Serum Metabolites Research Articles

A Comprehensive LC-MS Metabolomics Assay for Quantitative Analysis of Serum and Plasma.

Background/Objectives: Targeted metabolomics is often criticized for the limited metabolite coverage that it offers. Indeed, most targeted assays developed or used by researchers measure fewer than 200 metabolites. In an effort to both expand the coverage and improve the accuracy of metabolite quantification in targeted metabolomics, we decided to develop a comprehensive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay that could quantitatively measure more than 700 metabolites in serum or plasma. Methods: The developed assay makes use of chemical derivatization followed by reverse phase LC-MS/MS and/or direct flow injection MS (DFI-MS) in both positive and negative ionization modes to separate metabolites. Multiple reaction monitoring (MRM), in combination with isotopic standards and multi-point calibration curves, is used to detect and absolutely quantify the targeted metabolites. The assay has been adapted to a 96-well plate format to enable automated, high-throughput sample analysis. Results: The assay (called MEGA) is able to detect and quantify 721 metabolites in serum/plasma, covering 20 metabolite classes and many commonly used clinical biomarkers. The limits of detection were determined to range from 1.4 nM to 10 mM, recovery rates were from 80% to 120%, and quantitative precision was within 20%. LC-MS/MS metabolite concentrations of the NIST® SRM®1950 plasma standard were found to be within 15% of NMR quantified levels. The MEGA assay was further validated in a large dietary intervention study. Conclusions: The MEGA assay should make comprehensive quantitative metabolomics much more affordable, accessible, automatable, and applicable to large-scale clinical studies.

Metabolic Fingerprinting of Blood and Urine of Dairy Cows Affected by Bovine Leukemia Virus: A Mass Spectrometry Approach.

This study investigated metabolic changes associated with bovine leukemia virus (BLV) infection in dairy cows, focusing on pre-parturition alterations. Metabolite identification in serum and urine samples was performed using a targeted metabolomics method, employing the TMIC Prime kit in combination with flow injection analysis and liquid chromatography-tandem mass spectrometry. Of 145 cows examined, 42 (28.9%) were BLV-seropositive. Around 38% of infected cows showed high somatic cell counts indicative of subclinical mastitis, with 15 experiencing additional health issues such as ketosis, milk fever, and lameness. Despite these conditions, no significant differences in milk yield or composition were observed between the infected and control groups. Metabolomic analysis conducted at -8 and -4 weeks prepartum revealed significant metabolic differences between BLV-infected and healthy cows. At -8 weeks, 30 serum metabolites were altered, including sphingomyelins, lysophosphatidylcholines, amino acids, and acylcarnitines, suggesting disruptions in membrane integrity, energy metabolism, and immune function indicative of early neoplastic transformations. By -4 weeks, the number of altered metabolites decreased to 17, continuing to reflect metabolic disruptions in cows with leukemia. Multivariate analysis highlighted distinct metabolic profiles between infected and control cows, identifying key discriminating metabolites such as choline, aspartic acid, phenylalanine, and arginine. Urine metabolomics revealed significant prepartum shifts in metabolites related to glucose, asymmetric dimethylarginine, and pyruvic acid, among others. The research confirmed metabolomics' efficacy in defining a BLV infection metabolic profile, elucidating leukosis-associated metabolic disruptions. This approach facilitates the identification of BLV-infected cows and enhances understanding of infection pathophysiology, providing a foundation for advanced management and intervention strategies in dairy herds. The study underscores the profound impact of leukosis on metabolic processes and highlights urine metabolomics' utility in non-invasively detecting BLV infection, offering the potential for improved herd health management.

Unraveling the molecular mechanism of aqueous extract of Sargentodoxa cuneata against ulcerative colitis from serum metabolomics and bioinformatics perspectives

Symptoms of ulcerative colitis (UC) are like “intestinal carbuncle” in Chinese medicine. The aqueous extract of Sargentodoxa cuneata (AESc) has good therapeutic effects on UC, but the underlying mechanism needs to be further elucidated. The mechanism of AESc against UC was studied based on metabolomics and bioinformatics in mice with UC. Dextran sodium sulfate was applied to induce a mouse model of UC. After the intervention of AESc, the general condition of the animals was recorded, and efficacy-related indicators were measured. Information on serum metabolites was determined. Multivariate analysis combined with bioinformatics methods were used to identify the differential metabolites. Furthermore, “metabolite-target-disease” network was obtained, and differential metabolites of UC were screened, and further analysis of the metabolites were performed. Molecular docking validation was also carried out. AESc improved general conditions such as blood in stool, hair of animals, and weight loss, reduced disease activity index scores and shortening of colon length in mice with UC. A total of 3445 serum metabolites were obtained, and 64 differentiated metabolites of AESc against UC were screened. Enrichment analysis showed that arachidonic acid metabolism, bile secretion, drug metabolism-other enzymes, and tyrosine metabolism were associated with AESc in the treatment of UC. In addition, based on “metabolite-target-disease” network, the serum metabolites cholylleucine, 9,10,13-TriHOME, birabresib, anthramycin methyl ether, trans-hexadec-2-enoyl carnitine, and lucidumol A were found to have the therapeutic potential for UC. Further, 14 core targets were obtained, and lipids and atherosclerosis, rheumatoid arthritis and multiple immune-inflammatory pathways were associated with AESc for the treatment of UC. AESc corrects serum metabolic disturbances in UC mice, and multiple serum metabolites have therapeutic potential for UC. AESc may treat UC by regulating biological processes such as lipid metabolism, amino acid metabolism, thereby restoring normal physiological function of the intestine.

Astragalus polysaccharide alleviates asthma by modulating gut microbiota and serum metabolomics.

The aim of the present study was to examine the effects of Astragalus polysaccharide (APS) on gut microbiota and serum metabolites in asthmatic mice. For this purpose, a total of 36 BALB/c female mice were selected and randomly classified into the following groups: i) The normal control group sensitized with phosphate-buffered saline; ii) the asthma group sensitized and challenged with ovalbumin (OVA); iii) the OVA + APS (2.5 g/kg) treatment group; iv) the OVA + APS (5.0 g/kg) treatment group; v) the OVA + APS (10 g/kg) treatment group; and vi) the OVA + dexamethasone (2 mg/kg) treatment group, with 6 mice in each group. OVA was used to establish the mouse model of asthma. In the APS group, the asthmatic mice were intragastrically administered APS at various doses at 1 h prior to each OVA stimulation. The airway hyperreactivity (AHR) was measured, and hematoxylin and eosin staining was employed to evaluate pulmonary inflammatory infiltration. In addition, 16S rRNA sequencing and ultra-performance liquid chromatography-tandem mass spectrometry were used to detect the changes in the mouse gut microbiota and serum metabolites. The results revealed that compared with the asthma model group, APS improved airway inflammation and eosinophil infiltration in asthmatic mice. In asthmatic mice, the gut microbial imbalance mainly manifested as a low abundance of Bacteroidetes and a high abundance of Firmicutes, yielding an increased F/B ratio. In the high-dose APS group, the abundance of Firmicutes was reduced, and the abundance of Bacteroidetes was increased, which thereby decreased the F/B ratio and corrected the gut microbial imbalance. Through blood metabolomics, 145 and 105 significantly differential metabolites were detected in the medium- and high-dose APS groups, respectively. Moreover, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis demonstrated that the metabolic pathways in the medium-dose APS group included the biosynthesis of unsaturated fatty acids and the biosynthesis of arginine. On the other hand, the metabolic pathways enriched in high-dose APS group were the biosynthesis of unsaturated fatty acids, and pyrimidine metabolism. On the whole, the present study demonstrates that APS may regulate the gut microbiota and the metabolites to improve airway inflammation and AHR in asthmatic mice.

Palmitoyl-L-carnitine induces tau phosphorylation and mitochondrial dysfunction in neuronal cells.

Alzheimer's disease (AD) is characterized by cognitive decline and memory loss, involving mechanisms such as tau hyperphosphorylation and mitochondrial dysfunction. Increasing evidence suggests that age-related alterations in metabolite levels are crucial for the pathogenesis of AD. Here, we analyzed serum metabolites from mice of various ages (2, 4, 14, and 21 months old) using mass spectrometry. We identified palmitoyl-L-carnitine as a key metabolite with significantly increased levels in aged mice. In vitro experiments with SH-SY5Y neuronal cells demonstrated that palmitoyl-L-carnitine treatment enhanced tau phosphorylation, increased mitochondrial fission, and elevated intracellular calcium levels. Furthermore, the increased levels of tau phosphorylation were significantly reduced by the inhibition of GSK-3β, CDK5, and calpain, indicating that tau kinases activated by calcium overload are directly involved in the increase of tau phosphorylation. Considering that mitochondrial fission is related to mitochondrial dysfunction, we propose that the elevated level of serum palmitoyl-L-carnitine during aging contributes to AD pathology through these pathways. These findings highlight the significant role of lipid metabolism in neurodegeneration and offer potential therapeutic targets for age-related diseases, including AD.

Causal links of human serum metabolites on the risk of prostate cancer: insights from genome-wide Mendelian randomization, single-cell RNA sequencing, and metabolic pathway analysis.

Recently, serum metabolites have shown potential in predicting survival outcomes and may be related to the pathogenesis of prostate cancer. Nevertheless, the precise impact concerning the genetic effect of metabolites on prostate cancer risk remains obscure. In this context, we conducted a Mendelian randomization (MR) study aiming to explore the causality between genetically determined metabolites and the risk of prostate cancer. We conducted a two-sample MR analysis aiming to identify the underlying metabolites associated with prostate cancer. Exposure information was obtained from the largest metabolome-based genome-wide association (GWAS) data containing 7,824 Europeans. Genome-wide association analysis was utilized to detect instrumental variables (IVs) for metabolites. We applied the inverse-variance weighted (IVW) approach as the primary method, and to augment the reliability and robustness of our findings, additional analysis methods encompassing weighted median, MR-Egger, and leave-one-out analysis were utilized. MR-Egger intercept test was implemented to explore the pleiotropy. Cochran's Q test was utilized to quantify the degree of heterogeneity. Additionally, we performed metabolic pathway analysis and single-cell RNA sequencing analysis. We found that three serum metabolites were causally associated with prostate cancer after utilizing rigorous screening standards. Utilizing single nucleotide polymorphisms as IVs, a 1-SD increase in fructose was associated with 77% higher risk of prostate cancer (OR:1.77, 95%CI: 1.05-2.97, PIVW=0.031), a 1-SD increase in N1-methyl-3-pyridone-4-carboxamide was associated with 29% higher risk of prostate cancer (OR:1.29, 95%CI: 1.05-1.58, PIVW=0.017), and a 1-SD increase in 12-hydroxyeicosatetraenoate (12-HETE) was associated with 18% higher risk of prostate cancer (OR:1.18, 95%CI: 1.07-1.31, PIVW=0.0008). Metabolites that were causally linked to the risk of prostate cancer were mainly enriched in the valine, leucine and isoleucine biosynthesis pathway (P=0.026) and the nicotinate and nicotinamide metabolism pathway (P=0.048). Our MR analysis provided suggestive evidence supporting the causal relationships between three identified serum metabolites and prostate cancer, necessitating further investigation to elucidate the underlying mechanisms through which these blood metabolites and metabolic pathways may impact the initiation and progression of prostate cancer.

18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Large-Vessel Vasculitis During Active and Inactive Disease Stages Is Associated with the Metabolic Profile, but Not the Macrophage-Related Cytokines: A Proof-of-Concept Study.

Giant cell arteritis (GCA) is an autoimmune/autoinflammatory disease affecting large vessels in patients over 50 years old. The disease presents as an acute inflammatory response with two phenotypes, cranial GCA and large-vessel vasculitis (LV)-GCA, involving the thoracic aorta and its branches. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET-CT) is among the imaging techniques contributing to diagnosing patients with systemic disease. However, its association with soluble inflammatory markers is still elusive. This proof-of-concept study aims to identify novel soluble serum biomarkers in PET/CT-positive patients with LV-GCA and associate them with active (0 months) and inactive disease (6 months following treatment), in sequential samples. The most-diseased-segment target-to-background ratio (TBRMDS) was calculated for 13 LV-GCA patients, while 14 cranial GCA and 14 Polymyalgia Rheumatica patients with negative initial PET/CT scans served as disease controls. Serum macrophage-related cytokines were evaluated by cytometric bead array (CBA). Finally, previously published NMR/metabolomics data acquired from the same blood sampling were analyzed along with PET/CT findings. TBRMDS was significantly increased in active versus inactive disease (3.32 vs. 2.65, p = 0.006). The analysis identified nine serum metabolites as more sensitive to change from the active to inactive state. Among them, choline levels were exclusively altered in the LV-GCA group but not in the disease controls. Cytokine levels were not associated with PET/CT activity. Combining CRP, ESR, and TBRMDS with choline levels, a composite index was generated to distinguish active and inactive LV-GCA (20.4 vs. 11.62, p = 0.001). These preliminary results could pave the way for more extensive studies integrating serum metabolomic parameters with PET/CT imaging data to extract sensitive composite disease indexes useful for everyday clinical practice.

Serum Metabolome Signature Response to Different Types of Resistance Training.

Pneumatic resistance training (PRT) facilitates a longer time under tension that might lead to greater changes in body composition when compared to traditional resistance training (TRT), possibly enhancing serum metabolite concentrations indicative of healthy metabolic function. To assess the impact of PRT and TRT on muscular strength, body composition, and serum metabolome, 69 men (age: 31.8±7.2 years, height: 179.7±5.4 cm, weight: 81.1±9.9 kg) were randomized into two 10-week intervention groups (PRT:n=24 and TRT:n=24) and one control group (CON:n=21). Serum metabolite concentrations were assessed before and after the training intervention by high-throughput nuclear magnetic resonance. Fat mass and lean mass were obtained by bioimpedance analysis. The training intervention resulted in an increase in lean mass for both PRT (1.85±2.69%; p=0.003) and TRT (2.72±4.53%; p=0.004), while only PRT reduced statistically significantly in body fat percentage (PRT: -5.08±10.76%; p=0.019). Only in PRT and TRT significant increases in small high-density lipoproteins (S-HDL-L) and small HDL particles (S-HDL-P) were observed. When controlling for fat and lean mass, the effects on S-HDL-L/S-HDL-P diminished. Network analysis may suggest that PRT and TRT result in an increase in network connectivity and robustness. It appears that the observed improvements are associated with changes in body composition.

The association between metabolite profiles and impaired bone microstructure in adult growth hormone deficient rats

BackgroundAdult growth hormone deficiency (AGHD) is associated with an increased risk of fractures and impaired bone microstructure. Understanding the metabolic changes accompanying bone deterioration in AGHD might provide insights into mechanisms behind molecular changes and develop new biomarkers or nutritional strategies for bone destruction. Our study aimed to investigate the association between altered metabolite patterns and impaired bone microstructure in adult rats with growth hormone deficiency.MethodsThirty seven-week-aged adult Lewis dwarf homozygous (dw/dw) rats (five females and five males), and adult Lewis dwarf heterozygous (dw/ +) rats (five females and five males) rats were compared. Micro-computed tomography (Micro-CT) was used to examine the bone's microstructure. Hematoxylin and eosin (H&E) staining were used to quantify the histological characteristics. Liquid chromatography-mass spectrometry untargeted serum metabolomic analysis was applied in the study. ELISA was used to measure serum bone turnover markers and IGF-1 levels.ResultsAdult dw/dw rats exhibited great reductions in trabecular volume bone density (Tb.vBMD), bone volume/total volume (BV/TV), and cortical thickness (Ct. Th) compared with adult dw/ + rats (all p values < 0.05), indicating significant impairment in bone microstructure. The serum metabolite profiles revealed substantial differences between the dw/dw rats and dw/ + rats. A total of 134 differential metabolites in positive ion mode and 49 differential metabolites in negative mode were identified. Five metabolites, including Lysophosphatidylcholine(LPC) 20:3, LPC22:6, LPC22:4, cortisol and histamine levels were upregulated in dw/dw rats. The steroid hormone biosynthesis and bile secretion pathways were the main perturbed metabolic pathways. There were significant associations between differential metabolites and the impaired bone microstructure parameters, indicating that the selected metabolites might serve as potential biomarkers for deteriorated bone microstructure in AGHD.ConclusionAdult dw/dw rats exhibit impaired bone microstructure and distinct serum metabolic profiles, and the altered metabolites were significantly associated with bone microstructure destruction. This provides a new insight into understanding the mechanism of bone deterioration in AGHD patients from a metabolic perspective.

Chaihu Shugan powder restores fatty acid synthesis to alleviate insulin resistance in metabolic syndrome by regulating the LXRα/SREBP-1 signaling pathway.

Metabolic syndrome (MS) is a significant risk factor for cardiovascular and cerebrovascular diseases, primarily driven by insulin resistance (IR). Although the herbal compound Chaihu Shugan powder (CSP) has demonstrated the potential to improve IR in animal models of MS, its mechanism of action remains incompletely understood. Therefore, this study aimed to investigate the biological pathways through which CSP exerts its therapeutic effects on IR in MS using both in vitro and in vivo methods. The primary metabolites of CSP aqueous extract and CSP-containing serum were measured by LC-MS/MS. A mouse model of MS-related IR was induced by a high-fat, high-fructose diet combined with chronic immobilization stress. The CSP's therapeutic potential was evaluated through glucose and insulin tolerance tests and hepatic insulin signaling molecules (p-IRS-1, IRS-1, p-Akt, and Akt). The expression of lipid metabolism-related factors (FFA, DAG, LXRα, SREBP-1, FASN, and ACC) in the liver was also measured. Hepatocyte IR was modeled using high-glucose and high-insulin conditions, and CSP impact was evaluated using 2-NBDG uptake and insulin signaling molecule expression. The specific mechanism of CSP was explored using the LXRα agonist T0901317. The MS-related IR model exhibited a decreased p-Akt/Akt ratio and increased fasting glucose, insulin, homeostatic model assessment of IR, and hepatic lipid metabolism factors. Treatment with CSP mitigated these effects. In the hepatocyte IR model, CSP-containing serum improved glucose uptake and modulated the expression of insulin signaling and lipid metabolism factors. Furthermore, T0901317 reversed the beneficial effects of CSP, indicating the role of LXRα in CSP's therapeutic action. The CSP ameliorated IR in MS by restoring fatty acid metabolism through the regulation of the LXRα/SREBP-1 signaling pathway.

Gut microbiota and metabolomics unveil the mechanisms of Lomatogonium rotatum in ameliorating visceral fat and serum lipids in high-fat diet-induced obese mice.

Lomatogonium rotatum (LR) is a folk medicinal herb traditionally used as a lipid-lowering and anti-obesity agent; but its pharmacological mechanism is unclear. In this study, we assessed the alterations of LR on gut microbes and serum metabolites in obese mice and their associated mechanisms of modulation on visceral fat and serum lipid by integrating gut microbiota and metabolomics analyses. Mice were fed a high-fat diet (HFD) to generate obesity and were then given LR and Orlistat orally at different doses (0.18, 0.9, 1.8g/kg for LR and 0.048g/kg for Orlistat) for a duration of 9weeks. The impact of LR on weight loss was assessed through the examination of fat deposition, serum lipid indices, liver indices, and HE pathohistology. The effects of LR on gut microbiota and serum metabolites in obese mice were then investigated by 16S rRNA sequencing technology and untargeted metabolomics, and correlation analysis was performed. LR significantly reduced body weight, feed intake, Lee's index, visceral fat accumulation, serum TG, TC, AST and ALT, and elevated serum HDL levels in obese mice. In addition, 16S rRNA sequencing results indicated that the LR intervention remodeled microbial diversity and composition, increased the relative abundance of gut microbes Bacteroidetes and Porphyromonadaceae in HFD-induced obese mice, and decreased the Deferribacteres, Firmicutes and the Firmicutes/Bacteroidetes ratio. Correlation analyses showed that LR regulation of L-tyrosine and hesperetin metabolism, as well as alterations in the metabolic pathways of Phenylalanine, tyrosine and tryptophan biosynthesis, were associated with the changes in abundance of Bacteroidetes, Firmicutes, Porphyromonadaceae and Deferribacteres. Our study demonstrated that LR has lipid lowering and visceral fat reduction effects and its function may be closely related to the improvement of the gut microbiota and its associated metabolites.

Evaluation of Guanidinoacetic Acid Supplementation on Finishing Beef Steer Growth Performance, Skeletal Muscle Cellular Response, and Carcass Characteristics.

This study elucidated the effects of dosage-dependent guanidinoacetic acid (GAA) supplementation on growth performance, muscle responses, and carcass characteristics in finishing beef steers. Thirty crossbred Red Angus beef steers (395 ± 28.09kg) were randomly assigned one of three treatments during a 146-day feedlot study: basal diet without GAA supplementation (CONTROL), 1g of GAA per 100kg of BW daily (LOWGAA), and 2g of GAA per 100kg of BW daily (HIGHGAA). Individual feed intake was monitored daily, growth performance parameters were collected every 28 days, and longissimus muscle (LM) biopsies occurred every 56 days. In biopsied LM, greater (P = 0.048) mRNA expression of IGF-1 was observed in LOWGAA steers on d 112 compared to the CONTROL group. LOWGAA steers also exhibited greater expression of myosin heavy chain (MHC) I compared to CONTROL steers (P < 0.05) and MHC IIA compared to both CONTROL and HIGHGAA treatment groups (P < 0.01) on d 112. GAA supplementation resulted in no change in carcass characteristics, serum and LM tissue metabolites, LM composition, and Warner-Bratzler shear force (WBSF) values (P > 0.05). Data collected from this study demonstrate the influence of GAA supplementation on the gene expression of MHC isoforms and their role in skeletal muscle growth, differentiation, and muscle fiber-typing.

Altered serum metabolome is associated with disease activity and immune responses in rheumatoid arthritis

Rheumatoid arthritis (RA) is widespread globally, with the emergence of metabolites derived from both the host and microbes playing a pivotal role in its pathogenesis. This study aims to elucidate the relationships between serum metabolites and the immunological and clinical features of RA. Serum samples were collected from 35 RA patients and 37 healthy controls (HC). Metabolite profiling was performed using gas chromatography-mass spectrometry (GC/MS). Principal component analysis revealed a significant distinction between the RA and HC cohorts. Employing univariate statistical analysis, we identified 36 differential metabolites. Among these, 9 metabolites, including galactose and glucose, were found to be enriched, while the remaining metabolites, such as citric acid, fumaric acid, and inosine, were depleted in RA. These diverse metabolites encompassed various metabolic processes, including the biosynthesis of fatty acids, amino acids, and glucose. The enrichment of glucose and galactose in RA exhibited a substantial correlation with elevated IgG levels, as determined through correlation analysis. Conversely, the depletion of citric acid was correlated with elevated levels of C3 and CRP. Methionine, which also declined in RA patients, displayed a negative correlation with ESR. Furthermore, galactose and glucose exhibited significant positive correlations with naïve B cells, while the decreased eicosanoic acid level in RA was significantly associated with an increase in natural killer cells. Our findings suggest that the altered serum metabolite profile in RA is closely linked to disease severity and the dysregulated immune responses observed in RA patients. Key Points• Identified nine metabolites with upregulated expression and twenty-seven metabolites with downregulated expression.• Established a correlation between alterations in serum metabolite levels and inflammatory markers in RA patients.• Discovered a significant association between changes in serum metabolites and immune cell profiles in RA patients.

Intestinal microbiota-mediated serum pharmacochemistry reveals hepatoprotective metabolites of Platycodonis Radix against APAP-induced liver injury

The urgent need for new medications that regulate CYP2E1, CASP3, Nrf2, HO-1, TLR2, TLR4, STAT3, and NF-κB activities is paramount for the treatment of drug-induced liver injury (DILI), particularly from acetaminophen (APAP). Previous studies have suggested that platycosides of Platycodonis Radix exhibits hepatoprotective properties against APAP-induced liver injury (AILI), and their serum metabolites may be the effective agents. As the identify the serum metabolites of platycosides is a huge challenge, the mechanism whether platycosides exert effects through the serum metabolites regulating those targets still remain unclear. In this study, we propose a novel method termed intestinal microbiota-mediated serum pharmacochemistry (IMSP) to identify the serum metabolite profile of platycosides, using deglycosylated platycosides as template molecules. Our results identified a total of 44 prototype platycosides in the total platycosides fraction of Platycodonis Radix (PF). In rat serum, we identified 12 prototype platycosides and 45 metabolites derived from the 44 platycosides. Furthermore, our findings indicate that all 44 platycosides can enter the serum in the form of metabolites. The presence of these metabolites in serum is closely related to their oral bioavailability and the content of the prototypes. The in vivo animal experiments showed that the PF possessed significant anti-AILI effects and CYP2E1, CASP3, Nrf2, HO-1, TLR2, TLR4, STAT3, and NF-κB p65 regulation activities. And the in vitro cell experiments and molecular docking analyses further demonstrated that the hepatoprotective effects were mainly ascribed to the serum metabolites, which regulating targets of CYP2E1, CASP3, Nrf2, HO-1, TLR2, TLR4, STAT3, and NF-κB p65. Additionally, the activities of these metabolites are closely associated with their structures. In summary, the IMSP method significantly enhances the ability to identify platycoside metabolites in serum, reveals that all platycosides may contribute to anti-AILI activity through their metabolites, PF and some of these metabolites are promising candidate compounds for developing new medications with anti-AILI effects for the first time.

Association between seizure reduction during ketogenic diet treatment of epilepsy and changes in circulatory metabolites and gut microbiota composition

The ketogenic diet (KD) is a high fat, sufficient protein, and low carbohydrate dietary therapy for drug-resistant epilepsy. The underlying mechanisms of action of the KD remain unclear. In mice, the microbiota is necessary for the anti-seizure effect and specific microbes influence circulatory levels of metabolites that are linked to seizure reduction. However, it remains unclear which changes are linked to seizure reduction in patients with epilepsy. We analysed the serum metabolome of children with drug-resistant epilepsy (n=14) before and after three months on KD. Metabolomic changes were correlated to the gut microbiome and treatment outcome, i.e., seizure reduction. In this prospective observational study, we uncovered associations between microbial species and serum metabolites that correlated with seizure reduction. Plasmalogens were most strongly linked to seizure reduction and had significant positive correlations with several gut microbes (e.g., Faecalibacterium prausnitzii, Alistipes communis, Alistipes shahii, and Christensenella minuta) while significant negative correlations were found for five strains of Escherichia coli. Infant-type Bifidobacteria correlated negatively with other metabolites associated with seizure reduction. The microbes and metabolites identified here may contribute to the therapeutic effect of the KD in children with drug-resistant epilepsy. Several of these metabolites (e.g., plasmalogens) play important roles in neurobiology and may influence seizures. Based on our findings, anti-seizure therapeutic strategies could be developed involving the targeted manipulation of the gut microbiota and/or its metabolites. This study was supported by the Swedish Brain Foundation, Margarethahemmet Society, Sunnerdahls Handikappfond, Stockholm County Council Research Funds, and Linnea & Josef Carlssons Foundation.

Curcuma longa rhizome extract activates brown adipocytes and inhibits lipogenesis in high-fat diet-fed mice

Interactions between the gut, adipose, and liver tissues play important roles in metabolic endotoxemia and gut dysbiosis. This study explored the effectiveness of Curcuma longa rhizome extract (CRE) in improving high-fat diet (HFD)-induced metabolic disorders and modulating gut environments. CRE treatment inhibited lipid accumulation in 3T3-L1 white adipocytes and activated thermogenesis-related genes in T37i brown adipocytes. CRE was administered to HFD-fed mice for 8 weeks, and serum, feces, colon, white adipose, and liver tissue were analyzed. CRE ameliorated the symptoms of metabolic disorders in mice with HFD-induced obesity by suppressing body weight and fat mass gain, adipocyte size, insulin resistance, and hepatic steatosis. CRE regulated gut axis-based mechanisms by inhibiting gut permeability, metabolic endotoxemia, and de novo lipogenesis, and promoting gut barrier integrity. Serum metabolites were negatively correlated with most biomarkers for metabolic disorders. Therefore, CRE could alleviate metabolic disorders by improving the intestinal environment and modulating the gut axis.

Alterations in Gut Microbiota and Serum Metabolites in Children with Mycoplasma pneumoniae Pneumonia.

Over the past years, there has been a significant increase in the incidence of Mycoplasma pneumoniae (MP) infections, particularly among pediatric patients, nationwide. An emerging body of research has established a link between dysbiosis of the host microbiome and the metabolic functioning of the host, which contributes to the development of respiratory diseases. A total of 25 children were included in the study, comprising 15 pneumonia patients and 10healthy children. Stool samples were collected from all participants to analyze the 16S ribosomal RNA (16S rRNA) gene, while serum samples were prepared for untargeted metabolomics to qualitatively and quantitatively assess short-chain fatty acids. The gut microbial composition of individuals with Mycoplasma pneumoniae pneumonia (MPP) exhibited significant differences compared to healthy children. Notably, diseased children demonstrated higher microbial diversity and an enrichment of opportunistic pathogens, such as Erysipelatoclostridium and Eggerthella. Analysis revealed elevated levels of two specific short-chain fatty acids, namely acetic acid and isobutyric acid, in the MPP group, suggesting their potential as biomarkers for predicting MP infection. Metabolomic signature analysis identified a significant increase in major classes of glycerophospholipids in the MPP group. Moreover, we identified a total of 750 significant correlations between gut microbiota and circulating serum metabolites. MPP enriched genera Erysipelatoclostridium and Eggerthella, exhibited negative associations with indole-3-butyric acid. Additionally, Eggerthella showed a positive correlation with inflammatory metabolites LPC (18:0). Collectively, these findings provide novel insights into the selection of potential biomarkers and the pathogenesis of MPP in children based on the gut microbiota and systemic circulating metabolites.

Improvement of sleep quality and sub-health conditions through pasteurized fermented milk consumption: A human intervention study

The sub-health state refers to a transitional condition between optimal health and disease, impacting physical, psychological, and social well-being. In this 42-day human intervention trial, we investigated the effects of two pasteurized fermented milks on sub-health symptoms. These pasteurized fermented milks shared the same starter culture and probiotic strains (Lacticaseibacillus paracasei PC-01, Lactiplantibacillus plantarun Lp-6, Lactobacillus helveticus H9, and Bifidobacterium animalis subsp. lactis Probio-M8), differing only in the presence of inulin. Qualified subjects were randomly assigned to the probiotic group (received milk without inulin; n = 49 or synbiotic group (received milk with inulin; n = 51). Outcome measures included Sub-Health Measurement Scale (SHMS) and Pittsburgh Sleep Quality Index (PSQI) scores, fecal metagenomes, metabolomes, and short-chain fatty acids, and serum neurotransmitter levels at baseline, after a 4-week intervention (day 28), and a 2-week-follow-up period (day 42). Our results showed that both pasteurized fermented milks improved sleep quality and alleviated sub-health symptoms, with no significant added benefit from inulin. Fecal metagenome analysis revealed post-interventional changes in gut microbial composition, including increased Bifidobacterium longum and decreased potentially pro-inflammatory bacteria (Blautia sp. and Dorea sp.). Changes in Blautia sp. and B. longum correlated significantly with SHMS and PSQI scores, respectively. Fecal and serum metabolite analysis showed post-interventional modulation of fecal short-chain fatty acids, anti-inflammatory bioactive metabolites, and serum neurotransmitters such as gamma-aminobutyric and serotonin hydrochloride. In conclusion, pasteurized fermented milk intake alleviated sub-health symptoms, affected the gut microbiome, metabolome, and serum metabolites. These findings highlight the potential of pasteurized fermented milk for mitigating sub-health conditions.

Variable glucagon metabolic actions in diverse mouse models of obesity and type 2 diabetes

ObjectiveThe study aimed to investigate the effects of glucagon on metabolic pathways in mouse models of obesity, fatty liver disease, and type 2 diabetes (T2D) to determine the extent and variability of hepatic glucagon resistance in these conditions. MethodsWe investigated glucagon's effects in mouse models of fatty liver disease, obesity, and type 2 diabetes (T2D), including male BKS-db/db, high-fat diet-fed, and western diet-fed C57Bl/6 mice. Glucagon tolerance tests were performed using the selective glucagon receptor agonist acyl-glucagon (IUB288). Blood glucose, serum and liver metabolites include lipids and amino acids were measured. Additionally, liver protein expression related to glucagon signalling and a comprehensive liver metabolomics were performed. ResultsWestern diet-fed mice displayed impaired glucagon response, with reduced blood glucose and PKA activation. In contrast, high-fat diet-fed and db/db mice maintained normal glucagon sensitivity, showing significant elevations in blood glucose and phospho-PKA motif protein expression. Acyl-glucagon treatment also lowered liver alanine and histidine levels in high-fat diet-fed mice, but not in western diet-fed mice. Additionally, some amino acids, such as methionine, were increased by acyl-glucagon only in chow diet control mice. Despite normal glucagon sensitivity in PKA signalling, db/db mice had a distinct metabolomic response, with acyl-glucagon significantly altering 90 metabolites in db/+ mice but only 42 in db/db mice, and classic glucagon-regulated metabolites, such as cyclic adenosine monophosphate (cAMP), being less responsive in db/db mice. ConclusionsThe study reveals that hepatic glucagon resistance in obesity and T2D is complex and not uniform across metabolic pathways, underscoring the complexity of glucagon action in these conditions.

Sucla2 Knock-Out in Skeletal Muscle Yields Mouse Model of Mitochondrial Myopathy With Muscle Type-Specific Phenotypes.

Pathogenic variants in subunits of succinyl-CoA synthetase (SCS) are associated with mitochondrial encephalomyopathy in humans. SCS catalyses the conversion of succinyl-CoA to succinate coupled with substrate-level phosphorylation of either ADP or GDP in the TCA cycle. This report presents a muscle-specific conditional knock-out (KO) mouse model of Sucla2, the ADP-specific beta subunit of SCS, generating a novel invivo model of mitochondrial myopathy. The mouse model was generated using the Cre-Lox system, with the human skeletal actin (HSA) promoter driving Cre-recombination of a CRISPR-Cas9-generated Sucla2 floxed allele within skeletal muscle. Inactivation of Sucla2 was validated using RT-qPCR and western blot, and both enzyme activity and serum metabolites were quantified by mass spectrometry. To characterize the model invivo, whole-body phenotyping was conducted, with mice undergoing a panel of strength and locomotor behavioural assays. Additionally, exvivo contractility experiments were performed on the soleus (SOL) and extensor digitorum longus (EDL) muscles. SOL and EDL cryosections were also subject to imaging analyses to assess muscle fibre-specific phenotypes. Molecular validation confirmed 68% reduction of Sucla2 transcript within the mutant skeletal muscle (p < 0.001) and 95% functionally reduced SUCLA2 protein (p < 0.0001). By 3 weeks of age, Sucla2 KO mice were 44% the size of controls by body weight (p < 0.0001). Mutant mice also exhibited 34%-40% reduced grip strength (p < 0.01) and reduced spontaneous exercise, spending about 88% less cumulative time on a running wheel (p < 0.0001). Contractile function was also perturbed in a muscle-specific manner; although no genotype-specific deficiencies were seen in EDL function, SUCLA2-deficient SOL muscles generated 40% less specific tetanic force (p < 0.0001), alongside slower contraction and relaxation rates (p < 0.001). Similarly, a SOL-specific threefold increase in mitochondria (p < 0.0001) was observed, with qualitatively increased staining for both COX and SDH, and the proportion of Type 1 myosin heavy chain expressing fibres within the SOL was nearly doubled (95% increase, p < 0.0001) in the Sucla2 KO mice compared with that in controls. SUCLA2 loss within murine skeletal muscle yields a model of SCS-deficient mitochondrial myopathy with reduced body weight, muscle weakness and exercise intolerance. Physiological and morphological analyses of hindlimb muscles showed remarkable differences in exvivo function and cellular consequences between the EDL and SOL muscles, with SOL muscles significantly more impacted by Sucla2 inactivation. This novel model will provide an invaluable tool for investigations of muscle-specific and fibre type-specific pathogenic mechanisms to better understand SCS-deficient myopathy.