Systematic Review of NMR-Based Metabolomics Practices in Human Disease Research

Abstract

Nuclear magnetic resonance (NMR) spectroscopy is one of the principal analytical techniques for metabolomics. It has the advantages of minimal sample preparation and high reproducibility, making it an ideal technique for generating large amounts of metabolomics data for biobanks and large-scale studies. Metabolomics is a popular “omics” technology and has established itself as a comprehensive exploratory biomarker tool; however, it has yet to reach its collaborative potential in data collation due to the lack of standardisation of the metabolomics workflow seen across small-scale studies. This systematic review compiles the different NMR metabolomics methods used for serum, plasma, and urine studies, from sample collection to data analysis, that were most popularly employed over a two-year period in 2019 and 2020. It also outlines how these methods influence the raw data and the downstream interpretations, and the importance of reporting for reproducibility and result validation. This review can act as a valuable summary of NMR metabolomic workflows that are actively used in human biofluid research and will help guide the workflow choice for future research.

Polarising Agents and Spin Tags for Dynamic Nuclear Polarisation (DNP)-Enhanced Solid-State Nuclear Magnetic Resonance (ssNMR) Analysis of Biological Samples

“…The conformationally-restricted biradical bTbK (12) was used as the polarising agent in DNP-ssNMR measurements on oriented samples of a 15…”

“…Nuclear magnetic resonance (NMR) spectroscopy is a widely used and powerful analytical technique that can produce qualitative and quantitative chemical, structural and dynamic information from a wide range of samples including organic and inorganic compounds, pharmaceuticals, biomolecules and biological samples, food, industrial and environmental samples [1][2][3][4][5][6][7][8][9][10][11][12][13]. It is also the basis for the clinical technique of magnetic resonance imaging (MRI).…”

Ketone Body β-Hydroxy-Butyrate Sustains Progressive Motility in Capacitated Human Spermatozoa: A Possible Role in Natural Fertility

“…In addition to the possible retrieving of the proper endocrine pattern through weight lowering, other additional or parallel mechanisms on the testis function associated with nutritional-based ketosis, including fertility outcomes, are largely underinvestigated [ 6 , 15 ]. The biofluid profile of low/mid molecular weight metabolites has recently become a promising research field for the pathophysiological biomarkers of organ function [ 16 ]. This is particularly the case of human semen in which the analysis of metabolite composition showed interesting correlations with fertility outcomes that are currently uncovered by classical morphology-based semen analysis [ 17 ].…”

Matrix Linear Models for connecting metabolite composition to individual characteristics

“…PCA, followed by a supervised classification model and identifying key metabolites through variable importance scores. PCA is often utilized as a preliminary analysis and quality control measure for metabolomics data to examine whether there are distinctions between groups and outlier points (Huang et al ., 2022). Additionally, PCA can be used to assess whether quality control samples cluster together or if they show discrepancies which could suggest problems with the assay’s accuracy.…”

“…Factor analysis, PCA (principal component analysis), PLS-DA (partial least squares discriminant analysis), and cluster analysis have been used in this context. A multivariate analysis may begin with an unsupervised technique (Huang et al, 2022;Chen et al, 2022), e.g. PCA, followed by a supervised classification model and identifying key metabolites through variable importance scores.…”