Publications by authors named "Andrew Neilson"

Evidence suggests that a healthy gut microbiome is essential for metabolizing dietary phytochemicals. However, the microbiome's role in metabolite production and the influence of gut dysbiosis on this process remain unclear. Further, studies on the relationship among gut microbes, metabolites, and biological activities of phytochemicals are limited.

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The flavan-3-ol (-)-epigallocatechin gallate (EGCG) blunts obesity in inbred mice, but human clinical trials have yielded mixed results. Genetic homogeneity in preclinical models may explain translational disconnect between rodents and humans. The Diversity Outbred (DO) mouse model provides genotype and phenotype variability for characterization of gene x environment (i.

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  • The study examines the impact of a high-fat diet combined with low-dose streptozotocin on inducing type-2 diabetes in male and female mice to understand sex differences in diabetes development.
  • It found that while both sexes gained weight and showed impaired glucose tolerance, only male mice developed significant fasting hyperglycemia and insulin resistance, indicating distinct metabolic effects based on sex.
  • The results suggest that existing models for studying type-2 diabetes, particularly the HF diet plus STZ method, are inadequate for females, highlighting the need for new approaches that account for sexual dimorphism in metabolic disease research.
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  • - This study investigates whether cocoa and its polyphenol-rich fractions have anti-inflammatory effects in a mouse model of acute colonic inflammation induced by dextran sulfate sodium (DSS).
  • - Male mice received dietary cocoa treatments for two weeks before and during DSS-induced inflammation, but cocoa did not prevent weight loss or reduced colon size, although it improved spleen enlargement.
  • - Overall, the findings indicate that cocoa and cocoa polyphenols are not effective in reducing acute colonic inflammation, as evidenced by inflammatory markers and the similarity of treated mice to the control group subjected to DSS.
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Scope: Gut microbiota depletion using antibiotics in drinking water is a valuable tool to investigate the role of gut microbes and microbial metabolites in health and disease. However, there are challenges associated with this model. Animals avoid drinking water because of the antibiotic bitterness, which affects their metabolic health.

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Gut microbes play a pivotal role in host physiology by producing beneficial or detrimental metabolites. Gut bacteria metabolize dietary choline and L-carnitine to trimethylamine (TMA) which is then converted to trimethylamine-N-oxide (TMAO). An elevated circulating TMAO is associated with diabetes, obesity, cardiovascular disease, and cancer in humans.

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High circulating levels of trimethylamine N-oxide (TMAO) have been associated with cardiovascular disease risk. TMAO is formed through a microbiome-host pathway utilizing primarily dietary choline as a substrate. Specific gut microbiota transform choline into trimethylamine (TMA), and, when absorbed, host hepatic flavin-containing monooxygenase 3 (FMO3) oxidizes TMA into TMAO.

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  • Oxidative phosphorylation and glycolysis are the main pathways for generating ATP in mammalian cells, and their balance adjusts based on specific cellular needs and stimuli.
  • Current methods to measure changes in these pathways are mainly qualitative, making it hard to distinguish normal energy shifts from those caused by metabolic issues.
  • The study introduces a new method using Seahorse XF Analyzer data to quantitatively measure ATP production from both pathways, revealing important bioenergetic changes in macrophages, cancer cells, and during neuronal and T cell activations.
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Dietary flavanols are known for disease preventative properties but are often poorly absorbed. Gut microbiome flavanol metabolites are more bioavailable and may exert protective activities. Using metabolite mixtures extracted from the urine of rats supplemented with flavanols and treated with or without antibiotics, we investigated their effects on INS-1 832/13 β-cell glucose stimulated insulin secretion (GSIS) capacity.

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Vascular dysfunction: develops progressively with ageing; increases the risk of cardiovascular diseases (CVD); and is characterized by endothelial dysfunction and arterial stiffening, which are primarily mediated by superoxide-driven oxidative stress and consequently reduced nitric oxide (NO) bioavailability and arterial structural changes. Interventions initiated before vascular dysfunction manifests may have more promise for reducing CVD risk than interventions targeting established dysfunction. Gut microbiome-derived trimethylamine N-oxide (TMAO) induces vascular dysfunction, is associated with higher CV risk, and can be suppressed by 3,3-dimethyl-1-butanol (DMB).

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Type 2 diabetes (T2D) is characterized by hyperglycemia and insulin resistance. Cocoa may slow T2D development and progression. This study employed male and female BTBR.

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Consumption of a Western-style diet (WD; high fat, high sugar, low fiber) is associated with impaired vascular function and increased risk of cardiovascular diseases (CVD), which could be mediated partly by increased circulating concentrations of the gut microbiome-derived metabolite trimethylamine N-oxide (TMAO). We investigated if suppression of TMAO with 3,3-dimethyl-1-butanol (DMB; inhibitor of microbial TMA lyase) in mice could prevent: ) WD-induced vascular endothelial dysfunction and aortic stiffening and ) WD-induced reductions in endurance exercise tolerance and increases in frailty, as both are linked to WD, vascular dysfunction, and increased CVD risk. C57BL/6N mice were fed standard chow or WD (41% fat, ∼25% sugar, 4% fiber) for 5 mo beginning at ∼2 mo of age.

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Obesity causes inflammation which may lead to development of co-morbidities like cardiovascular diseases. Cocoa is a popular food ingredient that has been shown to mitigate obesity and inflammation in preclinical models. Cocoa typically undergoes fermentation and roasting prior to consumption, which can affect the polyphenol content in cocoa.

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The production of pro-atherogenic trimethylamine -oxide (TMAO) is dependent on the gut microbiota metabolism of quaternary amines (, choline) into trimethylamine (TMA). Nutritional strategies that target microbial conversion of choline into TMA could reduce cardiovascular disease and atherosclerosis burden by reducing subsequent formation of TMAO. This study aimed to evaluate (1) whether beverages rich in known inhibitors of TMA production (chlorogenic acid, catechin and epicatechin) can reduce TMA formation and (2) the effect of upper gastrointestinal digestion on efficacy.

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Insights into food matrix factors impacting bioavailability of bioactive carotenoids and chlorophylls from fruits and vegetable ingredients are essential to understanding their ability to promote health. The stability and bioaccessibility of carotenoids and chlorophylls were assessed from dehydrated, spray-dried, freeze-dried and fresh spinach ingredient forms using models simulating upper gastrointestinal (GI) digestion and lower GI anaerobic fecal fermentation. Intestinal transport of bioaccessible bioactives from both upper and lower GI compartments was assessed using the Caco-2 human intestinal cell model.

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Phenolic rich 100% grape juice has been associated with many health benefits, but its place in dietary guidance is controversial relative to whole fruit. Direct comparisons of phenolic profiles and bioavailability between these food forms are needed. Phenolic bioaccessibility and metabolism from Concord (CG) and Niagara (NG) grapes and corresponding 100% juices were investigated using an digestion coupled with anaerobic gut fermentation model.

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Age-related cognitive changes can be the first indication of the progression to dementias, such as Alzheimer's disease. These changes may be driven by a complex interaction of factors including diet, activity levels, genetics, and environment. Here we review the evidence supporting relationships between flavonoids, physical activity, and brain function.

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Trimethylamine -oxide (TMAO) is a pro-atherosclerotic product of dietary choline metabolism generated by a microbiome-host axis. The first step in this pathway is the enzymatic metabolism of choline to trimethylamine (TMA) by the gut microbiota. This reaction could be targeted to reduce atherosclerosis risk.

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Serum accumulation of the gut microbial metabolite trimethylamine N-oxide (TMAO) is associated with high caloric intake and type 2 diabetes (T2D). Impaired pancreatic β-cell function is a hallmark of diet-induced T2D, which is linked to hyperglycemia and hyperlipidemia. While TMAO production via the gut microbiome-liver axis is well defined, its molecular effects on metabolic tissues are unclear, since studies in various tissues show deleterious and beneficial TMAO effects.

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Mouse models are an essential tool in different areas of research, including nutrition and phytochemical research. Traditional inbred mouse models have allowed the discovery of therapeutical targets and mechanisms of action and expanded our knowledge of health and disease. However, these models lack the genetic variability typically found in human populations, which hinders the translatability of the results found in mice to humans.

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Prediabetes affects 84.1 million adults, and many will progress to type 2 diabetes (T2D). The objective of this proof-of-concept trial was to determine the efficacy of inulin supplementation to improve glucose metabolism and reduce T2D risk.

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Article Synopsis
  • Gut bacteria convert dietary components into trimethylamine (TMA), which the liver transforms into trimethylamine N-oxide (TMAO); high TMAO levels are linked to higher risks of type 2 diabetes and cardiovascular disease.
  • A study investigated whether an increase in TMAO levels after a high-fat diet (HFD) occurred in endurance-trained versus sedentary males; neither group showed significant changes in TMAO levels after dietary interventions.
  • Findings suggest that endurance training may influence TMAO production, indicating a need for further research in this area.
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Choline is metabolized by the gut microbiota into trimethylamine (TMA), the precursor of pro-atherosclerotic molecule trimethylamine N-oxide (TMAO). A reduction in TMA formation has shown cardioprotective effects, and some phytochemicals may reduce TMA formation. This study aimed to develop an optimized, high-throughput anaerobic fermentation methodology to study the inhibition of choline microbial metabolism into TMA by phenolic compounds with healthy human fecal starter.

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Trimethylamine-N-oxide (TMAO) has been reported as a risk factor for atherosclerosis development, as well as for other cardiovascular disease (CVD) pathologies. The objective of this review is to provide a useful summary on the use of phytochemicals as TMAO-reducing agents. This review discusses the main mechanisms by which TMAO promotes CVD, including the modulation of lipid and bile acid metabolism, and the promotion of endothelial dysfunction and oxidative stress.

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