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Nutrients May 2023Dietary fibers include non-digestible plant carbohydrates, lignin and resistant starch. Dietary fibers provide immune, cardiovascular, metabolic and intestinal... (Review)
Review
Dietary fibers include non-digestible plant carbohydrates, lignin and resistant starch. Dietary fibers provide immune, cardiovascular, metabolic and intestinal beneficial effects in humans. Fibers naturally present in foods (fruits, vegetables, legumes, cereals) or used as supplements have different physical, chemical and functional profiles. This narrative review provides an update to the knowledge on the effects of dietary fibers in healthy subjects and in children with gastrointestinal disorders. Soluble fibers are digested by gut bacteria, producing short-chain fatty acids and energy for colonocytes, and may exert prebiotic effects that promote the growth of bifidobacteria and lactobacilli. Non-soluble fibers are bulking agents and may improve intestinal transit. The exact amount and characteristics of the fiber requirement in infants and children need to be further established. There are limited data evaluating fibers in children with gastrointestinal disorders. The low intake of fibers has been associated with constipation, but the intake of excessive fibers is not recommended as it may cause flatulence and abdominal discomfort. Certain fibers (particularly psyllium in irritable bowel syndrome) have shown beneficial effects in children with gastrointestinal disorders, but the limited and heterogenous data do not currently allow a specific recommendation.
Topics: Infant; Humans; Child; Dietary Fiber; Gastrointestinal Diseases; Constipation; Resistant Starch; Flatulence; Vegetables
PubMed: 37432354
DOI: 10.3390/nu15092208 -
Advances in Nutrition (Bethesda, Md.) Dec 2022Nondigestible carbohydrates (NDCs) are food components, including nonstarch polysaccharides and resistant starches. Many NDCs are classified as dietary fibers by the US... (Review)
Review
Nondigestible carbohydrates (NDCs) are food components, including nonstarch polysaccharides and resistant starches. Many NDCs are classified as dietary fibers by the US FDA. Because of their beneficial effects on human health and product development, NDCs are widely used in the food supply. Although there are dietary intake recommendations for total dietary fiber, there are no such recommendations for individual NDCs. NDCs are heterogeneous in their chemical composition and physicochemical properties-characteristics that contribute to their tolerable intake levels. Guidance on tolerable intake levels of different NDCs is needed because overconsumption can lead to undesirable gastrointestinal side effects, further widening the gap between actual and suggested fiber intake levels. In this review, we synthesize the literature on gastrointestinal effects of NDCs that the FDA accepts as dietary fibers (β-glucan, pectin, arabinoxylan, guar gum, alginate, psyllium husk, inulin, fructooligosaccharides and oligofructose, galactooligosaccharides, polydextrose, cellulose, soy fiber, resistant maltodextrin/dextrin) and present tolerable intake dose recommendations for their consumption. We summarized the findings from 103 clinical trials in adults without gastrointestinal disease who reported gastrointestinal effects, including tolerance (e.g., bloating, flatulence, borborygmi/rumbling) and function (e.g., transit time, stool frequency, stool consistency). These studies provided doses ranging from 0.75-160 g/d and lasted for durations ranging from a single-meal tolerance test to 28 wk. Tolerance was NDC specific; thus, recommendations ranged from 3.75 g/d for alginate to 25 g/d for soy fiber. Future studies should address gaps in the literature by testing a wider range of NDC doses and consumption forms (solid compared with liquid). Furthermore, future investigations should also adopt a standard protocol to examine tolerance and functional outcomes across studies consistently.
Topics: Adult; Humans; Gastrointestinal Tract; Carbohydrates; Dietary Fiber; Feces; Alginates
PubMed: 36041173
DOI: 10.1093/advances/nmac094 -
Annals of Medicine Dec 2023Dietary fibre and cognitive function are associated with the risk of mortality, respectively. Inadequate dietary fibre intake and cognitive impairment frequently...
BACKGROUND
Dietary fibre and cognitive function are associated with the risk of mortality, respectively. Inadequate dietary fibre intake and cognitive impairment frequently co-occur in older adults, but the combined effect of dietary fibre and cognitive function on mortality remains unknown. The study was to investigate the combined effect of dietary fibre and cognitive function on mortality over a 13-year follow-up in a representative of older adults from the U.S.
METHODS
We analyzed data from two cycles of the National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002 with mortality follow-up data through 13 December 2015 obtained from Public-use Linked Mortality Files. Low dietary fibre intake was defined as the lowest quartile of dietary fibre intake. Cognitive impairment was defined as below the median of Digit Symbol Substitution Test. The separate and combined effects of low dietary fibre intake and cognitive impairment on all-cause and cause-specific mortality were assessed in older adults using weighted Cox proportional hazard models adjusting for potential confounders.
RESULTS
A total of 2012 participants (weighted sample was 32,765,094) aged 60 years and older were enrolled in the study. After a median follow-up of 13.4 years, 1017 participants (50.4%) were identified as all-cause deaths, including 183 (9.1%) participants dying from cancer, 199 (9.9%) participants dying from cardiovascular disease, and 635 (31.5%) participants dying from non-cancer/non-cardiovascular disease. Participants with low dietary fibre intake and cognitive impairment had nearly twice the risk of all-cause (HR, 2.030; 95% CI, 1.406-2.931) and non-cancer/non-cardiovascular (HR, 2.057; 95% CI, 1.297-3.262) mortality, and over triple cancer (HR, 3.334; 95% CI, 1.685-6.599) mortality, compared to those without both.
CONCLUSIONS
The combination of low dietary fibre intake and cognitive impairment was associated with an increased risk of all-cause, cancer and non-cancer/non- cardiovascular mortality in older adults.
Topics: Humans; Middle Aged; Aged; Nutrition Surveys; Cause of Death; Diet; Cardiovascular Diseases; Cognition; Neoplasms; Dietary Fiber
PubMed: 37287268
DOI: 10.1080/07853890.2023.2221036 -
Nutrients Oct 2020The prevalence of type 2 diabetes is on the increase worldwide, and it represents about 90% of adults who are diagnosed with diabetes. Overweight and obesity, lifestyle,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The prevalence of type 2 diabetes is on the increase worldwide, and it represents about 90% of adults who are diagnosed with diabetes. Overweight and obesity, lifestyle, genetic predisposition and gut microbiota dysbiosis have been implicated as possible risk factors in the development of type 2 diabetes. In particular, low intake of dietary fibre and consumption of foods high in fat and sugar, which are common in western lifestyle, have been reported to contribute to the depletion of specific bacterial taxa. Therefore, it is possible that intake of high dietary fibre may alter the environment in the gut and provide the needed substrate for microbial bloom.
AIM
The current review is a systematic review and meta-analysis which evaluated the role of dietary fibre in modulating gut microbiota dysbiosis in patients with type 2 diabetes.
METHODS
This is a systematic review and meta-analysis of randomised controlled trials which relied on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Electronic searches were conducted using EBSCOHost with links to Health Sciences Research Databases, EMBASE and Google Scholar. The reference lists of articles were also searched for relevant studies. Searches were conducted from date of commencement of the database to 5 August 2020. The search strategy was based on the Population, Intervention, Comparator, Outcomes, Studies (PICOS) framework and involved the use of synonyms and medical subject headings (MesH). Search terms were combined with Boolean operators (OR/AND).
RESULTS
Nine studies which met the inclusion criteria were selected for the systematic review and meta-analysis, and four distinct areas were identified: the effect of dietary fibre on gut microbiota; the role of dietary fibre on short-chain fatty acids (SCFAs); glycaemic control; and adverse events. There was significant difference ( < 0.01) in the relative abundance of Bifidobacterium with a mean difference of 0.72 (95% CI, 0.56, 0.89) between the dietary fibre group compared with placebo. In relation to the meta-analysis for SCFAs, while there was significant difference ( = 0.02) between the dietary fibre group and placebo with a standardised mean difference of 0.5 (95% CI, 0.08, 0.91) regarding total SCFAs, the differences were not significant ( > 0.05) in relation to acetic acid, propionic acid and butyric acid. There was only significant improvement ( = 0.002) with respect to glycated haemoglobin with a mean difference of -0.18 (95% CI, -0.29, -0.06) between the dietary fibre group and placebo group. Differences between the two groups were not significant ( > 0.05) in relation to fasting blood glucose and homeostatic model assessment of insulin resistance (HOMA-IR). Furthermore, there were no significant differences between the two groups in subjects who reported adverse events. It is possible that the promotion of SCFA producers in greater diversity and abundance by dietary fibre in this review led to improvement in glycated haemoglobin, partly due to increased glucagon-like peptide-1 (GLP-1) production. In addition, Bifidobacterium lactis has been reported to increase glycogen synthesis, decrease expression of hepatic gluconeogenesis genes, improve translocation of glucose transport-4 and promote glucose uptake. It is also possible that the reduction in body weight of participants in the intervention group compared with control may have contributed to the observed improvement in glycated haemoglobin.
CONCLUSION
This systematic review and meta-analysis have demonstrated that dietary fibre can significantly improve ( < 0.05) the relative abundance of Bifidobacterium, total SCFAs and glycated haemoglobin. However, dietary fibre did not appear to have significant effect ( > 0.05) on fasting blood glucose, HOMA-IR, acetic acid, propionic acid, butyric acid and adverse events.
Topics: Adult; Diabetes Mellitus, Type 2; Dietary Fiber; Dysbiosis; Fatty Acids, Volatile; Female; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycemic Control; Humans; Male; Randomized Controlled Trials as Topic
PubMed: 33113929
DOI: 10.3390/nu12113239 -
Nutrients May 2023The beneficial impact of dietary fiber on the prevention and management of several chronic conditions associated with aging, including diabetes, neurodegenerative,... (Review)
Review
The beneficial impact of dietary fiber on the prevention and management of several chronic conditions associated with aging, including diabetes, neurodegenerative, cardiovascular diseases, and cancer, is well-known. High fiber intake has been associated with reduced inflammatory mediators counteracting the low-grade chronic inflammation typical of older age. In addition, dietary fiber improves postprandial glucose response and insulin resistance. In contrast, during acute diseases, its effects on insulin resistance and modulation of immune response are unclear. The aim of this narrative is to summarize the evidence for the potential impact of dietary fiber on inflammation and insulin resistance in older adults, with a particular focus on those acutely ill. Available evidence suggests that dietary fiber has the potential to counteract acute inflammation and to improve metabolic health. In addition, modulation of gut microbiota composition may contribute to improved immune function, particularly in the setting of aging-associated dysbiosis. This phenomenon has relevant implications in those acutely ill, in whom dysbiosis can be exacerbated. Our review leads to the conclusion that dietary interventions based on fiber manipulation could exploit its beneficial effects on inflammation and insulin resistance, if conducted from a precision nutrition perspective. This could also be true for the acutely ill patient, even though strong evidence is lacking.
Topics: Humans; Aged; Insulin Resistance; Dysbiosis; Inflammation; Dietary Fiber; Glucose
PubMed: 37242248
DOI: 10.3390/nu15102365 -
Cell Reports Sep 2022Dietary fibers are potent modulators of immune responses that can restrain inflammation in multiple disease contexts. However, dietary fibers encompass a biochemically...
Dietary fibers are potent modulators of immune responses that can restrain inflammation in multiple disease contexts. However, dietary fibers encompass a biochemically diverse family of carbohydrates, and it remains unknown how individual fiber sources influence immunity. In a direct comparison of four different high-fiber diets, we demonstrate a potent ability of guar gum to delay disease and neuroinflammation in experimental autoimmune encephalomyelitis, a T cell-mediated mouse model of multiple sclerosis. Guar gum-specific alterations to the microbiota are limited, and disease protection appears to be independent of fiber-induced increases in short-chain fatty acid levels or regulatory CD4 T cells. Instead, CD4 T cells of guar gum-supplemented mice are less encephalitogenic due to reduced activation, proliferation, Th1 differentiation, and altered migratory potential. These findings reveal specificity in the host response to fiber sources and define a pathway of fiber-induced immunomodulation that protects against pathologic neuroinflammation.
Topics: Animals; Cyamopsis; Diet; Dietary Fiber; Encephalomyelitis, Autoimmune, Experimental; Galactans; Mannans; Mice; Plant Gums
PubMed: 36103823
DOI: 10.1016/j.celrep.2022.111328 -
Nutrients Jun 2023Dietary fiber is a functional substance with strong antioxidant activity that plays an important role in human health. Dietary fiber has been shown to reduce the risks...
BACKGROUND
Dietary fiber is a functional substance with strong antioxidant activity that plays an important role in human health. Dietary fiber has been shown to reduce the risks of many types of cancers, but whether it can reduce the risk of death in cancer survivors remains undetermined.
METHODS
This study included the dietary data of cancer survivors who participated in the National Health and Nutrition Examination Surveys from 2001 to 2018. Firstly, the relationship between fiber intake and composite dietary antioxidant index (CDAI) was explored by weighted multiple regression and smooth curve. Subsequently, multivariable Cox proportional hazards regression models were used to explore the effects of dietary fiber intake and CDAI level on the risks of all-cause, tumor, and cardiovascular death among cancer survivors.
RESULTS
A total of 2077 participants were included in the study, representing approximately 11,854,509 cancer survivors in the United States. The dietary fiber intake of tumor survivors had a nonlinear positive relationship with CDAI levels (β = 0.24, 95% CI: 0.08-0.40, = 0.004). Multivariable Cox proportional hazards regression models showed that high dietary fiber intake and CDAI levels were associated with reduced risks of all-cause and tumor death in tumor survivors, but were not associated with the risk of cardiovascular death.
CONCLUSION
An increased dietary fiber intake can enhance the body's antioxidant capacity. A higher dietary fiber intake and CDAI level may reduce the risk of all-cause and tumor death in tumor survivors.
Topics: Dietary Fiber; Antioxidants; Cancer Survivors; Nutrition Surveys; United States; Humans; Mortality; Male; Female; Middle Aged; Aged
PubMed: 37447293
DOI: 10.3390/nu15132968 -
International Journal of Molecular... Apr 2020Durum wheat is one of most important cereal crops that serves as a staple dietary component for humans and domestic animals. It provides antioxidants, proteins, minerals... (Review)
Review
Durum wheat is one of most important cereal crops that serves as a staple dietary component for humans and domestic animals. It provides antioxidants, proteins, minerals and dietary fibre, which have beneficial properties for humans, especially as related to the health of gut microbiota. Dietary fibre is defined as carbohydrate polymers that are non-digestible in the small intestine. However, this dietary component can be digested by microorganisms in the large intestine and imparts physiological benefits at daily intake levels of 30-35 g. Dietary fibre in cereal grains largely comprises cell wall polymers and includes insoluble (cellulose, part of the hemicellulose component and lignin) and soluble (arabinoxylans and (1,3;1,4)-β-glucans) fibre. More specifically, certain components provide immunomodulatory and cholesterol lowering activity, faecal bulking effects, enhanced absorption of certain minerals, prebiotic effects and, through these effects, reduce the risk of type II diabetes, cardiovascular disease and colorectal cancer. Thus, dietary fibre is attracting increasing interest from cereal processors, producers and consumers. Compared with other components of the durum wheat grain, fibre components have not been studied extensively. Here, we have summarised the current status of knowledge on the genetic control of arabinoxylan and (1,3;1,4)-β-glucan synthesis and accumulation in durum wheat grain. Indeed, the recent results obtained in durum wheat open the way for the improvement of these important cereal quality parameters.
Topics: Cell Wall; Chemical Phenomena; Dietary Fiber; Edible Grain; Glucans; Host-Pathogen Interactions; Molecular Structure; Nutrients; Polysaccharides; Quantitative Trait Loci; Quantitative Trait, Heritable; Triticum; Xylans
PubMed: 32331292
DOI: 10.3390/ijms21082933 -
Molecules (Basel, Switzerland) May 2020Food can be regarded as functional if it beneficially affects one or more target functions in the body in a way that is relevant to either the state of well-being and...
Food can be regarded as functional if it beneficially affects one or more target functions in the body in a way that is relevant to either the state of well-being and health or to the reduction of the risk of a disease [...].
Topics: Dietary Fiber; Food Analysis; Humans; Pharmaceutical Preparations
PubMed: 32455805
DOI: 10.3390/molecules25102403 -
Frontiers in Immunology 2023Intestinal health is closely associated with overall animal health and performance and, consequently, influences the production efficiency and profit in feed and animal... (Review)
Review
Intestinal health is closely associated with overall animal health and performance and, consequently, influences the production efficiency and profit in feed and animal production systems. The gastrointestinal tract (GIT) is the main site of the nutrient digestive process and the largest immune organ in the host, and the gut microbiota colonizing the GIT plays a key role in maintaining intestinal health. Dietary fiber (DF) is a key factor in maintaining normal intestinal function. The biological functioning of DF is mainly achieved by microbial fermentation, which occurs mainly in the distal small and large intestine. Short-chain fatty acids (SCFAs), the main class of microbial fermentation metabolites, are the main energy supply for intestinal cells. SCFAs help to maintain normal intestinal function, induce immunomodulatory effects to prevent inflammation and microbial infection, and are vital for the maintenance of homeostasis. Moreover, because of its distinct characteristics (e.g. solubility), DF is able to alter the composition of the gut microbiota. Therefore, understanding the role that DF plays in modulating gut microbiota, and how it influences intestinal health, is essential. This review gives an overview of DF and its microbial fermentation process, and investigates the effect of DF on the alteration of gut microbiota composition in pigs. The effects of interaction between DF and the gut microbiota, particularly as they relate to SCFA production, on intestinal health are also illustrated.
Topics: Swine; Animals; Gastrointestinal Microbiome; Intestines; Gastrointestinal Tract; Dietary Fiber; Nutrients
PubMed: 36865557
DOI: 10.3389/fimmu.2023.1095740