Altering environmental conditions induce shifts in simulated deep terrestrial subsurface bacterial communities-Secretion of primary and secondary metabolites.

The deep terrestrial subsurface (DTS) harbours a striking diversity of microorganisms. However, systematic research on microbial metabolism, and how varying groundwater composition affects the bacterial communities and metabolites in these environments is lacking. In this study, DTS groundwater bacterial consortia from two Fennoscandian Shield sites were enriched and studied. We found that the enriched communities from the two sites consisted of distinct bacterial taxa, and alterations in the growth medium composition induced changes in cell counts. The lack of an exogenous organic carbon source (ECS) caused a notable increase in lipid metabolism in one community, while in the other, carbon starvation resulted in low overall metabolism, suggesting a dormant state. ECS supplementation increased CO2 production and SO4 2- utilisation, suggesting activation of a dissimilatory sulphate reduction pathway and sulphate-reducer-dominated total metabolism. However, both communities shared common universal metabolic features, most probably involving pathways needed for the maintenance of cell homeostasis (e.g., mevalonic acid pathway). Collectively, our findings indicate that the most important metabolites related to microbial reactions under varying growth conditions in enriched DTS communities include, but are not limited to, those linked to cell homeostasis, osmoregulation, lipid biosynthesis and degradation, dissimilatory sulphate reduction and isoprenoid production.

Alterations in inflammasome-related immunometabolites in individuals with severe psychiatric disorders.

INTRODUCTION: Psychiatric disorders are common and significantly impact the quality of life. Inflammatory processes are proposed to contribute to the emergence of psychiatric disorders. In addition to inflammation, disturbances in metabolic pathways have been observed in individuals with different psychiatric disorders. A suggested key player in the interaction between inflammation and metabolism is the Nod-like receptor 3 (NLRP3) inflammasome, and NLRP3 is known to react to a number of specific metabolites. However, little is known about the interplay between these immunometabolites and the NLRP3 inflammasome in mental health disorders. AIM: To assess the interplay between immunometabolites and inflammasome function in a transdiagnostic cohort of individuals with severe mental disorders. METHODS: Mass spectrometry-based analysis of selected immunometabolites, previously known to affect inflammasome function, were performed in plasma from low-functioning individuals with severe mental disorders (n = 39) and sex and aged-matched healthy controls (n = 39) using a transdiagnostic approach. Mann Whitney U test was used to test differences in immunometabolites between psychiatric patients and controls. To assess the relationship between inflammasome parameters, disease severity, and the immunometabolites, Spearman's rank-order correlation test was used. Conditional logistic regression was used to control for potential confounding variables. Principal component analysis was performed to explore immunometabolic patterns. RESULTS: Among the selected immunometabolites (n = 9), serine, glutamine, and lactic acid were significantly higher in the patient group compared to the controls. After adjusting for confounders, the differences remained significant for all three immunometabolites. No significant correlations were found between immunometabolites and disease severity. CONCLUSION: Previous research on metabolic changes in mental disorders has not been conclusive. This study shows that severely ill patients have common metabolic perturbations. The changes in serine, glutamine, and lactic acid could constitute a direct contribution to the low-grade inflammation observed in severe psychiatric disorders.

Lipidomics in nutrition research.

PURPOSE OF REVIEW: This review focuses on the recent findings from lipidomics studies as related to nutrition and health research. RECENT FINDINGS: Several lipidomics studies have investigated malnutrition, including both under- and overnutrition. Focus has been both on the early-life nutrition as well as on the impact of overfeeding later in life. Multiple studies have investigated the impact of different macronutrients in lipidome on human health, demonstrating that overfeeding with saturated fat is metabolically more harmful than overfeeding with polyunsaturated fat or carbohydrate-rich food. Diet rich in saturated fat increases the lipotoxic lipids, such as ceramides and saturated fatty-acyl-containing triacylglycerols, increasing also the low-density lipoprotein aggregation rate. In contrast, diet rich in polyunsaturated fatty acids, such as n-3 fatty acids, decreases the triacylglycerol levels, although some individuals are poor responders to n-3 supplementation. SUMMARY: The results highlight the benefits of lipidomics in clinical nutrition research, also providing an opportunity for personalized nutrition. An area of increasing interest is the interplay of diet, gut microbiome, and metabolome, and how they together impact individuals' responses to nutritional challenges.

Metabolic changes in cucumber leaves are enhanced by blue light but differentially affected by UV interactions with light signalling pathways in the visible spectrum.

Ultraviolet radiation (UV, 280-400 nm) as an environmental signal triggers metabolic acclimatory responses. However, how different light qualities affect UV acclimation during growth is poorly understood. Here, cucumber plants (Cucumis sativus) were grown under blue, green, red, or white light in combination with UV. Their effects on leaf metabolites were determined using untargeted metabolomics. Blue and white growth light triggered increased levels of compounds related to primary and secondary metabolism, including amino acids, phenolics, hormones, and compounds related to sugar metabolism and the TCA cycle. In contrast, supplementary UV in a blue or white light background decreased leaf content of amino acids, phenolics, sugars, and TCA-related compounds, without affecting abscisic acid, auxin, zeatin, or jasmonic acid levels. However, in plants grown under green light, UV induced increased levels of phenolics, hormones (auxin, zeatin, dihydrozeatin-7-N-dihydrozeatin, jasmonic acid), amino acids, sugars, and TCA cycle-related compounds. Plants grown under red light with UV mainly showed decreased sugar content. These findings highlight the importance of the blue light component for metabolite accumulation. Also, data on interactions of UV with green light on the one hand, and blue or white light on the other, further contributes to our understanding of light quality regulation of plant metabolism.

Saturated Fat Is More Metabolically Harmful for the Human Liver Than Unsaturated Fat or Simple Sugars.

OBJECTIVE: Nonalcoholic fatty liver disease (i.e., increased intrahepatic triglyceride [IHTG] content), predisposes to type 2 diabetes and cardiovascular disease. Adipose tissue lipolysis and hepatic de novo lipogenesis (DNL) are the main pathways contributing to IHTG. We hypothesized that dietary macronutrient composition influences the pathways, mediators, and magnitude of weight gain-induced changes in IHTG. RESEARCH DESIGN AND METHODS: We overfed 38 overweight subjects (age 48 ± 2 years, BMI 31 ± 1 kg/m2, liver fat 4.7 ± 0.9%) 1,000 extra kcal/day of saturated (SAT) or unsaturated (UNSAT) fat or simple sugars (CARB) for 3 weeks. We measured IHTG (1H-MRS), pathways contributing to IHTG (lipolysis ([2H5]glycerol) and DNL (2H2O) basally and during euglycemic hyperinsulinemia), insulin resistance, endotoxemia, plasma ceramides, and adipose tissue gene expression at 0 and 3 weeks. RESULTS: Overfeeding SAT increased IHTG more (+55%) than UNSAT (+15%, P < 0.05). CARB increased IHTG (+33%) by stimulating DNL (+98%). SAT significantly increased while UNSAT decreased lipolysis. SAT induced insulin resistance and endotoxemia and significantly increased multiple plasma ceramides. The diets had distinct effects on adipose tissue gene expression. CONCLUSIONS: Macronutrient composition of excess energy influences pathways of IHTG: CARB increases DNL, while SAT increases and UNSAT decreases lipolysis. SAT induced the greatest increase in IHTG, insulin resistance, and harmful ceramides. Decreased intakes of SAT could be beneficial in reducing IHTG and the associated risk of diabetes.

High-dose simvastatin exhibits enhanced lipid-lowering effects relative to simvastatin/ezetimibe combination therapy.

Statins are the frontline in cholesterol reduction therapies; however, their use in combination with agents that possess complimentary mechanisms of action may achieve further reductions in low-density lipoprotein cholesterol. Thirty-nine patients were treated with either 80 mg simvastatin (n=20) or 10 mg simvastatin plus 10 mg ezetimibe (n=19) for 6 weeks. Dosing was designed to produce comparable low-density lipoprotein cholesterol reductions, while enabling assessment of potential simvastatin-associated pleiotropic effects. Baseline and post-treatment plasma were analyzed for lipid mediators (eg, eicosanoids and endocannabinoids) and structural lipids by liquid chromatography tandem mass spectrometry. After statistical analysis and orthogonal projections to latent structures multivariate modeling, no changes were observed in lipid mediator levels, whereas global structural lipids were reduced in response to both monotherapy (R(2)Y=0.74; Q(2)=0.66; cross-validated ANOVA P=7.0×10(-8)) and combination therapy (R(2)Y=0.67; Q(2)=0.54; cross-validated ANOVA P=2.6×10(-5)). Orthogonal projections to latent structures modeling identified a subset of 12 lipids that classified the 2 treatment groups after 6 weeks (R(2)Y=0.65; Q(2)=0.61; cross-validated ANOVA P=5.4×10(-8)). Decreases in the lipid species phosphatidylcholine (15:0/18:2) and hexosyl-ceramide (d18:1/24:0) were the strongest discriminators of low-density lipoprotein cholesterol reductions for both treatment groups (q<0.00005), whereas phosphatidylethanolamine (36:3e) contributed most to distinguishing treatment groups (q=0.017). Shifts in lipid composition were similar for high-dose simvastatin and simvastatin/ezetimibe combination therapy, but the magnitude of the reduction was linked to simvastatin dosage. Simvastatin therapy did not affect circulating levels of lipid mediators, suggesting that pleiotropic effects are not associated with eicosanoid production. Only high-dose simvastatin reduced the relative proportion of sphingomyelin and ceramide to phosphatidylcholine (q=0.008), suggesting a pleiotropic effect previously associated with a reduced risk of cardiovascular disease.

Isoenergetic diets differing in their n-3 fatty acid and polyphenol content reflect different plasma and HDL-fraction lipidomic profiles in subjects at high cardiovascular risk.

SCOPE: Dysregulation of lipid homeostasis is related to multiple major healthcare problems. The aim of this study was to investigate the effects of n-3 fatty acid (FA) and polyphenol rich diets on plasma and HDL fraction lipidomic profiles in subjects at high cardiovascular risk. METHODS AND RESULTS: Ultra performance LC coupled to quadrupole TOF/MS mass spectrometry global lipidomic profiling was applied to plasma and HDL fraction from an 8 wk randomized intervention with four isoenergetic diets, differing in their natural n-3 FA and polyphenols content, in 78 subjects with a high BMI, abdominal obesity, and at least one other feature of the metabolic syndrome. Dependency network analysis showed a different pattern of associations between lipidomics, dietary, and clinical variables after the dietary interventions. The most remarkable associations between variables were observed after the diet high in n-3 FA and polyphenols, as the inverse association between gallic acid intake and LDL cholesterol levels, which was indirectly associated with a HDL cluster exclusively comprised lysophospholipids. CONCLUSION: This is the first human randomized controlled trial showing direct and indirect associations with lipid molecular species and clinical variables of interest in the evaluation of the metabolic syndrome after diets naturally rich in polyphenols.

Characterization of microbial metabolism of Syrah grape products in an in vitro colon model using targeted and non-targeted analytical approaches.

PURPOSE: Syrah red grapes are used in the production of tannin-rich red wines. Tannins are high molecular weight molecules, proanthocyanidins (PAs), and poorly absorbed in the upper intestine. In this study, gut microbial metabolism of Syrah grape phenolic compounds was investigated. METHODS: Syrah grape pericarp was subjected to an enzymatic in vitro digestion model, and red wine and grape skin PA fraction were prepared. Microbial conversion was screened using an in vitro colon model with faecal microbiota, by measurement of short-chain fatty acids by gas chromatography (GC) and microbial phenolic metabolites using GC with mass detection (GC-MS). Red wine metabolites were further profiled using two-dimensional GC mass spectrometry (GCxGC-TOFMS). In addition, the effect of PA structure and dose on conversion efficiency was investigated by GC-MS. RESULTS: Red wine exhibited a higher degree of C1-C3 phenolic acid formation than PA fraction or grape pericarp powders. Hydroxyphenyl valeric acid (flavanols and PAs as precursors) and 3,5-dimethoxy-4-hydroxybenzoic acid (anthocyanin as a precursor) were identified from the red wine metabolite profile. In the absence of native grape pericarp or red wine matrix, the isolated PAs were found to be effective in the dose-dependent inhibition of microbial conversions and short-chain fatty acid formation. CONCLUSIONS: Metabolite profiling was complementary to targeted analysis. The identified metabolites had biological relevance, because the structures of the metabolites resembled fragments of their grape phenolic precursors or were in agreement with literature data.

Fish oil supplementation alters the plasma lipidomic profile and increases long-chain PUFAs of phospholipids and triglycerides in healthy subjects.

BACKGROUND: While beneficial health effects of fish and fish oil consumption are well documented, the incorporation of n-3 polyunsaturated fatty acids in plasma lipid classes is not completely understood. The aim of this study was to investigate the effect of fish oil supplementation on the plasma lipidomic profile in healthy subjects. METHODOLOGY/PRINCIPAL FINDINGS: In a double-blinded randomized controlled parallel-group study, healthy subjects received capsules containing either 8 g/d of fish oil (FO) (1.6 g/d EPA+DHA) (n = 16) or 8 g/d of high oleic sunflower oil (HOSO) (n = 17) for seven weeks. During the first three weeks of intervention, the subjects completed a fully controlled diet period. BMI and total serum triglycerides, total-, LDL- and HDL-cholesterol were unchanged during the intervention period. Lipidomic analyses were performed using Ultra Performance Liquid Chromatography (UPLC) coupled to electrospray ionization quadrupole time-of-flight mass spectrometry (QTOFMS), where 568 lipids were detected and 260 identified. Both t-tests and Multi-Block Partial Least Square Regression (MBPLSR) analysis were performed for analysing differences between the intervention groups. The intervention groups were well separated by the lipidomic data after three weeks of intervention. Several lipid classes such as phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine, sphingomyelin, phosphatidylserine, phosphatidylglycerol, and triglycerides contributed strongly to this separation. Twenty-three lipids were significantly decreased (FDR<0.05) in the FO group after three weeks compared with the HOSO group, whereas fifty-one were increased including selected phospholipids and triglycerides of long-chain polyunsaturated fatty acids. After seven weeks of intervention the two intervention groups showed similar grouping. CONCLUSIONS/SIGNIFICANCE: In healthy subjects, fish oil supplementation alters lipid metabolism and increases the proportion of phospholipids and triglycerides containing long-chain polyunsaturated fatty acids. Whether the beneficial effects of fish oil supplementation may be explained by a remodeling of the plasma lipids into phospholipids and triglycerides of long-chain polyunsaturated fatty acids needs to be further investigated. TRIAL REGISTRATION: ClinicalTrials.gov NCT01034423.

Spatial distribution of glycerophospholipids in the ocular lens.

Knowledge of the spatial distribution of lipids in the intraocular lens is important for understanding the physiology and biochemistry of this unique tissue and for gaining a better insight into the mechanisms underlying diseases of the lens. Following our previous study showing the spatial distribution of sphingolipids in the porcine lens, the current study used ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS) to provide the whole lipidome of porcine lens and these studies were supplemented by matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI) of the lens using ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) to determine the spatial distribution of glycerophospholipids. Altogether 172 lipid species were identified with high confidence and their concentration was determined. Sphingomyelins, phosphatidylcholines, and phosphatidylethanolamines were the most abundant lipid classes. We then determined the spatial and concentration-dependent distributions of 20 phosphatidylcholines, 6 phosphatidylethanolamines, and 4 phosphatidic acids. Based on the planar molecular images of the lipids, we report the organization of fiber cell membranes within the ocular lens and suggest roles for these lipids in normal and diseased lenses.

Comparison of GC-MS and LC-MS methods for the analysis of antioxidant phenolic acids in herbs.

Two methods were developed for the quantitative analysis of phenolic acids in herb extracts. The methods were based on liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS) and gas chromatography-mass spectrometry (GC-MS). The methods were compared in terms of their linearity, repeatability, selectivity, sensitivity and the speed of the analysis. The sensitivity was good for both methods, with limits of detection of <80 ng/ml for most of the compounds. The relative standard deviations (RSD) of the peak areas were on average 7.2% for the LC-TOFMS method and 1.4% for the GC-MS method. Both methods were found to be suitable for the determination of the target analytes, although GC-MS was better suited to the quantitative determination of compounds present at low concentrations.

Characterisation of Stevia rebaudiana by comprehensive two-dimensional liquid chromatography time-of-flight mass spectrometry.

Comprehensive two-dimensional liquid chromatography (LC x LC) connected on-line to electrospray ionisation time-of-flight mass spectrometry (ESI-TOF-MS) was employed for analysis of aqueous extract of Stevia rebaudiana. Different combinations of strong cation-exchange (SCX), amino (NH2), and octadecyl siloxane (C18) stationary phases were tested in the separation of all nine known sweet Stevia glycosides. A combination of C18 as the first-dimension column and NH2 as the second-dimension column fully separated all the glycosides from the matrix. The method proved to be quantitative and repeatable. The limit of detection (S/N=3) for stevioside, a widely used natural sweetener, was 43.4 ng/g in dry leaves. The RSD for retention times was <0.1% and that of peak areas 4.5%.