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Gut Microbes Mar 2017The gastrointestinal microbiota has an important role in human health, and there is increasing interest in utilizing dietary approaches to modulate the composition and... (Review)
Review
The gastrointestinal microbiota has an important role in human health, and there is increasing interest in utilizing dietary approaches to modulate the composition and metabolic function of the microbial communities that colonize the gastrointestinal tract to improve health, and prevent or treat disease. One dietary strategy for modulating the microbiota is consumption of dietary fiber and prebiotics that can be metabolized by microbes in the gastrointestinal tract. Human alimentary enzymes are not able to digest most complex carbohydrates and plant polysaccharides. Instead, these polysaccharides are metabolized by microbes which generate short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate. This article reviews the current knowledge of the impact of fiber and prebiotic consumption on the composition and metabolic function of the human gastrointestinal microbiota, including the effects of physiochemical properties of complex carbohydrates, adequate intake and treatment dosages, and the phenotypic responses related to the composition of the human microbiota.
Topics: Animals; Bacteria; Dietary Fiber; Gastrointestinal Microbiome; Gastrointestinal Tract; Humans; Prebiotics
PubMed: 28165863
DOI: 10.1080/19490976.2017.1290756 -
Nutrients Oct 2020Dietary fibre consists of non-digestible forms of carbohydrate, usually as polysaccharides that originate from plant-based foods. Over recent decades, our diet within... (Review)
Review
BACKGROUND
Dietary fibre consists of non-digestible forms of carbohydrate, usually as polysaccharides that originate from plant-based foods. Over recent decades, our diet within Westernised societies has changed radically from that of our hominid ancestors, with implications for our co-evolved gut microbiota. This includes increased ingestion of ultra-processed foods that are typically impoverished of dietary fibre, and associated reduction in the intake of fibre-replete plant-based foods. Over recent decades, there has been a transformation in our understanding of the health benefits of dietary fibre.
OBJECTIVE
To explore the current medical literature on the health benefits of dietary fibre, with a focus on overall metabolic health.
DATA SOURCES
We performed a narrative review, based on relevant articles written in English from a PubMed search, using the terms 'dietary fibre and metabolic health'.
RESULTS
In the Western world, our diets are impoverished of fibre. Dietary fibre intake associates with overall metabolic health (through key pathways that include insulin sensitivity) and a variety of other pathologies that include cardiovascular disease, colonic health, gut motility and risk for colorectal carcinoma. Dietary fibre intake also correlates with mortality. The gut microflora functions as an important mediator of the beneficial effects of dietary fibre, including the regulation of appetite, metabolic processes and chronic inflammatory pathways.
CONCLUSIONS
Multiple factors contribute to our fibre-impoverished modern diet. Given the plethora of scientific evidence that corroborate the multiple and varied health benefits of dietary fibre, and the risks associated with a diet that lacks fibre, the optimization of fibre within our diets represents an important public health strategy to improve both metabolic and overall health. If implemented successfully, this strategy would likely result in substantial future health benefits for the population.
Topics: Adiposity; Body Weight; Cardiovascular Diseases; Colorectal Neoplasms; Depression; Diet; Dietary Fiber; Eating; Gastrointestinal Microbiome; Gastrointestinal Motility; Health; Humans; Inflammation; Insulin Resistance; Mortality; Obesity
PubMed: 33096647
DOI: 10.3390/nu12103209 -
Nutrients May 2021Dietary fibre has long been established as a nutritionally important, health-promoting food ingredient. Modern dietary practices have seen a significant reduction in... (Review)
Review
Dietary fibre has long been established as a nutritionally important, health-promoting food ingredient. Modern dietary practices have seen a significant reduction in fibre consumption compared with ancestral habits. This is related to the emergence of low-fibre "Western diets" associated with industrialised nations, and is linked to an increased prevalence of gut diseases such as inflammatory bowel disease, obesity, type II diabetes mellitus and metabolic syndrome. The characteristic metabolic parameters of these individuals include insulin resistance, high fasting and postprandial glucose, as well as high plasma cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Gut microbial signatures are also altered significantly in these cohorts, suggesting a causative link between diet, microbes and disease. Dietary fibre consumption has been hypothesised to reverse these changes through microbial fermentation and the subsequent production of short-chain fatty acids (SCFA), which improves glucose and lipid parameters in individuals who harbour diseases associated with dysfunctional metabolism. This review article examines how different types of dietary fibre can differentially alter glucose and lipid metabolism through changes in gut microbiota composition and function.
Topics: Dietary Fiber; Fatty Acids, Volatile; Gastrointestinal Microbiome; Glucose; Humans; Lipid Metabolism
PubMed: 34068353
DOI: 10.3390/nu13051655 -
Molecules (Basel, Switzerland) Nov 2021Dietary fiber is a widely recognized nutrient for human health. Previous studies proved that dietary fiber has significant implications for gastrointestinal health by... (Review)
Review
Dietary fiber is a widely recognized nutrient for human health. Previous studies proved that dietary fiber has significant implications for gastrointestinal health by regulating the gut microbiota. Moreover, mechanistic research showed that the physiological functions of different dietary fibers depend to a great extent on their physicochemical characteristics, one of which is solubility. Compared with insoluble dietary fiber, soluble dietary fiber can be easily accessed and metabolized by fiber-degrading microorganisms in the intestine and produce a series of beneficial and functional metabolites. In this review, we outlined the structures, characteristics, and physiological functions of soluble dietary fibers as important nutrients. We particularly focused on the effects of soluble dietary fiber on human health via regulating the gut microbiota and reviewed their effects on dietary and clinical interventions.
Topics: Dietary Fiber; Energy Intake; Gastrointestinal Microbiome; Histone Deacetylase Inhibitors; Humans; Intestinal Absorption; Ligands; Molecular Structure; Polysaccharides; Receptors, G-Protein-Coupled; Satiation; Solubility
PubMed: 34833893
DOI: 10.3390/molecules26226802 -
Nutrients Oct 2020The consumption of whole grain products is often related to beneficial effects on consumer health. Dietary fibre is an important component present in whole grains and is... (Review)
Review
The consumption of whole grain products is often related to beneficial effects on consumer health. Dietary fibre is an important component present in whole grains and is believed to be (at least partially) responsible for these health benefits. The dietary fibre composition of whole grains is very distinct over different grains. Whole grains of cereals and pseudo-cereals are rich in both soluble and insoluble functional dietary fibre that can be largely classified as e.g., cellulose, arabinoxylan, β-glucan, xyloglucan and fructan. However, even though the health benefits associated with the consumption of dietary fibre are well known to scientists, producers and consumers, the consumption of dietary fibre and whole grains around the world is substantially lower than the recommended levels. This review will discuss the types of dietary fibre commonly found in cereals and pseudo-cereals, their nutritional significance and health benefits observed in animal and human studies.
Topics: Animals; Cellulose; Chronic Disease; Dietary Fiber; Edible Grain; Glucans; Health Promotion; Humans; Nutritive Value; Recommended Dietary Allowances; Whole Grains; Xylans; beta-Glucans
PubMed: 33027944
DOI: 10.3390/nu12103045 -
Central European Journal of Public... Sep 2019Trends in dietary nutrition and their personalization are progress in medical science and point out the necessity of adaptation and development of innovations in health... (Review)
Review
Trends in dietary nutrition and their personalization are progress in medical science and point out the necessity of adaptation and development of innovations in health system. The main objective of this article is to review the role of dietary fibre as prebiotics in nutrition with different functionality, its influence on modulation of intestinal microbiota, which has an essential role in maintenance of healthy organisms in people of all ages.
Topics: Diet; Dietary Fiber; Gastrointestinal Microbiome; Nutritional Status; Prebiotics
PubMed: 31580563
DOI: 10.21101/cejph.a5313 -
Alimentary Pharmacology & Therapeutics Jul 2015Application of modern rapid DNA sequencing technology has transformed our understanding of the gut microbiota. Diet, in particular plant-based fibre, appears critical in... (Review)
Review
BACKGROUND
Application of modern rapid DNA sequencing technology has transformed our understanding of the gut microbiota. Diet, in particular plant-based fibre, appears critical in influencing the composition and metabolic activity of the microbiome, determining levels of short-chain fatty acids (SCFAs) important for intestinal health.
AIM
To assess current epidemiological, experimental and clinical evidence of how long-term and short-term alterations in dietary fibre intake impact on the microbiome and metabolome.
METHODS
A Medline search including items 'intestinal microbiota', 'nutrition', 'diet', 'dietary fibre', 'SCFAs' and 'prebiotic effect' was performed.
RESULTS
Studies found evidence of fibre-influenced differences in the microbiome and metabolome as a consequence of habitual diet, and of long-term or short-term intervention (in both animals and humans).
CONCLUSIONS
Agrarian diets high in fruit/legume fibre are associated with greater microbial diversity and a predominance of Prevotella over Bacteroides. 'Western'-style diets, high in fat/sugar, low in fibre, decrease beneficial Firmicutes that metabolise dietary plant-derived polysaccharides to SCFAs and increase mucosa-associated Proteobacteria (including enteric pathogens). Short-term diets can also have major effects, particularly those exclusively animal-based, and those high-protein, low-fermentable carbohydrate/fibre 'weight-loss' diets, increasing the abundance of Bacteroides and lowering Firmicutes, with long-term adherence to such diets likely increasing risk of colonic disease. Interventions to prevent intestinal inflammation may be achieved with fermentable prebiotic fibres that enhance beneficial Bifidobacteria or with soluble fibres that block bacterial-epithelial adherence (contrabiotics). These mechanisms may explain many of the differences in microbiota associated with long-term ingestion of a diet rich in fruit and vegetable fibre.
Topics: Animals; Bacteroides; Bifidobacterium; Diet; Dietary Fiber; Feeding Behavior; Firmicutes; Gastrointestinal Microbiome; Humans; Male; Metabolome
PubMed: 26011307
DOI: 10.1111/apt.13248 -
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 -
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 -
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