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Oxidative Medicine and Cellular... 2021Dietary fiber has a long history in the intervention study of hyperlipidemia. In this review, current understandings of structures, sources, and natures of various kinds... (Review)
Review
Dietary fiber has a long history in the intervention study of hyperlipidemia. In this review, current understandings of structures, sources, and natures of various kinds of dietary fibers (DFs) were analyzed first. Available evidences for the use of different varieties of DFs in the lipid-lowering action both and were subsequently classified, including both soluble ones, such as glucans, pectins, and gums, and insoluble ones, including arabinooxylans and chitosans, in order to draw a primary conclusion of their dose and molecular weight relationship with lipid-lowering effect. Their potential mechanisms, especially the related molecular mechanism of protective action in the treatment and prevention of hyperlipidemia, were summarized at last. Five major mechanisms are believed to be responsible for the antihyperlipidemic benefits of DFs, including low levels of energy, bulking effect, viscosity, binding capacity, and fermentation thus ameliorating the symptoms of hyperlipidemia. From the molecular level, DFs could possibly affect the activities of HMG-CoA reductase, LDL receptors, CYP7A1, and MAPK signaling pathway as well as other lipid metabolism-related target genes. In summary, dietary fibers could be used as alternative supplements to exert certain lipid-lowering effects on humans. However, more clinical evidence is needed to strengthen this proposal and its fully underlying mechanism still requires more investigation.
Topics: Dietary Fiber; Humans; Hyperlipidemias
PubMed: 33897940
DOI: 10.1155/2021/5542342 -
The Proceedings of the Nutrition Society Feb 2020Dietary fibre comprises many different, mainly plant-based, compounds that are not fully digested in the human gut. Insoluble fibres include cellulose, hemi-celluloses... (Review)
Review
Dietary fibre comprises many different, mainly plant-based, compounds that are not fully digested in the human gut. Insoluble fibres include cellulose, hemi-celluloses and lignin and soluble fibres include pectins, β-glucan and hydro-colloids. In the UK, the daily recommended amount has increased to 30 g but only 13 % of men and 4 % of women meet this recommendation. Currently the mean intake for adults is 21 g for men and 17 g for women. There is a wealth of epidemiological evidence based on systematic reviews of trials and cohorts to support the higher fibre recommendation. This includes evidence of reductions in the risk for CVD (both heart disease and stroke) and lower risk of type 2 diabetes, lower blood pressure, lower LDL-cholesterol, as well as some cancers. Beneficial effects of fibre operate via a diverse range of mechanisms throughout the digestive system including the mouth, stomach and small and large intestine; some of which are still not completely understood. The updated recommendation for fibre is a long way from a typical British diet and requires several daily portions of fruit and vegetables and wholegrain foods. Improving dietary fibre intakes will require a variety of actions and policies from stakeholders; however, there is currently more of a focus on reducing sugar than increasing fibre. In order to increase the number of adults meeting the fibre recommendation, social marketing and labelling of high-fibre foods are warranted as well as reformulation and wider availability of wholegrain versions of popular foods.
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diet; Dietary Fiber; Female; Health Behavior; Health Promotion; Humans; Male; Nutrition Policy
PubMed: 31266545
DOI: 10.1017/S0029665119000673 -
Cell Sep 2022Great progress has been made in understanding gut microbiomes' products and their effects on health and disease. Less attention, however, has been given to the inputs...
Great progress has been made in understanding gut microbiomes' products and their effects on health and disease. Less attention, however, has been given to the inputs that gut bacteria consume. Here, we quantitatively examine inputs and outputs of the mouse gut microbiome, using isotope tracing. The main input to microbial carbohydrate fermentation is dietary fiber and to branched-chain fatty acids and aromatic metabolites is dietary protein. In addition, circulating host lactate, 3-hydroxybutyrate, and urea (but not glucose or amino acids) feed the gut microbiome. To determine the nutrient preferences across bacteria, we traced into genus-specific bacterial protein sequences. We found systematic differences in nutrient use: most genera in the phylum Firmicutes prefer dietary protein, Bacteroides dietary fiber, and Akkermansia circulating host lactate. Such preferences correlate with microbiome composition changes in response to dietary modifications. Thus, diet shapes the microbiome by promoting the growth of bacteria that preferentially use the ingested nutrients.
Topics: Animals; Bacteria; Diet; Dietary Fiber; Dietary Proteins; Gastrointestinal Microbiome; Lactates; Mice; Nutrients
PubMed: 36055202
DOI: 10.1016/j.cell.2022.07.020 -
Nutrients Dec 2021Many articles and manuscripts focusing on the structure, function, mechanism of action, and effects of β-glucan have been published recently [...].
Many articles and manuscripts focusing on the structure, function, mechanism of action, and effects of β-glucan have been published recently [...].
Topics: Dietary Fiber; Food Analysis; Health Promotion; Humans; Nutritive Value; beta-Glucans
PubMed: 35010971
DOI: 10.3390/nu14010096 -
International Journal of Biological... 2022Dysbiotic gut microbiota (GM) and NLRP3 inflammasome are proarrhythmic factors in atrial fibrillation (AF). Herein, whether short-chain fatty acid (SCFA) produced from...
Dysbiotic gut microbiota (GM) and NLRP3 inflammasome are proarrhythmic factors in atrial fibrillation (AF). Herein, whether short-chain fatty acid (SCFA) produced from GM fermentation of dietary fiber serving as invisible mediators is yet unclear. Thus, the current study aimed to determine whether SCFA alleviated from NLRP3 signaling-mediated atrial remodeling protects AF development. First, a cross-sectional study based on the GC-MS metabolomics was performed to explore the association between fecal SCFA levels and AF traits in a cohort consisted of 48 individuals. Then, a well-established mice model fed diet deficient or enriched in dietary fiber was established to elucidate the pathophysiological role of SCFA involved in AF susceptibility, atrial remodeling, and G-protein-coupled receptor 43 (GPR43)/NLRP3 signaling. Finally, the effects of SCFA were verified on HL-1 cells. Fecal SCFA levels were remarkably reduced in AF patients with a declining trend from paroxysmal to persistent AF. Prolonged P wave duration based on surface ECG and increased left atrial diameter gained from echocardiography was identified in low-fiber diet mice but lost in SCFA-supplemented group. Lack of dietary fiber enhanced susceptibility to AF under burst pacing, whereas SCFA might exert a protective effect. The supplementation of SCFA prevented dietary fiber deficiency-upregulated phosphorylation of calmodulin-dependent protein kinase II and ryanodine receptor 2, the disarray fibrosis, collagen expression, and NLRP3 inflammasome activation in atrial tissue. Finally, the AF protective roles of SCFA were identified through GPR43 mediated deactivation of NLRP3 by GPR43 knockdown in HL-1 cells. SCFA derived from dietary fiber fermentation by gut commensals alleviates AF development via GPR43/NLRP3 signaling.
Topics: Animals; Atrial Fibrillation; Atrial Remodeling; Cross-Sectional Studies; Dietary Fiber; Fatty Acids, Volatile; Humans; Inflammasomes; Mice; NLR Family, Pyrin Domain-Containing 3 Protein
PubMed: 35844801
DOI: 10.7150/ijbs.70644 -
BMC Medicine Apr 2022Higher dietary fibre intakes are associated with a reduced risk of developing cardiovascular disease (CVD), and increasing intake has been shown to reduce blood pressure... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Higher dietary fibre intakes are associated with a reduced risk of developing cardiovascular disease (CVD), and increasing intake has been shown to reduce blood pressure and other cardiometabolic risk factors. The extent to which dietary fibre can further reduce risk for those with CVD and treated with cardioprotective drugs has not been clearly established. We have examined the evidence for dietary fibre as adjunct therapy in those with CVD or hypertension.
METHODS
Ovid MEDLINE, Embase, PubMed, and CENTRAL were searched to June 2021. Prospective observational studies reporting on fibre intakes and mortality in those with pre-existing CVD and controlled trials of increasing fibre intakes on cardiometabolic risk factors in those with CVD or hypertension were eligible. Outcomes were mortality (studies) and cardiometabolic risk factors (trials). Data synthesis was with random effects and dose response. Certainty of evidence was assessed using GRADE.
RESULTS
Three prospective studies including 7469 adults with CVD, and 12 trials of 878 adults with CVD or hypertension were identified. Moderate certainty evidence indicates reduced all-cause mortality (relative risk, RR0.75 (95% confidence interval, CI 0.58-0.97)) when comparing higher with lower fibre intakes. Low certainty evidence from trials of adults with cardiovascular disease indicates increasing fibre intakes reduced total (mean difference, MD - 0.42 mmol/L (95%CI - 0.78 to - 0.05) and low-density lipoprotein (LDL) cholesterol (MD - 0.47mmol/L (95%CI - 0.85 to - 0.10)). High certainty evidence from trials of adults with hypertension indicates increasing fibre intakes reduces systolic (MD 4.3 mmHg (95% CI 2.2 to 5.8)) and diastolic blood pressure (MD 3.1 mmHg (95% CI 1.7 to 4.4)). Moderate and low certainty evidence indicated improvements in fasting blood glucose (MD 0.48 mmol/L (- 0.91 to - 0.05)) and LDL cholesterol (MD 0.29 mmol/L (95% CI 0.17 to 0.40)). Benefits were observed irrespective of cardioprotective drug use.
CONCLUSIONS
These findings emphasise the likely benefits of promoting greater dietary fibre intakes for patients with CVD and hypertension. Further trials and cohort analyses in this area would increase confidence in these results.
Topics: Adult; Cardiovascular Diseases; Dietary Fiber; Humans; Hypertension; Observational Studies as Topic; Primary Prevention; Prospective Studies
PubMed: 35449060
DOI: 10.1186/s12916-022-02328-x -
Cleveland Clinic Journal of Medicine Sep 2019Hemorrhoids are a common reason for office visits. Each patient is unique, and with a range of treatments available, treatment can be individualized. This article... (Review)
Review
Hemorrhoids are a common reason for office visits. Each patient is unique, and with a range of treatments available, treatment can be individualized. This article reviews the diagnosis and decision-making process for individualized treatment.
Topics: Clinical Decision-Making; Conservative Treatment; Diet; Dietary Fiber; Hemorrhoidectomy; Hemorrhoids; Humans; Ligation
PubMed: 31498764
DOI: 10.3949/ccjm.86a.18079 -
Archives of Disease in Childhood Nov 2022Fibre is an essential nutrient in the human diet that is crucial for human health. It provides a range of functional benefits, including stool bulking, and physiological... (Review)
Review
Fibre is an essential nutrient in the human diet that is crucial for human health. It provides a range of functional benefits, including stool bulking, and physiological benefits through fermentation of diverse fibre types by the gut microbiome including cholesterol lowering, glycaemic control and weight control. The by-products of the fermentation of fibre in the gut confer health benefits that extend beyond the gut to the immune system and organs such as the liver, kidneys and the brain. A lack of fibre in the diet has been associated with several disorders in children including constipation, irritable bowel syndrome, allergies and immune-related disorders. In paediatric practice, concerns exist over tolerance of dietary fibre which may lead to unnecessary restrictions, especially for children receiving nutritional support. One reason for this may be the terminology which has historically been used. Fibre is often described in terms of its physico-chemical properties (solubility, viscosity), rather than its physiological effects/functionality (fermentability, bulking effects). To describe fibre in these latter terms represents more clearly the important role it plays. Most international guidelines recommend a daily quantity of fibre, failing to mention the quality aspect of the fibre required for health. Here we consider the evidence base for the current recommendations for daily fibre intakes for healthy children, those requiring nutritional support and those with functional gastrointestinal disorders. We also consider the importance of the gut microbiome and the role of fibre in maintaining gut microbial health and its role in health beyond the gut.
Topics: Humans; Child; Dietary Fiber; Gastrointestinal Microbiome; Constipation; Irritable Bowel Syndrome; Diet
PubMed: 35277379
DOI: 10.1136/archdischild-2021-323571 -
The American Journal of Clinical... Oct 2022Chronic constipation is a prevalent disorder that remains challenging to treat. Studies suggest increasing fiber intake may improve symptoms, although recommendations on... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Chronic constipation is a prevalent disorder that remains challenging to treat. Studies suggest increasing fiber intake may improve symptoms, although recommendations on the fiber type, dose, and treatment duration are unclear.
OBJECTIVES
We investigated the effects of fiber supplementation on stool output, gut transit time, symptoms, and quality of life in adults with chronic constipation via a systematic review and meta-analysis of randomized controlled trials (RCTs).
METHODS
Studies were identified using electronic databases, backward citation, and hand searches of abstracts. RCTs reporting administration of fiber supplementation in adults with chronic constipation were included. Risks of bias (RoB) was assessed with the Cochrane RoB 2.0 tool. Results were synthesized using risk ratios (RRs), mean differences, or standardized mean differences (SMDs) and 95% CIs using a random-effects model.
RESULTS
Sixteen RCTs with 1251 participants were included. Overall, 311 of 473 (66%) participants responded to fiber treatment and 134 of 329 (41%) responded to control treatment [RR: 1.48 (95% CI: 1.17, 1.88; P = 0.001); I2 = 57% (P = 0.007)], with psyllium and pectin having significant effects. A higher response to treatment was apparent in fiber groups compared to control groups irrespective of the treatment duration, but only with higher fiber doses (>10 g/d). Fiber increased stool frequency [SMD: 0.72 (95% CI: 0.36, 1.08; P = 0.0001); I2 = 86% (P < 0.00001)]; psyllium and pectin had significant effects, and improvement was apparent only with higher fiber doses and greater treatment durations (≥4 weeks). Fiber improved stool consistency (SMD: 0.32; 95% CI: 0.18, 0.46; P < 0.0001), particularly with higher fiber doses. Flatulence was higher in fiber groups compared to control groups(SMD: 0.80; 95% CI: 0.47, 1.13; P < 0.00001).
CONCLUSIONS
Fiber supplementation is effective at improving constipation. Particularly, psyllium, doses >10 g/d and treatment durations of at least 4 weeks appear optimal, though caution is needed when interpreting the results due to considerable heterogeneity. These findings provide promising evidence on the optimal type and regime of fiber supplementation, which could be used to standardize recommendations to patients. The protocol for this review is registered at PROSPERO as CRD42020191404.
Topics: Adult; Constipation; Dietary Fiber; Dietary Supplements; Humans; Pectins; Psyllium; Randomized Controlled Trials as Topic
PubMed: 35816465
DOI: 10.1093/ajcn/nqac184 -
Advances in Nutrition (Bethesda, Md.) Dec 2021
Topics: Dietary Fiber; Humans
PubMed: 34687531
DOI: 10.1093/advances/nmab116