Publications by authors named "Megan Rossi"

Increasing evidence suggests a microbial pathogenesis in irritable bowel syndrome (IBS) but the relationship remains elusive. Fecal DNA samples from 120 patients with IBS, 82 Mexican (IBS-C: n = 33, IBS-D: n = 24, IBS-M: n = 25) and 38 British (IBS-C: n = 6, IBS-D: n = 27, IBS-M: n = 5), were available for analysis using 16S rRNA gene sequencing. Firmicutes (mean: 82.

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Background: The low FODMAP diet (LFD) leads to clinical response in 50%-80% of patients with irritable bowel syndrome (IBS). It is unclear why only some patients respond.

Aims: To determine if differences in baseline faecal microbiota or faecal and urine metabolite profiles may separate clinical responders to the diet from non-responders allowing predictive algorithms to be proposed.

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Background: Almonds contain lipid, fiber, and polyphenols and possess physicochemical properties that affect nutrient bioaccessibility, which are hypothesized to affect gut physiology and microbiota.

Objectives: To investigate the impact of whole almonds and ground almonds (almond flour) on fecal bifidobacteria (primary outcome), gut microbiota composition, and gut transit time.

Methods: Healthy adults (n = 87) participated in a parallel, 3-arm randomized controlled trial.

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Article Synopsis
  • The human microbiota interacts with various factors like diet and lifestyle, significantly impacting bone health across different life stages.
  • Research suggests a connection between gut microbes and bone metabolism, indicating possible roles in osteoporosis prevention and treatment.
  • The paper outlines key findings from a workshop on microbiota and bone health, highlighting necessary research directions and recommendations for effective study methodologies in this emerging field.
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Background: Short-term trials demonstrate the low FODMAP diet improves symptoms of irritable bowel syndrome (IBS) but impacts nutrient intake and the gastrointestinal microbiota. The aim of this study was to investigate clinical symptoms, nutrient intake, and microbiota of patients with IBS 12 months after starting a low FODMAP diet.

Methods: Participants enrolled in a previous short-term clinical trial and who had been through structured FODMAP restriction, reintroduction, and personalization were invited to participate in a follow-up study at one time point at 12 months.

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Article Synopsis
  • Researchers wanted to see if taking psyllium with inulin would help IBS patients avoid gas problems caused by inulin.
  • They tested 19 patients by giving them different drinks and measuring how much gas was produced over six hours.
  • The results showed that combining psyllium with inulin did lower the gas from inulin, but it didn't stop the body from making gas altogether.
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The global burden of inflammatory bowel disease [IBD] has increased over the 21st century. Despite multiple studies investigating the pathogenesis of IBD, the causative mechanisms pertaining to its increased prevalence remain unclear. There is growing evidence that aspects of a 'Western diet' increase the risk of developing IBD.

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Epidemiological studies have consistently demonstrated the benefits of dietary fibre on gastrointestinal health through consumption of unrefined whole foods, such as wholegrains, legumes, vegetables and fruits. Mechanistic studies and clinical trials on isolated and extracted fibres have demonstrated promising regulatory effects on the gut (for example, digestion and absorption, transit time, stool formation) and microbial effects (changes in gut microbiota composition and fermentation metabolites) that have important implications for gastrointestinal disorders. In this Review, we detail the major physicochemical properties and functional characteristics of dietary fibres, the importance of dietary fibres and current evidence for their use in the management of gastrointestinal disorders.

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There is an association between food additive emulsifiers and the prevalence of Crohn's disease. This study aimed to investigate: (i) the effect of different classes of emulsifiers on markers of intestinal inflammation in mice and (ii) the feasibility, nutritional adequacy and symptom impact of restricting all emulsifier classes in Crohn's disease. Mice were exposed to different classes of emulsifiers (carboxymethycellose, polysorbate-80, soy lecithin, gum arabic) in drinking water for 12-weeks, after which markers of inflammation and metabolism were measured.

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Background: Clinical guidelines provide limited and conflicting recommendations regarding dietary fiber supplementation in irritable bowel syndrome (IBS). Nopal (Opuntia ficus-indica) is a cactus plant fiber containing both insoluble and soluble fibers that may have therapeutic potential in IBS. Our aim was to evaluate the dose-response effect of extracted nopal fiber powder on symptoms in IBS.

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Article Synopsis
  • The rise in "ultra-processed" food consumption has led to increased intake of food additive emulsifiers, which may have negative effects on gastrointestinal and metabolic health.
  • This review evaluates the use, exposure, and safety of emulsifiers, highlighting challenges due to the variety of emulsifiers and inconsistent labeling worldwide.
  • Current research on emulsifiers is limited, mostly relying on lab studies and small human trials, indicating a need for more comprehensive, longer-term human studies to better understand their health impacts.
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Background: Wheat bran, nopal, and psyllium are examples of particulate, viscous and particulate, and viscous fibers, respectively, with laxative properties yet contrasting fermentability.

Objectives: We assessed the fermentability of these fibers in vitro and their effects on intestinal function relevant to laxation in vivo using MRI.

Methods: Each fiber was predigested prior to measuring gas production in vitro during 48-h anaerobic incubation with healthy fecal samples.

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Introduction: The low FODMAP diet (LFD) reduces symptoms and bifidobacteria in irritable bowel syndrome (IBS). β-galactooligosaccharides (B-GOS) may reduce the symptoms and increase bifidobacteria in IBS. We investigated whether B-GOS supplementation alongside the LFD improves IBS symptoms while preventing the decline in bifidobacteria.

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Fermented foods are defined as foods or beverages produced through controlled microbial growth, and the conversion of food components through enzymatic action. In recent years, fermented foods have undergone a surge in popularity, mainly due to their proposed health benefits. The aim of this review is to define and characterise common fermented foods (kefir, kombucha, sauerkraut, tempeh, natto, miso, kimchi, sourdough bread), their mechanisms of action (including impact on the microbiota), and the evidence for effects on gastrointestinal health and disease in humans.

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Background: Irritable bowel syndrome (IBS) and other functional bowel disorders (FBDs) are prevalent disorders with altered microbiota. Prebiotics positively augment gut microbiota and may offer therapeutic potential.

Objectives: The aim of this study was to investigate the effect of prebiotics compared with placebo on global response, gastrointestinal symptoms, quality of life (QoL), and gut microbiota, via systematic review and meta-analysis of randomized controlled trials (RCTs) in adults with IBS and other FBDs.

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Background: Dysfunction of the gut microbiota is frequently reported as a manifestation of chronic diseases, and therefore presents as a modifiable risk factor in their development. Diet is a major regulator of the gut microbiota, and certain types of dietary fiber may modify bacterial numbers and metabolism, including short-chain fatty acid (SCFA) generation.

Objective: A systematic review and meta-analysis were undertaken to assess the effect of dietary fiber interventions on gut microbiota composition in healthy adults.

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Article Synopsis
  • * Participants were randomly assigned to either follow the low-FODMAP diet or receive placebo dietary advice for 4 weeks, with some also taking probiotics. Results showed a significantly higher response rate in the low-FODMAP group compared to the sham group.
  • * Analysis revealed that specific VOC profiles could accurately classify patient responses to the low-FODMAP diet and probiotics, suggesting potential biomarkers for dietary effectiveness in IBS management.
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Purpose Of Review: The aim is to review the most recent advances in the evidence supporting the use of various dietary interventions for the management of irritable bowel syndrome (IBS).

Recent Findings: There is insufficient evidence of the effect of fibres other than psyllium in IBS, whereas the recent studies on prebiotics suggest a limited effect in IBS. Recent probiotic trials continue to provide varying results, with some probiotic strains exhibiting beneficial effects, whereas others show no effect.

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People with kidney disease are advised to restrict individual nutrients, such as sodium, potassium, and phosphate, in line with current best practice guidelines. However, there is limited evidence to support the efficacy of single nutrient strategies, and compliance remains a challenge for clinicians to overcome. Many factors contribute to poor compliance with dietary prescriptions, including conflicting priorities for single nutrient restriction, the arduous self-monitoring required, and the health-related knock-on effects resulting from targeting these nutrients in isolation.

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Dietary restriction of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) is an effective management approach for functional bowel disorders; however, its application is limited by the paucity of food composition data available for ethnic minority groups. The aim was to identify and measure the FODMAP content of these commonly consumed foods. According to their perceived importance to clinical practise, the top 20 ranked foods underwent FODMAP analysis using validated analytical techniques (total fructans, Megazyme hexokinase (HK) assay; all others, high-performance liquid chromatography (HPLC) with evaporative light scattering detectors).

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Background And Objectives: The generation of key uremic nephrovascular toxins, indoxyl sulfate (IS), and p-cresyl sulfate (PCS), is attributed to the dysbiotic gut microbiota in CKD. The aim of our study was to evaluate whether synbiotic (pre- and probiotic) therapy alters the gut microbiota and reduces serum concentrations of microbiome-generated uremic toxins, IS and PCS, in patients with CKD.

Design, Setting, Participants, & Measurements: Predialysis adult participants with CKD (eGFR=10-30 ml/min per 1.

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Background: Global longitudinal strain (GLS) has emerged as a superior method for detecting left ventricular (LV) systolic dysfunction compared to ejection fraction (EF) on the basis that it is less operator dependent and more reproducible. The 2-dimensional strain (2DS) method is easily measured and integrated into a standard echocardiogram. This study aimed to determine the relationship between GLS and traditional and chronic kidney disease (CKD)-related risk factors of cardiovascular disease (CVD) in patients with CKD.

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Objective: Phosphorus-based food additives may pose a significant risk in chronic kidney disease given the link between hyperphosphatemia and cardiovascular disease. The objective of the study was to determine the prevalence of phosphorus-based food additives in best-selling processed grocery products and to establish how they were reported on food labels.

Design: A data set of 3000 best-selling grocery items in Australia across 15 food and beverage categories was obtained for the 12 months ending December 2013 produced by the Nielsen Company's Homescan database.

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There is increasing clinical evidence that patients with chronic kidney disease (CKD) have a distinctly dysbiotic intestinal bacterial community, termed the gut microbiota, which in turn drives a cascade of metabolic abnormalities, including uremic toxin production, inflammation, and immunosuppression, that ultimately promotes progressive kidney failure and cardiovascular disease. As the gut microbiota is intimately influenced by diet, the discovery of the kidney-gut axis has created new therapeutic opportunities for nutritional intervention. This review discusses the metabolic pathways linking dysbiotic gut microbiota with adverse health outcomes in patients with CKD, as well as novel therapeutic strategies for targeting these pathways involving dietary protein, fiber, prebiotics, probiotics, and synbiotics.

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Objectives: Patients with chronic kidney disease have impaired muscle metabolism, resulting in muscle atrophy. Oxidative stress has previously been identified as a significant contributor to muscle atrophy in other populations, but the contribution in chronic kidney disease is unknown. The aim of this study was to investigate the association between oxidative stress, grip strength, and lean mass in patients with chronic kidney disease.

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