Metabolites

16 pages, 2278 KB

Open AccessArticle

Headspace SPME GC–MS Analysis of Urinary Volatile Organic Compounds (VOCs) for Classification Under Sample-Limited Conditions

by Lea Woyciechowski, Tushar H. More, Sabine Kaltenhäuser, Sebastian Meller, Karolina Zacharias, Friederike Twele, Alexandra Dopfer-Jablonka, Tobias Welte, Thomas Illig, Georg M. N. Behrens, Holger A. Volk and Karsten Hiller

Metabolites 2026, 16(1), 57; https://doi.org/10.3390/metabo16010057 - 8 Jan 2026

Abstract

Background/Objectives: Volatile organic compounds (VOCs) are emerging as non-invasive biomarkers of metabolic and disease-related processes, yet their reliable detection from complex biological matrices such as urine remains analytically challenging. This study aimed to establish a robust, non-targeted headspace solid-phase microextraction gas chromatography–mass spectrometry [...] Read more.

Background/Objectives: Volatile organic compounds (VOCs) are emerging as non-invasive biomarkers of metabolic and disease-related processes, yet their reliable detection from complex biological matrices such as urine remains analytically challenging. This study aimed to establish a robust, non-targeted headspace solid-phase microextraction gas chromatography–mass spectrometry (HS–SPME GC–MS) workflow optimized for very small-volume urinary samples. Methods: We systematically evaluated the effects of pH adjustment and NaCl addition on VOC extraction efficiency using a 75 µm CAR/PDMS fiber and a sample volume of only 0.75 mL. Method performance was further assessed using concentration-dependent experiments with representative VOC standards and by application to real human urine samples analyzed in technical triplicates. Results: Acidification to pH 3 markedly improved extraction performance, increasing both total signal intensity and the number of detectable VOCs, whereas alkaline conditions and additional NaCl produced only minor effects. Representative VOC standards showed compound-specific linear dynamic ranges with minimal carry-over within the relevant analytical range. Application to real urine samples confirmed high analytical reproducibility, with triplicates clustering tightly in principal component analysis and most metabolites exhibiting relative standard deviations below 25%. Conclusions: The optimized HS–SPME GC–MS method enables comprehensive, non-targeted urinary VOC profiling from limited sample volumes. This workflow provides a robust analytical foundation for exploratory volatilomics studies under sample-limited conditions and supports subsequent targeted method refinement once specific compounds or chemical classes have been prioritized. Full article

(This article belongs to the Section Endocrinology and Clinical Metabolic Research)

► Show Figures

Graphical abstract

9 pages, 709 KB

Open AccessCommunication

Towards Next-Generation Sequencing as a First-Tier Diagnostic Test for Fructose-1,6-Bisphosphatase Deficiency

by Nadine Yazbeck, Abir Barhoumi and Pascale E. Karam

Metabolites 2026, 16(1), 56; https://doi.org/10.3390/metabo16010056 - 8 Jan 2026

Abstract

Background: Advances in genomic technologies combined with tandem mass newborn screening have enabled early detection and management of several common inborn errors of metabolism. Fructose-1,6-bisphosphatase deficiency, an autosomal recessive treatable disorder reported in around 150 patients worldwide, remains underdiagnosed despite an excellent prognosis [...] Read more.

Background: Advances in genomic technologies combined with tandem mass newborn screening have enabled early detection and management of several common inborn errors of metabolism. Fructose-1,6-bisphosphatase deficiency, an autosomal recessive treatable disorder reported in around 150 patients worldwide, remains underdiagnosed despite an excellent prognosis with early detection. Although common in highly consanguineous populations, diagnosis is often delayed due to the non-specific clinical and biochemical profile. Methods: This report explores the diagnostic pathway using first-tier next-generation sequencing of three novel cases of fructose-1,6-bisphosphatase deficiency in a tertiary care center in Lebanon. Results: Two patients were diagnosed with first-tier exome sequencing within one month of presentation and had an excellent outcome at 6 years of follow-up. The third patient, undiagnosed for 10 years, suffered from neurological sequalae. The molecular profile was remarkable in two patients for exon 2 deletion in the FBP1 gene, a founder mutation reported in Turkish and Armenian patients, and a rare frameshift mutation in the third case. Conclusions: The use of next-generation sequencing as as a first-tier test for FBP deficiency is a non-invasive and rapid method for early diagnosis and management of this rare yet treatable disorder. It can detect both disease-causing variants and large deletions, founder mutations as well, delineating the molecular profile in populations where this disorder is highly prevalent. Full article

(This article belongs to the Special Issue The Future Perspective on Screening and Diagnosis of Inborn Errors of Metabolism)

► Show Figures

Graphical abstract

16 pages, 816 KB

Open AccessArticle

Urinary Equol Production Capacity, Dietary Habits, and Premenstrual Symptom Severity in Healthy Young Japanese Women

by Nanae Kada-Kondo, Natsuka Kimura, Kurea Isobe, Akari Kaida, Saki Ota, Akari Fujita, Yuu Haraki, Ryozo Nagai and Kenichi Aizawa

Metabolites 2026, 16(1), 55; https://doi.org/10.3390/metabo16010055 - 8 Jan 2026

Abstract

Background/Objectives: Equol, a gut microbial metabolite of the soy isoflavone, daidzein, is associated with estrogenic activity and potential benefits for women’s health. While equol production depends on individual gut microbial composition, its dietary and clinical correlates in young women remain incompletely characterized. [...] Read more.

Background/Objectives: Equol, a gut microbial metabolite of the soy isoflavone, daidzein, is associated with estrogenic activity and potential benefits for women’s health. While equol production depends on individual gut microbial composition, its dietary and clinical correlates in young women remain incompletely characterized. This study explored the relationship between urinary equol production, dietary habits, and premenstrual symptom severity in healthy university-aged women. Methods: We conducted a cross-sectional study of 41 Japanese women, aged 19–20 years. Urinary equol was measured using a validated liquid chromatography–tandem mass spectrometry (LC–MS/MS) method, following enzymatic hydrolysis. Participants were classified as either equol producers or non-producers, based on urinary concentration thresholds. Dietary intake was evaluated using a dietary questionnaire focused on soy products and dietary fiber sources. Premenstrual symptoms were assessed using a standardized Japanese questionnaire for premenstrual syndrome and premenstrual dysphoric disorder. Results: Twelve percent of participants were classified as equol producers. Compared with non-producers, equol producers reported higher consumption of pumpkin, soybean sprouts, and green tea. Among non-producers, higher consumption of certain vegetables and fiber-rich foods, including broccoli, pickled radish, konjac, and konjac jelly, was associated with greater premenstrual symptom severity, whereas such associations were not observed among equol producers. The analytical method demonstrated high sensitivity and reproducibility for urinary equol measurement. Conclusions: These findings suggest that equol production status may be associated with distinct dietary patterns and with differences in the relationship between food intake and premenstrual symptom severity in young women. Although the cross-sectional design and limited sample size preclude causal inference, these findings suggest that urinary equol is a promising candidate biomarker for future research on diet-related modulation of premenstrual symptoms. Full article

(This article belongs to the Special Issue Application of Urinary Metabolomics in Early Disease Detection)

► Show Figures

Figure 1

20 pages, 5920 KB

Open AccessArticle

Metabolic Signatures of Breast Cancer Subtypes and the Metabolic Impact of Chemotherapy

by Aubrey Mattingly, Zoe Vickery, Alex Fiorentino, Ethan Wilson, Sydney McCune, Sydney Clark, Eric Blanchard, Jillian Spencer, Abigail Broom, Diana Ivankovic, Brooklyn Pace, Lauren Baskin, Ludovico Abenavoli, W. Jeffery Edenfield, Ki Chung, Christopher L. Farrell, Hakon Hakonarson and Luigi Boccuto

Metabolites 2026, 16(1), 54; https://doi.org/10.3390/metabo16010054 - 8 Jan 2026

Abstract

Background/Objectives: Breast cancer is a prevalent and heterogeneous disease with multiple subtypes, which are defined by characteristics such as molecular biomarkers and metastatic status. This study aimed to profile the metabolic activity of various breast cancer subtypes, both with and without chemotherapy [...] Read more.

Background/Objectives: Breast cancer is a prevalent and heterogeneous disease with multiple subtypes, which are defined by characteristics such as molecular biomarkers and metastatic status. This study aimed to profile the metabolic activity of various breast cancer subtypes, both with and without chemotherapy (doxorubicin) application. Methods: Six human breast cell lines were evaluated, two non-tumorigenic controls and four cancerous lines. The cancer lines were clustered as primary-derived, metastasis-derived, triple-negative (TNBC), and strong hormone receptor-positive (ER+/PR+) and analyzed using the Biolog phenotype mammalian microarrays (PM-M1 to PM-M8) to assess metabolic activity via NADH production under a wide array of substrate parameters. Results: Unique metabolic profiles emerged across the subtypes and clusters; the TNBC and metastatic cells demonstrated enhanced utilization of glycolytic and anaerobic substrates consistent with the Warburg effect. The ER+/PR+ cells showed heightened glucose utilization and unique sensitivity to metabolic effectors and doxorubicin. Additionally, significant metabolic differences were observed in nucleoside and amino acid utilization between cancer and control cells, particularly in metastatic and TNBC lines. Conclusions: Our findings reveal the profound metabolic diversity among breast cancer subtypes and highlight distinct substrate dependencies for proliferation. The results additionally provide a framework for developing metabolic biomarkers and targeted therapies for chemotherapy resistance in breast cancer subtypes. Full article

(This article belongs to the Special Issue Novel Approaches for Metabolomics in Drugs and Biomarkers Discovery: 2nd Edition)

► Show Figures

Graphical abstract

18 pages, 3656 KB

Open AccessArticle

Free Fatty Acids and Endotoxins Synergically Induce Pyroptosis in Bovine Hepatocytes

by Dan Li, Yuan Tian, Lei Tian, Hang Yu, Le Zhang, Song Wang, Changsheng Lei, Pin Long, Tao Peng, Lei Liu and Yingfang Zhou

Metabolites 2026, 16(1), 53; https://doi.org/10.3390/metabo16010053 - 8 Jan 2026

Abstract

Background/Objectives: Elevated circulating non-esterified fatty acids (NEFAs) are closely associated with hepatic inflammatory injury in dairy cattle, simultaneously with the entry of lipopolysaccharide (LPS) into the liver. This study aimed to investigate the synergistic effects of NEFAs and LPS on pyroptosis in [...] Read more.

Background/Objectives: Elevated circulating non-esterified fatty acids (NEFAs) are closely associated with hepatic inflammatory injury in dairy cattle, simultaneously with the entry of lipopolysaccharide (LPS) into the liver. This study aimed to investigate the synergistic effects of NEFAs and LPS on pyroptosis in bovine hepatocytes. Methods: Primary bovine hepatocytes were allocated into control, NEFA, NEFA + LPS, NEFA + LPS + Caspase-1 inhibitor, and NEFA + LPS + NLRP3 inhibitor groups. Levels and activation of pyroptosis-related markers (NLRP3, ASC, Caspase-1, GSDMD, IL-18 and IL-1β) were measured. Results: NEFAs alone upregulated these markers in a dose-dependent manner. Compared to NEFAs alone, NEFA + LPS co-treatment significantly enhanced levels of the markers, increased IL-1β secretion, and promoted NLRP3/Caspase-1 co-localization and Caspase-1activity. Notably, these effects of NEFA + LPS were attenuated by the NLRP3 or Caspase-1 inhibitors. Similar results were obtained when repeating the experiments in carcinoma HepG2 cells. Also, a random liver section from the subclinical ketotic cows displayed a higher fluorescence intensity of NLRP3 and Caspase-1 and stronger co-localization than that from a healthy cow. Conclusions: NEFAs and LPS synergistically contribute to pyroptosis in bovine hepatocytes by enhancing NLRP3 inflammasome assembly and subsequent Caspase-1 activation, providing a potential target for mitigating hepatic injury. Full article

(This article belongs to the Special Issue Metabolic Research in Dairy Cattle Health)

► Show Figures

Graphical abstract

14 pages, 1545 KB

Open AccessArticle

CAR Intrinsic Design Pre-Shapes Transcriptional and Metabolic Networks in CAR T Cells

by Didem Agac Cobanoglu, Samantha Franklin, Yue Hu, Devon J. Boland and Xiaotong Song

Metabolites 2026, 16(1), 52; https://doi.org/10.3390/metabo16010052 - 7 Jan 2026

Abstract

Background/Objectives: Chimeric antigen receptor (CAR) T cells are a powerful cancer therapy, but their function depends heavily on internal signaling domains and metabolic adaptability. Most studies evaluate CAR behavior upon antigen exposure, yet intrinsic signaling properties may pre-program CAR T cell states even [...] Read more.

Background/Objectives: Chimeric antigen receptor (CAR) T cells are a powerful cancer therapy, but their function depends heavily on internal signaling domains and metabolic adaptability. Most studies evaluate CAR behavior upon antigen exposure, yet intrinsic signaling properties may pre-program CAR T cell states even in the absence of stimulation. This study investigates how CAR design and metabolic support shape baseline transcriptional programs, focusing on tonic signaling and NF-κB-related pathways. Methods: We engineered CAR T cells targeting HER2 or GPC3 antigens, incorporating either 4-1BB or CD28 co-stimulatory domains, respectively. A subset of cells was further modified with adenosine deaminase 1 (ADA1) and CD26 to degrade extracellular adenosine and supply inosine, a metabolic strategy termed metabolic refueling (MR). Bulk RNA-seq was performed on resting T cells without antigen stimulation. We analyzed differential gene expression, gene set enrichment (GO, KEGG, Hallmarks), and transcription factor activity (DoRothEA) to assess the impact of CAR design and MR on T cell programming. Results: All CAR T cells exhibited activation of NF-κB–centered inflammatory programs at baseline, indicating tonic signaling. GPC3 CAR T cells showed stronger baseline activation than HER2 CAR T cells. Metabolic refueling amplified these programs without altering their directionality, enhancing inflammatory, survival, and effector modules. Transcription factor activity scores mirrored these trends, highlighting RELA, FOS, and STATs as key regulatory nodes. Conclusions: CAR-intrinsic features, notably co-stimulatory domain choice, define the tonic NF-κB activation tone in resting CAR T cells. Metabolic refueling boosts these baseline states without overstimulation, suggesting it may be especially valuable for weaker CAR constructs. These findings provide a framework for tuning CAR T cell function through combinatorial design strategies targeting signaling and metabolism. Full article

(This article belongs to the Special Issue Metabolic Reprogramming in Cancer: New Frontiers for Therapeutic Intervention)

► Show Figures

Figure 1

14 pages, 2007 KB

Open AccessArticle

Metabolomics Analysis Reveals the Potential Advantage of Artificial Diet-Fed Bombyx Batryticatus in Disease Treatment

by Han Chen, Yuting Feng, Daorui Pang, Qiong Yang, Yuxiao Zou, Ping Lin, Guanwang Shen and Dongxu Xing

Metabolites 2026, 16(1), 51; https://doi.org/10.3390/metabo16010051 - 7 Jan 2026

Abstract

Background: Beauveria bassiana infection of silkworm forms Bombyx Batryticatus (BB). It is a medicinal material with significant pharmacological potential. While artificial diet feeding improves the production efficiency of BB, it might alter host metabolism, consequently affecting its bioactive components and efficacy. To [...] Read more.

Background: Beauveria bassiana infection of silkworm forms Bombyx Batryticatus (BB). It is a medicinal material with significant pharmacological potential. While artificial diet feeding improves the production efficiency of BB, it might alter host metabolism, consequently affecting its bioactive components and efficacy. To address this, we conducted a metabolomics analysis of BB reared under different feeding conditions; Methods: UPLC-MS/MS was employed to conduct metabolomic analysis of BB under three rearing conditions: all instars mulberry leaf feeding (MF), all instars artificial diet feeding (AF), and mixed feeding (AMF). The sample collection time was selected as the time when silkworms died after infection (D0), and the fifth day after death (D5), which is the time when fungus produces biologically active secondary metabolites to reach a stable state; Results: Compared to MF, AF did not significantly alter the levels of the index component induced by B. bassiana infection—beauvericin. Moreover, the overall metabolic profile differences between the two groups decreased at the later stage (D5). Specifically, the average Pearson correlation between these groups was 0.659 ± 0.102, and the first two principal components of PCA explained 49.6% of the total variance. This suggests a reduction in the differences in their pharmacological active components. KEGG enrichment analysis revealed that AF promoted the accumulation of certain flavonoids (e.g., apigenin, luteolin), but, overall, the biosynthesis of flavone and flavonol is suppressed. Additionally, several metabolites, including N,N′-diferuloylputrescine, N-methyl-4-aminobutyric acid, and 3,4-dimethoxyphenylacetic acid, were identified to be significantly positively correlated with artificial diet supplementation; Conclusions: This study reveals metabolic differences in BB under different rearing methods at the metabolomic level, providing a scientific basis for evaluating the quality of this medicinal material. Full article

(This article belongs to the Section Animal Metabolism)

► Show Figures

Figure 1

14 pages, 1993 KB

Open AccessArticle

Plasma Galectin-7 (Gal-7) and Galectin-8 (Gal-8) as Emerging Biomarkers in Psoriasis: Associations with Disease Activity and Metabolic Status

by Julia Nowowiejska-Purpurowicz, Anna Baran, Justyna Magdalena Hermanowicz, Beata Sieklucka, Krystyna Pawlak, Dariusz Pawlak and Iwona Flisiak

Metabolites 2026, 16(1), 50; https://doi.org/10.3390/metabo16010050 - 7 Jan 2026

Abstract

Background: Psoriasis is a chronic, immune-mediated skin disorder characterized by accelerated epidermal turnover. Galectins are a family of carbohydrate-binding proteins that play crucial roles in various biological processes. Methods: This study aimed to assess the plasma concentrations of galectin 7 and 8 (gal-7 [...] Read more.

Background: Psoriasis is a chronic, immune-mediated skin disorder characterized by accelerated epidermal turnover. Galectins are a family of carbohydrate-binding proteins that play crucial roles in various biological processes. Methods: This study aimed to assess the plasma concentrations of galectin 7 and 8 (gal-7 and 8) in 60 psoriatic patients compared to the control group of 30 individuals without dermatoses. Results: The median gal-7 plasma concentration in patients was 188.8 (11.43–1406) pg/mL, and it was significantly higher than in controls (p < 0.001). There was a positive correlation between gal-7 concentration and psoriasis area and severity index (PASI; R = 0.3, p = 0.0199), and a negative with RBC (R = −0.41, p < 0.001), hemoglobin concentration (R = −0.34, p < 0.01), total cholesterol (R = −0.38, p < 0.01) and LDL concentration (R = −0.36, p < 0.05). In contrast, gal-7 was not correlated with psoriasis duration or patients’ age or sex (p > 0.05). The median gal-8 plasma concentration in patients was 0.07 (0.02–0.5) ng/mL, and was significantly higher in patients than controls (p < 0.05). There was a positive correlation between gal-8 concentration and glucose concentration (R = 0.26, p < 0.05). Gal-8 concentration was not correlated with PASI, BMI, age or sex of patients (p > 0.05). We also analyzed the receiver operating characteristic (ROC) curve to evaluate the predictive power of gal-7 and 8 for psoriasis. Gal-7 achieved statistical significance in predicting psoriasis and had an area under the curve (AUC) value of 0.842 (p < 0.001), a sensitivity of 80%, and a specificity of 86.7%, whereas gal-8 had an AUC value of 0.644 (p = 0.025), a sensitivity of 81%, and a specificity of 47%. Conclusions: Gal-7 and gal-8 could potentially serve as psoriasis biomarkers, whereby gal-7 could also serve as a marker of its severity. Future studies are needed to clarify their actual role or potential as therapeutic targets in psoriasis. Understanding their precise functions may open new perspectives for personalized treatment strategies in psoriatic patients. Full article

(This article belongs to the Special Issue Novel Approaches for Metabolomics in Drugs and Biomarkers Discovery: 2nd Edition)

► Show Figures

Figure 1

38 pages, 4718 KB

Open AccessReview

Mass Spectrometry-Based Metabolomics in Pediatric Health and Disease

by Debasis Sahu, Andrei M. Matusa, Alicia DiBattista, Bradley L. Urquhart and Douglas D. Fraser

Metabolites 2026, 16(1), 49; https://doi.org/10.3390/metabo16010049 - 6 Jan 2026

Abstract

Mass spectrometry-based metabolomics is a valuable tool for advancing pediatric health research. Along with nuclear magnetic resonance, it enables detailed biochemical analysis from minimal sample volumes, a critical feature for pediatric diagnosis. Metabolomics supports early detection of inherited metabolic disorders, monitors metabolic changes [...] Read more.

Mass spectrometry-based metabolomics is a valuable tool for advancing pediatric health research. Along with nuclear magnetic resonance, it enables detailed biochemical analysis from minimal sample volumes, a critical feature for pediatric diagnosis. Metabolomics supports early detection of inherited metabolic disorders, monitors metabolic changes during growth, and identifies disease markers for a range of conditions, including metabolic, neurodevelopmental, oncological, and infectious diseases. Integrating metabolomic data with genomic, proteomic (i.e., multi-omics approaches), and clinical information enables more precise and preventive care by enhancing risk assessment and informing targeted treatments. However, routine clinical use faces several challenges, including establishing age- and sex-specific reference ranges, standardizing sample collection and processing, ensuring consistency across platforms and laboratories, expanding reference databases, and improving data comparability. Ethical and regulatory issues, including informed consent, data privacy, and equitable access, also require careful consideration. Advances in high-resolution and single-cell metabolomics, artificial intelligence for data analysis, and cost-effective testing are expected to address these barriers and support broader clinical adoption. As standards and data-sharing initiatives grow, metabolomics will play an increasingly important role in pediatric diagnostics and personalized care, enabling earlier disease detection, improved treatment monitoring, and better long-term outcomes for children. Full article

(This article belongs to the Special Issue Mass Spectrometry-Based Metabolomics in Health and Disease: Targeted Analysis and Its Trends)

► Show Figures

Graphical abstract

29 pages, 21720 KB

Open AccessArticle

5-Hydroxymethylfurfural and Isoverbascoside Alleviate Oxidative Damage INS-1 and MIN6 β-Cells by Activating Autophagy and Inhibiting Apoptosis

by Xianglong Meng, Yuting Li, Xiang Han, Ziang Li, Zhulin Bu, Yuhui Wu, Xiaofen Li, Shuosheng Zhang and Yuting Dai

Metabolites 2026, 16(1), 48; https://doi.org/10.3390/metabo16010048 - 6 Jan 2026

Abstract

Background/Objectives: In type 2 diabetes (T2DM), dysregulated glucose and lipid metabolism impair cellular energy sensing and inhibit autophagy, leading to the accumulation of dysfunctional cellular components, increased inflammation and oxidative stress, and activation of the intrinsic apoptotic pathway. Prepared Rehmannia glutinosa is [...] Read more.

Background/Objectives: In type 2 diabetes (T2DM), dysregulated glucose and lipid metabolism impair cellular energy sensing and inhibit autophagy, leading to the accumulation of dysfunctional cellular components, increased inflammation and oxidative stress, and activation of the intrinsic apoptotic pathway. Prepared Rehmannia glutinosa is an anti-diabetic traditional Chinese medicine whose active monomers, including 5-Hydroxymethylfurfural (5-HMF) and isoverbascoside, exhibit potential antioxidant and anti-apoptotic effects. However, their role in β-cell protection remains unexplored. This study aims to investigate the protective mechanisms of 5-HMF and isoverbascoside against H₂O₂-induced oxidative damage in pancreatic β-cells. Methods: INS-1 and MIN6 β-cells were treated with 5-HMF and isoverbascoside (20 μM, 40μM) for 24 h under H₂O₂-induced oxidative stress. Multiple techniques were employed, including transcriptomics, proteomics, machine learning, Western blot analysis, and molecular docking. Flow cytometry and Hoechst 33342 staining were used to assess apoptosis, while autophagy was evaluated via LC3 fluorescence intensity and Beclin-1 expression. Chloroquine (CQ), an autophagy inhibitor, was applied to further examine autophagy’s role. Conclusions: 5-HMF and isoverbascoside enhance autophagic activity in pancreatic β-cells, attenuate oxidative stress-induced apoptosis, and improve cell survival and proliferation. These findings underscore their potential as protective agents in T2DM by modulating the autophagy–apoptosis balance. Full article

(This article belongs to the Special Issue Metabolomics in Plant Natural Products Research, 2nd Edition)

► Show Figures

Figure 1

26 pages, 1911 KB

Open AccessArticle

Metabolic Outcomes in Bariatric/Metabolic Surgery Individuals: Impact of Metabolic Health Definition, Type of Surgery, and Follow-Up Duration—An Observational, Retrospective Study

by Anna Pluemacher, Cláudia Camila Dias, Bárbara Peleteiro, Denise Pinheiro, Paula Freitas, Eduardo Lima, Alexandra Leitão, Elisabete Martins and Maria João Martins

Metabolites 2026, 16(1), 47; https://doi.org/10.3390/metabo16010047 - 5 Jan 2026

Abstract

Background: There is no standardized definition for metabolic health. Overweight and obesity are often linked to metabolic dysfunction. Bariatric surgery promotes body weight loss and cardiometabolic health improvement. Objective: We aim to characterize metabolic health using distinct definitions and evaluate anthropometric and cardiometabolic [...] Read more.

Background: There is no standardized definition for metabolic health. Overweight and obesity are often linked to metabolic dysfunction. Bariatric surgery promotes body weight loss and cardiometabolic health improvement. Objective: We aim to characterize metabolic health using distinct definitions and evaluate anthropometric and cardiometabolic features, both before and after different surgery procedures. Methods: We studied 3313 individuals from CRI-O [Porto, PT; BMI 39.56 (42.60; 46.20) kg/m²; 36 (43; 51) y; 82.7% women] who underwent Roux-en-Y gastric bypass (RYGB; 61.7%), sleeve gastrectomy (30.9%), or gastric band (7.5%) surgery. Anthropometric and cardiometabolic features were assessed at baseline and at yearly follow-ups, up to 4 years; the same for cardiometabolic dysfunction characterization using NCEP ATP III, Karelis, Meigs, Khan, Pluemacher, and Schulze definitions. Results: Baseline metabolic health classification and metabolically unhealthy phenotype (MUH) post-surgery prevalence decrease show substantial variability depending on the definition used. Unlike relative body weight loss, the altered metabolic feature number in MUH remains unchanged. Changes in MUH prevalence do not reflect body weight loss, nor does the variation in MUH percentage fully align with changes in altered metabolic features. Blood pressure, C-reactive protein, antihypertensive medication, and HOMA-IR are key contributors to baseline MUH. Post-surgical changes in body weight, lipid profile, and C-reactive protein vary by procedure. RYGB yields greater weight loss and more often improves cardiometabolic markers. However, post-operative metabolic phenotype is independent of surgery type. Conclusions: Metabolic health phenotypes pre- and post-surgery vary by definition, and the latter are not solely driven by weight loss or surgery type. In this cohort, RYGB shows the strongest beneficial impact. Full article

(This article belongs to the Special Issue Diabetes and Metabolic Diseases: From Prevention to Clinical Management, 2nd Edition)

► Show Figures

Graphical abstract

20 pages, 3007 KB

Open AccessArticle

Plant-Derived Secondary Metabolites Tetrahydropalmatine and Rutaecarpine Alleviate Paclitaxel-Induced Neuropathic Pain via TRPV1 and TRPM8 Modulation

by Keun-Tae Park, Hyesang Yun, Juyeol Kang, Jae-Chul Lee and Woojin Kim

Metabolites 2026, 16(1), 46; https://doi.org/10.3390/metabo16010046 - 4 Jan 2026

Abstract

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting adverse effect of paclitaxel and is characterized by cold and mechanical allodynia. Effective therapeutic strategies for CIPN remain limited. This study evaluated the analgesic potential of Corydalis yanhusuo (CY) and Evodia rutaecarpa (ER), as [...] Read more.

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting adverse effect of paclitaxel and is characterized by cold and mechanical allodynia. Effective therapeutic strategies for CIPN remain limited. This study evaluated the analgesic potential of Corydalis yanhusuo (CY) and Evodia rutaecarpa (ER), as well as their major alkaloids tetrahydropalmatine (THP) and rutaecarpine, in a mouse model of paclitaxel-induced neuropathic pain. Methods: Neuropathic pain was induced by paclitaxel administration (2 mg/kg, i.p., four injections). CY and ER extracts were orally administered at doses of 100 or 300 mg/kg, either alone or in combination, and cold and mechanical allodynia were assessed from days 0 to 8. The analgesic effects of THP and rutaecarpine were also examined. Gene and protein expression analyses were performed to evaluate the involvement of TRPV1 and TRPM8 signaling pathways, and high-performance liquid chromatography (HPLC) was used to confirm the presence of THP in CY and rutaecarpine in ER. Results: Paclitaxel reliably induced robust cold and mechanical hypersensitivity. Oral administration of CY or ER significantly alleviated allodynia in a dose-dependent manner, with greater efficacy at 300 mg/kg. Combined CY–ER treatment produced stronger anti-allodynic effects than either extract alone. THP and rutaecarpine also exhibited dose-dependent analgesic effects, and their co-administration yielded the most pronounced inhibition of paclitaxel-evoked hypersensitivity. Molecular analyses confirmed the involvement of TRPV1- and TRPM8-related pathways in these analgesic effects. Collectively, these findings indicate that CY, ER, and their representative alkaloids effectively attenuate paclitaxel-induced neuropathic pain and highlight CY–ER-based natural products as promising candidates for managing CIPN through modulation of TRPV1/TRPM8 signaling. Full article

(This article belongs to the Special Issue Plant Metabolites for Managing Chemotherapy-Induced Side Effects)

► Show Figures

Figure 1

14 pages, 960 KB

Open AccessReview

A Comprehensive Review on Medium- and Long-Chain Fatty Acid-Derived Metabolites: From Energy Sources to Metabolic Signals

by Jin-Byung Park, Sungyun Cho and Sung-Joon Lee

Metabolites 2026, 16(1), 45; https://doi.org/10.3390/metabo16010045 - 4 Jan 2026

Abstract

Medium- and long-chain fatty acids (MLFAs) are increasingly recognized not only as metabolic substrates but also as precursors of diverse bioactive metabolites generated through host and microbial transformations. Recent advances in analytical chemistry and microbiome research have revealed that gut microorganisms catalyze extensive [...] Read more.

Medium- and long-chain fatty acids (MLFAs) are increasingly recognized not only as metabolic substrates but also as precursors of diverse bioactive metabolites generated through host and microbial transformations. Recent advances in analytical chemistry and microbiome research have revealed that gut microorganisms catalyze extensive modifications of dietary MLFAs—producing hydroxylated, conjugated, and keto-fatty acids with enhanced potency toward host receptors. These metabolites exhibit dual activity on classical metabolic receptors, including FFAR1/4 and PPARα/γ, as well as ectopically expressed chemosensory receptors such as olfactory receptors (ORs) and bitter taste receptors (TAS2Rs). This expanded receptor landscape establishes a previously unrecognized chemosensory–metabolic axis that integrates dietary signals, microbial metabolism, and host physiology. Microbial MLFA derivatives such as 10-hydroxyoctadecenoic acid and conjugated linoleic acid regulate incretin secretion, adipogenesis, macrophage polarization, and intestinal barrier function through coordinated activation of FFARs and PPARs. Concurrently, dicarboxylic acids such as azelaic acid activate Olfr544 to modulate lipolysis, ketogenesis, GLP-1 release, and feeding behavior. TAS2Rs also sense oxidized lipids, linking lipid metabolism to immune regulation and enteroendocrine signaling. Collectively, these pathways highlight the microbiome as a metabolic transducer that converts dietary lipids into signaling molecules influencing endocrine, immune, and gut–brain circuits. Understanding the mechanisms governing MLFA bioconversion and receptor engagement provides new opportunities for therapeutic and nutritional intervention. Targeting ORs and TAS2Rs, engineering probiotics to enhance beneficial FA-derived metabolites, and developing receptor-selective synthetic analogs represent promising strategies. Future progress will require integrative approaches combining physiology, biochemistry, metabolomics, and microbial genomics to elucidate receptor specificity and host variability. Full article

(This article belongs to the Topic Advances in Analysis Methods for Metabolomics and Lipidomics)

► Show Figures

Figure 1

15 pages, 963 KB

Open AccessArticle

Development and Validation of a Targeted Metabolomic Tool for Metabotype Classification in Schoolchildren

by Sheyla Karina Hernández-Ramírez, Diego Arturo Velázquez-Trejo, Eduardo Sandoval-Colín, Cristóbal Fresno, Mariana Flores-Torres, Ernestina Polo-Oteyza, María José Garcés-Hernández, Nayely Garibay-Nieto, Isabel Ibarra-González, Marcela Vela-Amieva, Guadalupe Estrada-Gutierrez and Felipe Vadillo-Ortega

Metabolites 2026, 16(1), 44; https://doi.org/10.3390/metabo16010044 - 4 Jan 2026

Abstract

Background: Metabolomic profiling can uncover metabolic differences among seemingly healthy children, providing opportunities for personalized medicine and early detection of risk biomarkers for future metabolic disorders. This study aimed to identify and internally validate metabotypes in apparently healthy schoolchildren using targeted serum metabolomics [...] Read more.

Background: Metabolomic profiling can uncover metabolic differences among seemingly healthy children, providing opportunities for personalized medicine and early detection of risk biomarkers for future metabolic disorders. This study aimed to identify and internally validate metabotypes in apparently healthy schoolchildren using targeted serum metabolomics and to assess the external validity of this metabotype classification tool in two separate groups of children. Methods: Data from schoolchildren aged 6–11 years were analyzed in two phases. In the first phase, we developed and validated a classification tool using targeted serum metabolomics in healthy children. Metabotypes were identified through unsupervised clustering with a self-organizing map, followed by assessment of cluster stability and classification accuracy. In the second phase, we tested the tool’s consistency by applying it to two additional groups: the same children from phase 1 after a 10-month physical activity intervention, and a separate group diagnosed with metabolic syndrome. Results: Three metabotypes were identified in healthy children: METBA (balanced profile), METLI (high lipid and glucose levels), and METAA (high amino acid levels). Internal validation showed strong cluster stability (ARI = 0.79) and high classification accuracy (0.95). After the intervention, 55% of children were reclassified, indicating diverse metabolic responses to physical activity. Among children with metabolic syndrome, 83% were classified as METLI and 13% as METAA. Conclusions. This tool revealed serum metabolomic diversity, enabling classification of healthy children into three distinct metabotypes. It also detects changes in metabotype classification associated with a physical activity intervention and identifies the majority of children diagnosed with metabolic syndrome within two groups. This supports the potential use of metabotypes as biomarkers and eventually for personalized interventions. Full article

(This article belongs to the Special Issue Proteomics and Metabolomics in Human Health and Disease)

► Show Figures

Graphical abstract

15 pages, 4760 KB

Open AccessArticle

Plasma Metabolome and Metabolite Toxicity Profiling of Moderate-Intensity Running in Human Females

by Qintong Fei, Tiantian Liang, Maodi Liang, Jing Cao, Huilin Yao, Ping Zhu and Qinghua Cui

Metabolites 2026, 16(1), 43; https://doi.org/10.3390/metabo16010043 - 2 Jan 2026

Abstract

Background: Existing exercise metabolomics studies have predominantly focused on changes in the type and abundance of metabolites, while rarely addressing the toxicity risk of differential metabolites. Metabolic toxicity refers to the potential of endogenous or exogenous metabolites to induce oxidative stress, cell [...] Read more.

Background: Existing exercise metabolomics studies have predominantly focused on changes in the type and abundance of metabolites, while rarely addressing the toxicity risk of differential metabolites. Metabolic toxicity refers to the potential of endogenous or exogenous metabolites to induce oxidative stress, cell death, and other forms of biological damage when excessively accumulated and serves as a key driver of metabolic disorders. This study aims to characterize the toxicity risk of plasma differential metabolites before and after a single session of moderate-intensity running, so as to investigate the exercise-induced changes in metabolic toxicity. Methods: A single-group self-pretest–posttest control design was adopted in this study. Participants were recruited from Wuhan Sports University, China, with the inclusion criteria of healthy females aged 22–30 years and BMI 18.5–24.9. Individuals with a history of metabolic diseases or who met other exclusion criteria were excluded, and 5 females were finally enrolled. The exercise protocol consisted of a single 40 min session of moderate-intensity running on a treadmill. We collected plasma samples from five healthy females before and after exercise and performed untargeted LC-MS/MS metabolomic profiling. The gap-Δenergy algorithm was applied to calculate the toxicity scores of differential metabolites, and the proportion of metabolites with high toxic potential (score > 0.6) was compared. Results: Plasma metabolic profiles underwent notable remodeling after exercise. Thirty-two metabolites were upregulated and the phosphosphingolipid SM(d18:2(4E,14Z)/16:0) was the most significant. Meanwhile 32 metabolites were downregulated and the phosphosphingolipid PC(18:1(9Z)/14:0) was the most significant. The 64 differential metabolites were enriched in 9 KEGG pathways including amino acid metabolism and lipid metabolism. Moreover, we systematically evaluated the toxicity of these metabolites using the gap-Δenergy algorithm and found that the downregulated metabolites exhibited a significantly higher toxicity score compared to the upregulated ones. In addition, 37.5% of the downregulated metabolites had a high toxicity score, while the proportion of high toxicity in the upregulated group was only 15.6%. Conclusions: This study demonstrates that moderate-intensity running may confer metabolic health benefits to individuals by reducing metabolic toxicity, specifically through the downregulation of metabolites with high toxic potential. These findings offer novel evidence for exercise’s role in improving metabolic health. They also open a new direction for exercise-based interventions in metabolic disease–toxicity regulation. Full article

(This article belongs to the Section Endocrinology and Clinical Metabolic Research)

► Show Figures

Figure 1

15 pages, 1361 KB

Open AccessArticle

Detecting and Grouping In-Source Fragments with Low-Energy Stepped HCD, Together with MS³, Increases Identification Confidence in Untargeted LC–Orbitrap Metabolomics of Plantago lanceolata Leaves and P. ovata Husk

by Vilmantas Pedišius, Tim Stratton, Lukas Taujenis, Valdas Jakštas and Vytautas Tamošiūnas

Metabolites 2026, 16(1), 42; https://doi.org/10.3390/metabo16010042 - 2 Jan 2026

Abstract

Background: Comprehensive and accurate compound composition characterization in natural sources has high relevance in food and nutrition, health and medicine, environmental and agriculture research areas, though profiling of plant metabolites is a challenging task due to the structural complexity of natural products. This [...] Read more.

Background: Comprehensive and accurate compound composition characterization in natural sources has high relevance in food and nutrition, health and medicine, environmental and agriculture research areas, though profiling of plant metabolites is a challenging task due to the structural complexity of natural products. This study delves into the identification and characterization of compounds within the Plantago genus, leveraging state-of-the-art analytical techniques. Methods: Utilizing an ultra-high-performance liquid chromatography (UHPLC) system in conjunction with Orbitrap™ IQ-X™ Tribrid™ mass spectrometer (MS), we employed a Phenyl-Hexyl HPLC column alongside optimized extraction protocols to analyze both husk and leaf samples. To maximize compound identification, we implemented data-dependent acquisition (DDA) methods including MS² (ddMS2), MS³ (ddMS3), AcquireX™ deep scan, and real-time library search (RTLS). Results: Our results demonstrate a significant increase in the number of putatively yet confidently assigned compounds, with 472 matches in P. lanceolata leaves and 233 in P. ovata husk identified through combined acquisition methods. The inclusion of an additional fragmentation level (MS³) noticeably enhanced the confidence in compound annotation, facilitating the differentiation of isomeric compounds. Furthermore, the application of low-energy fragmentation (10 normalized collision energy (NCE) for higher-energy collisional dissociation (HCD)) improved the detection and grouping of MS¹ fragments by 55% in positive mode and by 16% in negative mode, contributing to a more comprehensive analysis with minimal loss in compound identification. Conclusions: These advancements underscore the potential of our methodologies in expanding the chemical profile of plant materials, offering valuable insights into natural product analysis and dereplication of untargeted data. Full article

(This article belongs to the Section Advances in Metabolomics)

► Show Figures

Graphical abstract

16 pages, 4803 KB

Open AccessArticle

The Effect of Acute Supplementation of Branched Chain Amino Acids on Serum Metabolites During Endurance Exercise in Healthy Young Males: An Integrative Metabolomics and Correlation Analysis Based on a Randomized Crossover Study

by Xinxin Zhang, Xintang Wang, Chenglin Luan, Yizhang Wang, Junxi Li, Wei Shan, Zhen Ni, Chunyan Xu and Lijing Gong

Metabolites 2026, 16(1), 41; https://doi.org/10.3390/metabo16010041 - 2 Jan 2026

Abstract

Background: Branched-chain amino acids (BCAAs) are popular as sports supplements due to their ability to enhance performance and recovery. However, the full spectrum of metabolic alterations triggered by acute supplementation with BCAAs in conjunction with exercise remains incompletely understood. Methods: A randomized crossover [...] Read more.

Background: Branched-chain amino acids (BCAAs) are popular as sports supplements due to their ability to enhance performance and recovery. However, the full spectrum of metabolic alterations triggered by acute supplementation with BCAAs in conjunction with exercise remains incompletely understood. Methods: A randomized crossover trial was conducted in 8 healthy active young males, who received either BCAA or placebo supplementation for three consecutive days prior to a high-intensity cycling test. Plasma samples were collected pre- and post-exercise and analyzed by ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry, followed by correlation and enrichment analyses. Results: Acute BCAA supplementation was significantly associated with enhanced fat oxidation and attenuated post-exercise increases in plasma ammonia, creatine kinase, and lactate dehydrogenase, suggesting the potential improvements in energy supply and membrane stability. Metabolomics analysis identified differential metabolites primarily involved in lipid, amino acid, and glucose metabolism. Pathway enrichment revealed coordinated regulation of fatty acid oxidation (FAO) and tryptophan-related pathways. Correlation analysis further showed that changes in metabolite profiles were strongly associated with biochemical outcomes, particularly linking enhanced fat oxidation and ammonia clearance with BCAA intake. Conclusions: Short-term BCAA supplementation could enhance FAO and membrane stability via coordinated regulation of lipid and amino acid metabolism post exercise, supporting its potential role as a precision nutrition strategy. Full article

(This article belongs to the Special Issue The Role of Diet and Nutrition in Relation to Metabolic Health)

► Show Figures

Graphical abstract

13 pages, 910 KB

Open AccessArticle

Extracellular Water and Phase Angle, Markers of Heightened Inflammatory State, and Their Extrapolative Potential for Body Composition Outcomes in Adults

by Selma Cvijetić, Dario Boschiero, Hyehyung Shin, Andrew S. Reilly, Sarah T. Noorani, Nadja Vasiljevic and Jasminka Z. Ilich

Metabolites 2026, 16(1), 40; https://doi.org/10.3390/metabo16010040 - 2 Jan 2026

Abstract

Background/Aim: Extracellular-to-total body water ratio (ECW/TBW) and phase angle (PhA, PA) reflect hydration and cellular health, but their relationship with bone, muscle, and fat, as primary components of body composition, is not fully elucidated. This study aimed to evaluate sex-specific differences in body [...] Read more.

Background/Aim: Extracellular-to-total body water ratio (ECW/TBW) and phase angle (PhA, PA) reflect hydration and cellular health, but their relationship with bone, muscle, and fat, as primary components of body composition, is not fully elucidated. This study aimed to evaluate sex-specific differences in body composition and assess the diagnostic potential of ECW/TBW and PhA for identifying low bone/muscle mass, as well as increased fat mass, in generally healthy adults. Methods: This post hoc analysis utilized data from a multicenter, cross-sectional, Italian study (2010–2014) that included 20–90 years adults (n = 9717). Body composition was measured by bioelectrical impedance (BIA-ACC, BioTekna^®), assessing bone, muscle mass, fat mass, ECW, TBW, and PhA. Low bone/muscle mass, as well as adiposity, were defined using standard cutoffs. Associations were examined using nonparametric tests and multiple regression analyses. Results: The mean age of men and women was similar (mean ~48 years). Men had significantly higher body mass index (BMI), intramuscular adipose tissue (IMAT%), T-score (bone), S-score (muscle), and PhA, while women had significantly higher fat mass (FM%) and ECW/TBW. ECW/TBW showed excellent discrimination for low muscle mass (AUC 0.845–0.922) and low bone mass (AUC 0.696–0.885), outperforming PhA. Neither ECW/TBW nor PhA reliably predicted increased fat mass. Regression models indicated ECW/TBW was strongly associated with age, sex, BMI, fat mass, and bone/muscle scores (R² = 0.943), whereas PhA’s association was moderate (R² = 0.368). Conclusions: ECW/TBW and PhA reflected sex-specific differences for body composition and effectively identified low muscle and bone mass (with better predictability of the former). Both showed a limited predictive ability for fat mass. Overall, both parameters provide complementary insights into sarcopenia and osteopenia and could be used for easy and non-invasive screening for these conditions. Full article

(This article belongs to the Special Issue Changes in Body Composition (Bone, Muscle, Adipose Tissue) with Age and Accompanying Biomarkers for Each Tissue)

► Show Figures

Graphical abstract

32 pages, 5791 KB

Open AccessArticle

Metabolomics and Transcriptomics Reveal the Effects of Fermented Lycium barbarum (Goji) Berry Residue on Muscle Nutrition and Flavor Quality in Fattening Tan Sheep

by Cong Zhan, Meng Li, Dan Li, Pan Li, Qiming Zhang, Mirou Wu, Guowei Zhong and Xiaochun Xu

Metabolites 2026, 16(1), 39; https://doi.org/10.3390/metabo16010039 - 1 Jan 2026

Abstract

Background/Objectives: In the context of increasing consumer demand for high-quality meat, this study aimed to evaluate the effects of 4% fermented goji berry residue supplementation on meat quality and flavor characteristics in finishing Tan sheep. Methods: Thirty-six male lambs were randomly assigned to [...] Read more.

Background/Objectives: In the context of increasing consumer demand for high-quality meat, this study aimed to evaluate the effects of 4% fermented goji berry residue supplementation on meat quality and flavor characteristics in finishing Tan sheep. Methods: Thirty-six male lambs were randomly assigned to a control and FGB group and fed for 68 days. Results: FGB supplementation significantly enhanced Longissimus Dorsi (LD) brightness (L*), redness (a*), and crude protein content, while reducing crude fat (p < 0.05). Amino acid analysis revealed significant increases in lysine, methionine, histidine, glycine, proline, arginine, cysteine, and total sweet-tasting amino acids in the FGB group (p < 0.05). Lactate and inosine monophosphate (IMP) levels were significantly elevated, whereas hypoxanthine levels decreased (p < 0.05). Metabolomics identified 189 metabolites, with 12 differentially expressed, mainly enriched in butanoate metabolism, glycolysis/gluconeogenesis, PI3K-Akt, and HIF-1 signaling pathways. Transcriptomics revealed 382 differentially expressed genes, including key regulators of lipid metabolism (FOXO1, SLC2A4, LPIN1, IGF1, SPP1) and amino acid metabolism (COL3A1, GLUL, PSMC1). Conclusions: Fermented goji residue altered amino acid and lipid metabolism in the LD muscle of Tan sheep, affecting meat quality and flavor traits. However, effects on color (L*, a*, b*), protein content, and shear force varied across the four muscles studied, indicating that responses to supplementation are muscle-specific. These findings offer a sustainable strategy for improving meat quality and provide insights into the molecular mechanisms underlying flavor development in ruminants. Full article

(This article belongs to the Section Animal Metabolism)

► Show Figures

Graphical abstract

Journal Description

Metabolites

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Topical Collections

Further Information

Guidelines

MDPI Initiatives

Follow MDPI