Elaine Holmes

The Mediterranean diet (MD), known for its high intake of fruits, vegetables, whole grains, legumes, and healthy unsaturated fats, has been linked to a diverse and beneficial gut microbiome. However, its effect on the gut microbiome during pregnancy remains understudied. This study aimed to investigate the impact of high adherence to a Mediterranean diet on gut microbiome composition and function in pregnant women by analysing their metabolic profiles and faecal microbiome composition. Stool, serum, and urine samples were collected from 48 pregnant women at weeks 20/28 and at week 36. Participants were stratified based on MD adherence using a validated questionnaire. Stool samples underwent 16 S rRNA gene amplicon sequencing, and serum short-chain fatty acids (SCFAs) were measured using UPLC-MS. Women with high MD adherence showed significantly higher α-diversity in their faecal microbiomes at both time points. Significant differences in microbiome composition were observed between low and high adherence groups at weeks 20/28, but not at week 36. No significant differences in serum short-chain fatty acid concentrations were found between the groups. Our findings suggest that adherence to the Mediterranean diet during pregnancy is associated with changes in gut microbiome diversity and function. These results contribute to a better understanding of how dietary patterns during pregnancy may influence gut microbiome ecology.

Background
Evidence increasingly suggests a connection between cardiovascular disease and brain health in later life; however, the mechanistic pathways from human studies remain unclear. This study aimed to investigate whether urinary metabolites account for part of the association between cognition and cardiometabolic risk.

Methods
Data from 606 participants (aged 48–60; 55% female; 45.5% Black/African American) in the Year 30 follow-up of the Coronary Artery Risk Development in Young Adults Study were analyzed. Urinary metabolites were profiled using nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry; brain magnetic resonance imaging data were available for 281 participants. Structural equation models were used to assess pathways linking cardiometabolic factors to cognitive outcome, with urinary metabolites and brain MRI-derived parameters as mediators.

Results
Fasting glucose showed a negative association with cognition. Valine, isoleucine, leucine, and phenylalanine were positively associated with fasting glucose. Valine and aminoadipic acid also showed positive associations between fasting glucose and cognition, while tryptophan was correlated with both fasting glucose and cognition. Indole-3-acetic acid showed negative associations with systolic blood pressure and fasting glucose. Brain MRI-derived parameters in memory-related medial temporal areas were associated with waist circumference.

Conclusions
Urinary metabolites and brain imaging markers were linked with hyperglycemia, obesity, and cognitive performance, highlighting multimodal biomarkers relevant to global cognitive function in individuals with cardiometabolic risk.

Broad-spectrum viral biomarkers offer a promising approach to distinguishing viral from bacterial infections, thereby reducing inappropriate antibiotic use and improving diagnostic response during emerging infectious disease outbreaks. Among these, the deoxydidehydronucleoside (ddhN) class of nucleoside derivatives has emerged as a potential tool for early detection of viral infections in settings where pathogen-specific diagnostics are unavailable. To assess the clinical utility of these compounds, we investigated the metabolism and excretion rates of four principal ddhN metabolites, 3'-deoxy-3',4'-didehydrocytidine (ddhC), 3'-deoxy-3',4'-didehydrocytidine-5'-carboxylate (ddhC-5'CA), 3'-deoxy-3',4'-didehydrouridine (ddhU), and 3'-deoxy-3',4'-didehydrocytidine-5'-homocysteine (ddhC-5'Hcy), in the Sprague-Dawley rat model following a single intravenous dose. Time-resolved biological sampling was used to characterize urinary excretion and downstream biotransformation. All four metabolites exhibited rapid urinary clearance, ranging from approximately 3 to 8 h, consistent with a transient acute-phase profile. Notably, ddhC-5'Hcy underwent extensive biotransformation, with key metabolites produced via functionalization and conjugation identified following integration of nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) analyses. No adverse clinical signs were observed in any treatment group at any time point. These findings support further research into the ddhN series as markers of active viral infection for clinical application, particularly in critical care environments, where timely differentiation of infectious etiology is essential.

Methoxyacetic acid (MAA) is a testicular toxin that targets spermatocytes and round spermatids by disrupting mitochondrial function, leading to cellular energy depletion. Male Sprague-Dawley rats were given single oral doses of MAA (150 or 650 mg/kg), resulting in no mortality but transient toxicity signs and modest body weight effects, especially at the higher dose. Histopathology revealed dose- and time-dependent testicular damage, with selective germ cell necrosis by 48 h and extensive germ cell loss, spermatic giant cells, and epididymal inflammation observed in high-dose animals by 168 h. Metabolic analysis using high resolution 1H NMR spectroscopy and OPLS-DA identified elevated urinary excretion of N-butyryl glycine, a marker of mitochondrial dysfunction and impaired β-oxidation. The persistence of N-butyryl glycine and altered energy metabolites up to 168 h indicates sustained mitochondrial stress and disruption of ATP-dependent processes essential for spermatogenesis. Moreover, the close structural similarity between MAA and butyrate raises the possibility that MAA interacts directly with enzymes involved in butyryl-CoA turnover during the terminal steps of β-oxidation in rodents.

Paediatric burn injuries are a global health concern with long-term health consequences, such as psychological, immune, and cardiovascular complications, that can persist even after non-severe injuries. Emerging evidence suggests that biological sex may influence post-burn outcomes in children, as female burn survivors have been shown to experience higher mortality, scarring, anxiety, depression, and poorer quality of life compared to males. This study addresses a critical research gap by examining sex-specific lipidomic and inflammatory responses following paediatric non-severe burn injury. Children under five years were recruited as a part of the Childhood Burn Injury Biobank at hospital admission, with longitudinal follow-ups, and non-burn controls aged 1 and 3 were collected from the ORIGINS cohort. Plasma lipid profiling and acute-phase glycoprotein systemic inflammatory markers (GlycA and GlycB) were quantified using metabolic phenotyping with hair cortisol provided as a longitudinal measure of stress. Lipidomic analysis revealed acute-phase disruptions in fatty acids and lysophospholipids in both sexes but only females demonstrated a persistent increase of arachidonic acid (FA 20:4) and depletion of monoacylglycerols more than a year post-injury. Females also had significantly higher acute-phase GlycA/GlycB levels around the time of injury and exhibited increasing variability in hair cortisol over time, while male burn survivors did not. These findings highlight a sex-specific response between lipid metabolism, systemic inflammation and stress in paediatric recovery from non-severe burns. Understanding these differences may guide the development of targeted psychological and physiological strategies to improve long-term outcomes for young burn survivors.

Objective Chronic venous disease (CVD) is a condition presenting a great burden to patients and society, with poorly characterised pathophysiology. Metabolic phenotyping can elucidate mechanisms of disease and identify candidate biomarkers. The aim of this study was to determine differences in the metabolic signature between symptomatic patients with CVD and asymptomatic volunteers using proton nuclear magnetic resonance spectroscopy (H-1-NMR). Methods This was a prospective case control study of consecutive patients with symptomatic CVD and asymptomatic volunteers recruited from a single centre. Participants underwent clinical assessment, venous duplex ultrasound, and blood and urine sampling. Disease stage was defined according to the Clinical-Etiology-Anatomy-Pathophysiology (CEAP) classification. H-1-NMR experiments were performed, with data analysed via multivariable statistical techniques. Results A total of 622 participants were recruited, including 517 symptomatic patients with CVD (telangiectasia [C1] 0.6%, varicose veins [C2] 48.5%, swelling [C3] 12.0%, skin changes [C4] 27.7%, healed or active ulceration [C5/6] 11.2%) and 105 asymptomatic participants (no disease [C0] 69.5%, telangiectasia [C1] 29.6%). Multivariable analysis revealed differences between the metabolic profile of the symptomatic CVD and asymptomatic groups, and between CEAP clinical classes in the CVD group. Serum aromatic amino acids positively correlated with increasing CEAP clinical class (p < .001). Urinary formate, creatinine, glycine, citrate, succinate, pyruvate, and 2-hydroxyisobutyrate negatively correlated with increasing CEAP clinical class (p < .001). These metabolites are involved in the tricarboxylic acid cycle, hypoxia inducible factor pathway, and one carbon metabolism. Conclusion Untargeted biofluid analysis via H-1-NMR has detected metabolites associated with the presence and severity of CVD, highlighting biological pathways of relevance and providing candidate biomarkers to explore in future research.

Background
The phenotyping of individuals using robust tools as lipidomics is crucial to implement preventive personalised medicine. Combining the findings from multiomics can result in broader CV risk-capturing, uncovering relevant molecules in highly prevalent syndromes conditions such as the Cardiovascular-Kidney-Metabolic (CKM).

Purpose
To discern the lipid metabolites with predictive power for the correct identification of patients at CKM Stage 4 and those who required advanced revascularization interventions, coronary artery bypass graft (CABG) and percutaneous coronary intervention (PCI).

Methods
Participants scheduled for a coronary angiogram in the CARDINOX agreed to provide blood. PBMCs were isolated for flow cytometry and plasma samples were processed for immunoassay and targeted lipidomics using liquid chromatography–mass spectrometry, spanning 1143 lipids from 20 different classes. Patients were assigned to stages using the AHA CKM definition. Statistical analyses were performed in R and GraphPad prism, using the LipidR package for analysis and multiple logistic regression for biomarker performance estimation.

Results
200 subjects were recruited, median age 67 years (IQR 58-74), 21% female, 42.5% had obesity, 42% had diabetes and 31% presented with an acute coronary syndrome (ACS). 39% were at CKM-Stage 3 and 20% at CKM-Stage 4; 31.5% required PCI and 13% of patients required CABG. The best predictive model for CKM-Stage 4 included NOX5 in PBMCs, Monocytes and plasma, two lysophosphatidylcholines (LPC) 18:1, LPC 20:0 and two phosphatidylcholines (PC) 14:0/18:2, PC 18:2/18:2, AUC=0.90, p<0.0001, NPV=91.0%, PPV=85.2%. The best model for those needing PCI included NOX5 in PBMCs and Monocytes, and five lipids: phosphatidylinositol (PI) 20:0/18:1, TG 54:3/16:0, TG 56:6/20:3, PC 18:1/18:3, and the diacylglycerol (DG) 16:0/20:5, AUC=0.92, p<0.0001, NPV=88.3%, PPV=85%. In the case of CABG, the best model included NOX5 in Monocytes and PBMCs, PC 18:1/18:3, PC 16:1/18:2, two triacylglycerols (TG) 54:3/16:0, TG 56:6/20:3 and the PI 18:0/20:3, AUC=0.96, p<0.0001, NPV=96.7%, PPV=90.9%. These models outperformed the predictive power of considering only the clinical or lipid parameters and achieved perfect discrimination when routine clinical variables were added.

Conclusions
Using a targeted lipidomic approach can substantially improve the classification of patients at advanced CV risk. When combining a few of the most differentially expressed lipids with other novel biomarkers such as NOX5, we obtained a clear distinction of patients that presented with CKM Stage 4 and those who required advanced revascularization (PCI and CABG). Additionally, these lipids hold the potential to inform biologically relevant pathways in CVD. When validated in prospective and external populations, NOX5 and lipidomic panels can be easily translated to the clinic for earlier identification of individuals at risk of adverse coronary outcomes.
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Nuclear magnetic resonance (NMR) spectroscopy is increasingly employed in research to quantify lipoprotein subfractions, offering potential utility in clinical diagnostics, particularly for cardiovascular risk assessment. However, the independent validation of proprietary NMR-based lipoprotein profiling methods is crucial for verifying clinical accuracy and reliability. This study presents a posthoc evaluation of concordance between the NMR-based B.I.LISA method and standard enzymatic assays for total cholesterol (TC), triglycerides (TGs), and high-density lipoprotein cholesterol (HDL-C), measured in 620 plasma samples from the OMNI-Heart study, focusing on their performance in evaluating the dietary intervention outcomes. Despite involving independently acquired data not designed for an intermethod validation, the comparison showed a high correlation between methods (R = 0.85–0.92), with median deviations of −4, −5, and −15% for HDL-C, TC, and TGs, respectively. The larger TG deviations are attributed to known issues arising from heterogeneity in high-TG samples, although intervention outcomes remained unaffected. Albumin was identified as a potential interfering factor affecting the TC and HDL-C measurements. HDL-C could also be affected by lipoprotein degradation, contributing to divergence in comparisons of marginal intervention outcomes. Extreme discrepancies were observed in atypical hypercholesterolemia samples. These findings highlight the reliability of the NMR approach despite revealing minor but significant deviations that warrant further research.

Interplay between the maternal diet and gut microbiome may impact fetal immune development and allergic disease risk. This study investigated associations between maternal prenatal urinary metabolites and infant food allergy and then extended to potentially relevant dietary and microbial precursors.
We investigated 599 mother-infant dyads from an Australian population-derived prebirth cohort. Maternal dietary data and fecal and urine samples were collected in the third trimester. NMR was used to measure prenatal urinary metabolites. Infant food allergy status was determined at 1 year by skin prick allergy testing and food challenge. Regression techniques were used to investigate associations and adjust for pre-specific confounding factors.
Higher concentration of hippuric acid in maternal urine, an end-product of dietary polyphenol metabolism, was associated with a lower risk of infant food allergy (odds ratio (OR) 0.62 (95% CI 0.42, 0.93)). Consistent with this, dietary proanthocyanidins, a polyphenol, were positively associated with both higher urinary hippuric acid concentration (0.11 log units, CI 0.01, 0.22) and lower risk of infant food allergy (OR 0.58 (CI 0.36, 0.96)). Maternal carriage of the gut commensal Prevotella copri, previously associated with protection against infant allergic disease, was associated with 21% higher urinary hippuric acid concentrations (CI 4%, 40%, corresponding to 0.19 log units CI 0.04, 0.34); however there was no evidence of mediation.
Further studies are required to confirm whether higher dietary intake of proanthocyanidins during pregnancy is associated with protection against allergic disease in the infant via gut microbiome production of hippuric precursors and other immune-active metabolites.