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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 -
The Proceedings of the Nutrition Society Aug 2015The role of dietary fibre in promoting sustained health has been studied for several decades and in adults there is good evidence that diets rich in high-fibre foods... (Review)
Review
The role of dietary fibre in promoting sustained health has been studied for several decades and in adults there is good evidence that diets rich in high-fibre foods reduce the risk of chronic diseases, including CVD and cancer. Research in this area, however, has been hampered by uncertainties about the definition of dietary fibre which has resulted in many studies measuring fibre in different ways. There is also a wide range of properties and actions of different fibres in the human body, depending on their solubility, viscosity and fermentability by the colonic microbiota. This review considers the epidemiological evidence for dietary fibre and health in children and the current dietary recommendations and measured intakes in several countries using national surveys. In children and adolescents, there is a particular lack of relevant research on which to formulate appropriate dietary fibre recommendations and these are often based on extrapolation from adult data. However, children are not little adults and have differing physiology and nutritional needs as they grow. The dietary recommendations in different countries are based on varying premises and daily amounts. Intakes vary from country to country and on the whole do not meet recommendations. Much more research is needed in children to fully understand the impact of dietary fibre on growth and health in the young to allow more appropriate recommendations to be made.
Topics: Adolescent; Child; Child Development; Child Nutritional Physiological Phenomena; Diet; Dietary Fiber; Health Promotion; Health Surveys; Humans; Recommended Dietary Allowances
PubMed: 26186674
DOI: 10.1017/S0029665115002335 -
Food Chemistry Nov 2022Bifidobacteria are considered as probiotics due to their role in promoting intestinal health, including regulating intestinal flora, controlling glycolipid metabolism,...
Bifidobacteria are considered as probiotics due to their role in promoting intestinal health, including regulating intestinal flora, controlling glycolipid metabolism, anti-colitis effects. Dietary fiber is considered as prebiotic favoring gut health. It also can be used as carbon source to support the growth and colonization of probiotics like bifidobacteria. However, because of genetic diversity, different bifidobacterial species differ in their ability to utilize dietary fiber. Meanwhile, dietary fiber with different structural properties has different effects on the bifidobacteria proliferation. The interaction between dietary fiber and bifidobacteria will consequently lead to a synergistic or antagonistic function in promoting intestinal health, therefore affecting the application of combined use of dietary fiber and bifidobacteria. In this case, we summarize the biological function of bifidobacteria, and their interaction with different dietary fiber in promoting gut health, and finally provide several strategies about their combined use.
Topics: Bifidobacterium; Dietary Fiber; Gastrointestinal Microbiome; Prebiotics; Probiotics
PubMed: 35696956
DOI: 10.1016/j.foodchem.2022.133407 -
The Proceedings of the Nutrition Society Sep 2022The aim of this review is to provide an overview of how person-specific interactions between diet and the gut microbiota could play a role in affecting diet-induced... (Review)
Review
The aim of this review is to provide an overview of how person-specific interactions between diet and the gut microbiota could play a role in affecting diet-induced weight loss responses. The highly person-specific gut microbiota, which is shaped by our diet, secretes digestive enzymes and molecules that affect digestion in the colon. Therefore, weight loss responses could in part depend on personal colonic fermentation responses, which affect energy extraction of food and production of microbial metabolites, such as short-chain fatty acids (SCFAs), which exert various effects on host metabolism. Colonic fermentation is the net result of the complex interplay between availability of dietary substrates, the functional capacity of the gut microbiome and environmental (abiotic) factors in the gut such as pH and transit time. While animal studies have demonstrated that the gut microbiota can causally affect obesity, causal and mechanistic evidence from human studies is still largely lacking. However, recent human studies have proposed that the baseline gut microbiota composition may predict diet-induced weight loss-responses. In particular, individuals characterised by high relative abundance of have been found to lose more weight on diets rich in dietary fibre compared to individuals with low abundance. Although harnessing of personal diet-microbiota interactions holds promise for more personalised nutrition and obesity management strategies to improve human health, there is currently insufficient evidence to unequivocally link the gut microbiota and weight loss in human subjects. To move the field forward, a greater understanding of the mechanistic underpinnings of personal diet-microbiota interactions is needed.
Topics: Animals; Humans; Diet; Weight Loss; Gastrointestinal Microbiome; Dietary Fiber; Diet, Reducing; Obesity; Fatty Acids, Volatile
PubMed: 35258446
DOI: 10.1017/S0029665122000805 -
Current Medicinal Chemistry 2019Functional foods are designed to have physiological benefits and reduce the risk of chronic disease beyond basic nutritional functions. Conditions related to... (Review)
Review
BACKGROUND
Functional foods are designed to have physiological benefits and reduce the risk of chronic disease beyond basic nutritional functions. Conditions related to overnutrition such as Metabolic Syndrome and Type 2 diabetes are increasingly serious concerns in Western societies. Several nutrient classes are considered to protect against these conditions and this review focuses on the latest clinical and preclinical evidence supporting their efficacy and the molecular mechanisms by which they act.
METHODS
The review searched the literature for information and data on the following functional food components and their protective effects against Metabolic Syndrome and Type 2 Diabetes: Dietary fiber; Medium-chain triglycerides and Ketone esters; ω3 Polyunsaturated fatty acids and Antioxidants.
RESULTS
Data from a hundred and four studies were reviewed and summarized. They indicate that dietary fiber results in the production of beneficial short chain fatty acids via intestinal microbiota, as well as increasing intestinal secretion of incretins and satiety peptides. Medium chain triglycerides and ketone esters promote thermogenesis, inhibit lipolysis and reduce inflammation. They also decrease endogenous synthesis of triglycerides and fatty acids. ω3-PUFA's act to soften inflammation through an increase in adiponectin secretion. Antioxidants are involved in the protection of insulin sensitivity by PTP1B suppression and SIRT1 activation.
CONCLUSION
Functional foods have actions that complement and/or potentiate other lifestyle interventions for reversing Metabolic Syndrome and Type 2 Diabetes. Functional foods contribute to reduced food intake by promoting satiety, less weight gain via metabolic uncoupling and improved insulin sensitivity via several distinct mechanisms.
Topics: Animals; Antioxidants; Diabetes Mellitus, Type 2; Dietary Fiber; Fatty Acids, Omega-3; Functional Food; Gastrointestinal Microbiome; Humans; Metabolic Syndrome
PubMed: 28545368
DOI: 10.2174/0929867324666170523130123 -
Carbohydrate Polymers Jan 2022Inulin, a fructan-type non-digestible carbohydrate, is a natural functional dietary fiber found in selected plants including chicory, garlic, onion, leeks and asparagus.... (Review)
Review
Inulin, a fructan-type non-digestible carbohydrate, is a natural functional dietary fiber found in selected plants including chicory, garlic, onion, leeks and asparagus. Due to increasing popularity of inulin and rising awareness toward its low calorie value and prebiotic related health implications, consumers are becoming more conscious on consuming inulin incorporated foods. In this review, the scientific studies published in recent years regarding potential applications of inulin in meat products; and their effects on physicochemical and sensory properties, and health implications are discussed. Meat based functional foods with inulin can lead to enhance digestive health by reducing the risk of diseases like constipation, irritable bowel syndrome, inflammatory bowel disease and colorectal cancer. Inulin can be an interesting prebiotic ingredient in healthier meat formulations, apart from being a fat replacer and dietary fiber enhancer.
Topics: Dietary Fiber; Functional Food; Humans; Inulin; Meat Products
PubMed: 34742431
DOI: 10.1016/j.carbpol.2021.118706 -
Expert Review of Gastroenterology &... Nov 2017The bacteria received upon birth are the start of colonization of the approximately 10 bacteria that are present in the mature human gastrointestinal tract, better known... (Review)
Review
The bacteria received upon birth are the start of colonization of the approximately 10 bacteria that are present in the mature human gastrointestinal tract, better known as the microbiota. The gut microbiota is implicated in gastrointestinal health, nutrient metabolism and benefits such as prevention of infection. Dietary fiber, including prebiotics, escape digestion in the small intestine and reach the colon intact, where they are partially or completely fermented by the gut microbiota. Areas covered: The possible interactions between dietary fiber, prebiotics and microbiota are discussed as well as how this relates to functional gastrointestinal disorders. During the first years of life the microbiota have not yet reached a stable state and is sensitive to disturbance by environmental factors. An imbalance in the microbiota early in life is found to be associated with several functional gastrointestinal disorders such as colic, functional abdominal pain, irritable bowel syndrome and constipation. Expert commentary: A better understanding of how gut microbial changes in early-life can impact gastrointestinal health might lead to new treatments or disease prevention. Nutritional strategies with fiber or prebiotics may support health due to modification of colonic microbiota composition and metabolic activity, for example by growth stimulation of Bifidobacterium and Lactobacillus.
Topics: Adolescent; Adolescent Nutritional Physiological Phenomena; Age Factors; Child; Child, Preschool; Dietary Fiber; Digestion; Gastrointestinal Diseases; Gastrointestinal Microbiome; Humans; Infant; Infant Nutritional Physiological Phenomena; Infant, Newborn; Intestines; Nutritional Status; Prebiotics; Recommended Dietary Allowances; Treatment Outcome
PubMed: 28737484
DOI: 10.1080/17474124.2017.1359539 -
Critical Reviews in Food Science and... Sep 2017Observational studies suggest an association between dietary fiber intake and risk of Barrett's esophagus and esophageal cancer. However, the results are inconsistent. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Observational studies suggest an association between dietary fiber intake and risk of Barrett's esophagus and esophageal cancer. However, the results are inconsistent.
OBJECTIVE
To conduct a meta-analysis of observational studies to assess this association.
DESIGN
All eligible studies were identified by electronic searches in PubMed and Embase through February 2015. Dose-response, subgroup, sensitivity, and publication bias analyses were performed.
RESULTS
A total of 15 studies involving 16,885 subjects were included in the meta-analysis. The pooled odds ratio for the highest compared with the lowest dietary fiber intake was 0.52 (95% CI, 0.43-0.64). Stratified analyses for tumor subtype, study design, geographic location, fiber type, publication year, total sample size, and quality score yielded consistent results. Dose-response analysis indicated that a 10-g/d increment in dietary fiber intake was associated with a 31% reduction in Barrett's esophagus and esophageal cancer risk. Sensitivity analysis restricted to studies with control for conventional risk factors produced similar results, and omission of any single study had little effect on the overall risk estimate.
CONCLUSIONS
Our findings indicate that dietary fiber intake is inversely associated with risk of Barrett's esophagus and esophageal cancer. Further large prospective studies are warranted.
Topics: Barrett Esophagus; Dietary Fiber; Dose-Response Relationship, Drug; Esophageal Neoplasms; Humans; Odds Ratio; Prospective Studies; Risk Factors
PubMed: 26462851
DOI: 10.1080/10408398.2015.1067596 -
The Proceedings of the Nutrition Society May 2023The present paper reviews progress in research on dietary fibre and human health over the past five decades. There is now convincing evidence from prospective cohort... (Review)
Review
The present paper reviews progress in research on dietary fibre and human health over the past five decades. There is now convincing evidence from prospective cohort studies that diets low in dietary fibre are associated with increased risk of common non-communicable diseases including CVD, type 2 diabetes and colorectal cancer. These findings provide strong support for hypotheses proposed by Denis Burkitt 50 years ago, based on very limited evidence but with considerable imagination and insight. For the first two to three decades of this period, research on dietary fibre was hampered by the lack of consensus about the definition, and measurement, of this complex and diverse dietary component and by the lack of appropriate tools for investigating the gut microbiome that is central to understanding mechanisms of action. Recent technical and scientific advances in microbiome research (based on fast, low-cost, DNA sequencing) are facilitating investigation of the associations between dietary fibre, the gut microbiome and human health. Current challenges include the need for agreement about the characteristics of a healthy gut microbiome. Although the health benefits attributed to higher dietary fibre intake are likely to be shared with most types of dietary fibre, one should anticipate that different sources of dietary fibre and the other components (resistant starch and non-digestible oligosaccharides) that make up dietary fibre will have characteristically different effects on human physiology and disease risk. In conclusion, population-level intakes of dietary fibre are low and there is a public health priority to develop and implement more effective interventions to increase intake.
Topics: Humans; Diabetes Mellitus, Type 2; Prospective Studies; Dietary Fiber; Diet; Gastrointestinal Microbiome
PubMed: 36786062
DOI: 10.1017/S0029665123002215 -
Advances in Experimental Medicine and... 2016During the last century, human nutrition has evolved from the definition of our nutritional needs and the identification of ways to meet them, to the identification of... (Review)
Review
During the last century, human nutrition has evolved from the definition of our nutritional needs and the identification of ways to meet them, to the identification of food components that can optimise our physiological and psychological functions. This development, which aims to ensure the welfare, health and reduced susceptibility to disease during life, gave birth to the concept of "functional foods". In this context, there is an increasing interest in the physiological effects induced by the dense and diverse microbiota which inhabits the human colon and whose development depends on the fermentation of undigested food residues. Thus, much research aims at identifying ways to guide these impacts in order to benefit the health of the host. It is in this context that the concept of "prebiotics" was developed in the 1990s. Since then, prebiotics have stimulated extensive work in order to clarify their definition, their nature and their physiological properties in accordance with the evolution of knowledge on the intestinal microbiota. However many questions remain open about their specificities, their mechanism(s) of action and therefore the relevance of their current categorisation.
Topics: Colon; Dietary Fiber; Fructans; Functional Food; Gastrointestinal Diseases; Gastrointestinal Microbiome; Humans; Nutritional Status; Oligosaccharides; Prebiotics; Probiotics; Starch
PubMed: 27161355
DOI: 10.1007/978-3-319-31248-4_9