycin (TOR) signaling pathway, and Solute Carrier Family 38 Member 9 (SLC38A9) was identified to participate in the amino acid-dependent activation of TOR in humans. However, the regulations of arginine on the TOR signaling pathway in abalone are still unclear. In this study, slc38a9 of abalone was cloned, and the slc38a9 was knocked down and overexpressed to explore its function in the regulation of the TOR signaling pathway. The results showed that knockdown of slc38a9 decreased the expression of tor, ribosomal s6 protein kinase (s6k) and eukaryotic translation initiation factor 4e (eif4e) and inhibited the activation of the TOR signaling pathway by arginine. Overexpression of slc38a9 up-regulated the expression of TOR-related genes. In addition, hemocytes of abalone were treated with 0, 0.2, 0.5, 1, 2 and 4 mmol/L of arginine, and abalones were fed diets with 1.17%, 1.68% and 3.43% of arginine, respectively, for 120 days. Supplementation of arginine (0.5–4 mmol/L) increased the expressions of slc38a9, tor, s6k and eif4e in hemocytes, and abalone fed with 1.68% of dietary arginine showed higher mRNA levels of slc38a9, tor, s6k and eif4e and phosphorylation levels of TOR, S6 and 4E-BP. In conclusion, the TOR signaling pathway of abalone can be regulated by arginine, and SLC38A9 plays an essential role in this regulation.

Pharmacologic approaches to amino acid depletion for cancer therapy

Cancer cells undergo metabolic reprogramming to support increased demands in bioenergetics and biosynthesis and to maintain reactive oxygen species at optimum levels. As metabolic alterations are broadly observed across many cancer types, metabolic reprogramming is considered a hallmark of cancer. A metabolic alteration commonly seen in cancer cells is an increased demand for certain amino acids. Amino acids are involved in a wide range of cellular functions, including proliferation, redox balance, bioenergetic and biosynthesis support, and homeostatic functions. Thus, targeting amino acid dependency in cancer is an attractive strategy for a number of cancers. In particular, pharmacologically mediated amino acid depletion has been evaluated as a cancer treatment option for several cancers. Amino acids that have been investigated for the feasibility of drug-induced depletion in preclinical and clinical studies for cancer treatment include arginine, asparagine, cysteine, glutamine, lysine, and methionine. In this review, we will summarize the status of current research on pharmacologically mediated amino acid depletion as a strategy for cancer treatment and potential chemotherapeutic combinations that synergize with amino acid depletion to further inhibit tumor growth and progression.

The 10,000-Year Success Story of Wheat!

Wheat is one of the most important cereal crops in the world as it is used in the production of a diverse range of traditional and modern processed foods. The ancient varieties einkorn, emmer, and spelt not only played an important role as a source of food but became the ancestors of the modern varieties currently grown worldwide. Hexaploid wheat (Triticum aestivum L.) and tetraploid wheat (Triticum durum Desf.) now account for around 95% and 5% of the world production, respectively. The success of this cereal is inextricably associated with the capacity of its grain proteins, the gluten, to form a viscoelastic dough that allows the transformation of wheat flour into a wide variety of staple forms of food in the human diet. This review aims to give a holistic view of the temporal and proteogenomic evolution of wheat from its domestication to the massively produced high-yield crop of our day.

Free threonine in human breast milk is related to infant intestinal microbiota composition

BACKGROUND

Accumulating evidence indicates that free amino acids (FAA) might be bioactive compounds with potential immunomodulatory capabilities. However, the FAA composition in human milk is still poorly characterized with respect to its correlation to maternal serum levels and its physiological significance for the infant. Studies addressing the relation of human milk FAA to the infants' intestinal microbiota are still missing.

METHODS

As part of a pilot study, maternal serum and breast milk FAA concentrations as well as infant intestinal microbiota (16S rRNA) were determined 2 months after birth. The study cohort consisted of 41 healthy mothers and their term delivered, healthy infants with normal birthweight. The relationship between maternal serum and milk FAA was determined by correlation analyses. Associations between (highly correlated) milk FAA and infant intestinal beta diversity were tested using PERMANOVA, LefSe and multivariate regression models adjusted for common confounders.

RESULTS

Seven breast milk FAA correlated significantly with serum concentrations. One of these, threonine showed a negative association with abundance of members of the class Gammaproteobacteria (R²adj = 17.1%, p = 0.006; β= - 0.441). In addition, on the level of families and genera, threonine explained 23.2% of variation of the relative abundance of Enterobacteriaceae (R²adj; p = 0.001; β = - 0.504) and 11.1% of variability in the abundance of Escherichia/Shigella (R²adj, p = 0.025; β  = - 0.368), when adjusted for confounders.

CONCLUSION

Our study is the first to suggest potential interactions between breast milk FAA and infant gut microbiota composition during early lactation. The results might be indicative of a potential protective role of threonine against members of the Enterobacteriaceae family in breast-fed infants. Still, results are based on correlation analyses and larger cohorts are needed to support the findings and elucidate possible underlying mechanisms to assess the complex interplay between breast milk FAA and infant intestinal microbiota in detail.

Effects of dietary inclusion of yerba mate (Ilex paraguariensis) extract on lamb muscle metabolomics and physicochemical properties in meat

This study aimed to evaluate the effect of dietary yerba mate (Ilex paraguariensis) extract (YME) on muscle metabolomics and physicochemical properties of lamb meat. Thirty-six uncastrated male lambs (90 d old) were fed experimental diets, which treatments consisted of 0%, 1%, 2%, and 4% inclusion of YME. Animals were fed for 50 d before slaughter. Muscle and meat samples were collected for metabolomics and meat quality analysis, respectively. The experiment was carried out in a randomized block design and analyzed using orthogonal contrasts. There was a quadratic effect of YME inclusion in tenderness (P < 0.05) and a positive linear effect on meat lightness (P < 0.05). No qualitative changes (P > 0.05) on individual metabolites were observed; however, changes in the quantitative metabolic profile were observed, showing that animals fed 1% and 2% of YME have a greater concentration of desirable endogenous muscle antioxidants, with direct impact on metabolic pathways related to beta-alanine metabolism and glutathione metabolism. Therefore, YME dietary supplementation up to 2% of the diet to lambs had little to no effects on the majority of meat quality traits evaluated; moreover, 4% of YME inclusion negatively affected feed intake and meat quality traits.

Animal source foods, rich in essential amino acids, are important for linear growth and development of young children in low- and middle-income countries

Growth faltering under 5 years of age is unacceptably high worldwide, and even more children, while not stunted, fail to reach their growth potential. The time between conception and 2 years of age is critical for development. The period from 6 to 23 months, when complementary foods are introduced, coincides with a time when growth faltering and delayed neurocognitive developments are most common. Fortunately, this is also the period when diet exercises its greatest influence. Growing up in an adverse environment, with a deficient diet, as typically seen in low‐ and middle‐income countries (LMICs), hampers growth and development of children and prevents them from realising their full developmental and economic future potential. Sufficient nutrient availability and utilisation are paramount to a child's growth and development trajectory, especially in the period after breastfeeding. This review highlights the importance of essential amino acids (EAAs) in early life for linear growth and, likely, neurocognitive development. The paper further discusses signalling through mammalian target of rapamycin complex 1 (mTORC1) as one of the main amino acid (AA)‐sensing hubs and the master regulator of both growth and neurocognitive development. Children in LMICs, despite consuming sufficient total protein, do not meet their EAA requirements due to poor diet diversity and low‐quality dietary protein. AA deficiencies in early life can cause reductions in linear growth and cognition. Ensuring AA adequacy in diets, particularly through inclusion of nutrient‐dense animal source foods from 6 to 23 months, is strongly encouraged in LMICs in order to compensate for less than optimal growth during complementary feeding.

Nutraceutical Study on Maianthemum atropurpureum, a Wild Medicinal Food Plant in Northwest Yunnan, China

Maianthemum atropurpureum (Franch) LaFrankie (Asparagaceae), called nibai in Tibetan or dongka in Drung or zhu-ye-cai in local Chinese, is a wild vegetable consumed by the Tibetan people and other ethnic groups in Northwest Yunnan, China. It is also a traditional medicinal plant used by different linguistic groups for antimicrobial purposes. However the nutritional and phytochemical compositions of this important medicinal food plant have not been well studied previously. In this study, the nutrient content for nibai was determined by the China National Standards (GB) methods, and the phytochemical analysis involved multiple chromatographic and spectral methods including LC-TOF-MS analysis. Dried nibai is a rich source of protein (ca. 24.6%), with 18 of the 21 common amino acids. The amino acid content of nibai can reach up to 17.9/100 g, with the essential amino acids as major contributors, corresponding to 42.3% of the total amino acids. Nibai contains rich mineral elements, dietary fiber, vitamins, β-carotene, carbohydrates, and lipids. The phytochemical content of nibai was examined by conventional isolation strategies, as well as HR-ESI-TOF-MS to detect and identify 16 compounds including nine steroid saponins and seven flavonoids. Among these compounds, uridine, adenosine, guanosine, and β-methyl-6-methyl-d-glucopyranoside were found from the genus Maianthemum for the first time. These results help to demonstrate that the local people's practice of consuming Maianthemum atropurpureum is reasonable due to its high levels of vitamins, minerals, essential amino-acids, and phytochemicals. Nibai may be further developed in Tibet and surrounding regions, and beyond as a health food, nutraceutical, and/or dietary supplement product.

Effects of feeding rumen-protected methionine pre- and postpartum on reproductive outcomes of multiparous Holstein cows

Our primary objective was to evaluate the effect of feeding rumen-protected Met (RPM) in the pre- and postpartum total mixed ration (TMR) on pregnancy per artificial insemination (AI) and pregnancy loss in multiparous Holstein cows. We also evaluated multiple secondary reproductive physiological outcomes before and after AI, including uterine health, ovarian cyclicity, response to synchronization of ovulation, and markers of embryo development and size. A total of 470 multiparous Holstein cows [235 at the University of Wisconsin (UW) and 235 at Cornell University (CU)] were used for this experiment. Experimental treatment diets were applied at the pen level (2 and 4 close-up pens at CU and UW, respectively, and 12 and 6 postfresh pens at CU and UW, respectively); thus, pen was the experimental unit, and cow was the observational unit. Cows were enrolled and randomly assigned to be fed the experimental treatment diets at approximately 4 wk before parturition until 67 d of gestation [147 d in milk (DIM)] after their first service. Close-up dry cow and replicated lactation pens were randomly assigned to treatment diets: RPM, prepartum = 2.83% (UW) and 2.85% (CU), postpartum = 2.58% (UW) and 2.65% (CU); and control (CON), prepartum = 2.30% (UW) and 2.22% (CU), postpartum = 2.09% (UW) and 2.19% (CU; Met as percentage of metabolizable protein). Vaginal discharge and uterine cytology (percentage of polymorphonuclear leucocytes) were evaluated at 35 ± 3 DIM. Cows received timed AI (TAI) at 80 ± 3 DIM after synchronization of ovulation with the Double-Ovsynch protocol. Ovarian cyclicity status, response to synchronization of ovulation, and luteal function were determined by measuring circulating concentrations of progesterone at 35 and 49 ± 3 DIM, 48 and 24 h before TAI, and 8, 18, 22, 25, and 29 d after TAI. Interferon-stimulated gene expression in white blood cells were compared on 18 d after TAI (CU only) and pregnancy-specific protein B concentrations at 22, 25, 29, 32, and 67 d after TAI. Pregnancy status was determined using pregnancy-specific protein B at 25 and 29 d after TAI, and by transrectal ultrasonography at 32, 39, and 67 d after TAI. Embryo and amniotic vesicle size were determined at 32 and 39 d after TAI. Pregnancy per AI (25 d: 64.7 vs. 64.0%, 32 d: 54.3 vs. 55.1% for CON and RPM, respectively) and pregnancy loss (25 to 67 d: 22.6 vs. 19.2% for CON and RPM, respectively) for synchronized cows did not differ. The proportion of cows with purulent vaginal discharge (CON = 7.7 vs. RPM = 4.6%) and cytological endometritis (CON = 20.8 vs. RPM = 23.6%) did not differ. Cyclicity status, ovarian responses to the synchronization protocol, and synchronization rate also did not differ. In addition, fold change for interferon-stimulated genes, concentrations of pregnancy-specific protein B, and embryo size were not affected by treatments. In conclusion, feeding RPM in the pre- and postpartum TMR at the amounts used in this experiment did not affect uterine health, cyclicity, embryo development, or reproductive efficiency in dairy cows.

Impact of gestational electronic cigarette vaping on amino acid signature profile in the pregnant mother and the fetus

Background

Electronic cigarettes (e-cigs) are a form of tobacco product that has become increasingly popular over the past decade. Despite the known health consequences of tobacco product exposure during pregnancy, a substantial number of daily smokers will continue to smoke during pregnancy. Our current knowledge on the effects of e-cig aerosol exposure during pregnancy is limited to a small number of animal studies, which have identified several e-cig aerosol-induced disruptions to the physiology of normal development.

Methods

To further assess the impact of prenatal e-cig aerosol exposure on maternal and fetal health, we examined the amino acid signature profiles in maternal and fetal plasma, as well as in the fetal lungs, a sensitive target organ for prenatal tobacco product exposure. Pregnant Sprague Dawley rats were randomly assigned to one of three groups and were exposed to either e-cig aerosols containing nicotine, e-cig aerosols without nicotine, or room air. Dams were exposed utilizing a state-of-the-art custom engineered e-cig vaping system that is compatible with commercially available e-cig atomizers and enables a translational inhalation delivery method comparable to human vaping.

Results

We determined that gestational exposure to e-cig aerosols results in significant alterations to the amino acid profile in the maternal and fetal compartments, including the fetal lungs. The data shows a targeted disruption to the nitric oxide pathway, branched-chain amino acid metabolism, fetal protein synthesis, and urea cycle.

Conclusion

The data presented herein provides additional support that gestational e-cig aerosol exposure can impact crucial biological processes and exemplifies the need for extensive research on exposure to e-cig aerosols.

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First report of e-cig induced alterations to maternal/fetal amino acid profile.

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Translational vaping paradigm utilizing custom engineered vaping system.

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Analysis of amino acids show gestational e-cig exposure has significant effects.

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Fetal lungs may be a sensitive target to gestational e-cig aerosol exposure.

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Marker of dysregulation in branched-chain amino acid metabolism and urea cycle.

Identification of amino acid response element of SLC38A9 as an ATF4-binding site in porcine skeletal muscle cells

Amino acids can affect protein synthesis by activating mammalian target of rapamycin complex 1 (mTORC1) signaling pathway. Amino acid transporters SLC38A9 on the lysosomal membrane not only transport amino acids, but also can sense amino acids and activate mTORC1 signaling pathway. Activating transcription factor 4 (ATF4) can promote the expression of amino acid transporters by binding with amino acid response element (AARE). In this study, two AAREs were found in the SLC38A9 promoter region of pig, and both of them bound to ATF4. The AARE in the first intron was located in the core promoter region of SLC38A9. ATF4 regulated mRNA expression level of SLC38A9 in porcine skeletal muscle cells. In the absence of amino acids, the expression of ATF4 decreased and the expression of SLC38A9 increased. After leucine addition, the expression levels of ATF4 and SLC38A9 increased. It suggested that in the absence of amino acids, the expression of SLC38A9 was increased via binding of ATF4 to AARE binding factors in SLC38A9 promoter fragment; after the addition of leucine, ATF4 was activated, resulting in the increase of SLC38A9 expression.

Potential Metabolic Biomarkers in Adult Asthmatics

Asthma is the most common chronic airway inflammation, with multiple phenotypes caused by complicated interactions of genetic, epigenetic, and environmental factors. To date, various determinants have been suggested for asthma pathogenesis by a new technology termed omics, including genomics, transcriptomics, proteomics, and metabolomics. In particular, the systematic analysis of all metabolites in a biological system, such as carbohydrates, amino acids, and lipids, has helped identify a novel pathway related to complex diseases. These metabolites are involved in the regulation of hypermethylation, response to hypoxia, and immune reactions in the pathogenesis of asthma. Among them, lipid metabolism has been suggested to be related to lung dysfunction in mild-to-moderate asthma. Sphingolipid metabolites are an important mediator contributing to airway inflammation in obese asthma and aspirin-exacerbated respiratory disease. Although how these molecular variants impact the disease has not been completely determined, identification of new causative factors may possibly lead to more-personalized and precise pathway-specific approaches for better diagnosis and treatment of asthma. In this review, perspectives of metabolites related to asthma and clinical implications have been highlighted according to various phenotypes.

Nanotechnology and Reproductive Management of Farm Animals: Challenges and Advances

Reproductive efficiency of farm animals has central consequences on productivity and profitability of livestock farming systems. Optimal reproductive management is based on applying different strategies, including biological, hormonal, nutritional strategies, as well as reproductive disease control. These strategies should not only guarantee sufficient reproductive outcomes but should also comply with practical and ethical aspects. For example, the efficiency of the biological- and hormonal-based reproductive strategies is mainly related to several biological factors and physiological status of animals, and of nutritional strategies, additional factors, such as digestion and absorption, can contribute. In addition, the management of reproductive-related diseases is challenged by the concerns regarding the intensive use of antibiotics and the development of antimicrobial resistant strains. The emergence of nanotechnology applications in livestock farming systems may present innovative and new solutions for overcoming reproductive management challenges. Many drugs (hormones and antibiotics), biological molecules, and nutrients can acquire novel physicochemical properties using nanotechnology; the main ones are improved bioavailability, higher cellular uptake, controlled sustained release, and lower toxicity compared with ordinary forms. In this review, we illustrate advances in the most common reproductive management strategies by applying nanotechnology, considering the current challenges of each strategy.

The nutritional profile of indonesian salmon van Java mahseer T. soro species

T. soro, in Indonesia called salmon van Java is of high economic value, and due to high demand, its culture has been intensively studied and developed. This study aimed to assess the nutritional value of wild and cultured T. soro. The fish’s proximate compositions, minerals, as well as amino and fatty acid profiles were analyzed. A t-test analysis was used to identify differences between treatments. Results showed that the fat content of wild T. soro was higher than that of cultured fish, but the protein, water, and ash contents between the two groups were not significantly different (p >0.05). T. soro was considered a lean fish with higher concentrations of PUFAs (polyunsaturated fatty acids) than MUFAs (monounsaturated fatty acids). The amino acid profile was dominated by lysine, phenylalanine, and allo-isoleucine. Both groups of fish were a good source of macro- (Na, K, Ca) and microminerals (Zn, Fe), except for selenium (Se). The two groups were not significantly different (p >0.05) in ω3, ω6, and PUFAs, indicating that culturing T. soro in proper ways could substitute for wild T. soro.

Characterization, stability, and in vivo effects in Caenorhabditis elegans of microencapsulated protein hydrolysates from stripped weakfish (Cynoscion guatucupa) industrial byproducts

This study aimed to microencapsulate protein hydrolysates from stripped weakfish (Cynoscion guatucupa) industrial byproducts produced by Alcalase (HA) and Protamex (HP) by spray drying, using maltodextrin as wall material. The physicochemical characteristics, and in vitro antioxidant and Angiotensin-I converting enzyme-inhibitory activities were evaluated during storage. Both microencapsulated hydrolysates showed spherical shape (~3.6 µm particle diameter), low water activity (<0.155) during storage and reduced hygroscopicity (~30%) compared to the free hydrolysate. Infrared spectroscopy evidenced the maltodextrin-hydrolysate interaction. Based on the in vitro results, nematoid C. elegans in L1 larval stage were treated with free and microencapsulated HP, which demonstrated a protective effect on nematoid exposed to oxidative stress (survival ~ 13% control, 77% free HP, and 85% microencapsulated HP) and improved their growth and reproduction rate. Thus, microencapsulation appears to be a good alternative to maintain hydrolysates stability during storage, showing bioactivity in C. elegans.

Combined Effects of Calcium Addition and Thermal Processing on the Texture and In Vitro Digestibility of Starch and Protein of Black Beans (Phaseolus vulgaris)

Legumes are typically soaked overnight to reduce antinutrients and then cooked prior to consumption. However, thermal processing can cause over-softening of legumes. This study aimed to determine the effect of calcium addition (0, 100, 300, and 500 ppm in the form of calcium chloride, CaCl₂), starting from the overnight soaking step, in reducing the loss of firmness of black beans during thermal processing for up to 2 h. The impact of calcium addition on the in vitro starch and protein digestibility of cooked beans was also assessed. Two strategies of calcium addition were employed in this study: (Strategy 1/S1) beans were soaked and then cooked in the same CaCl₂ solution, or (Strategy 2/S2) cooked in a freshly prepared CaCl₂ solution after the calcium-containing soaking medium was discarded. Despite the texture degradation of black beans brought about by increasing the cooking time, texture profile analysis (TPA) revealed that their hardness, cohesiveness, springiness, chewiness, and resilience improved significantly (p < 0.05) with increasing calcium concentration. Interestingly, beans cooked for 2 h with 300 ppm CaCl₂ shared similar hardness with beans cooked for 1 h without calcium addition. Starch and protein digestibility of calcium-treated beans generally improved with prolonged cooking. However, calcium-treated beans cooked for 1 h under S2 achieved a reduced texture loss and a lower starch digestibility than those beans treated in S1. A lower starch digestion could be desired as this reflects a slow rise in blood glucose levels. Findings from this result also showed that treating black beans with high level of CaCl₂ (i.e., 500 ppm) was not necessary, otherwise this would limit protein digestibility of cooked black beans.

Free and Total Amino Acids in Human Milk in Relation to Maternal and Infant Characteristics and Infant Health Outcomes: The Ulm SPATZ Health Study

Free amino acids (FAAs) are important regulators of key pathways necessary for growth, development, and immunity. Data on FAAs in human milk (HM) and their roles in infant development are limited. We investigated the levels of FAAs and total amino acids (TAA, i.e., the sum of conjugated amino acids and FAAs) in HM in relation to infant and maternal characteristics and immunological conditions. FAA and TAA levels in HM sampled at 6 weeks (n = 671) and 6 months (n = 441) of lactation were determined using high-performance liquid chromatography. Child growth was ascertained at 4–5 weeks and at 6–7 months of age. Child allergy and lower respiratory tract infections were assessed in the first years of life. Associations of amino acid (AA) levels in HM with child growth and health outcomes were determined by Spearman correlation and modified Poisson regression, respectively. Free glutamine, glutamate, and serine in 6-week HM positively correlated with infant weight gain in the first 4–5 weeks of age. Maternal pre-pregnancy weight and body mass index (BMI) were negatively correlated with free glutamine and asparagine in 6-week and 6-month HM and positively correlated with the sum of TAAs in 6-month HM, but significance was lost following confounder adjustment. Free glutamine was lower in 6-month HM of mothers with an allergy (either active or non-active). No consistent associations were found between FAAs in HM and child health outcomes. However, potential negative associations were observed between specific FAAs and the risk of food allergy. These results suggest that specific FAAs play a role in infant growth. Moreover, these findings warrant further investigations into the relation of FAAs in HM with infant health outcomes and maternal allergy.

A longer adaptation period to a functional amino acid-supplemented diet improves growth performance and immune status of Salmonella Typhimurium-challenged pigs

We recently showed that dietary supplementation with key functional amino acids (FAA) improves growth performance and immune status of Salmonella Typhimurium (ST)-challenged pigs. It is not known if ST-challenged pigs will benefit from a longer adaptation period to FAA. The objective of this study was to evaluate the effects of different adaptation periods to diets containing FAA above requirements for growth on performance and immune response of weaned pigs subsequently challenged with ST. A total of 32 mixed-sex weanling pigs (11.6 ± 0.3 kg) were randomly assigned to 1 of 4 dietary treatments, being a basal amino acid (AA) profile fed throughout the experimental period (FAA-) or a functional AA profile (FAA+; Thr, Met, and Trp at 120% of requirements) fed only in the postinoculation (FAA+0), for 1 wk pre- and postinoculation (FAA+1), or throughout the experimental period (FAA+2). After a 14-d adaptation period, pigs were inoculated with ST (2.15 × 109 CFU/mL). Growth performance, body temperature, fecal score, acute-phase proteins, oxidant/antioxidant balance, score for ST shedding in feces and intestinal colonization, and fecal and digesta myeloperoxidase (MPO) were measured pre- and postinoculation. Postinoculation body temperature and fecal score, serum haptoglobin, plasma superoxide dismutase (SOD), malondialdehyde (MDA), and fecal MPO were increased while serum albumin and plasma reduced glutathione (GSH):oxidized glutathione (GSSG) were reduced compared to pre-inoculation (P < 0.05). Average daily gain and G:F were greater in FAA+2 pigs compared to FAA- pigs (P < 0.05). Serum albumin was higher in FAA+2 and FAA+1 compared to FAA+0 and FAA- pigs (P < 0.05) while FAA+2 pigs had lower haptoglobin compared to FAA- (P < 0.05). Plasma SOD was increased and GSH:GSSG was decreased in FAA- pigs compared to the other treatments (P < 0.05). Score for ST shedding in feces was progressively lower from d 1 to 6 regardless of treatment (P < 0.05) and was lower in FAA+2 pigs compared to FAA- and FAA+0 (P < 0.05). Counts of ST in colon digesta were higher in FAA- and FAA+0 pigs compared to FAA+2 (P < 0.05). Fecal and colonic digesta MPO were lower in FAA+2 and FAA+1 pigs compared to FAA- (P < 0.05). These results demonstrate a positive effect of a longer adaptation period to FAA-supplemented diets on performance and immune status of weaned pigs challenged with Salmonella.

Microalgae as sustainable food and feed sources for animals and humans - Biotechnological and environmental aspects

Offering a potential solution for global food security and mitigating environmental issues caused by the expansion of land-based food production, the carbon-hunger and nutrient-rich microalgae emerged as a sustainable food source for both humans and animals. Other than as an alternative source for protein, microalgae offer its most valuable nutrients, omega-3 and 6 long-chain polyunsaturated fatty acids where the content can compete with that of marine fish with lower chemicals contamination and higher purity. Furthermore, the colorful pigments of microalgae can act as antioxidants together with many other health-improving properties as well as a natural colorant. In addition, the supplementation of algae as animal feed provides plentiful benefits, such as improved growth and body weight, reduced feed intake, enhanced immune response and durability towards illness, antibacterial and antiviral action as well as enrichment of livestock products with bioactive compounds. The significant breakthrough in algal biotechnology has made algae a powerful "cell factory" for food production and lead to the rapid growth of the algal bioeconomy in the food and feed industry. The first overview of this review was to present the general of microalgae and its potential capability. Subsequently, the nutritional compositions of microalgae were discussed together with its applications in human foods and animal feeds, followed by the exploration of their economic feasibility and sustainability as well as market trends. Lastly, both challenges and future perspectives were also discussed.

Measures Matter-Determining the True Nutri-Physiological Value of Feed Ingredients for Swine

Many types of feed ingredients are used to provide energy and nutrients to meet the nutritional requirements of swine. However, the analytical methods and measures used to determine the true nutritional and physiological ("nutri-physiological") value of feed ingredients affect the accuracy of predicting and achieving desired animal responses. Some chemical characteristics of feed ingredients are detrimental to pig health and performance, while functional components in other ingredients provide beneficial health effects beyond their nutritional value when included in complete swine diets. Traditional analytical procedures and measures are useful for determining energy and nutrient digestibility of feed ingredients, but do not adequately assess their true physiological or biological value. Prediction equations, along with ex vivo and in vitro methods, provide some benefits for assessing the nutri-physiological value of feed ingredients compared with in vivo determinations, but they also have some limitations. Determining the digestion kinetics of the different chemical components of feed ingredients, understanding how circadian rhythms affect feeding behavior and the gastrointestinal microbiome of pigs, and accounting for the functional properties of many feed ingredients in diet formulation are the emerging innovations that will facilitate improvements in precision swine nutrition and environmental sustainability in global pork-production systems.

Seafood Intake as a Method of Non-Communicable Diseases (NCD) Prevention in Adults

Seafood (fish in particular) is one of the main food groups in nutrition models with proven health benefits. Seafood has long been considered a very valuable dietary component, mainly due to presence of n-3 polyunsaturated fatty acids (n-3 PUFA) but it is also an important source of protein (including collagen), anserine, taurine, iodine, selenium, vitamin A, vitamin K, vitamin D, tocopherols, B vitamins and astaxanthin. Considering the beneficial effects of these ingredients on blood pressure, lipid profile and the inflammatory process, seafood should be an essential component of the diet. Non-communicable diseases (NCD) such as cardiovascular diseases, cancer, diabetes and mental disorder, chronic respiratory diseases are common diseases associated with advanced age. Promotion of a healthy lifestyle (including proper nutritional behavior) and prevention of diseases are the most effective and efficient ways to decrease premature mortality from NCD and to maintain mental health and well-being. This review article shows the potential preventive and therapeutic effects of seafood with an emphasis on fish. Our narrative review presents the results of systematic reviews and meta-analysis.

Impact of Cooking Preparation on In Vitro Digestion of Eggs Simulating Some Gastrointestinal Alterations in Elders

This study aimed to in vitro assess the impact of the cooking process of eggs (hard-boiled, poached, and omelet) on nutrients digestibility and vitamins A and D3 bioaccessibility under elderly gastrointestinal (GI) conditions. Three elderly digestion models were mimicked: oral (E1); oral and gastric (E2); and oral, gastric, and intestinal (E3), and a healthy adult model (C). Proteolysis extent reduced after digestion of omelet under the E3 model (p < 0.05) (up to 37% of reduction). Thus, hard-boiled and poached were more recommendable to enhance protein digestibility in elders. Altered GI conditions negatively influence neither the absorbable lipid fraction nor the cholesterol stability. Finally, vitamin A bioaccessibility was not affected but D3 slightly decreased with the elderly (E3). Hence, the digestion of nutrients was dependent on the resulting matrix, poached being the greater supplier of protein and lipid end-digestion products. Poached and omelet, however, offer a high net supply of bioaccessible vitamin D3 for elders.

Effects of feeding rumen-protected methionine pre- and postpartum in multiparous Holstein cows: Lactation performance and plasma amino acid concentrations

Objectives were to evaluate the effect of feeding rumen-protected methionine (RPM) in pre- and postpartum total mix ration (TMR) on lactation performance and plasma AA concentrations in dairy cows. A total of 470 multiparous Holstein cows [235 cows at University of Wisconsin (UW) and 235 cows at Cornell University (CU)] were enrolled approximately 4 wk before parturition, housed in close-up dry cow and replicated lactation pens. Pens were randomly assigned to treatment diets (pre- and postpartum, respectively): UW control (CON) diet = 2.30 and 2.09% of Met as percentage of metabolizable protein (MP) and RPM diet = 2.83 and 2.58% of Met as MP; CU CON = 2.22 and 2.19% of Met as percentage of MP, and CU RPM = 2.85 and 2.65% of Met as percentage of MP. Treatments were evaluated until 112 ± 3 d in milk (DIM). Milk yield was recorded daily. Milk samples were collected at wk 1 and 2 of lactation, and then every other week, and analyzed for milk composition. For lactation pens, dry matter intake (DMI) was recorded daily. Body weight and body condition score were determined from 4 ± 3 DIM and parturition until 39 ± 3 and 49 DIM, respectively. Plasma AA concentrations were evaluated within 3 h after feeding during the periparturient period [d -7 (±4), 0, 7 (±1), 14 (±1), and 21 (±1); n = 225]. In addition, plasma AA concentrations were evaluated (every 3 h for 24 h) after feeding in cows at 76 ± 8 DIM (n = 16) and within 3 h after feeding in cows at 80 ± 3 DIM (n = 72). The RPM treatment had no effect on DMI (27.9 vs. 28.0 kg/d) or milk yield (48.7 vs. 49.2 kg/d) for RPM and CON, respectively. Cows fed the RPM treatment had increased milk protein concentration (3.07 vs. 2.95%) and yield (1.48 vs. 1.43 kg/d), and milk fat concentration (3.87 vs. 3.77%), although milk fat yield did not differ. Plasma Met concentrations tended to be greater for cows fed RPM at 7 d before parturition (25.9 vs. 22.9 µM), did not differ at parturition (22.0 vs. 20.4 µM), and were increased on d 7 (31.0 vs. 21.2 µM) and remained greater with consistent concentrations until d 21 postpartum (d 14: 30.5 vs. 19.0 µM; d 21: 31.0 vs. 17.8 µM). However, feeding RPM decreased Leu, Val, Asn, and Ser (d 7, 14, and 21) and Tyr (d 14). At a later stage in lactation, plasma Met was increased for RPM cows (34.4 vs. 16.7 µM) consistently throughout the day, with no changes in other AA. Substantial variation was detected for plasma Met concentration (range: RPM = 8.9-63.3 µM; CON = 7.8-28.8 µM) among cows [coefficient of variation (CV) > 28%] and within cow during the day (CV: 10.5-27.1%). In conclusion, feeding RPM increased plasma Met concentration and improved lactation performance via increased milk protein production.

Low intake of essential amino acids and other risk factors of stunting among under-five children in Malang City, East Java, Indonesia

Background: The lack of energy-protein intake has been shown to increase the risk of stunting in under-five children. The quality of protein in food is assessed by the completeness of amino acid content. This study aims to determine the amount of essential amino acid (EAAs) intake and other risk factors of stunting among under-five children.

Design and methods: A descriptive, case-control study was performed in the work area of Kedungkandang Health Center Malang. The subjects were 24–59-month-old children with a total of 23 stunted (height-for-age Z-score (HAZ) <-2 SD) and 57 normal children (HAZ ≥-2 SD). Furthermore, the data were collected using anthropometric measurement, validated and pre-tested questionnaires, which were analyzed using multiple logistic regression.

Results: The intake of all the nine EAAs in stunted children was lower than that of non-stunted children. However, only histidine, isoleucine, and methionine were significantly different (p<0.05). The significant risk factors of stunting include a family income per month fewer than the Regional Minimum Wages [OR=12.06, 95% CI 1.83-79.53], being underweight [OR=7.11, 95% CI 1.49-33.93], breastfeeding of less than 6 months [OR=5.34, 95% CI 1.28-22.20], and the lack of EAA methionine intake [OR=0.14, 95% CI 0.03-0.67].

Conclusions: Stunted children may not receive sufficient dietary intake of EAAs in their diet. Furthermore, the lack of EAAs intake, especially methionine, alongside low family income, underweight, lack of breastfeeding and variety in food consumption were the risk factors of stunting among under-five children in a selected Health Center in Malang City, Indonesia.

Proximate Analyses and Amino Acid Composition of Selected Wild Indigenous Fruits of Southern Africa

A literature survey revealed that several wild indigenous Southern African fruits had previously not been evaluated for their proximate and amino acid composition, as well as the total energy value (caloric value). Fourteen species including Carissa macrocarpa, Carpobrotus edulis, Dovyalis caffra, Halleria lucida, Manilkara mochisia, Pappea capensis, Phoenix reclinata, and Syzygium guineense were analyzed in this study. The nutritional values for several species such as C. edulis, H. lucida, P. reclinata, and M. mochisia are being reported here for the first time. The following fruits had the highest proximate values: C. macrocarpa (ash at 20.42 mg/100 g), S. guineense (fat at 7.75 mg/100 g), P. reclinata (fiber at 29.89 mg/100 g), and H. lucida (protein at 6.98 mg/100 g and carbohydrates at 36.98 mg/100 g). Essential amino acids such as histidine, isoleucine, lysine, methionine, phenylalanine, tryptophan, and valine were reported in all studied indigenous fruits. The high protein content in H. lucida was exhibited by the highest amino acid quantities for histidine. However, the fruits are a poor source of proteins since the content is lower than the recommended daily intake. The jacket-plum (Pappea capensis), on the other hand, meets and exceeds the required daily intake of lysine (0.0003 g/100 g or 13 mg/kg) recommended by the World Health Organization.

Amino Acids in Swine Nutrition and Production

Amino acids are the building blocks of proteins in animals, including swine. With the development of new analytical methods and biochemical research, there is a growing interest in fundamental and applied studies to reexamine the roles and usage of amino acids (AAs) in swine production. In animal nutrition, AAs have been traditionally classified as nutritionally essential (EAAs) or nutritionally nonessential (NEAAs). AAs that are not synthesized de novo must be provided in diets. However, NEAAs synthesized by cells of animals are more abundant than EAAs in the body, but are not synthesized de novo in sufficient amounts for the maximal productivity or optimal health (including resistance to infectious diseases) of swine. This underscores the conceptual limitations of NEAAs in swine protein nutrition. Notably, the National Research Council (NRC 2012) has recognized both arginine and glutamine as conditionally essential AAs for pigs to improve their growth, development, reproduction, and lactation. Results of recent work have also provided compelling evidence for the nutritional essentiality of glutamate, glycine, and proline for young pigs. The inclusion of so-called NEAAs in diets can help balance AAs in diets, reduce the dietary levels of EAAs, and protect the small intestine from oxidative stress, while enhancing the growth performance, feed efficiency, and health of pigs. Thus, both EAAs and NEAAs are needed in diets to meet the requirements of pigs. This notion represents a new paradigm shift in our understanding of swine protein nutrition and is transforming pork production worldwide.

Alterations in serum amino acid profiles in children with attention deficit/hyperactivity disorder

The objective of the present study was to evaluate the circulating serum amino acid levels in children with attention deficit/hyperactivity disorder (ADHD). A total of 71 children with untreated ADHD and 31 neurotypical controls aged 7-14 years old were examined. Serum amino acid levels were evaluated using high-performance liquid chromatography (HPLC) with UV-detection. Laboratory quality control was performed with reference materials of human plasma amino acid levels. The obtained data demonstrated that children with ADHD were characterized by 29, 10 and 20% lower serum histidine (His), glutamine (Gln) and proline (Pro) levels compared with neurotypical children, respectively. In contrast, circulating aspartate (Asp), glutamate (Glu) and hydroxyproline (Hypro) levels exceeded the respective control values by 7, 7 and 42%. Correspondingly, the Gln-to-Glu and Pro-to-Hypro ratios were 28% and 49%, respectively, lower in ADHD cases compared with the controls. Total Gln/Glu levels were also significantly lower in ADHD patients. No significant group differences were observed between the groups in the other amino acids analyzed, including phenylalanine. Multiple linear regression analysis revealed significant associations between circulating serum Gln, lysine (Lys) (both negative) and Glu (positive) levels with total ADHD Rating Scale-IV scores. The observed alterations in Pro/Hypro and Gln/Glu levels and ratios are likely associated with the coexisting connective tissue pathology and alterations in glutamatergic neurotransmission in ADHD, respectively. Altered circulating levels of His, Lys and Asp may also be implicated in ADHD pathogenesis. However, further in vivo and in vitro studies are required in order to investigate the detailed mechanisms linking amino acid metabolism with ADHD pathogenesis.

High animal protein diet and gut microbiota in human health

The role of the intestinal flora in health and disease has become a research hotspot. Compared with carbohydrates and fats, proteins are metabolized primarily by microbial fermentation in the intestine. The production of protein fermentation products and metabolites depends on the composition, diversity, and metabolism of the gut microbiota. Several protein fermentation products, including indoles, phenols, polyamines, hydrogen sulfide (H₂S), amines, and carnitine, are toxic. This study analyzes the relationship between high-protein diets (HPDs), the intestinal microbiota, and human health and disease. Long-term HPDs increase the risk of intestinal diseases, type 2 diabetes (T2DM), obesity, central nervous system (CNS) diseases, and cardiovascular diseases (CVD) by producing toxic metabolites in the colon, including amines, H₂S, and ammonia. Short-term HPDs have little effect on the metabolism of healthy individuals under 65 years old. However, meeting the protein requirements of individuals over 65 years old using HPDs is more challenging. The adverse effects of HPDs on athletes are minimal. Natural compounds (plant extracts, whose main constituents are polysaccharides and polyphenols), prebiotics, probiotics, and regular physical exercise improve gut dysbiosis and reduce disease risk.

Electrochemical biosensor for glycine detection in biological fluids

We present herein the very first amperometric biosensor for the quantitative determination of glycine in diverse biological fluids. The biosensor is based on a novel quinoprotein that catalyzes the oxidation of glycine with high specificity. This process is coupled to the redox conversion of Prussian blue in the presence of hydrogen peroxide originating from the enzymatic reaction. The optimized tailoring of the biosensor design consists of the effective encapsulation of the quinoprotein in a chitosan matrix with the posterior addition of an outer Nafion layer, which is here demonstrated to suppress matrix interference. This is particularly important in the case of ascorbic acid, which is known to influence the redox behavior of the Prussian blue. The analytical performance of the biosensor demonstrates fast response time (<7 s), acceptable reversibility, reproducibility, and stability (<6% variation) as well as a wide linear range of response (25-500 μM) that covers healthy (and even most unhealthy) physiological levels of glycine in blood/serum, urine and sweat. A total of 6 real samples from healthy patients and animals were analyzed: two serum, two urine and two sweat samples. The results were validated via commercially available fluorescence kit, displaying discrepancy of less than 9% in all the samples. The unique analytical features and effortless preparation of the new glycine biosensor position it at the forefront of current technologies towards decentralized clinical applications and sport performance monitoring.

Gangba sheep in the Tibetan plateau: Validating their unique meat quality and grazing factor analysis

Gangba sheep are known for having typical sensory characteristics attributed to free range conditions and grazing on wild plants. The genuine Gangba mutton was selected as the experimental group, and the commercial Tibetan mutton was selected as the control group, the nutritive composition of basic chemical components, amino acids and fatty acids in mutton were investigated to correlate its unique meat quality and eating satisfaction. The results showed that fatty acids were significantly higher (P<0.05) in Gangba mutton than in commercial mutton, and the higher content of flavoring amino acids (glutamic acid and aspartame) were primarily responsible for the taste attributes umami of meat juices. Moreover, the trace elements analysis in mutton and grazing factors (forage, water source and soil) were conducted, to explain the source of essential trace elements in mutton. The concentrations of essential trace elements show that the Gangba mutton was a valuable source for highly available Cu and Zn in human nutrition, and well managed with few detected of toxicity metal. The concentrations of essential trace elements in mutton are closely related to the trace elements in environmental grazing factors. In conclusion, the congenital grazing conditions (a highly mineralized water resource, natural forages and clean soils) were shown to contribute to the unique meat characteristics of Gangba sheep.

Dietary Lysine Levels Improved Antioxidant Capacity and Immunity via the TOR and p38 MAPK Signaling Pathways in Grass Carp, Ctenopharyngodon idellus Fry

An 8-week rearing trial was designed to appraise the dietary lysine levels on intestinal antioxidant capacity and immunity of grass carp fry. Six practical diets were prepared with graded levels of lysine (1.44, 1.79, 1.97, 2.44, 2.56 and 2.87% dry matter), and these diets were fed to grass carp fry. The results showed that the activities of intestinal antioxidant factors including catalase and glutathione peroxidase were markedly improved by the 2.44% dietary lysine compared with the control diet (1.44% dietary lysine) (P < 0.05). In terms of antioxidants, compared with the control diet, the 2.44% diet markedly upregulated the mRNA expression levels of target of rapamycin, S6 kinase1 and nuclear factor erythroid 2-related factor 2 pathway-related antioxidant genes, containing catalase and glutathione peroxidase 1α (P < 0.05) and downregulated the mRNA levels of Kelch-like ECH-associated protein 1 (P > 0.05). The mRNA levels of 4E-binding protein 2 showed the opposite trend compared with those of target of rapamycin, and the minimum value was observed in the group of 1.97% dietary lysine (P < 0.05). In terms of immunity, compared with the 1.44% diet, the 2.44% diet markedly suppressed the intestinal p38 mitogen-activated protein kinase and interferon γ2 mRNA levels (P < 0.05). Moreover, nuclear factor-kappa B p65, tumor necrosis factor α, interleukin 6, interleukin 8, and interleukin 15 mRNA levels all exhibited the same trend as p38 mitogen-activated protein kinase and interferon γ2; however, the difference among all the lysine treatments groups was not significant (P > 0.05). The anti-inflammatory cytokines transforming growth factor β2 and interleukin 4/13B mRNA levels in the intestine were remarkably upregulated by high dietary lysine levels (2.56 and 2.87%) (P < 0.05), and when the dietary lysine level reached 2.44%, the interleukin 4/13A mRNA levels were strikingly increased (P < 0.05). Overall, the data suggested that 2.44% dietary lysine could strengthen the immune and antioxidant capacities of grass carp fry via activating the target of rapamycin (TOR) signaling pathway, and suppressing the p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway, which then improve the survival rate.

Dietary supplementation with N-carbamylglycinate (CGly) improved feed source proline absorption and reproductive performance in sows

Nutrient requirements are increased in the late-gestation period due to the faster growth of the foetal-placental unit and maternal erythrocyte mass. Glycine, proline and arginine are important amino acids that could improve foetal growth and development. The present study aims to investigate the effects of a derivative of glycine (N-carbamylglycinate, CGly) on the amino acid profiles and reproductive performances of late gestation sows. Thirty-two multiparous gestating sows (∼d 80) were selected, and randomly assigned into two groups: (1) control and (2) treatment (CGly, 800 mg kg-1) from day 85 of gestation to parturition. The serum amino acid profiles at day 110 of gestation and reproductive performance were investigated. The results showed that dietary supplementation of CGly in the late gestation period significantly improved the levels of glycine (p < 0.05) and proline (p < 0.01) in the serum of the perinatal sows, and thereafter improved the litter birth weights (p < 0.05) and number born alive (p < 0.1). Based on the in vitro studies, the improvement of proline levels is probably due to the induced expression of SLC6A20 and SLC38A2. Further studies should focus on the details of amino acid absorption, especially the competitive and cooperative absorption processes for different amino acids and derivatives.

Gestational diabetes mellitus-associated changes in the breast milk metabolome alters the neonatal growth trajectory

BACKGROUND

Gestational diabetes mellitus (GDM) is the most common metabolic disturbance during pregnancy and leads to an altered metabolic profile of human breast milk (HBM). The association between HBM metabolites and neonatal growth in GDM pregnancies has not been thoroughly investigated.

AIMS

The primary aim was to quantify differences in the HBM metabolome between normal and GDM pregnancies. The secondary aim was to identify metabolites associated with neonatal growth during the first year postpartum.

METHODS

In the present study, mothers intending to exclusively breastfeed (BF) and their newborns (mother-infant pairs) were recruited at delivery (n = 129 normal pregnancies and n = 98 GDM pregnancies). HBM samples (colostrum, transition milk, and mature milk) from mothers with normal pregnancies (n = 50) and GDM pregnancies (n = 50) were subjected to metabolomic profiling via liquid chromatography tandem mass spectrometry (LC-MS/MS). Receiver operating characteristic (ROC) analysis revealed the metabolomic fingerprints of GDM-associated mature HBM. Correlations between metabolites and neonatal body weight gain (BWG) were evaluated by Spearman correlation analysis.

RESULTS

In total, 620 metabolites were identified in each HBM sample; 253 compounds had the same variation patterns, whereas 38 compounds had significantly different pattern transitions between the GDM and normal groups. Moreover, 12, 49 and 28 metabolites exhibited significant differences in the 3 milk types between the 2 groups. Twenty-two metabolites were confirmed by ROC analysis as metabolomic fingerprints in the mature BM of GDM patients. Ten compounds were significantly negatively correlated with neonatal growth, and only 2 unsaturated lipids (eicosatrienoic acid (FA 20:3) and lysophosphatidylcholine (LysoPC) (22:6)) were positively correlated with neonatal BWG.

CONCLUSIONS

GDM is associated with alterations in the HBM metabolome. Only a small subset of compounds are associated with neonatal body weight (BW).

TRIAL REGISTRATION

ChiCTR-ROC-17011508. Prospectively registered on 26 May 2017 (http://www.chictr.org.cn/listbycreater.aspx).

Proximate Chemical Composition of Dried Shrimp and Tilapia Waste Bioflocs Produced by Two Drying Methods

The effects of two waste sources, red hybrid tilapia (Oreochromis sp.) and whiteleg shrimp (Litopenaeus vannamei), and two drying methods (freeze-drying and oven-drying) on the proximate chemical composition of bioflocs were investigated. In total, four kinds of experimentally treated bioflocs were compared to identify the best waste source and drying method to produce biofloc of an acceptable nutrient value: freeze-dried shrimp biofloc (FDSBF), oven-dried shrimp biofloc (ODSBF), freeze-dried tilapia biofloc (FDTBF), and oven-dried tilapia biofloc (ODTBF). The protein, lipid, ash, fiber, total nitrogen free extract (NFE), and energy contents of the dried bioflocs ranged from 12.12 to 24.09 g/100 g, 0.35 to 0.92 g/100 g, 42.45 to 61.01 g/100 g, 7.43 to 17.11 g/100 g, 16.45 to 18.59 g/100 g, and 0.99 to 1.94 Kcal g−1, respectively. Statistically, there were significant differences within the means of the two biofloc sources in terms of their proximate compositions (p < 0.05). The average values between the drying methods for protein, lipid, total NFE, and energy were also significantly different, while no significant differences (p > 0.05) were recorded for ash and fiber. Amino acids (AAs) were higher in FDTBF, followed by ODTBF. The mineral profiles showed that phosphorous, potassium, manganese, selenium, and copper were higher in the tilapia waste bioflocs, while calcium, zinc, iron, copper, chromium, and cobalt were higher in the shrimp waste bioflocs. Although the statistical analysis showed that the shrimp waste bioflocs had higher levels of lipid, fiber, total NFE, and minerals, the tilapia waste bioflocs contained higher levels of potential AAs, energy, and protein, which are regarded as expensive ingredients in aquaculture feeding. This study indicates that biofloc derived from tilapia waste can be regarded as a more suitable source of biofloc meal (in terms of protein, ash, energy, and AAs) than biofloc derived from shrimp waste. Our findings also suggest that freeze-drying is a more effective drying method for drying biofloc, as it efficiently maintains nutritional quality.

Determination of seventeen free amino acids in human urine and plasma samples using quadruple isotope dilution mass spectrometry combined with hydrophilic interaction liquid chromatography - Tandem mass spectrometry

Taking into account the growing demand for new analytical procedures that are appropriate for analysis of complex biological samples with increased sensitivity, accuracy and precision, a novel analytical method was described for the determination of underivatized amino acids in human plasma and urine samples. The presented analytical procedure involved the direct analysis of urine samples and the analysis of plasma samples followed by a simple protein precipitation protocol. Samples were analyzed using a simple and fast chromatographic method developed for the determination of 17 different amino acids by liquid chromatography - tandem mass spectrometry. The limit of detection and quantification values for amino acids were ranged between 0.03-2.26 µmol kg^-1 and 0.09-7.54 µmol kg^-1. Matrix effects of plasma and urine on the quantification of analytes were determined by spiking experiments. The accuracy of method was evaluated by matrix matching and quadruple isotope dilution strategies. Excellent accuracy and precision were obtained with the use isotope labeled amino acids demonstrating the high reliability and reproducibility of the proposed method. The percent recovery values were found to be between 98.70 - 101.68% with%RSD below than 1.62% for human plasma and 99.14 - 101.78% with%RSD below than 2.44% for urine samples.

Effects of monosodium glutamate on testicular structural and functional alterations induced by quinine therapy in rat: An experimental study

BACKGROUND

Quinine (QU) as an anti-malarial drug induces alterations in testicular tissue. Toxic effects of monosodium glutamate (MSG) on the male reproductive system have been recognized.

OBJECTIVE

To investigate the impact of MSG administration on the intensity of gonadotoxicity of QU.

MATERIALS AND METHODS

Sixty eight-wk old Wistar rats weighing 180-200 gr were divided into six groups (n = 10/each): the first group as a control; the second and third groups received low and high doses of MSG (2 & 4 gr/kg i.p.), respectively, for 28 days; the fourth group received QU for seven days (25 mg/kg); and in the fifth and sixth groups, QU was gavaged following the MSG administration (MSG + QU) from day 22 to day 28. Serum testosterone and malondialdehyde (MDA) levels were measured. Testes samples were prepared for tissue MDA levels, histomorphometry, and immunohistochemistry of p53. Sperm analysis was performed on cauda epididymis.

RESULTS

Serum and tissue MDA levels were increased in treated groups compared to the control group. This increment was higher in the MSG + QU groups. The testosterone levels were reduced significantly (p < 0.0001) in all treated groups. In addition, histomorphometric indices and tubular epithelium population were reduced significantly (p < 0.0001) in QU, MSG + QU, and consequently in high-dose MSG, QU, MSG + QU groups. All spermatogenic indices were reduced in the treated groups, particularly in the MSG + QU groups. Sperm motility and viability indices were reduced significantly (p = 0.003) in the MSG + QU groups. Finally, the overexpression of p53 was observed in the MSG + QU groups.

CONCLUSION

The administration of MSG before and during QU therapy may intensify testicular tissue alterations.

Dietary supplementation with aromatic amino acids decreased triglycerides and alleviated hepatic steatosis by stimulating bile acid synthesis in mice

Emerging evidence shows that amino acids can modulate lipid metabolism. Aromatic amino acids (AAAs) serve as important precursors of several neurotransmitters and metabolic regulators that play a vital role in regulating nutrient metabolism. But whether AAAs have a lipid-lowering function remains unknown. Here mice were fed amino acid-defined diets containing AAAs at 1.82% and 3.64% for 3 weeks. We demonstrated that double AAA intake significantly decreased the serum and hepatic triglycerides and serum low-density lipoprotein cholesterol, but increased the high-density lipoprotein cholesterol as well as insulin tolerance. Combined metabolomic and transcriptomic analysis showed that the hepatic acidic pathway of bile acid synthesis was responsible for the improvement in lipid metabolism by AAA treatment. This study suggests that AAAs have the potential to ameliorate steatosis and provides a new alternative to improve lipid metabolism.

Composition of Amino Acids in Foodstuffs for Humans and Animals

Amino acids (AAs) are the building blocks of proteins that have both structural and metabolic functions in humans and other animals. In mammals, birds, fish, and crustaceans, proteinogenic AAs are alanine, arginine, asparagine, aspartate, cysteine, glutamate, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine. All animals can synthesize de novo alanine, asparagine, aspartate, glutamate, glutamine, glycine, proline, and serine, whereas most mammals (including humans and pigs) can synthesize de novo arginine. Results of extensive research over the past three decades have shown that humans and other animals have dietary requirements for AAs that are synthesizable de novo in animal cells. Recent advances in analytical methods have allowed us to determine all proteinogenic AAs in foods consumed by humans, livestock, poultry, fish, and crustaceans. Both plant- and animal-sourced foods contain high amounts of glutamate, glutamine, aspartate, asparagine, and branched-chain AAs. Cysteine, glycine, lysine, methionine, proline, threonine, and tryptophan generally occur in low amounts in plant products but are enriched in animal products. In addition, taurine and creatine (essential for the integrity and function of tissues) are absent from plants but are abundant in meat and present in all animal-sourced foods. A combination of plant- and animal products is desirable for the healthy diets of humans and omnivorous animals. Furthermore, animal-sourced feedstuffs can be included in the diets of farm and companion animals to cost-effectively improve their growth performance, feed efficiency, and productivity, while helping to sustain the global animal agriculture (including aquaculture).

Nutrition and Functions of Amino Acids in Aquatic Crustaceans

Crustaceans (e.g., shrimp and crabs) are a good source of protein-rich foods for human consumption. They are the second largest aquaculture species worldwide. Understanding the digestion of dietary protein, as well as the absorption, metabolism and functions of amino acids (AAs) and small peptides is essential to produce cost-effective and sustainable aquafeeds. Hepatopancreas (the midgut gland) is the main site for the digestion of dietary protein as well as the absorption of small peptides and AAs into the hemolymph. Besides serving as the building blocks of protein, AAs (particularly aspartate, glutamate, glutamine and alanine) are the primary metabolic fuels for the gut and extra-hepatopancreas tissues (e.g., kidneys and skeletal muscle) of crustaceans. In addition, AAs are precursors for the syntheses of glucose, lipids, H₂S, and low-molecular-weight molecules (e.g., nitric oxide, glutathione, polyamines, histamine, and hormones) with enormous biological importance, such as physical barrier, immunological and antioxidant defenses. Therefore, both nutritionally essential and nonessential AAs are needed in diets to improve the growth, development, molt rate, survival, and reproduction of crustaceans. There are technical difficulties and challenges in the use of crystalline AAs for research and practical production due to the loss of free AAs during feed processing, the leaching of in-feed free AAs to the surrounding water environment, and asynchronous absorption with peptide-bounded AAs. At present, much knowledge about AA metabolism and functions in crustaceans is based on studies of mammals and fish species. Basic research in this area is necessary to lay a solid foundation for improving the balances and bioavailability of AAs in the diets for optimum growth, health and wellbeing of crustaceans, while preventing and treating their metabolic diseases. This review highlights recent advances in AA nutrition and metabolism in aquatic crustacean species at their different life stages. The new knowledge is expected to guide the development of the next generation of their improved diets.

Amino Acid Nutrition and Metabolism in Chickens

Both poultry meat and eggs provide high-quality animal protein [containing sufficient amounts and proper ratios of amino acids (AAs)] for human consumption and, therefore, play an important role in the growth, development, and health of all individuals. Because there are growing concerns about the suboptimal efficiencies of poultry production and its impact on environmental sustainability, much attention has been paid to the formulation of low-protein diets and precision nutrition through the addition of low-cost crystalline AAs or alternative sources of animal-protein feedstuffs. This necessitates a better understanding of AA nutrition and metabolism in chickens. Although historic nutrition research has focused on nutritionally essential amino acids (EAAs) that are not synthesized or are inadequately synthesized in the body, increasing evidence shows that the traditionally classified nutritionally nonessential amino acids (NEAAs), such as glutamine and glutamate, have physiological and regulatory roles other than protein synthesis in chicken growth and egg production. In addition, like other avian species, chickens do not synthesize adequately glycine or proline (the most abundant AAs in the body but present in plant-source feedstuffs at low content) relative to their nutritional and physiological needs. Therefore, these two AAs must be sufficient in poultry diets. Animal proteins (including ruminant meat & bone meal and hydrolyzed feather meal) are abundant sources of both glycine and proline in chicken nutrition. Clearly, chickens (including broilers and laying hens) have dietary requirements for all proteinogenic AAs to achieve their maximum productivity and maintain optimum health particularly under adverse conditions such as heat stress and disease. This is a paradigm shift in poultry nutrition from the 70-year-old "ideal protein" concept that concerned only about EAAs to the focus of functional AAs that include both EAAs and NEAAs.

Growth performance responses to increased tryptophan supplementation in growing barrows fed three different very low crude protein corn and soybean meal-based diets fortified with essential amino acids

Seventy-five individually fed barrows averaging 35 kg were used in a series of three experiments for 6-week growth assays (25 barrows each) to determine the effects of l-tryptophan (Trp) supplementation on growth performance and to establish the lower limits of dietary crude protein (CP) levels. Corn and soybean meal (SBM)-based diets containing 9% (Experiment 1), 10% (Experiment 2), and 11% CP (Experiment 3) fortified with deficient essential amino acids (AAs) except Trp were used as basal diets for each experiment. The experimental diets were supplemented with 0.00%, 0.02%, 0.04%, or 0.06% Trp. A 16% CP corn-SBM-based diet was set as a positive control in each experiment, and feed and water were provided ad libitum. Average daily gain and gain-to-feed ratio improved quadratically (P < 0.05) as supplemented Trp increased in the 9% and 10% CP group, although these positive effects were not observed in the 11% CP group. Because the maximum performance parameters in 9%, 10%, and 11% CP groups were not different from that of the 16% CP positive control group, the marginally reduced level of dietary CP without growth performance being affected appears to be around 9% at most. A potential reduction of nitrogen intake was clearly indicated.

Amino Acid Nutrition for Optimum Growth, Development, Reproduction, and Health of Zoo Animals

Proteins are large polymers of amino acids (AAs) linked via peptide bonds, and major components for the growth and development of tissues in zoo animals (including mammals, birds, and fish). The proteinogenic AAs are alanine, arginine, aspartate, asparagine, cysteine, glutamate, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine. Except for glycine, they are all present in the L-isoform. Some carnivores may also need taurine (a nonproteinogenic AA) in their diet. Adequate dietary intakes of AAs are necessary for the growth, development, reproduction, health and longevity of zoo animals. Extensive research has established dietary nutrient requirements for humans, domestic livestock and companion animals. However, this is not true for many exotic or endangered species found in zoos due to the obstacles that accompany working with these species. Information on diets and nutrient profiles of free-ranging animals is needed. Even with adequate dietary intake of crude protein, dietary AAs may still be unbalanced, which can lead to nutrition-related diseases and disorders commonly observed in captive zoo species, such as dilated cardiomyopathy, urolithiasis, gut dysbiosis, and hormonal imbalances. There are differences in AA metabolism among carnivores, herbivores and omnivores. It is imperative to consider these idiosyncrasies when formulating diets based on established nutritional requirements of domestic species. With optimal health, populations of zoo animals will have a vastly greater chance of thriving in captivity. For endangered species especially, maintaining stable captive populations is crucial for conservation. Thus, adequate provision of AAs in diets plays a crucial role in the management, sustainability and expansion of healthy zoo animals.

Role of Dietary Amino Acids and Nutrient Sensing System in Pregnancy Associated Disorders

Defective implantation is related to pregnancy-associated disorders such as spontaneous miscarriage, intrauterine fetal growth restriction and others. Several factors proclaimed to be involved such as physiological, nutritional, environmental and managemental that leads to cause oxidative stress. Overloading of free radicals promotes oxidative stress, and the internal body system could not combat its ability to encounter the damaging effects and subsequently leading to pregnancy-related disorders. During pregnancy, essential amino acids display important role for optimum fetal growth and other necessary functions for continuing fruitful pregnancy. In this context, dietary amino acids have received much attention regarding the nutritional concerns during pregnancy. Arginine, glutamine, tryptophan and taurine play a crucial role in fetal growth, development and survival while ornithine and proline are important players for the regulation of gene expression, protein synthesis and angiogenesis. Moreover, amino acids also stimulate the mammalian target of rapamycin (mTOR) signaling pathway which plays a central role in the synthesis of proteins in placenta, uterus and fetus. This review article explores the significances of dietary amino acids in pregnancy development, regulation of nutrient-sensing pathways such as mTOR, peroxisome proliferator-activated receptors (PPARs), insulin/insulin-like growth factor signaling pathway (IIS) and 5' adenosine monophosphate-activated protein kinase (AMPK) which exhibit important role in reproduction and its related problems. In addition, the antioxidant function of dietary amino acids against oxidative stress triggering pregnancy disorders and their possible outcomes will also be enlightened. Dietary supplementation of amino acids during pregnancy could help mitigate reproductive disorders and thereby improving fertility in animals as well as humans.

Lysine in Combination With Estradiol Promote Dissemination of Estrogen Receptor Positive Breast Cancer via Upregulation of U2AF1 and RPN2 Proteins

The majority of estrogen receptor positive (ER+) breast cancer (BC) maintain the ER at metastatic sites. Despite anti-estrogen therapy, almost 30% of ER+ BC patients relapse. Thus, new therapeutic targets for ER+ BC are needed. Amino acids (AAs) may affect the metastatic capacity by affecting inflammatory cells. Essential AAs (EAAs) cannot be produced by human cells and might therefore be targetable as therapeutics. Here we sampled extracellular EAAs in vivo by microdialysis in human BC. Mass spectrometry-based proteomics was used to identify proteins affected after EAA and estradiol (E2) exposure to BC cells. Proteins relevant for patient survival were identified, knocked down in BC cells, and metastatic capability was determined in vivo in the transgenic zebrafish model. We found that lysine was the most utilized EAA in human ER+BC in vivo. In zebrafish, lysine in presence of E2 increased neutrophil-dependent dissemination of ER+ BC cells via upregulation of U2AF1 and RPN2 proteins, which both correlated with poor prognosis of ER+ BC patients in clinical databases. Knockdown of U2AF1 and RPN2 decreased the expression of several cell-adhesion molecules resulting in diminished dissemination. Dietary lysine or its related metabolic pathways may be useful therapeutic targets in ER+ BC.