A "Foodomic" Approach for the Evaluation of Food Quality and its Impact on the Human Metabolome

In recent years, omic sciences have been increasingly employed in many research fields thanks to their high-throughput capabilities and holistic approach. Among the omics sciences, metabolomics and foodomics have recently emerged for the investigation of food and nutrition and their relation to the individual health and wellness status. The analytical platforms used are ideal for non-targeted analysis, due to their capability of detecting and identifying a large set of variables (or metabolites) in complex biological samples. The most employed metabolomics techniques are mass spectrometry and nuclear magnetic resonance spectroscopy, empowered by the advent and advancement of multivariate data analysis. This thesis outlines the analytical pipeline of the foodomic approach and highlights the current challenges in the field, tracing the path of modern foodomics from the definition and description of food quality to the profiling of the human metabolome, and the investigation of the impact of food on human health, the prevention of diseases and the identification of biomarkers of health status. The impact of factors such as genetic modification or farming method was investigated in plant-based foods. And the effect of the food matrix and digestion on the stability and bioaccessibility of specific molecules was assessed. The animal metabolome was also studied, for example investigating the effect of antibiotic treatment on necrotizing enterocolitis as a model for the treatment of this condition in human newborns, too. The human metabolome (plasma, serum, urine) was then explored, firstly to develop specific algorithms for the search of dietary biomarkers in observational studies. Moreover, food intake biomarkers have been discovered in an intervention study (i.e. galactose for milk intake) and will be further investigated. Research was also carried out to investigate on specific disease-related biomarkers and to discover possible trajectories from a disease state to a healthier condition

Identification of weak and gender specific effects in a short 3 weeks intervention study using barley and oat mixed linkage β-glucan dietary supplements:a human fecal metabolome study by GC-MS

Introduction: Mixed-linkage (1\ue2\u86\u923),(1\ue2\u86\u924)-\uce\ub2-d-glucans (BG) reduce cholesterol level and insulin response in humans. Despite this, their role in human metabolism and a mode of action remains largely unknown. Objectives: To investigate the effects of three structurally different BG on human fecal metabolome in a full cross-over intervention using GC-MS metabolomics. Methods: Over three weeks of intervention, young healthy adults received food supplemented with BG from oat, two different BG from barley or a non-fiber control in a full cross-over design. Untargeted metabolomics and short chain fatty acid analysis was performed on day three fecal samples. ANOVA-simultaneous component analysis was applied to partition the data variation according to the study design, and PLS-DA was used to select most discriminative metabolite markers. Results: Univariate and multivariate data analysis revealed a dominating effect of inter-individual variances followed by a gender effect. Weak effects of BG intake were identified including an increased level of gamma-amino-butyrate and palmitoleic acid in males and a decreased level of enterolactone in females. Barley and oat derived BG were found to influence the human fecal metabolome differently. Barley BG increased the relative level of formate in males and isobutyrate, isovalerate, 2-methylbutyrate in females. In total 15, 3 and 11 human fecal metabolites were significantly different between control vs. BG, control vs. oat BG, and barley BG vs. oat BG, respectively. Conclusions: The study show that human fecal metabolome largely reflects individual (\ue2\u88\ubc28% variation) and gender (\ue2\u88\ubc15% variation) differences, whereas the treatment\uc2\ua0effect of the BG (\ue2\u88\ubc8% variation) only manifests in a few key metabolites (primarily by the metabolites: d-2-aminobutyric acid, palmitoleic acid, linoleic acid and 11-eicosenoic acid)

Nutrimetabolomics: An Integrative Action for Metabolomic Analyses in Human Nutritional Studies

The life sciences are currently being transformed by an unprecedented wave of developments in molecular analysis, which include important advances in instrumental analysis as well as biocomputing. In light of the central role played by metabolism in nutrition, metabolomics is rapidly being established as a key analytical tool in human nutritional studies. Consequently, an increasing number of nutritionists integrate metabolomics into their study designs. Within this dynamic landscape, the potential of nutritional metabolomics (nutrimetabolomics) to be translated into a science, which can impact on health policies, still needs to be realized. A key element to reach this goal is the ability of the research community to join, to collectively make the best use of the potential offered by nutritional metabolomics. This article, therefore, provides a methodological description of nutritional metabolomics that reflects on the state‐of‐the‐art techniques used in the laboratories of the Food Biomarker Alliance (funded by the European Joint Programming Initiative "A Healthy Diet for a Healthy Life" (JPI HDHL)) as well as points of reflections to harmonize this field. It is not intended to be exhaustive but rather to present a pragmatic guidance on metabolomic methodologies, providing readers with useful "tips and tricks" along the analytical workflow

An NMR Metabolomics Approach to Investigate Factors Affecting the Yoghurt Fermentation Process and Quality

A great number of factors can influence milk fermentation for yoghurt production such as fermentation conditions, starter cultures and milk characteristics. It is important for dairy companies to know the best combinations of these parameters for a controlled fermentation and for the desired qualities of yoghurt. This study investigates the use of a 1H-NMR metabolomics approach to monitor the changes in milk during fermentation from time 0 to 24 h, taking samples every hour in the first 8 h and then at the end-point at 24 h. Three different starter cultures (L. delbrueckii ssp. bulgaricus, S. thermophilus and their combination) were used and two different heat treatments (99 or 105 °C) were applied to milk. The results clearly show the breakdown of proteins and lactose as well as the concomitant increase in acetate, lactate and citrate during fermentation. Formate is found at different initial concentrations depending on the heat treatment of the milk and its different time trajectory depends on the starter cultures: Lactobacillus cannot produce formate, but needs it for growth, whilst Streptococcus is able to produce formate from pyruvate, therefore promoting the symbiotic relationship between the two strains. On the other hand, Lactobacillus can hydrolyze milk proteins into amino acids, enriching the quality of the final product. In this way, better insight into the protocooperation of lactic acid bacteria strains and information on the impact of a greater heat treatment in the initial matrix were obtained. The global chemical view on the fermentations provided using NMR is key information for yoghurt producers and companies producing starter cultures

A 1H NMR-Based Metabolomics Approach on Dietary Biomarker Research in Human Urine

The analysis of the metabolome has become particularly important in human studies, allowing the identification of typical and atypical metabolites in determined biofluids and tissues. This is clearly fundamental for medical investigations, since it could be possible to assess the presence or absence of certain diseases and syndromes or risk conditions. Another widespread use of the metabolomic approach is the research on specific dietary effects on the metabolic profile. It is necessary to take research further and investigate the presence of determined food molecules in fluids or tissues from individuals without a controlled dietary intervention. NMR spectroscopy techniques can be very useful in different nutrimetabonomics approaches, thanks to the quickness, high-throughput efficacy and high-reproducibility of its methods. In this paper the two main nutrimetabolomic strategies were highlighted, both greatly aided by the use of NMR spectroscopy. The first one requires a direct intervention on a sample population in order to assess the direct effects on the metabolome after the intake of a particular food product or category. In the other technique, instead, observational studies in free-eating populations are carried out. At first nutritional data is analysed in order to find possible dietary patterns, then these have to be proved by the inspection of biofluid spectra, in order to find molecules capable in discriminating among the dietary behaviours