# Applications and Challenges for Metabolomics via Nuclear Magnetic Resonance Spectroscopy
###### Abstract  
A new approach to the development of the  
antioxidants and of other protective species, whereas the chronic effect of NP exposure seems to be associated with alterations in glutamine and glutamate metabolism, and the purine metabolism pathways. The paper authored by [PERSON] et al. [5] characterizes the effects of surgery on the serum metabolomic profiles of colorectal cancer (CRC) patients and explores the possibility that metabolic variations among preoperative and postoperative serum samples could be informative on future cancer recurrence. A total of 41 patients diagnosed with early-stage CRC and scheduled for radical resection were enrolled for this study. Serum samples collected preoperatively (t0) and 4-6 weeks after surgery but before the start of any treatment (t1) were analyzed via \({}^{1}\)H NMR spectroscopy. A clear discrimination between t0 and t1 emerged: after surgery, there are significant increases in pyruvate, HDL cholesterol, HDL phospholipids, HDL Apo-A1, and HDL Apo-A2 levels, coupled with significant decreases in acetone, 3-hydroxybutyrate, LDL-Chol/HDL-Chol ratio, and Apo-A1/Apo-B100 ratio. Taken together, these results point to a relevant rearrangement of the metabolic pathways related to lipoproteins, ketone bodies, and energy metabolism. Furthermore, several differences between post- and pre-operative serum samples, in particular those related to the HDL-Chol and VLDL-Chol subfractions, seem to be associated with cancer recurrence. These data pave the way for novel strategies for risk stratification in patients with early-stage CRC. The paper by [PERSON] et al. [6] is the last research article related to biomedical applications of NMR metabolomics included in our issue. It proposes an analysis of urine samples of preterm infants with neonatal sepsis, a systemic infection difficult to diagnose in its early stages and thus reporting high rates of morbidity and mortality. In this study, the urine metabolomic profiles of 34 septic neonates, 14 preterm neonates without sepsis or other serious morbidity but hospitalized in the NICU, and 23 healthy preterm neonates were examined. Multivariate and univariate statistical analyses showed clear discriminations between septic and healthy newborns. In particular, alterations in the levels of gluconate, myo-inositol, hyppurate, taurine, N, N-Dimethylglycine, betaine, creatinine, glucose and lactose emerged as the most significant. These data represent a promising basis for future large-scale multicenter studies and give new perspectives for clinical research in the field of neonatology. We decided to address also foodomics in our issue, which refers to metabolomic approaches applied to foodstuff for investigating topics related to nutrition, fraud detection and traceability of the geographical origin and production/processing procedures of food. In this regard, in our issue, we decided to publish an NMR-based metabolomic study based on water extracts of green and roasted coffee beans of different cultivars from three distinct Nicaraguan farms [7]. We think that this study can show well the potential and versatility of NMR metabolomics. Here, the authors demonstrate the potential of NMR metabolomics not only to define the geographical origin and the farm of provenance but also to characterize the effect of the environment (microclimates, irrigation, fertilizers, etc.) and the post-harvest practices (e.g., drying and fermentation) that are responsible for different aroma precursors in coffee and thus affect its distinct taste. The ensemble of these studies offers a representative overview of the applications of NMR metabolomics raging from the biomedical fields to food science. The capabilities of NMR, coupled with an ever-growing list of statistical chemometric techniques, make NMR-based metabolomics a versatile technique. Applying correct and suitable statistical techniques has become of fundamental importance for metabolomics studies. For this reason the review of [PERSON] et al.