Search Results (673)

Background: Exercise-induced fatigue arises primarily from energy substrate depletion and the accumulation of metabolites such as lactate and ammonia, which impair performance and delay recovery. Emerging evidence implicates gut microbiota modulation—particularly via probiotics—as a means to optimize host energy metabolism and accelerate clearance of fatigue-associated by-products. Objective: This study aimed to determine whether live or heat-inactivated Lacticaseibacillus paracasei NB23 can enhance exercise endurance and attenuate fatigue biomarkers in a murine model. Methods: Forty male Institute of Cancer Research (ICR) mice were randomized into four groups (n = 10 each) receiving daily gavage for six weeks with vehicle, heat-killed NB23 (3 × 10¹⁰ cells/human/day), low-dose live NB23 (1 × 10¹⁰ CFUs/human/day), or high-dose live NB23 (3 × 10¹⁰ CFUs/human/day). Forelimb grip strength and weight-loaded swim-to-exhaustion tests assessed performance. Blood was collected post-exercise to measure serum lactate, ammonia, blood urea nitrogen (BUN), and creatine kinase (CK). Liver and muscle glycogen content was also quantified, and safety was confirmed by clinical-chemistry panels and histological examination. Results: NB23 treatment produced dose-dependent improvements in grip strength (p < 0.01) and swim endurance (p < 0.001). All NB23 groups exhibited significant reductions in post-exercise lactate (p < 0.0001), ammonia (p < 0.001), BUN (p < 0.001), and CK (p < 0.0001). Hepatic and muscle glycogen stores rose by 41–59% and 65–142%, respectively (p < 0.001). No changes in food or water intake, serum clinical-chemistry parameters, or tissue histology were observed. Conclusions: Our findings suggest that both live and heat-treated L. paracasei NB23 may contribute to improved endurance performance, increased energy reserves, and faster clearance of fatigue-related metabolites in our experimental model. However, these results should be interpreted cautiously given the exploratory nature and limitations of our study. Full article

Diabetes mellites (DM) is a chronic disease with increasing prevalence worldwide and multiple health implications. Among them, sarcopenia is a metabolic disorder characterized by loss of muscle mass and function. The two age-related diseases, DM and sarcopenia, share underlying pathophysiological pathways. This narrative literature review aims to provide an overview of the existing evidence on metabolomic studies evaluating DM associated with sarcopenia. Advancements in targeted and untargeted metabolomics techniques could provide better insight into the pathogenesis of sarcopenia in DM and describe their entangled and fluctuating interrelationship. Recent evidence showed that sarcopenia in DM induced significant changes in protein, lipid, carbohydrate, and in energy metabolisms in humans, animal models of DM, and cell cultures. Newer metabolites were reported, known metabolites were also found significantly modified, while few amino acids and lipids displayed a dual behavior. In addition, several therapeutic approaches proved to be promising interventions for slowing the progression of sarcopenia in DM, including physical activity, newer antihyperglycemic classes, D-pinitol, and genetic USP21 ablation, although none of them were yet validated for clinical use. Conversely, ceramides had a negative impact. Further research is needed to confirm the utility of these findings and to provide potential metabolomic biomarkers that might be relevant for the pathogenesis and treatment of sarcopenia in DM. Full article

The kallikrein–kinin system and its B1 and B2 receptors are key regulators in metabolic disorders such as obesity, diabetes, and insulin resistance. Obesity, a chronic and multifactorial condition often associated with comorbidities like type 2 diabetes and dyslipidemia, remains poorly understood at the metabolic level. The kinin B2 receptor (B2R) is involved in blood pressure regulation and glucose metabolism, promoting glucose uptake in skeletal muscle via bradykinin. Studies in B2R-KO mice demonstrate that the absence of this receptor predisposes animals to glucose intolerance under a high-fat diet and impairs adaptive thermogenesis, indicating a protective role for B2R in metabolic homeostasis and insulin sensitivity. In contrast, the kinin B1 receptor (B1R) is inducible under pathological conditions and is activated by kinin metabolites. Mouse models lacking B1R exhibit improved metabolic profiles, including protection against high-fat diet-induced obesity and insulin resistance, enhanced energy expenditure, and increased leptin sensitivity. B1R inactivation in adipocytes enhances insulin responsiveness and glucose tolerance, supporting its role in the development of insulin resistance. Moreover, B1R deficiency improves energy metabolism and thermogenic responses to adrenergic and cold stimuli, promoting the activation of brown adipose tissue and the browning of white adipose tissue. Collectively, these findings suggest that B1R and B2R represent promising therapeutic targets for the treatment of metabolic disorders. Full article

Background: The causation of type 2 diabetes remains under debate, but evidence supports both abdominal lipid and ectopic lipid overspill into tissues including muscle as key. How these depots differentially alter cardiometabolic profile and change during body weight and fat loss is not known. Methods: Women with obesity scheduled to undergo bariatric surgery were assessed at baseline (BL, n = 28) and at 6-month follow-up (6m_FU, n = 26) after weight loss. Fasting plasma (Pla), subcutaneous thigh adipose (STA), subcutaneous abdominal adipose, (SAA), and thigh vastus lateralis muscle (VLM) samples were collected at BL through surgery and at 6m_FU using needle biopsy. An untargeted liquid chromatography mass spectrometry metabolomics platform was used. Pla and tissue-specific lipid and polar metabolite profiles were modelled as changes from BL and 6m_FU. Results: There was significant body weight (−24.5 kg) loss at 6m_FU (p < 0.05). BL vs. 6m_FU tissue metabolomics profiles showed the largest difference in lipid profiles in SAA tissue in response to surgery. Conversely, polar metabolites were more susceptible to change in STA and VLM. In Pla samples, both lipid and polar metabolite profiles showed significant differences between timepoints. Jaccard–Tanimoto coefficient t-tests identified a sub-group of gut microbiome and dietary-derived omega-3-fatty-acid-containing lipid species and core energy metabolism and adipose catabolism-associated polar metabolites that are trafficked between sample types in response to bariatric surgery. Conclusions: In this first report on channelling of lipids and polar metabolites to alternative tissues in bariatric-induced weight loss, adaptive shuttling of small molecules was identified, further promoting adipose processing and highlighting the dynamic and coordinated nature of post-surgical metabolic regulation. Full article

Pancreatic cancer is frequently accompanied by cancer-associated cachexia, a debilitating metabolic syndrome marked by progressive skeletal muscle wasting and systemic metabolic dysfunction. This study presents a systems biology framework to simultaneously identify therapeutic targets for both pancreatic ductal adenocarcinoma (PDAC) and its associated cachexia (PDAC-CX), using cell-specific genome-scale metabolic models (GSMMs). The human metabolic network Recon3D was extended to include protein synthesis, degradation, and recycling pathways for key inflammatory and structural proteins. These enhancements enabled the reconstruction of cell-specific GSMMs for PDAC and PDAC-CX, and their respective healthy counterparts, based on transcriptomic datasets. Medium-independent metabolic biomarkers were identified through Parsimonious Metabolite Flow Variability Analysis and differential expression analysis across five nutritional conditions. A fuzzy multi-objective optimization framework was employed within the anticancer target discovery platform to evaluate cell viability and metabolic deviation as dual criteria for assessing therapeutic efficacy and potential side effects. While single-enzyme targets were found to be context-specific and medium-dependent, eight combinatorial targets demonstrated robust, medium-independent effects in both PDAC and PDAC-CX cells. These include the knockout of SLC29A2, SGMS1, CRLS1, and the RNF20–RNF40 complex, alongside upregulation of CERK and PIKFYVE. The proposed integrative strategy offers novel therapeutic avenues that address both tumor progression and cancer-associated cachexia, with improved specificity and reduced off-target effects, thereby contributing to translational oncology. Full article

Traditionally studied in isolation, the oral and gut microbiota are now being recognized as interconnected through anatomical and physiological pathways forming a dynamic “oral–gut microbiota axis”. Both oral and gut microbiota undergo changes with aging, characterized by a decline in microbial diversity and a shift toward potentially harmful species. The aim of this review is, therefore, to provide an overview of oral–gut communications in mediating frailty and sarcopenia. PubMed, EMBASE and Scopus databases were searched for relevant articles. We limited our search to manuscripts published in the English language. Interactions between oral and gut microbiota occur mainly through three pathways namely the enteral, the bloodstream and the fecal-oral routes. Alterations in the oral–gut microbiota axis contribute to chronic low-grade inflammation (i.e., “inflamm-ageing”) and mitochondrial dysfunction, key mechanisms underlying frailty and sarcopenia. Microbial metabolites, such as short-chain fatty acids and modified bile acids, appear to play an emerging role in influencing microbial homeostasis and muscle metabolism. Furthermore, poor oral health associated with microbial dysbiosis may contribute to altered eating patterns that negatively impact gut microbiota eubiosis, further exacerbating muscle decline and the degree of frailty. Strategies aimed at modulating the microbiota, such as healthy dietary patterns with reduced consumption of ultra-processed foods, refined carbohydrates and alcohol, ensuring an adequate protein intake combined with physical exercise, as well as supplementation with prebiotics, probiotics, and omega-3 polyunsaturated fatty acids, are increasingly recognized as promising interventions to improve both oral and gut microbiota health, with beneficial effects on frailty and sarcopenia. A better understanding of the oral–gut microbiota axis offers promising insights into nutritional interventions and therapeutic strategies for the age-related muscle decline, frailty and systemic health maintenance. Full article

Dietary advanced glycation end-products (dAGEs) contained in high-sugar/fat and ultra-processed foods of the “Western diet” (WD) pattern predispose to several diseases by altering protein function or increasing oxidative stress and inflammation via RAGE (receptor for advanced glycation end-products). Although elevated endogenous AGEs are associated with loss of muscle mass and functionality (i.e., muscle wasting; MW), the impact of dAGEs on MW has not been elucidated. Here, we show that the most common dAGEs or their precursor, methylglyoxal (MGO), induce C2C12 myotube atrophy as endogenous AGE-derived BSA. ROS production, mitochondrial dysfunction, mitophagy, ubiquitin–proteasome activation, and inhibition of myogenic potential are common atrophying mechanisms used by MGO and AGE-BSA. Although of different origins, ROS are mainly responsible for AGE-induced myotube atrophy. However, while AGE-BSA activates the RAGE-myogenin axis, reduces anabolic mTOR, and causes mitochondrial damage, MGO induces glycolytic stress and STAT3 activation without affecting RAGE expression. Among thirty selected natural compounds, Vaccinium macrocarpon (VM), Camellia sinensis, and chlorophyll showed a surprising ability in counteracting in vitro AGE formation. However, only the standardized VM, containing anti-glycative metabolites as revealed by UHPLC-HRMS analysis, abrogates AGE-induced myotube atrophy. Collectively, our data suggest that WD-linked dAGE consumption predisposes to MW, which might be restricted by VM food supplements. Full article

The abnormal growth of smooth muscle cells (SMCs) contributes to the vascular remodeling associated with coronary artery disease, a leading cause of death in women. Estradiol (E2) mediates cardiovascular protective actions, in part, by inhibiting the abnormal growth (proliferation and migration) of SMCs through various mechanism. Since microRNAs (miRNAs) play a major role in regulating cell growth and vascular remodeling, we hypothesize that miRNAs may mediate the protective actions of E2. Following preliminary leads from E2-regulated miRNAs, we found that platelet-derived growth factor (PDGF)-BB-induced miR-193a in SMCs is downregulated by E2 via estrogen receptor (ER)α, but not the ERβ or G-protein-coupled estrogen receptor (GPER). Importantly, miR-193a is actively involved in regulating SMC functions. The ectopic expression of miR-193a induced vascular SMC proliferation and migration, while its suppression with antimir abrogated PDGF-BB-induced growth, effects that were similar to E2. Importantly, the restoration of miR-193a abrogated the anti-mitogenic actions of E2 on PDGF-BB-induced growth, suggesting a key role of miR-193a in mediating the growth inhibitory actions of E2 in vascular SMCs. E2-abrogated PDGF-BB, but not miR-193a, induced SMC growth, suggesting that E2 blocks the PDGF-BB-induced miR-193a formation to mediate its anti-mitogenic actions. Interestingly, the PDGF-BB-induced miR-193a formation in SMCs was also abrogated by 2-methoxyestradiol (2ME), an endogenous E2 metabolite that inhibits SMC growth via an ER-independent mechanism. Furthermore, we found that miR-193a induces SMC growth by activating the phosphatidylinositol 3-kinases (PI3K)/Akt signaling pathway and promoting the G1 to S phase progression of the cell cycle, by inducing Cyclin D1, Cyclin Dependent Kinase 4 (CDK4), Cyclin E, and proliferating-cell-nuclear-antigen (PCNA) expression and Retinoblastoma-protein (RB) phosphorylation. Importantly, in mice, treatment with miR-193a antimir, but not its control, prevented cuff-induced vascular remodeling and significantly reducing the vessel-wall-to-lumen ratio in animal models. Taken together, our findings provide the first evidence that miR-193a promotes SMC proliferation and migration and may play a key role in PDGF-BB-induced vascular remodeling/occlusion. Importantly, E2 prevents PDGF-BB-induced SMC growth by downregulating miR-193a formation in SMCs. Since, miR-193a antimir prevents SMC growth as well as cuff-induced vascular remodeling, it may represent a promising therapeutic molecule against cardiovascular disease. Full article

Long-term storage may induce lipid oxidation in brown rice and impact its utilization in animal diets. One-day-old male Ross 308 broiler chickens (with an initial body weight of 20 g) were randomly divided into three groups: corn-based diet (Corn), fresh brown rice-based diet (BR1) and stored brown rice-based diet (BR6), with 8 replicates of 10 birds per pen, in a 42-day feeding trial. The results showed that lipid oxidation indexes increased and fatty acid composition changed significantly in BR6 (p < 0.05). The dietary replacement of corn with brown rice showed no effects on growth performance of broilers (p > 0.05). However, palmitic acid and oleic acid increased, and stearic acid, linoleic acid and docosadienoic acid decreased in the broiler breast muscle of the BR1 and BR6 groups (p < 0.05). Ileum antioxidant enzyme activities increased in the BR1 and BR6 groups compared to the Corn group (p < 0.05), and the activities of α-amylase, trypsin, chymotrypsin and lipase decreased in the BR6 group compared to the BR1 and Corn groups (p < 0.05). Also, compared to the BR1 group, the overall expression of metabolites involved in drug metabolism—cytochrome P450, GnRH secretion and the estrogen signaling pathway in broiler ileum were down-regulated in the BR6 group (p < 0.05). In conclusion, the lipid oxidation of stored brown rice decreased digestive enzyme activities and changed metabolic characteristics in the ileum of broilers. While replacing corn with brown rice did not affect broiler growth performance, it reduced the contents of unsaturated and essential fatty acids in breast muscle and enhanced the ileal antioxidant functions of broilers. Full article

In this study, we investigated the dynamic changes in muscle lipid content (MLC) deposition in the breast muscle of Jingyuan chickens at different stages (42-, 126-, and 180- days old) using metabolomics. The pH_45min, a*, and L* were significantly increased in the breast muscle of 126-day-old chickens, and MLC and b* were significantly increased in the breast muscle of 180-day-old chickens. A total of 4643 differentially expressed metabolites (DEMs) were identified, of which 10 decreased and 29 increased with age. Key pathways associated with meat quality traits included oxidative phosphorylation, β-alanine metabolism, and glycerophospholipid metabolism. Combined transcriptomic and phenotypic correlation analyses revealed significant positive correlations of MLC, pH_45min, a*, and L* with LysoPC 20:4, CD3E, TARP, IL7R, ENSGALG00010025331, and RASSF5. In the 42- and 180-day-old chickens, MLC, pH_45min, a*, and L* were significantly and positively correlated with L-Anserine, Dihydroxyacetone phosphate, ENSGALG00010006904, and HSPB7. MLC, pH_45min, a*, and L* were significantly and positively correlated with beta-Nicotinamide adenine dinucleotide in the 126- and 180-day-old chickens. This study deepens our understanding of the differences in MLC deposition at different stages of Jingyuan chickens and its relationship with meat quality traits. Full article

Skeletal muscle fiber type composition critically influences lamb meat quality. This study examined the relationships between muscle fiber types and key quality traits, including tenderness, color, lipid and amino acid profiles, and volatile flavor compounds. MyHC I (slow-twitch oxidative fibers) positively correlated with desirable traits such as increased redness, water-holding capacity, unsaturated fatty acids, and essential amino acids. Conversely, MyHC IIb (fast glycolytic fibers) was linked to reduced tenderness and higher levels of off-flavor compounds. MyHC IIa and IIx showed minimal effects. Untargeted metabolomics comparing muscles with high versus low slow-twitch fiber proportions revealed differential metabolites enriched in sphingolipid and arginine-proline metabolism pathways. These results suggest that a higher proportion of oxidative fibers enhances both the sensory and nutritional qualities of lamb meat by modulating lipid metabolism, amino acid availability, and flavor formation. Full article

Tan sheep outperform Dorper sheep in meat-quality traits, including muscle fiber characteristics and fatty acid composition, while Dorper sheep excel in carcass weight. However, the molecular mechanisms underlying these breed-specific traits, especially gut microbiota–bile acid (BA) interactions, remain poorly understood. As host–microbiota co-metabolites, BAs are converted by colonic microbiota via bile salt hydrolase (BSH) and dehydroxylases into secondary BAs, which activate BA receptors to regulate host lipid and glucose metabolism. This study analyzed colonic BA profiles in 8-month-old Tan and Dorper sheep, integrating microbiome and longissimus dorsi muscle transcriptome data to investigate the gut–muscle axis in meat-quality and carcass trait regulation. Results showed that Tan sheep had 1.6-fold higher secondary BA deoxycholic acid (DHCA) levels than Dorper sheep (p < 0.05), whereas Dorper sheep accumulated conjugated primary BAs glycocholic acid (GCA) and tauro-α-muricholic acid (p < 0.05). Tan sheep exhibited downregulated hepatic BA synthesis genes, including cholesterol 7α-hydroxylase (CYP7A1) and 27-hydroxylase (CYP27A1), alongside upregulated transport genes such as bile salt export pump (BSEP), sodium taurocholate cotransporting polypeptide (NTCP), and ATP-binding cassette subfamily B member 4 (ABCB4), with elevated gut BSH activity (p < 0.05). DHCA was strongly correlated with g_Ruminococcaceae_UCG-014, ENSOARG00000001393, and ENSOARG00000016726, muscle fiber density, diameter, and linoleic acid (C18:2n6t) (|r| > 0.5, p < 0.05). In contrast, GCA was significantly associated with g_Lachnoclostridium_10, g_Rikenellaceae_RC9_gut_group, ENSOARG0000001232, carcass weight, and net meat weight (|r| > 0.5, p < 0.05). In conclusion, breed-specific colonic BA profiles were shaped by host–microbiota interactions, with DHCA potentially promoting meat quality in Tan sheep via regulation of muscle fiber development and fatty acid deposition, and GCA influencing carcass traits in Dorper sheep. This study provides novel insights into the gut microbiota–bile acid axis in modulating ruminant phenotypic traits. Full article

Rice-field eel (Monopterus albus) slices, an important aquatic product in Southeast Asia, are prone to spoilage and deterioration during cold chain storage. In this study, the effects of a composite preservative (ε-polylysine, Vitamin C (Vc), epigallocatechin gallate (EGCG), and phloretin) on the muscle quality (color, texture, water holding capacity (WHC)) of rice-field eel slices during refrigeration storage at 4 °C for up to 7 days was investigated, and the underlying mechanism was elucidated by the integrated microbiome and metabolomics, in addition to Elisa and Low-Field Nuclear Magnetic Resonance (LF-NMR). After 7 days of storage, the WHC, shear force, and a* decreased by 11.39%, 34.37%, and 49.20% in treated samples, and by 19.18%, 38.38%, and 54.87% in control samples, respectively. The addition of the composite preservative significantly increased Hexokinase, Pyruvate kinase, and Creatine kinase, while it decreased the total viable count (TVC), total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substance (TBARS), and Lactic acid. Preservative treatment maintained the moisture content of the eel slices during storage and prevented bright red oxymyoglobin from transforming into brown metmyoglobin. Microbiota composition (especially Pseudomonas) and metabolic pathways (including amino acid and its metabolites, nucleotide and its metabolite, and organic acid and its derivatives, etc.) were obviously altered by the preservative treatment. Pseudomonas, tryptophan-aspartic acid (Trp-Asp), D-Glucose 6-phosphate, Succinic Acid, Biliverdin 1, 5-Diaminopentane, and Tyramine, etc., are potential biomarkers for the quality changes of eel slices during refrigeration. These findings provide an in-depth understanding of the improvement of the eel slice quality during refrigeration storage by the composite preservative. Full article

Inflammatory bowel disease (IBD) is characterized by chronic inflammation in the gastrointestinal tract, which can result in several muscular complications, including sarcopenia, the loss of muscle mass, and impaired muscle function. Recently, postbiotics derived from lactic bacteria, such as Lactobacillus and Bifidobacterium, have emerged as potential therapeutic modulators for these complications. Postbiotics are bioactive metabolites, such as short-chain fatty acids (SCFAs), antimicrobial peptides, and other compounds produced by microorganisms during fermentation, which have anti-inflammatory, antioxidant, and metabolic regulatory effects. These metabolites are important due to their potential to positively influence muscle health in patients with IBD, mainly by reducing systemic and local inflammation, improving gut microbiota, and modulating muscle metabolism. Studies suggest that these postbiotics may help minimize muscle degradation and promote muscle tissue regeneration, assisting in the prevention or management of IBD-associated sarcopenia. Despite the promising results, challenges remain, such as variability in postbiotic production and the need for further clinical studies to establish clear therapeutic guidelines. This review article explores the mechanisms of action of postbiotics derived from lactic acid bacteria and their potential applications in the treatment of muscle complications in patients with IBD, highlighting future therapeutic perspectives. Full article

Short-chain fatty acids (SCFAs) are microbial metabolites involved in immune regulation, energy metabolism, and intestinal barrier integrity. Among them, the role of hexanoic acid (C6), predominantly derived from dietary sources, remains poorly understood in chronic heart failure (CHF) and sarcopenia. A total of 636 patients with confirmed CHF were screened between 2019 and 2021. Sarcopenia was diagnosed in 114 patients, with 74 meeting the inclusion criteria for analysis. Plasma levels of SCFAs—including butanoic, propanoic, isobutyric, 2- and 3-methylbutanoic, hexanoic, pentanoic, and 4-methylpentanoic acids—were measured using HPLC-MS/MS. Muscle strength, mass, and physical performance were assessed using handgrip dynamometry, bioelectrical impedance analysis, and SPPB, respectively. All patients showed elevated SCFA levels compared to reference values. Butanoic acid levels exceeded reference values by 32.8-fold, propanoic acid by 10.9-fold, and hexanoic acid by 1.09-fold. Patients with plasma hexanoic acid levels above the 50th percentile had a seven-fold increased mortality risk (OR = 7.10; 95% CI: 1.74–28.9; p < 0.01). Kaplan–Meier analysis confirmed significantly lower survival in this group (p = 0.00051). The mean left ventricular ejection fraction was 41.2 ± 7.5%, and the mean SPPB score was 6.1 ± 1.8, indicating impaired physical performance. Elevated plasma hexanoic acid is associated with poor prognosis in CHF patients with sarcopenia. These findings suggest that C6 may serve as a potential prognostic biomarker and therapeutic target in this population. Full article