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Journal of Agricultural and Food... Oct 2023Dietary fiber is a carbohydrate polymer with ten or more monomeric units that are resistant to digestion by human digestive enzymes, and it has gained widespread... (Review)
Review
Dietary fiber is a carbohydrate polymer with ten or more monomeric units that are resistant to digestion by human digestive enzymes, and it has gained widespread attention due to its significant role in health improvement through regulating gut microbiota. In this review, we summarized the interaction between dietary fiber, gut microbiota, and obesity, and the beneficial effects of dietary fiber on obesity through the modulation of microbiota, such as modifying selective microbial composition, producing starch-degrading enzymes, improving gut barrier function, reducing the inflammatory response, reducing trimethylamine N-oxide, and promoting the production of gut microbial metabolites (e.g., short chain fatty acids, bile acids, ferulic acid, and succinate). In addition, factors affecting the gut microbiota composition and metabolites by dietary fiber (length of the chain, monosaccharide composition, glycosidic bonds) were also concluded. Moreover, strategies for enhancing the biological activity of dietary fiber (fermentation technology, ultrasonic modification, nanotechnology, and microfluidization) were subsequently discussed. This review may provide clues for deeply exploring the structure-activity relationship between dietary fiber and antiobesity properties by targeting specific gut microbiota.
Topics: Humans; Gastrointestinal Microbiome; Obesity; Microbiota; Fatty Acids, Volatile; Dietary Fiber
PubMed: 37815013
DOI: 10.1021/acs.jafc.3c03923 -
The Journal of Neuroscience : the... Sep 2023Alzheimer's disease (AD) is a neurodegenerative disorder with poorly understood etiology. AD has several similarities with other "Western lifestyle" inflammatory...
Alzheimer's disease (AD) is a neurodegenerative disorder with poorly understood etiology. AD has several similarities with other "Western lifestyle" inflammatory diseases, where the gut microbiome and immune pathways have been associated. Previously, we and others have noted the involvement of metabolite-sensing GPCRs and their ligands, short-chain fatty acids (SCFAs), in protection of numerous Western diseases in mouse models, such as Type I diabetes and hypertension. Depletion of GPR43, GPR41, or GPR109A accelerates disease, whereas high SCFA yielding diets protect in mouse models. Here, we extended the concept that metabolite-sensing receptors and SCFAs may be a more common protective mechanism against Western diseases by studying their role in AD pathogenesis in the 5xFAD mouse model. Both male and female mice were included. Depletion of GPR41 and GPR43 accelerated cognitive decline and impaired adult hippocampal neurogenesis in 5xFAD and WT mice. Lack of fiber/SCFAs accelerated a memory deficit, whereas diets supplemented with high acetate and butyrate (HAMSAB) delayed cognitive decline in 5xFAD mice. Fiber intake impacted on microglial morphology in WT mice and microglial clustering phenotype in 5xFAD mice. Lack of fiber impaired adult hippocampal neurogenesis in both W and AD mice. Finally, maternal dietary fiber intake significantly affects offspring's cognitive functions in 5xFAD mice and microglial transcriptome in both WT and 5xFAD mice, suggesting that SCFAs may exert their effect during pregnancy and lactation. Together, metabolite-sensing GPCRs and SCFAs are essential for protection against AD, and reveal a new strategy for disease prevention. Alzheimer's disease (AD) is one of the most common neurodegenerative diseases; currently, there is no cure for AD. In our study, short-chain fatty acids and metabolite receptors play an important role in cognitive function and pathology in AD mouse model as well as in WT mice. SCFAs also impact on microglia transcriptome, and immune cell recruitment. Out study indicates the potential of specialized diets (supplemented with high acetate and butyrate) releasing high amounts of SCFAs to protect against disease.
Topics: Female; Male; Pregnancy; Animals; Mice; Alzheimer Disease; Cognition; Dietary Fiber; Microbiota; Butyrates; Disease Models, Animal
PubMed: 37596052
DOI: 10.1523/JNEUROSCI.0724-23.2023 -
Trends in Immunology Nov 2023Dietary fibers, including chitin, have a major impact on gastrointestinal (GI) physiology and immunity. Two recent articles, by Parrish et al. and Kim et al., credit...
Dietary fibers, including chitin, have a major impact on gastrointestinal (GI) physiology and immunity. Two recent articles, by Parrish et al. and Kim et al., credit depletion of dietary fibers or supplementation with chitin, with negative and positive effects, respectively, on the immune system of the murine digestive tract. This has relevant implications for food allergies and systemic metabolism.
Topics: Humans; Animals; Mice; Verrucomicrobia; Dietary Fiber; Gastrointestinal Tract; Chitin
PubMed: 37806931
DOI: 10.1016/j.it.2023.09.008 -
Missouri Medicine 2023Dietary fiber (DF) is an essential, albeit under-consumed, component in the North American diet. DF is thought to have anti-inflammatory disease-modifying effects via...
Dietary fiber (DF) is an essential, albeit under-consumed, component in the North American diet. DF is thought to have anti-inflammatory disease-modifying effects via DF-related gut microbiota degradation products called short chain fatty acids. Thus far studies have shown the greatest associations between DF intake and risk reduction in obesity, improved weight loss outcomes, and risk reduction of cardiovascular disease (CVD). There is weak evidence associating DF intake and inflammatory bowel disease (IBD) risk, IBD remission, reduced risk of Crohn's disease (CD flares, and no evidence showing any benefit towards ulcerative colitis (UC) specifically. Evidence on DF intake and the risk reduction of colorectal cancer (CRC) has been equivocal. Studies were limited by a lack of randomization or in controlling fiber types and sources. Based on the current beneficial associations of DF on obesity management and CVD, counseling patients to increase DF intake may be a cost-effective measure to decrease the burden of chronic disease.
Topics: Humans; Crohn Disease; Inflammatory Bowel Diseases; Dietary Fiber; Chronic Disease; Cardiovascular Diseases
PubMed: 37841565
DOI: No ID Found -
Frontiers in Immunology 2023"Dietary fiber" (DF) refers to a type of carbohydrate that cannot be digested fully. DF is not an essential nutrient, but it plays an important part in enhancing... (Review)
Review
"Dietary fiber" (DF) refers to a type of carbohydrate that cannot be digested fully. DF is not an essential nutrient, but it plays an important part in enhancing digestive capacity and maintaining intestinal health. Therefore, DF supplementation in the daily diet is highly recommended. Inulin is a soluble DF, and commonly added to foods. Recently, several studies have found that dietary supplementation of inulin can improve metabolic function and regulate intestinal immunity. Inulin is fermented in the colon by the gut microbiota and a series of metabolites is generated. Among these metabolites, short-chain fatty acids provide energy to intestinal epithelial cells and participate in regulating the differentiation of immune cells. Inulin and its intestinal metabolites contribute to host immunity. This review summarizes the effect of inulin and its metabolites on intestinal immunity, and the underlying mechanisms of inulin in preventing diseases such as type 2 diabetes mellitus, inflammatory bowel disease, chronic kidney disease, and certain cancer types.
Topics: Humans; Inulin; Diabetes Mellitus, Type 2; Intestines; Colon; Dietary Fiber
PubMed: 37638034
DOI: 10.3389/fimmu.2023.1224092 -
Nutrients Oct 2023Grains are widely consumed all over the world, providing calories, macronutrients, micronutrients, dietary fiber, minerals, and plenty of phytochemicals [...].
Grains are widely consumed all over the world, providing calories, macronutrients, micronutrients, dietary fiber, minerals, and plenty of phytochemicals [...].
Topics: Humans; Edible Grain; Nutritional Status; Energy Intake; Dietary Fiber; Cardiovascular Diseases; Diet
PubMed: 37960258
DOI: 10.3390/nu15214605 -
Cell Reports Oct 2023Dietary fiber strongly impacts the microbiota. Here, we show that a low-fiber diet changes the small intestinal (SI) microbiota and impairs SI Th17, TCRαβCD8αβ and...
Dietary fiber strongly impacts the microbiota. Here, we show that a low-fiber diet changes the small intestinal (SI) microbiota and impairs SI Th17, TCRαβCD8αβ and TCRαβCD8αα intraepithelial T cell development. We restore T cell development with dietary fiber supplementation, but this defect becomes persistent over generations with constant low-fiber diets. Offspring of low-fiber diet-fed mice have reduced SI T cells even after receiving a fiber-rich diet due to loss of bacteria important for T cell development. In these mice, only a microbiota transplant from a fiber-rich diet-fed mouse and a fiber-rich diet can restore T cell development. Low-fiber diets reduce segmented filamentous bacteria (SFB) abundance, impairing its vertical transmission. SFB colonization and a fiber-rich diet partially restore T cell development. Finally, we observe that low-fiber diet-induced T cell defects render mice more susceptible to Citrobacter rodentium infection. Together, these results demonstrate the importance of fiber to microbiota vertical transmission and host immune system development.
Topics: Mice; Animals; Intraepithelial Lymphocytes; Intestine, Small; Microbiota; Gastrointestinal Microbiome; Receptors, Antigen, T-Cell, alpha-beta; Intestinal Mucosa; Dietary Fiber; Mice, Inbred C57BL
PubMed: 37768824
DOI: 10.1016/j.celrep.2023.113140 -
The Journal of Experimental Medicine May 2024Innate lymphoid cells (ILCs) can promote host defense, chronic inflammation, or tissue protection and are regulated by cytokines and neuropeptides. However, their...
Innate lymphoid cells (ILCs) can promote host defense, chronic inflammation, or tissue protection and are regulated by cytokines and neuropeptides. However, their regulation by diet and microbiota-derived signals remains unclear. We show that an inulin fiber diet promotes Tph1-expressing inflammatory ILC2s (ILC2INFLAM) in the colon, which produce IL-5 but not tissue-protective amphiregulin (AREG), resulting in the accumulation of eosinophils. This exacerbates inflammation in a murine model of intestinal damage and inflammation in an ILC2- and eosinophil-dependent manner. Mechanistically, the inulin fiber diet elevated microbiota-derived bile acids, including cholic acid (CA) that induced expression of ILC2-activating IL-33. In IBD patients, bile acids, their receptor farnesoid X receptor (FXR), IL-33, and eosinophils were all upregulated compared with controls, implicating this diet-microbiota-ILC2 axis in human IBD pathogenesis. Together, these data reveal that dietary fiber-induced changes in microbial metabolites operate as a rheostat that governs protective versus pathologic ILC2 responses with relevance to precision nutrition for inflammatory diseases.
Topics: Humans; Animals; Mice; Immunity, Innate; Interleukin-33; Inulin; Lymphocytes; Dietary Fiber; Bile Acids and Salts; Inflammation; Inflammatory Bowel Diseases
PubMed: 38506708
DOI: 10.1084/jem.20232148 -
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 -
Carbohydrate Polymers Sep 2023Intake of dietary fiber has been proven to have several beneficial effects in maintaining host homeostasis and health. Here, we investigated the effects of different...
Intake of dietary fiber has been proven to have several beneficial effects in maintaining host homeostasis and health. Here, we investigated the effects of different fibers on gut microbiota and related metabolites in rats. Healthy rats were supplemented with guar gum, carrageenan, glucomannan, β-glucan, arabinoxylan, apple pectin, xylan, arabinogalactan, and xanthan gum, and these dietary fibers exhibited commonality and specificity on gut microbiota and related metabolites. The abundance of Phascolarctobacterium, Prevotella, Treponema, Butyricimonas, Bacteroides, and Lactobacillus was selectively increased by different dietary fibers, whereas the abundance of Clostridium perfringens and Bacteroides fragilis were decreased by all of these fibers. Indole-3-lactic acid was significantly increased by β-glucan treatment, indicating the relationship between indole-3-lactic acid and Lactobacillus. Furthermore, Some species from Bacteroides were validated to produce indole-3-lactic acid, indole-3-acetic acid, and kynurenine (such as B. fragilis, B. ovatus, B. thetaiotaomicron, and B. xylanisolvens). These results provide important information on dietary guidelines based on the modification of gut microecology.
Topics: Rats; Animals; Gastrointestinal Microbiome; Dietary Fiber; Dietary Supplements; Bacteroides; beta-Glucans
PubMed: 37321707
DOI: 10.1016/j.carbpol.2023.120986