Metabolites

Background/Objectives: This study subjected four-week-old oats (Avena sativa L. cv. Qinqiong and Avena sativa L. cv. Menglong) to saline–alkali stress for 6, 12, 24, and 48 h, and non-targeted metabolomics was used to analyse root metabolites under stress. Differential metabolites in oat roots after saline–alkali stress were primarily concentrated in substances such as carbohydrates, amino acids, acids, purines, and pyrimidines. Methods: In addition, 16S rRNA high-throughput sequencing was used to analyse changes in the rhizosphere microbial community structure of oats under saline–alkali stress. The abundance of some taxa, such as Nocardioides, Bacillus, and Proteobacteria, increased. Spearman’s correlation analysis was used to determine correlations between differential microorganisms and metabolites. Results: Oats can secrete carbohydrate substances into the rhizosphere to recruit strains such as Saccharothrix, Kineococcus, and Streptomyces; aliphatic and heterocyclic amino acid substances to recruit Arthrobacter, Bacillus, and Nostoc; and acid substances to recruit Accumulibacter, thereby alleviating saline–alkali stress. Conclusions: These findings are significant for further studies on saline–alkali resistance in oats and for exploring the potential of oats’ inherent saline–alkali resistance. They also provide basic data and theoretical and practical support for promoting the sustainable development of agriculture in saline–alkali soils through the utilisation of microorganisms and metabolites.

Background: The ergogenic role of caffeine in taekwondo-specific performance has not been comprehensively synthesized. This study aimed to evaluate the effects of caffeine supplementation on performance outcomes in taekwondo athletes. Methods: PubMed, Web of Science, Cochrane Library, and SPORTDiscus were searched up to April 2026. Randomized controlled trials comparing caffeine supplementation with placebo in taekwondo athletes were included, including both acute and longer/repeated intervention protocols where eligible. Effect sizes were pooled as Hedges’ g, a small-sample-corrected standardized mean difference, using random-effects models. Evidence certainty was assessed using the GRADE approach. Results: Caffeine supplementation was associated with favorable pooled effects for explosive performance (Hedges’ g = 0.40; 95% CI 0.07–0.72; moderate-certainty evidence), reaction agility (g = 1.43; 95% CI 0.79–2.08; low-certainty evidence), technical accuracy (g = 1.05; 95% CI 0.32–1.77; low-certainty evidence), FSKT-10s performance (g = 3.31; 95% CI 1.42–5.19; very-low-certainty evidence), and FSKT-mult performance (g = 4.29; 95% CI 1.88–6.70; very-low-certainty evidence). No significant pooled effect was observed for endurance performance (g = 0.10; 95% CI −0.19–0.39; low-certainty evidence). Conclusions: Across the clinically heterogeneous acute and longer/repeated protocols included in this review, caffeine supplementation was associated with favorable pooled effects for explosive performance, reaction agility, and technical accuracy, whereas no significant pooled effect was observed for endurance outcomes. These estimates represent averages across different intervention protocols and should not be interpreted as a uniform effect of either acute or repeated supplementation. FSKT-based effects were large but should be interpreted cautiously given high heterogeneity. Observed dose-related patterns should be considered hypothesis-generating because formal subgroup or dose–response analyses were not conducted; independent replication is needed.

Background: Nasopharyngeal carcinoma (NPC) is a malignancy highly prevalent in southern China. Metabolic reprogramming is a hallmark of cancer, yet the interplay between the systemic and local metabolic landscapes of NPC remains poorly characterized. This study aimed to identify serum metabolic biomarkers and characterize local tissue metabolic alterations through integrated metabolomics. Methods: We conducted a dual-compartment metabolomic investigation. Untargeted serum metabolomics was performed on 80 NPC patients and 35 healthy controls. Air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) was applied to nasopharyngeal tissues (3 NPC vs. 3 chronically inflamed tissues). Cross-platform integration was performed to identify overlapping metabolic signatures, followed by least absolute shrinkage and selection operator (LASSO) regression for feature selection and logistic regression for biomarker panel construction. Results: Serum metabolomics revealed systemic perturbations involving amino acid and propanoate metabolism. Spatial metabolomics identified glycerophospholipid metabolism as the most significantly altered pathway in NPC tissues, with markedly reduced phosphatidylserine in tumor regions, and the ferroptosis pathway was significantly enriched. Cross-omics integration identified 8 overlapping metabolites, of which 5 were mapped to the biosynthesis of unsaturated fatty acids. Cysteine demonstrated excellent diagnostic performance (area under the receiver operating characteristic curve (AUC) = 0.903). A 5-metabolite combined model achieved an AUC of 0.904 (95% confidence interval (CI): 0.892–0.916). Conclusions: NPC exhibits compartmentalized metabolic reprogramming characterized by systemic amino acid and propanoate perturbations alongside local glycerophospholipid remodeling and ferroptosis susceptibility. The identified 5-metabolite serum panel shows considerable potential as a non-invasive diagnostic tool for NPC.