Search Results (94)

Childhood obesity is a major global health problem, and its management involves a multidisciplinary approach that includes lifestyle changes, dietary interventions, and the use of dietary supplements. In this review, we summarize current findings on the role of amino acids in pediatric obesity, with a particular focus on their involvement in metabolic pathways and weight regulation. The involvement of branched-chain and aromatic amino acids in the pathophysiology and potential management of pediatric obesity is highlighted in recent studies. Both experimental and clinical studies have shown that obese children often exhibit altered plasma amino acid profiles, including increased levels of leucine, isoleucine, valine, phenylalanine, and tyrosine, as well as decreased levels of glycine and serine. These imbalances are correlated with insulin resistance, inflammation, and early metabolic dysfunction. One of the mechanisms through which branched-chain amino acids can promote insulin resistance is the activation of the mammalian target of rapamycin (mTOR) signaling pathway. Metabolomic profiling has demonstrated the potential of specific amino acid patterns to predict obesity-related complications before they become clinically evident. Early identification of these biomarkers could be of great help for individualized interventions. Although clinical studies indicate that changes in dietary amino acids could lead to modest weight loss, improved metabolic profiles, and increased satiety, further studies are needed to establish standardized recommendations. Full article

This study aimed to investigate the effects of adding 360 mg/kg niacinamide (NAM) to diets on nutrient metabolism, providing insights into how dietary NAM supplementation enhances nitrogen utilization and growth performance in pigs. Forty growing–finishing pigs were randomly assigned to one of four experimental diets as follows: basal diet + 30 mg/kg NAM (CON), basal diet + 360 mg/kg NAM (CON + NAM), low-protein diet + 30 mg/kg NAM (LP), and low-protein diet + 360 mg/kg NAM (LP + NAM). Results showed that supplementation of both the CON and LP diets with 360 mg/kg NAM resulted in decreased urea nitrogen concentrations and carbamyl phosphate synthetase-I activity (p < 0.05). The pyruvate dehydrogenase activity in the serum and liver, as well as the activity of pyruvate dehydrogenase, citrate synthase, and glutamate dehydrogenase 1 in the ileum mucosa, was increased by supplementing the LP diet with 360 mg/kg NAM (p < 0.05). The LP diet with 360 mg/kg NAM increased the villi length to crypt depth, mRNA expression of glucose transporters 1 and 2 and alanine-serine-cysteine transporter 1, and mRNA expression of mechanistic target of the rapamycin 1 in the ileum (p < 0.05). Additionally, 360 mg/kg NAM supplementation in the LP diet reduced ileal Lactobacillus abundance (LDA > 4) and increased ileal microbial nucleotide and purine metabolism (p < 0.05). Our findings suggest that addition of 360 mg/kg NAM to the LP diet reduced urea production in the liver, enhanced glucose and amino acid absorption and transport in the ileum, and improved glucose metabolism. Full article

The objective of this study was to evaluate the effects of dietary supplementation with different levels of Rhodotorula mucilaginosa (0.0 g/kg, 0.1 g/kg, 1.0 g/kg, and 10.0 g/kg) on resistance to Aeromonas veronii infection in red claw crayfish (Cherax quadricarinatus) (initial body weight of 0.13 ± 0.06 g). The investigation combined a 56-day feeding trial with a subsequent 7-day infection challenge to assess cumulative mortality, immune and antioxidant enzyme activities, and the relative expression of immune-related genes. During the A. veronii infection test, the cumulative mortalities for the 0.1 g/kg, 1.0 g/kg, and 10.0 g/kg groups were 44.44%, 38.89%, and 38.89%, respectively, all significantly lower (p < 0.05) than that of the control group (58.33%). Compared with the control group, after infection with A. veronii, the activities of acid phosphatase, alkaline phosphatase, catalase, and superoxide dismutase in the hepatopancreas and alkaline phosphatase, lysozyme in the hemolymph of red claw crayfish in the 1.0 g/kg group significantly increased (p < 0.05). The activities of aspartate aminotransferase and alanine aminotransferase in the hemolymph of red claw crayfish in the 1.0 g/kg group significantly decreased (p < 0.05). The relative expression levels of serine protease inhibitor, crustacean hyperglycemic hormone, anti-lipopolysaccharide factor, and superoxide dismutase genes in the hepatopancreas of red claw crayfish in the 1.0 g/kg group were significantly upregulated (p < 0.05). In conclusion, R. mucilaginosa could significantly improve the antibacterial ability of red claw crayfish against A. veronii. In this experimental context, the ideal addition level of R. mucilaginosa is determined to be 1.0 g/kg. Full article

This study investigated the effects of adding fermented mixed feed (FMF, composed of several unconventional protein feeds, such as brown rice, rice bran, rice bran meal, sunflower meal, cottonseed meal, and corn starch residue) into the diet of Longyan Shan-ma ducks on their egg quality and intestinal health. The ducks were randomly divided into two groups: one group served as the control and received a standard diet, while the other group received a diet in which 4% of the feed was substituted with FMF. Compared to unfermented feed, FMF had elevated lactic acid levels and reduced phytic acid and crude fiber, along with higher amounts of crude protein and a range of amino acids, including serine, histidine, arginine, alanine, valine, methionine, cysteine, isoleucine, and lysine. FMF significantly enhanced egg production and improved the overall egg quality, such as eggshell strength and thickness. It also enhanced total antioxidant capacity and glutathione peroxidase concentrations in serum while reducing serum urea nitrogen and interleukin-1β levels. Histological analysis showed that FMF supplementation improved the ileal villus height-to-crypt depth ratio. Microbiota analysis demonstrated that FMF had a significant impact on β-diversity by increasing Firmicutes, Actinobacteriota, and Desulfobacterota and decreasing Proteobacteria and Myxococcota at the phylum level. The abundance of Corynebacterium, Lactobacillus, and Gallicola was found to be elevated due to FMF at the genus level, whereas Kocuria, Rothia, Helicobacter, and Escherichia-Shigella were decreased. Additionally, diets supplemented with FMF resulted in higher intestinal valeric acid levels among ducks. Our findings indicate that incorporating FMF into laying duck diets can enhance production performance, egg quality, and gut health. Full article

Background: Prenatal alcohol exposure (PAE) can reduce fetal growth and cause neurodevelopmental disability. Prenatal choline supplements attenuate PAE-induced behavioral and growth deficits; however, the underlying mechanisms are unknown. Alcohol alters nutrient metabolism and potentially increases nutrient needs. Here, we investigate how alcohol affects choline metabolism in the maternal–fetal dyad and the role of supplemental choline. Methods: Pregnant C57BL/6J mice were assigned to one of four groups: alcohol-exposed (3 g/kg alcohol/day) or control +/− 100 mg/kg choline daily from embryonic day (E)8.5–17.5. We performed an exploratory hypothesis-generating analysis of targeted metabolomics on choline-related metabolites in the maternal liver, plasma, placenta, and fetal brain at E17.5 and Spearman correlation analyses to determine their association with gestational and fetal growth outcomes. Results: Although choline levels were largely unaffected by alcohol or choline, alcohol increased many lipid products in the CDP–choline pathway; this was not normalized by choline. Alcohol increased placental CDP–ethanolamine and reduced the maternal hepatic SAM/SAH ratio as well as dimethylglycine and the serine/glycine ratio across the dyad, suggesting a functional insufficiency in methyl donor pools. These outcomes were rescued by supplemental choline. Correlation analyses among choline metabolites and fetal growth outcomes suggest that maternal plasma methionine, serine, and the serine/glycine ratio may be predictive of maternal–fetal choline status. Conclusions: The increased hepatic lipid synthesis that characterizes chronic alcohol exposure may draw choline into phospholipid biosynthesis at the expense of its use as a methyl donor. We propose that PAE increases choline needs, and that its supplementation is necessary to fulfill these competing demands for lipid and methyl use. Full article

Background: In humans, vitamin D₃ synthesis follows a day–night rhythm due to its UV-B-dependent production. Results: As part of the VitDHiD intervention study, we identified 87 in vivo vitamin D target genes with circadian expression patterns in immune cells, forming a regulatory network centered on transcription factors and membrane receptors. These genes exhibit a narrow basal expression range, with 80% downregulated upon vitamin D₃ supplementation. Clustering analysis revealed six distinct gene groups, with the two most prominent clusters driven by the transcription factor CSRNP1 (cysteine- and serine-rich nuclear protein 1) and GAS7 (growth arrest-specific 7), a known differentiation inducer. Among the 25 VitDHiD study participants, we identified two subgroups distinguished by significant differences in the responsiveness of 14 in vivo vitamin D target genes. These genes encode transcription factors like CSRNP1, as well as metabolic enzymes and transporters, including NAMPT (nicotinamide phosphoribosyltransferase), PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3), and SLC2A3 (solute carrier family 2 member 3). Notably, all 14 genes possess a vitamin D receptor-binding enhancer within a reasonable distance of their transcription start site. Conclusions: These findings highlight a novel link between vitamin D signaling and circadian gene regulation, with potential implications for personalized supplementation strategies. Full article

Metabolic disorders and brain insulin resistance (IR) are major risk factors for the development of neurodegenerative conditions. Kumquat fruit (KF) administration has demonstrated significant anti-dysmetabolic effects, improving peripheral IR in murine models of metabolic syndrome. Along these lines, this study evaluated the neuroprotective effects of KF supplementation in a model of dysmetabolism-induced neuronal damage and its ability to counteract the disruption of brain insulin signalling. To this end, biochemical and histological analysis assessed neuroapoptosis, disruption of brain insulin signalling and neuroinflammation in a model of high-fat diet (HFD)-induced neuronal damage. Our findings demonstrate, for the first time, that KF supplementation significantly counteracts HFD-induced neuroapoptosis downregulating pro-apoptotic genes (FAS-L, BIM and P27) and upregulating the anti-apoptotic ones (BDNF and BCL-2). Coherently, KF positively influenced the expression of selected genes related to Alzheimer’s Disease. Relevantly, these effects were associated to KF ability to restore brain insulin signalling by increasing insulin receptor expression, reducing IRS-1 serine phosphorylation, enhancing both AKT activation and GSK-3β inactivation. Accordingly, KF suppressed HFD-neuroinflammation, counteracting the overexpression of NF-κB and its downstream enzymatic products, iNOS and COX-2. Collectively, these findings demonstrate the neuroprotective benefits of KF administration, supporting its potential as a dietary intervention for dysmetabolic-related neurodegenerative disorders. Full article

The interaction between selenomethionine (SeMet) and n-3 polyunsaturated fatty acids (n-3 PUFA) in producing n-3 PUFA-enriched pork remains unknown. This study investigates the effect of different n-3 PUFA sources (linseed oil vs. fish oil) and SeMet supplementation on meat quality and fatty acid composition in finishing pigs. Key findings demonstrate that dietary supplementation with 0.3 mg/kg SeMet significantly enhances the L*_24h value (lightness) of the longissimus thoracis et lumborum (LTL) tissue compared to 3% linseed oil or fish oil treatments alone (p < 0.05). Pork flavor improvement is further supported by increased serine content (p < 0.05) and a notable tendency toward elevated total sweet amino acids (Thr + Ser + Gly + Ala + Pro) in LTL tissue (p = 0.077). Compared with 3% sunflower oil (control group), 3% linseed oil or fish oil significantly enhances n-3 PUFA content while reducing the n-6/n-3 ratio in both LTL and subcutaneous adipose tissue (p < 0.05). The synergistic interaction between SeMet and oil (linseed oil or fish oil) is observed, increasing α-linolenic acid (ALA; C18:3n-3), eicosatrienoic acid (C20:3n-3), and total n-3 PUFA deposition in subcutaneous fat tissue (p < 0.05). SeMet increases the activities of total superoxide dismutase (T-SOD) and catalase (CAT). Meanwhile, the SeMet-fish oil combination decreases lipids oxidation compared to individual treatments (p < 0.05). Collectively, 3% linseed oil or fish oil effectively enhances unsaturated fatty acid profiles, while concurrent SeMet addition may synergistically enhance certain nutritional attributes (improved oxidative stability) and sensory scores (enhanced L_{24 h}* value and flavor precursors). We, therefore, recommend adding 0.3 mg/kg SeMet to the n-3 PUFA-enriched pork production process. Full article

This study evaluated the impact of reduced crude protein (CP) diets supplemented with four essential amino acids (EAAs) on production efficiency and meat quality characteristics in Bamei pigs. Thirty-six castrated Bamei pigs (half male and half female, 100 days old, with an average body weight of 50.65 kg) were randomly assigned to three different dietary CP levels: control group (16.0% CP), group I (14.0% CP + EAA), and group II (12.0% CP + EAA). In both experiments, the group I and group II diets were supplemented with crystalline AA to achieve equal contents of standardized ileal digestible (SID) lysine, methionine, threonine, and tryptophan. After a 70-day feeding trial, the results showed that (1) low-protein diets of different levels supplemented with four EAAs had no significant effect on the growth performance of Bamei pigs (p > 0.05) but had a tendency to increase average daily feed intake (ADFI). (2) In terms of slaughter performance, compared with the control group, the low-protein amino-acid-balanced diet significantly reduced the pH of gastric contents (p = 0.045), and tended to increase the backfat thickness and dressing percentage (p > 0.05). (3) The effect of low-protein diets on muscle amino acids showed that group I was significantly improved, including increased Threonine, Serine, Glycine and Bitter amino acids. (4) Compared with the control group, the low-protein group increased the ratio of unsaturated fatty acid (UFA)/total fatty acids (TFAs), Monounsaturated Fatty Acid (MUFA)/TFA, and Polyunsaturated Fatty Acid (PUFA)/TFA, and the content of decanoic acid, myristic acid, and cis-11-eicosenoic acid in group II was significantly higher than that in the other two groups (p ≤ 0.012). (5) The total number of flavor compounds in the muscle of the low-protein group was higher than that of the control group, including Aldehyde, Alcohol, sulfide, Alkane, and Furan compounds. Among them, the relative contents of Hexanal, Heptaldehyde, Benzaldehyde, E-2-Octenal, 2,3-Octanedione, and 2-Pentylfuran in group II were significantly higher than in those groups (p < 0.05). Notably, the 14% dietary protein level group had the most significant effect on the meat quality and flavor of Bamei pigs. Therefore, under the condition of amino acid balance, reducing the use of protein feed raw materials and adding synthetic amino acids can not only improve the meat quality and flavor of finishing pigs, but also save the feed cost. Full article

P. multocida is notorious for inducing excessive inflammation with high lethality in multiple animals, such as cattle, pigs, and chickens. Our previous study revealed that L-serine was decreased in the lungs of mice infected with P. multocida capsular type A strain CQ2 (PmCQ2), and 2 mg/kg of L-serine could alleviate PmCQ2-induced lung inflammation in vivo, which may largely depend on macrophages. However, the underlying intrinsic alterations remain unknown. Here, we demonstrated that 10 mM of L-serine significantly inhibited the release of inflammatory cytokines (e.g., IL-1β and TNF-α) by blocking inflammasome activation (including NALP1, NLRP3, NLRC4, AIM2, and Caspase-1) in PmCQ2-infected macrophages. Furthermore, the results of RNA-seq and metabonomics revealed that exogenous L-serine supplementation substantially reprogrammed macrophage transcription and metabolism. Mechanically, L-serine reduced inflammatory responses via the inhibition of glycolysis in macrophages based on a seahorse assay. Together, these findings characterize the intrinsic molecular alterations in activated macrophages and provide new targets for modulating P. multocida infection-induced macrophage inflammation. Full article

This study investigated the effects of dietary Cannabis sativa residues (CR) on broiler growth and meat characteristics. A total of 256 one-day-old male Ross-308 broilers were randomly assigned to four treatments: a basal diet (control) and diets containing 0.5%, 1%, and 2% CR. CR supplementation had no effect on growth performance, survival rate, or European production index but reduced average daily feed intake (p < 0.01). No significant differences were found in meat pH, color, drip loss, thawing loss, cooking loss, or shear force (p > 0.05). However, the ΔE values (0.5% CR: 3.97, 1.0% CR: 3.71, 2.0% CR: 4.95) indicated perceptible color differences compared to the control. CR significantly reduced C12:0, C20:1n9, and C22:1n9 fatty acids (p < 0.05) while increasing free amino acids, including aspartic acid, serine, proline, methionine, and phenylalanine (p < 0.05). It also increased moisture content and decreased fat content, especially at 2% CR (p < 0.05). In conclusion, CR supplementation improves the flavor and nutritional value of broiler meat and is a potential alternative to conventional feed additives. Full article

The solute carrier family 1 member 4 (SLC1A4) gene encodes a neutral amino acid transporter, also referred to as alanine-serine-cysteine transporter 1, ASCT1, that helps maintain amino acid balance in the brain and periphery. In the brain, SLC1A4 plays an important role in transporting levo (L) and dopa (D) isomers of serine. L-serine is required for many cellular processes, including protein and sphingolipid synthesis, while D-serine is a co-agonist required for normal neurotransmission through N-methyl-D-aspartate receptors. Through its roles transporting L-serine across the blood–brain barrier and regulating synaptic D-serine levels, SLC1A4 helps establish and maintain brain health across the lifespan. This review examines the role of SLC1A4 in neurodevelopment and neurodegeneration and assesses the therapeutic potential of serine supplementation to treat neurodevelopmental symptoms associated with mutations in SLC1A4, as well as schizophrenia, depression, traumatic brain injury, and Alzheimer’s and Parkinson’s diseases. Full article

Brain function declines because of aging and several metabolites change their concentration. However, this decrease may be a consequence or a driver of aging. It has been described that taurine levels decrease with age and that taurine supplementation increases health span in mice and monkeys, finding taurine as a driver of aging. The frontal cortex is one of the most key areas studied to know the normal processes of cerebral aging, due to its relevant role in cognitive processes, emotion, and motivation. In the present work, we analyzed by intracerebral microdialysis in vivo in the prefrontal cortex of young (3 months) and old (24 months) awake rats, the basal- and K⁺-evoked release of taurine, and its precursors methionine and serine. The taurine/serine/methionine (TSM) ratio was also calculated as an index of transmethylation reactions. No changes were found in the basal levels of taurine, serine, or methionine between young and aged animals. On the contrary, a significant decrease in the K⁺-evoked release of serine and taurine appeared in aged rats when compared with young animals. No changes were seen in methionine. TSM ratio also decreased with age in both basal- and K⁺-stimulated conditions. Therefore, taurine and its related precursor serine decrease with age in the frontal cortex of aged animals under K⁺-stimulated but not basal conditions, which supports the importance of the decline of evoked taurine in its functions at the brain level, also supporting the idea proposed by other authors of a pharmacological and/or nutritional intervention to its restoration. A deficit of precursors for transmethylation reactions in the brain with age is also considered. Full article

Background: Osteoporosis is a bone remodeling disease characterized by an imbalance between bone formation and resorption, leading to bone fragility. Current treatments focus on bone resorption suppression but often have adverse effects. This study aimed to explore the potential of sericin, a silkworm-derived protein, as a dual-action therapeutic agent that enhances bone formation through its component L-serine and inhibits bone resorption via D-serine, which is derived from L-serine by the action of serine racemase. Methods: Cellular experiments were conducted to evaluate the effects of L-serine on osteoblast differentiation and D-serine on osteoclast inhibition. Serum levels of D-serine were measured following sericin administration in an osteoporosis animal model. μ-CT analysis assessed trabecular and cortical bone quality, and bone-related protein expression was analyzed using immunoprecipitation-based high-performance liquid chromatography (IP-HPLC). Results: L-serine significantly upregulated osteogenic markers, including alkaline phosphatase (ALP), Runx2, osterix, and Col1a1, in osteoblasts (p < 0.05). D-serine inhibited osteoclast activation by suppressing cathepsin K expression (p < 0.001). Sericin feeding elevated serum D-serine levels (p < 0.001) and upregulated bone-related proteins such as BMP-2, osterix, and Runx2. Micro-computed tomography (μ-CT) analysis revealed significant improvements in trabecular bone parameters in the OVX-sericin group, including increased trabecular bone volume (Tb.BV/TV; p < 0.05) and reduced trabecular separation (Tb.Sp; p < 0.05), compared to the OVX and OVX-amino acid groups. Cortical bone parameters, including cortical bone volume (Ct.BV/TV) and cortical area (Ct.Ar), did not significantly differ among OVX groups, but all were lower than in the sham group (p < 0.05). Conclusions: This study demonstrates that sericin modulates bone metabolism by enhancing osteoblast activity through L-serine and inhibiting osteoclastogenesis via D-serine. Sericin supplementation improved trabecular bone mass in an osteoporosis model, highlighting its potential for bone health. Full article

Reduced glutathione (GSH) is a main nonenzymatic antioxidant, but its effects and underlying mechanisms on growth and intestinal health in weaned piglets still require further assessment. A total of 180 weaned piglets were randomly allotted to 5 groups: a basal diet (CON), and a basal diet supplemented with antibiotic chlortetracycline (ABX), 50 (GSH1), 65 (GSH2), or 100 mg/kg GSH (GSH3). Results revealed that dietary GSH1, GSH2, and ABX improved body weight and the average daily gain of weaned piglets, and ABX decreased albumin content but increased aspartate aminotransferase (AST) activity and the ratio of AST to alanine transaminase levels in plasma. GSH2 significantly decreased glucose content but increased the content of triglyceride and cholesterol in the plasma. Both GSH1 and GSH2 improved the jejunal mucosa architecture (villus height, crypt depth, and the ratio of villus height to crypt depth), tight junction protein (ZO-1 and Occludin), and antioxidant capacity (CAT and MDA), and the effects were superior to ABX. Dietary GSH improved the jejunal barrier by probably inhibiting the myosin light chain kinas pathway to up-regulate the transcript expression of tight junction protein (ZO-1 and Occludin) and Mucins. Through the proteomics analysis of the jejunal mucosa using 4D-DIA, the KEGG pathway enrichment analysis showed that differentiated proteins were significantly enriched in redox homeostasis-related pathways such as glutathione metabolism, cytochrome P450, the reactive oxygen species metabolic pathway, the oxidative phosphorylation pathway, and the phosphatidylinositol 3-kinase-serine/threonine kinase pathway in GSH2 vs. CON and in GSH2 vs. ABX. The results of proteomics and qRT-PCR showed that GSH supplementation might dose-dependently promote growth performance and that it alleviated the weaning stress-induced oxidative injury of the jejunal mucosa in piglets by activating SIRTI and Akt pathways to regulate GPX4, HSP70, FoxO1. Therefore, diets supplemented with 50–65 mg/kg GSH can promote the growth of and relieve intestinal oxidative injury in weaned piglets. Full article