Metabolomics provide an unbiased tool for exploring the modulation of the human metabolome in response to food intake. This study applied metabolomics to capture the postprandial metabolic response to breakfast meals corresponding to vegan (VE), lacto ovo-vegetarian (LOV), and omnivore (OM) diets. In a cross over design 32 healthy volunteers (16 men and 16 females) consumed breakfast meals in a randomized order during three consecutive days. Fasting and 3 h postprandial serum samples were collected and then subjected to metabolite profiling using ¹H-nuclear magnetic resonance (NMR) spectroscopy. Changes in concentration of identified and discriminating metabolites, between fasting and postprandial state, were compared across meals. Betaine, choline, and creatine displayed higher concentration in the OM breakfast, while 3-hydroxyisobutyrate, carnitine, proline, and tyrosine showed an increase for the LOV and unidentified free fatty acids displayed a higher concentration after the VE breakfast. Using ¹H NMR metabolomics it was possible to detect and distinguish the metabolic response of three different breakfast meals corresponding to vegan, lacto-ovo vegetarian, and omnivore diets in serum.

Known and consistent bioactivity between samples of insulin is essential to correctly estimate the dose. Insulin concentration is not the same thing as bioactivity, however, and methods to correctly determine both are required. Here we show that one dimensional nuclear magnetic resonance (1D NMR), in contrast to, for example, reverse phase high pressure liquid chromatography, can be used to determine both insulin concentration as well as confirm the structural integrity required for activity. In response to the report by Carter and Heinemann, we decided to investigate insulin intended for public use. Insulin from several manufacturers was investigated. Correct insulin concentrations were found in all tested samples although the general sample variability, which possibly could influence the bioactivity, varied depending on insulin type and manufacturer.

In the Microvascular Outcomes after Metabolic Surgery randomised clinical trial (MOMS RCT, NCT01821508), combined metabolic surgery (gastric bypass) plus medical therapy (CSM) was superior to medical therapy alone (MTA) as a means of achieving albuminuria remission at 2-year follow-up in patients with obesity and early diabetic kidney disease (DKD). In the present study, we assessed the urinary ¹H-NMR metabolome in a subgroup of patients from both arms of the MOMS RCT at baseline and 6-month follow-up. Whilst CSM and MTA both reduced the urinary excretion of sugars, CSM generated a distinctive urinary metabolomic profile characterised by increases in host–microbial co-metabolites (N-phenylacetylglycine, trimethylamine N-oxide, and 4-aminobutyrate (GABA)) and amino acids (arginine and glutamine). Furthermore, reductions in aromatic amino acids (phenylalanine and tyrosine), as well as branched-chain amino acids (BCAAs) and related catabolites (valine, leucine, 3-hydroxyisobutyrate, 3-hydroxyisovalerate, and 3-methyl-2-oxovalerate), were observed following CSM but not MTA. Improvements in BMI did not correlate with improvements in metabolic and renal indices following CSM. Conversely, urinary metabolites changed by CSM at 6 months were moderately to strongly correlated with improvements in blood pressure, glycaemia, triglycerides, and albuminuria up to 24 months following treatment initiation, highlighting the potential involvement of these shifts in the urinary metabolomic profile in the metabolic and renoprotective effects of CSM.

The metabolome, which is the final down-stream global product of metabolic processes in organisms, is not sufficiently described in multiple myeloma (MM) patients. The aim of this study was, therefore, to study the serum metabolomic profile using proton nuclear magnetic resonance (1H-NMR) spectroscopy, and its relationship to clinical characteristics and patient outcome. Serum samples, which were taken at diagnosis, from 201 MM patients who underwent high-dose melphalan followed by autologous stem cell transplantation (ASCT) as the first-line therapy, were analyzed. We found that the metabolomic profile differed between patients with different MM International Staging System (ISS) stages. The profile showed increased levels of cholesterol, phospholipids, high-density lipoprotein (HDL), low-density lipoprotein (LDL), apolipoproteins A1 and A2, valine, and leucine in ISS I patients compared with ISS III patients. The metabolomic profile also differed between patients with IgA and IgG paraprotein, predominantly because of higher levels of LDL and HDL subfractions in IgA patients. The exact pathway of metabolism leading to accumulation of these metabolites is still elusive, but this study shows an area of interest for further investigation in the search for new therapy targets and prognostic markers for this disease.

Background: Epidemiological studies show associations between chronic noise exposure and disease, but the biological pathways remain poorly understood. In this explorative pilot study, we investigate the mechanisms that may link sleep disruption by environmental noise with disease, and the efficacy of a non-pharmacological intervention to mitigate these effects. Methods: We conducted a cross-over trial (ClinicalTrials.gov: NCT05319262; 2022-03-09) where N = 12 healthy individuals slept for five consecutive nights in acoustically isolated bedrooms. Nights included one familiarisation night; one quiet baseline night; one night with road, rail and air traffic noise of levels 45-65 dB L _AS,max ; one night with continuous 45 dB broadband pink noise; and one night with both traffic noise and pink noise. Sleep was measured with polysomnography. Perceived sleep quality and recouperation were measured with morning questionnaires. Daily blood samples were collected for metabolomics analysis. Results: Here we show that discrete traffic noise events induced acute elevations of the odds ratio product, indicating acute sleep fragmentation, even while total sleep time and overall sleep macrostructure were preserved. Traffic noise is further associated with significant elevations in concentrations of leucine, lactic acid, and acetone relative to quiet control. Sleep and metabolic disturbances by traffic noise are attenuated when pink noise is played continuously throughout the night. Conclusions: Noise-induced sleep fragmentation is followed by changes in metabolic processes that in the long-term may be precursors for cardiometabolic disorders. Masking of traffic noise by continuous, neutral sound may mitigate acute physiological sleep disturbance and downstream metabolic effects. These results should be interpreted cautiously, given the limited sample size and subject homogeneity.

The preanalytical handling of plasma, how it is drawn, processed, and stored, influences its composition. Samples in biobanks often lack this information and, consequently, important information about their quality. Especially metabolite concentrations are affected by preanalytical handling, making conclusions from metabolomics studies particularly sensitive to misinterpretations. The perturbed metabolite profile, however, also offers an attractive choice for assessing the preanalytical history from the measured data. Here we show that it is possible using Orthogonal Projections to Latent Structures Discriminative Analysis to divide plasma NMR data into a multivariate "original sample space" suitable for further less biased metabolomics analysis and an orthogonal "preanalytical handling space" describing the changes occurring from preanalytical mishandling. Apart from confirming established preanalytical effects on metabolite levels, e.g., the consequent changes in glucose, lactate, ornithine, and pyruvate, the sample preparation protocol involved methanol precipitation which allowed the observation of reversible changes in short-chain fatty acid concentrations as a function of temperature.