The effect of single dietary fibre (DF) on lowering uric acid (UA) level has been reported in the literature. However, the potential protective mechanism of DF against potassium oxybate-induced hyperuricaemia (HUA), as modelled by prophylactic administration, remains unclear. The data demonstrate that DF significantly decreased serum and cerebral tissue UA concentrations, inhibited xanthine oxidase expression and activity in the liver and reduced levels of creatinine and urea nitrogen in the serum. Additionally, it mitigated the deposition of amyloid-β in cerebral tissue. Correlation analysis showed that DF modulated the Toll-like receptor 4/NF-κB signalling pathway, attenuating oxidative stress and inflammatory responses in HUA mice. Additionally, DF helps to maintain the composition of the gut microbiota, reducing harmful Desulfovibrio and enriching beneficial Akkermansia and Ruminococcus populations. The results of the faecal metabolomics analysis indicate that DF facilitates the regulation of metabolic pathways involved in oxidative stress and inflammation. These pathways include pyrimidine metabolism, tryptophan metabolism, nucleotide metabolism and vitamin B6 metabolism. Additionally, the study found that DF has a preventive effect on anxiety-like behaviour induced by HUA. In summary, DF shows promise in mitigating HUA and cognitive deficits, primarily by modulating gut microbiota and metabolites.

Hypertension, characterised by elevated blood pressure (BP), continues to be a major global public health problem. It is defined as systolic blood pressure (SBP) ≥140 mmHg and/or diastolic BP (DBP) ≥90 mmH(1) and is the leading risk factor for cardiovascular diseases(2). Nutritional metabolomics (Nutrimetabolomics) presents an objective approach to explore the interplay between diet and health outcomes(3). Through analysis of intermediate molecules and metabolic byproducts, metabolomic profiles can objectively reflect an individual’s dietary intake and assess variations in metabolism(3). To date, no review has been conducted that investigates the relationship between diet, metabolites and BP regulation. This systematic review aimed to identify and synthesise findings of human dietary feeding intervention studies that have examined the role of metabolites in BP regulation. A comprehensive search was conducted in November 2022 across EMBASE, Medline, CINAHL, PsychINFO, Scopus and Cochrane databases. Search terms were defined using a combination of keywords, including “metabolome”, “diet”, and “blood pressure”. All included intervention studies explored the dietary metabolome from food provision, meals or supplements to a comparator or control intervention and, examined the relationship between dietary-related metabolites and BP in humans and published in English. The initial search identified 1,109 studies, with a final six studies meeting all eligibility criteria and included in the final review. Metabolites were identified in urine (n = 4), plasma (n = 2), or faeces (n = 1). Various analytical techniques were employed, including H-NMR, LC-MS, and GC-MS, while majority of studies used untargeted metabolomics (n = 4). Among included studies, five reported a significant association between individual metabolites and BP or change in BP. These investigations emphasised dietary patterns as the primary focus of analysis. In contrast, one study revealed no relationship between the investigated metabolites and BP. However, this particular study evaluated the impact of a single food product rather than dietary patterns. In total, 39 metabolites were linked to BP, with 36 associated with SBP and 25 with DBP. Several super-pathways involved in blood pressure regulation were identified, across metabolism of amino acids, carbohydrates, cofactors, vitamins, lipids, nucleotides, peptides, and xenobiotics. Within these, 17 distinct sub-pathways were delineated. The only metabolite found to have a significant relationship with BP measures across multiple studies was N-Acetylneuraminate. In one study, it showed a relationship with DBP, while another study linked it to a decrease in both 24-hour DBP and SBP. No other metabolites were consistently replicated between studies. Nutrimetabolomics appears to be a promising field in evaluation of diet and BP reduction. However, further research is required to understand which metabolites influence BP regulation.

Early supplementation with oregano essential oil (EO) in milk replacer (MR) may improve growth, immune responses, the microbiota and the metabolome in dairy calves during pre-weaning and in adulthood. Sixteen female dairy calves (3 days of age) were divided in two groups (n = 8/group): the control group (no EO) and the EO group (0.23 ml of EO in MR during 45 days). After weaning, calves were kept in a feedlot and fed ad libitum. The animals were weighed, and blood and faecal samples were collected on days 3 (T0), 45 (T1) and 370 (T2) to measure the biochemical profile and characterise peripheral blood mononuclear cells (PBMCs; CD4+, CD8+, CD14+, CD21+ and WC1+), the metabolome and microbiota composition. The EO group only had greater average daily weight gain during the suckling (EO supplementation) period (P = 0.030). The EO group showed higher average CD14+ population (monocytes) values, a lower abundance of Ruminococcaceae UCG-014, Faecalibacterium, Blautia and Alloprevotella and increased abundances of Allistipes and Akkermansia. The modification of some metabolites in plasma, such as butyric acid, 3-indole-propionic acid and succinic acid, particularly at T1, are consistent with intestinal microbiota changes. The data suggest that early EO supplementation increases feed efficiency only during the suckling period with notable changes in the microbiota and plasma metabolome; however, not all of these changes can be considered desirable from a gut health point of view. Additional research studies is required to demonstrate that EOs are a viable natural alternative to antibiotics for improving calf growth performance and health.

Microbiome, the study of microbial communities in specific environments, has developed significantly since the Human Microbiome Project began. Microbiomes have been associated with changes within environmental niches and the development of various diseases. The development of high-throughput technology such as next-generation sequencing has also allowed us to perform transcriptome studies, which provide accurate functional profiling data. Metabolome studies, which analyse the metabolites found in the environment, are the most direct environmental condition indicator. Although each dataset provides valuable information on its own, the integration of multiple datasets provides a deeper understanding of the relationship between the host, agent and environment. Therefore, network analysis using multiple datasets might give a clearer understanding of disease pathogenesis.

Major depression is a complex disorder with no single, direct causal mechanism. Morbidity has been linked to genetic processes, developmental history, and unique environmental exposures. Epigenetic mechanisms, especially DNA methylation, are also likely important factors in the pathogenesis of major depressive disorder (MDD). A community-based twin sample has many advantages for epigenetic studies, given the shared genetic and developmental histories of same-sex twin pairs. This article describes the rationale and study design for the Mood and Methylation Study in which 133 twin pairs (101 monozygotic and 32 dizygotic), both discordant and concordant for lifetime history of MDD, were evaluated on a large number of variables related to MDD. The twins also provided blood samples for an epigenome-wide association study of differentially methylated regions (DMR) relevant to MDD. Although MDD is typically considered a disorder of the central nervous system, it is unfeasible to obtain a large sample of brain tissues. However, epigenetic variation is not limited to the affected tissue but can also be detected in peripheral blood leukocytes. Thus, this study focused on monocytes for the major analyses. Additional plans for the study include gene expression analysis from the same set of twins using RNA-seq and validation of significant DMRs in postmortem brain tissues from a separate sample. Moreover, sufficient samples have been collected to perform future ‘multi-omic’ analyses, including metabolome, microbiome, and transcriptome. Our long-term goal is to understand how epigenomic and other ‘omic’ factors can be manipulated for diagnostic, preventive, and therapeutic purposes for MDD and its related conditions.

Seed dormancy and germination involve the concerted operation of molecular and biochemical programmes. It has become feasible to study these processes in great detail, using the current methods for transcriptome, proteome and metabolome analysis. Yet, the large amounts of data generated by these methods are often dazzling and demand efficient tools for data visualization. We have used the freely available PageMan/MapMan package (http://MapMan.gabipd.org) to visualize transcriptome and metabolome changes in Arabidopsis thaliana seeds during dormancy and germination. Using this package we developed two seed-specific MapMan pathways, which efficiently capture the most important molecular processes in seeds. The results demonstrated the usefulness of the PageMan/MapMan package for seed research.