Combining MALDI-MS with Machine Learning for Metabolomic Characterization of Lung Cancer Patient Sera

An increasing amount of evidence have proven that serum metabolites can instantly reflect disease states. Therefore, sensitive and reproducible detection of serum metabolites in a high-throughput way is urgently desirable...

Hormone Replacement Therapy Reverses Gut Microbiome and Serum Metabolome Alterations in Premature Ovarian Insufficiency

ObjectiveWe explored the gut microbiome and serum metabolome alterations in patients with premature ovarian insufficiency (POI) and the effects of hormone replacement therapy (HRT) with the aim to unravel the pathological mechanism underlying POI.MethodsFecal and serum samples obtained from healthy females (HC, n = 10) and patients with POI treated with (n = 10) or without (n = 10) HRT were analyzed using 16S rRNA gene sequencing and untargeted metabolomics analysis, respectively. Peripheral blood samples were collected to detect serum hormone and cytokine levels. Spearman’s rank correlation was used to evaluate correlations between sex hormones and cytokines and between the gut microbiota and serum metabolites. To further confirm the correlation between Eggerthella and ovarian fibrosis, the mice were inoculated with Eggerthella lenta (E. lenta) through oral gavage.ResultsThe abundance of genus Eggerthella significantly increased in the fecal samples of patients with POI compared to that observed in the samples of HCs. This increase was reversed in patients with POI treated with HRT. Patients with POI showed significantly altered serum metabolic signatures and increased serum TGF-β1 levels; this increase was reversed by HRT. The abundance of Eggerthella was positively correlated with altered metabolic signatures, which were, in turn, positively correlated with serum TGF-β1 levels in all subjects. Estrogen ameliorated ovarian fibrosis induced by E. lenta in mice.ConclusionsThe interactions between the gut microbiota, serum metabolites, and serum TGF-β1 in patients with POI may play a critical role in the development of POI. HRT not only closely mimicked normal ovarian hormone production in patients with POI but also attenuated gut microbiota dysbiosis and imbalance in the levels of serum metabolites and TGF-β1, which are reportedly associated with fibrosis. The findings of this study may pave the way for the development of preventive and curative therapies for patients with POI.

Gut Microbiota and Serum Metabolic Signatures of High-Fat-Induced Bone Loss in Mice

BackgroundAccumulating evidence indicates that high-fat diet (HFD) is a controllable risk factor for osteoporosis, but the underlying mechanism remains to be elucidated. As a primary biological barrier for nutrient entry into the human body, the composition and function of gut microbiota (GM) can be altered rapidly by HFD, which may trigger abnormal bone metabolism. In the current study, we analyzed the signatures of GM and serum metabolomics in HFD-induced bone loss and explored the potential correlations of GM and serum metabolites on HFD-related bone loss.MethodsWe conducted a mouse model with HFD-induced bone loss through a 12-week diet intervention. Micro-CT, Osmium-μCT, and histological analyses were used to observe bone microstructure and bone marrow adipose tissue. Quantitative Real-Time PCR was applied to analyze gene expression related to osteogenesis, adipogenesis, and osteoclastogenesis. Enzyme-linked immunosorbent assay was used to measure the biochemical markers of bone turnover. 16s rDNA sequencing was employed to analyze the abundance of GM, and UHPLC-MS/MS was used to identify serum metabolites. Correlation analysis was performed to explore the relationships among bone phenotypes, GM, and the metabolome.ResultsHFD induced bone loss accompanied by bone marrow adipose tissue expansion and bone formation inhibition. In the HFD group, the relative abundance of Firmicutes was increased significantly, while Bacteroidetes, Actinobacteria, Epsilonbacteraeota, and Patescibacteria were decreased compared with the ND group. Association analysis showed that thirty-two bacterial genera were significantly related to bone volume per tissue volume (BV/TV). One hundred and forty-five serum metabolites were identified as differential metabolites associated with HFD intervention, which were significantly enriched in five pathways, such as purine metabolism, regulation of lipolysis in adipocyte and cGMP-PKG signaling pathway. Sixty-four diffiential metabolites were matched to the MS2 spectra; and ten of them were positively correlated with BV/TV and five were negatively correlated with BV/TV.ConclusionsThese findings indicated that the alternations of GM and serum metabolites were related to HFD-induced bone loss, which might provide new insights into explain the occurrence and development of HFD-related osteoporosis. The regulatory effects of GM and metabolites associated with HFD on bone homeostasis required further exploration.

Metabolomics Profile in Acute Respiratory Distress Syndrome By Nuclear Magnetic Resonance Spectroscopy In Patients With Community-Acquired Pneumonia

Background: Acute respiratory distress syndrome (ARDS) is a challenging clinical problem. To date, no standardized diagnostic biomarker has been validated for community-acquired pneumonia (CAP)-induced ARDS. An integrated analysis of changes in the metabolic profile could help detect biomarkers for early prediction of ARDS development and evaluation of treatment efficacy.Methods: A total of 88 patients were enrolled for the final analysis and divided into two groups: the ARDS group (n = 43) and the no-ARDS group (n = 45). We examined differences in serum and urine metabolites and explored dynamic changes with nuclear magnetic resonance (NMR) spectroscopy.Results: A total of 20 serum and 42 urine metabolites were identified using NMR spectroscopy. Serum metabolites, including leucine, 3-hydroxybutyrate, lactate, acetone, citrate, and choline, and urine metabolites, including creatine and creatinine, could distinguish patients with CAP with and without ARDS, with areas under the receiver operating characteristic curve (AUC) values of 0.790 and 0.747, respectively. The treatment efficacy of patients with ARDS was achieved at an AUC of 0.862 with serum metabolites 3-hydroxybutyrate, lactate, acetone, acetoacetate, citrate, and choline, and of 0.691 with urine metabolites taurine and glucose. The treatment efficacy of patients without ARDS was achieved at an AUC of 0.845 with serum metabolites alanine, acetate, acetoacetate, glutamine, creatine, and glucose and 0.891 with urine metabolites choline, tryptamine, and 3-indoxyl sulfate. We also proposed a combined biomarker of associated serum and urine metabolites to predict ARDS in patients with CAP (AUC = 0.865) and evaluate treatment efficacy for patients with and without ARDS (AUC = 0.921 and 0.893, respectively).Conclusions: Serum and urine analyses showed that metabolomics provides potential circulatory markers for early prediction and evaluation of treatment efficacy in patients with CAP with and without ARDS.

Effect of protein and glucogenic precursor supplementation on forage digestibility, serum metabolites, energy utilization, and rumen parameters in sheep

Supplementation of glucogenic precursors in roughage diets may increase production responses due to improved efficiencies of nutrient utilization. Therefore, the objective of this study was to determine the effect of source of supplemental glucogenic potential (GP) on forage digestibility, serum metabolites, energy utilization, and rumen parameters of growing wethers consuming a roughage diet (8.8% crude protein, 71.4% ash-free neutral detergent fiber). Crossbred wethers (49.1 ± 4.7 kg initial BW; n = 16) were utilized in a 4 × 4 replicated Latin Square design with four periods of 21 d. Supplements were designed to supplement increasing amount of GP: (1) no supplementation (CON; 0 g), (2) 40 g of calcium propionate (CAP; 30 g of GP), (3) 70 g of blood meal + 100 g of feather meal (BF; 40 g of GP), or (4) combination of CAP and BF (COMBO; 70 g of GP). Total fecal and urine collection was conducted from d 13 – 17 to calculate digestibility estimates and urinary losses. An acetate tolerance test was administered on d 17 to determine the effect of GP on acetate clearance. Blood samples were collected on d 19 and were analyzed for serum concentrations of glucose, urea N (SUN), non-esterified fatty acids, and amino acids. Rumen fluid was collected on d 21 to determine supplementation effects on ruminal volatile fatty acid (VFA) and ammonia concentrations. Wethers receiving BF and COMBO supplementation had greatest (P ≤ 0.01) DM and OM total tract digestibility. Supplementation did not affect (P ≥ 0.37) NDF digestibility or digestible energy. Urinary nitrogen excretion was greatest (P = 0.02) for BF and COMBO. Circulating serum essential amino acid concentration was increased (P < 0.01) in BF and COMBO compared to CAP and CON. In addition, BF and COMBO had increased (P < 0.01) SUN concentrations compared to CAP and CON. Acetate half-life was not affected (P = 0.39) by supplementation strategy. However, area under the curve (AUC) for acetate was decreased (P = 0.04) with supplementation of BF and COMBO compared to CON-fed wethers. Ruminal propionate concentration was increased (P ≤ 0.01) for wethers fed CAP and COMBO supplementation, which resulted in decreased (P ≤ 0.01) A:P ratio. Overall, these results indicate that the increased propionate supply by providing propionate salts did not result in a protein sparing impact or increased N retention.

Effects of Sporisorium Reiliana Polysaccharides and Phoenix Dactylifera Monosaccharides on the Gut Microbiota and Serum Metabolism in Mice with Fructose-Induced Hyperuricaemia

In recent decades, the prevalence of hyperuricaemia has increased, and dietary fructose is an important risk factor for the development of this disease. This study investigated and compared the effects of Sphacelotheca reiliana polysaccharides and Phoenix dactylifera monosaccharides on a series of physiological and biochemical indicators and on metagenomes and serum metabolites in mice with hyperuricaemia caused by a high-fructose diet. S. reiliana polysaccharides inhibited uric acid biosynthesis and promoted uric acid excretion, thereby alleviating the hyperuricaemia phenotype. In addition, hyperuricaemia was closely related to the gut microbiota. After treatment with S. reiliana polysaccharides, the abundance of Bacteroidetes and Proteobacteria in the mouse intestines was decreased, the expression of genes involved in glycolysis/gluconeogenesis metabolic pathways and purine metabolism was downregulated, and the dysfunction of the gut microbiota was alleviated. With regard to serum metabolism, the abundance of hippuric acid, uridine, kynurenic acid, propionic acid and arachidonoyl decreased, and the abundance of serum metabolites in inflammatory pathways involved in kidney injury and gout, such as bile acid metabolism, purine metabolism and tryptophan metabolism pathways, decreased. P. dactylifera monosaccharides aggravated hyperuricaemia. This research provides a valuable reference for the development of sugar applications.

Effects of Serum Metabolites on the Pancreatic Transcriptome in Acute Acalculous Cholecystitis

Background. To provide a basis for the diagnosis and treatment of acalculous biliary pancreatitis, this study investigated the impact of serum metabolites on the pancreatic transcriptome in acute acalculous cholecystitis (AAC). Methods. Fourteen rabbits were randomly divided into two groups (a normal control group of 7 rabbits and an AAC group of 7 rabbits), blood was collected from the 14 rabbits, and metabolomic analysis was performed through 1H NMR. Two pancreatic tissue chips of the AAC group and the normal control group were prepared and sequenced. We utilized the limma package of R software, the DAVID database, the STRING database, Cytoscape software, and the CFinder analysis tool to perform differential expression gene analysis, gene function enrichment analysis, protein interaction network (PPI) construction, and network module mining, and we performed gene enrichment analysis in each module. Results. Serum metabolism analysis showed that in AAC, the metabolism of sugar, lipids, and protein, that is, the three major nutrients, was affected to varying degrees, and levels of serum trimethylamine N-oxide (TMAO) increased. Bioinformatic methods were utilized to identify a total of 183 differentially expressed genes and 3 key genes. Enrichment analysis showed that differentially expressed genes were significantly enriched in cation transport, the inflammatory response, the NF-κB pathway, and the cancer signaling pathway. Conclusion. Metabolomic analysis and functional analysis of 3 key genes demonstrated that abnormal serum metabolites affected the pancreatic transcriptome and induced a sensitive state of inflammation in the pancreas. These metabolites may represent important targets for future research on the pathogenesis, clinical diagnosis, and treatment of noncalculous biliary pancreatitis.