-
Critical Reviews in Food Science and... Nov 2023Firmicutes and Bacteroidetes are the predominant bacterial phyla colonizing the healthy human gut. Accumulating evidence suggests that dietary fiber plays a crucial role... (Review)
Review
Firmicutes and Bacteroidetes are the predominant bacterial phyla colonizing the healthy human gut. Accumulating evidence suggests that dietary fiber plays a crucial role in host health, yet most studies have focused on how the dietary fiber affects health through gut Bacteroides. More recently, gut Firmicutes have been found to possess many genes responsible for fermenting dietary fiber, and could also interact with the intestinal mucosa and thereby contribute to homeostasis. Consequently, the relationship between dietary fiber and Firmicutes is of interest, as well as the role of Firmicutes in host health. In this review, we summarize the current knowledge regarding the molecular mechanism of dietary fiber degradation by gut Firmicutes and explain the communication pathway of the dietary fiber-Firmicutes-host axis, and the beneficial effects of dietary fiber-induced Firmicutes and their metabolites on health. A better understanding of the dialogue sustained by the dietary fiber-Firmicutes axis and the host could provide new insights into probiotic therapy and novel dietary interventions aimed at increasing the abundance of Firmicutes (such as , , and ) to promote health.
Topics: Humans; Firmicutes; Health Promotion; Dietary Fiber; Bacteria; Homeostasis
PubMed: 35822206
DOI: 10.1080/10408398.2022.2098249 -
Nature Microbiology Aug 2023Non-alcoholic steatohepatitis (NASH) is the severe form of non-alcoholic fatty liver disease, and is characterized by liver inflammation and fat accumulation. Dietary...
Non-alcoholic steatohepatitis (NASH) is the severe form of non-alcoholic fatty liver disease, and is characterized by liver inflammation and fat accumulation. Dietary interventions, such as fibre, have been shown to alleviate this metabolic disorder in mice via the gut microbiota. Here, we investigated the mechanistic role of the gut microbiota in ameliorating NASH via dietary fibre in mice. Soluble fibre inulin was found to be more effective than insoluble fibre cellulose to suppress NASH progression in mice, as shown by reduced hepatic steatosis, necro-inflammation, ballooning and fibrosis. We employed stable isotope probing to trace the incorporation of C-inulin into gut bacterial genomes and metabolites during NASH progression. Shotgun metagenome sequencing revealed that the commensal Parabacteroides distasonis was enriched by C-inulin. Integration of C-inulin metagenomes and metabolomes suggested that P. distasonis used inulin to produce pentadecanoic acid, an odd-chain fatty acid, which was confirmed in vitro and in germ-free mice. P. distasonis or pentadecanoic acid was protective against NASH in mice. Mechanistically, inulin, P. distasonis or pentadecanoic acid restored gut barrier function in NASH models, which reduced serum lipopolysaccharide and liver pro-inflammatory cytokine expression. Overall this shows that gut microbiota members can use dietary fibre to generate beneficial metabolites to suppress metabolic disease.
Topics: Animals; Mice; Non-alcoholic Fatty Liver Disease; Inulin; Fatty Acids; Inflammation; Dietary Fiber
PubMed: 37386075
DOI: 10.1038/s41564-023-01418-7 -
Nutrients Jul 2023Crohn's disease (CD) is a subtype of inflammatory bowel disease (IBD). CD is a health problem in Western countries such as the US and European nations and is an... (Meta-Analysis)
Meta-Analysis Review
Crohn's disease (CD) is a subtype of inflammatory bowel disease (IBD). CD is a health problem in Western countries such as the US and European nations and is an idiopathic disease; however, certain cases of CD have been associated with intestinal dysbiosis. A systematic review with a meta-analysis was carried out to determine the efficacy of a diet rich in fiber with or without cointervention to improve remission rates for CD. The literature in the PubMed, Scopus, Web of Science, and ClinicalTrials databases was reviewed. The quality of the studies was evaluated using the Johanna Briggs Institute (JBI) scale. This review was conducted in accordance with the structure outlined in the PRISMA statement. In addition, a meta-analysis was performed with a 95% confidence interval (CI) and a random effects model. Eleven studies were included, totaling 2389 patients with CD. Applying a diet rich in fiber with or without the administration of routine therapies improved CD remission rates. Data regarding CD activity, remission time, and adverse effects derived from fiber consumption were analyzed. Consumption of fiber in the diet could improve remission rates for CD patients who receive or do not receive other treatment to maintain remission.
Topics: Humans; Crohn Disease; Dietary Fiber; Diet; Remission Induction
PubMed: 37513532
DOI: 10.3390/nu15143114 -
Nutrients Aug 2023Gastroesophageal reflux disease (GERD) is a common esophageal disorder characterized by troublesome symptoms associated with increased esophageal acid exposure. The... (Review)
Review
Gastroesophageal reflux disease (GERD) is a common esophageal disorder characterized by troublesome symptoms associated with increased esophageal acid exposure. The cornerstones of therapy in this regard include treatment with acid-suppressive agents, lifestyle modifications, and dietary therapy, although the latter has not been well defined. As concerns regarding long-term proton pump inhibitor (PPI) use continue to be explored, patients and healthcare providers are becoming increasingly interested in the role of diet in disease management. However, dietary interventions lack evidence of the synthesis effect of functional foods. The following is a review of dietary therapy for GERD, emphasizing food components' impact on GERD pathophysiology and management. Although the sequential dietary elimination of food groups is a common practice, the literature supports broader intervention, including reduced overall sugar intake, increased dietary fiber, and changes in overall eating practices. While the primary concern of food companies is to provide safe products, the caloric, nutritional, and functional composition of foods is also generating interest in the food industry due to consumers' concerns.
Topics: Humans; Functional Food; Gastroesophageal Reflux; Esophageal Diseases; Behavior Therapy; Dietary Fiber
PubMed: 37630773
DOI: 10.3390/nu15163583 -
Nature Communications Nov 2023Gut microbiota plays a key role in insulin resistance (IR). Here we perform a case-control study of Chinese adults (ChiCTR2200065715) and identify that Parabacteroides...
Gut microbiota plays a key role in insulin resistance (IR). Here we perform a case-control study of Chinese adults (ChiCTR2200065715) and identify that Parabacteroides distasonis is inversely correlated with IR. Treatment with P. distasonis improves IR, strengthens intestinal integrity, and reduces systemic inflammation in mice. We further demonstrate that P. distasonis-derived nicotinic acid (NA) is a vital bioactive molecule that fortifies intestinal barrier function via activating intestinal G-protein-coupled receptor 109a (GPR109a), leading to ameliorating IR. We also conduct a bioactive dietary fiber screening to induce P. distasonis growth. Dendrobium officinale polysaccharide (DOP) shows favorable growth-promoting effects on P. distasonis and protects against IR in mice simultaneously. Finally, the reduced P. distasonis and NA levels were also validated in another human type 2 diabetes mellitus cohort. These findings reveal the unique mechanisms of P. distasonis on IR and provide viable strategies for the treatment and prevention of IR by bioactive dietary fiber.
Topics: Animals; Humans; Mice; Case-Control Studies; Diabetes Mellitus, Type 2; Dietary Fiber; Insulin Resistance
PubMed: 38007572
DOI: 10.1038/s41467-023-43622-3 -
Gastroenterology Feb 2024Dietary fibers are mainly fermented by the gut microbiota, but their roles in colorectal cancer (CRC) are largely unclear. Here, we investigated the associations of...
BACKGROUND & AIMS
Dietary fibers are mainly fermented by the gut microbiota, but their roles in colorectal cancer (CRC) are largely unclear. Here, we investigated the associations of different fibers with colorectal tumorigenesis in mice.
METHODS
Apc mice and C57BL/6 mice with azoxymethane (AOM) injection were used as CRC mouse models. Mice were fed with mixed high-fiber diet (20% soluble fiber and 20% insoluble fiber), high-inulin diet, high-guar gum diet, high-cellulose diet, or diets with different inulin dose. Germ-free mice were used for validation. Fecal microbiota and metabolites were profiled by shotgun metagenomic sequencing and liquid chromatography-mass spectrometry, respectively.
RESULTS
Mixed high-fiber diet promoted colorectal tumorigenesis with increased tumor number and tumor load in AOM-treated and Apc mice. Antibiotics use abolished the pro-tumorigenic effect of mixed high-fiber diet, while transplanting stools from mice fed with mixed high-fiber diet accelerated tumor growth in AOM-treated germ-free mice. We therefore characterized the contribution of soluble and insoluble fiber in CRC separately. Our results revealed that soluble fiber inulin or guar gum, but not insoluble fiber cellulose, promoted colorectal tumorigenesis in AOM-treated and Apc mice. Soluble fiber induced gut dysbiosis with Bacteroides uniformis enrichment and Bifidobacterium pseudolongum depletion, accompanied by increased fecal butyrate and serum bile acids and decreased inosine. We also identified a positive correlation between inulin dosage and colorectal tumorigenesis. Moreover, transplanting stools from mice fed with high-inulin diet increased colonic cell proliferation and oncogene expressions in germ-free mice.
CONCLUSION
High-dose soluble but not insoluble fiber potentiates colorectal tumorigenesis in a dose-dependent manner by dysregulating gut microbiota and metabolites in mice.
Topics: Mice; Animals; Gastrointestinal Microbiome; Inulin; Mice, Inbred C57BL; Carcinogenesis; Dietary Fiber; Cellulose; Azoxymethane; Colorectal Neoplasms
PubMed: 37858797
DOI: 10.1053/j.gastro.2023.10.012 -
FP Essentials Apr 2024Macronutrients are nutrients the body needs in large quantities, such as fats, carbohydrates, fiber, protein, and water. The exact quantity of macronutrients needed for... (Review)
Review
Macronutrients are nutrients the body needs in large quantities, such as fats, carbohydrates, fiber, protein, and water. The exact quantity of macronutrients needed for an individual depends on multiple factors such as height, weight, sex, physical activity level, and medical conditions. For adequate intake, the () recommend an overall healthy eating pattern rather than specific macronutrient amounts. A healthy eating pattern includes consumption of minimally processed, nutrient-dense foods and beverages such as vegetables, fruits, grains, dairy, proteins, and oils. Nutrition labels on food packaging can be used to guide food choices. Healthy dietary patterns have been shown to reduce the risk of diet-related chronic diseases. Consumption of foods containing unsaturated fats, complex carbohydrates, and high levels of fiber is recommended. Protein should be obtained from a variety of sources, particularly plant-based sources. Intake of foods and beverages higher in added sugars, saturated fat, and sodium should be limited. Family physicians should obtain a nutrition history for every patient regardless of body mass index. The evaluation should include a diet assessment questionnaire and information about patient nutrition insight and motivation, dietary intake pattern, metabolic demands, comorbid conditions, and dietary supplement and substance use (eg, caffeine, alcohol). Physicians can counsel patients by sharing current recommendations for following a healthy eating pattern.
Topics: Humans; Nutrients; Diet, Healthy; Dietary Fats; Dietary Proteins; Dietary Fiber; Nutrition Policy; Nutrition Assessment; Dietary Carbohydrates
PubMed: 38648169
DOI: No ID Found -
Food Chemistry May 2024Dietary fiber (DF) was established as a key dietary constituent some decades ago, as were some of its mechanisms of action and health effects. Although there is... (Review)
Review
Dietary fiber (DF) was established as a key dietary constituent some decades ago, as were some of its mechanisms of action and health effects. Although there is consolidated evidence on many features regarding DF, at the same time there are still many aspects to be explored in the field, e.g., deeper explorations of the contribution of phenolic compounds linked to cell walls to the biological activities of DF, or of the relevance of the gut-brain axis. At the same time, increasing DF intake should be seen as a major public health problem since worldwide intakes are quite far from recommendations. The awareness of this fact by public bodies should lead, among others, to the assessment of effective strategies for promoting DF intake among general population or specific groups; and to consider potential regulatory modifications in order to clarify several aspects potentially misleading for consumers.
Topics: Humans; Dietary Fiber; Diet; Phenols; Public Health
PubMed: 38039615
DOI: 10.1016/j.foodchem.2023.138076 -
Pediatric Nephrology (Berlin, Germany) Sep 2023Dietary fiber is considered an essential constituent of a healthy child's diet. Diets of healthy children with adequate dietary fiber intake are characterized by a... (Review)
Review
Dietary fiber is considered an essential constituent of a healthy child's diet. Diets of healthy children with adequate dietary fiber intake are characterized by a higher diet quality, a higher nutrient density, and a higher intake of vitamins and minerals in comparison to the diets of children with poor dietary fiber intake. Nevertheless, a substantial proportion of children do not meet the recommended dietary fiber intake. This is especially true in those children with kidney diseases, as traditional dietary recommendations in kidney diseases have predominantly focused on the quantities of energy and protein, and often restricting potassium and phosphate, while overlooking the quality and diversity of the diet. Emerging evidence suggests that dietary fiber and, by extension, a plant-based diet with its typically higher dietary fiber content are just as important for children with kidney diseases as for healthy children. Dietary fiber confers several health benefits such as prevention of constipation and fewer gastrointestinal symptoms, reduced inflammatory state, and decreased production of gut-derived uremic toxins. Recent studies have challenged the notion that a high dietary fiber intake confers an increased risk of hyperkalemia or nutritional deficits in children with kidney diseases. There is an urgent need of new studies and revised guidelines that address the dietary fiber intake in children with kidney diseases.
Topics: Child; Humans; Diet; Dietary Fiber; Constipation; Vitamins; Gastrointestinal Tract
PubMed: 36471146
DOI: 10.1007/s00467-022-05837-2 -
Current Opinion in Clinical Nutrition... Jul 2023The aim of this study was to introduce novel metrics of dietary carbohydrates quality relevant for products and diets. (Review)
Review
PURPOSE OF REVIEW
The aim of this study was to introduce novel metrics of dietary carbohydrates quality relevant for products and diets.
RECENT FINDINGS
Carbohydrate quality has long been associated with a low glycemic index. More recently, novel metrics of carbohydrate quality featuring variations of total carbohydrates-fibers-free sugars ratios have been applied to carbohydrate-rich foods, including grains, beans, vegetables, and fruit. High scoring products had higher levels of health-promoting nutrients (protein, dietary fiber, iron, magnesium, zinc, potassium, selenium, and various B-vitamins) and lower levels of nutrients of public health concern (total sugar, added/free sugars, and fat profile). Cross-sectional studies also found variants of carbohydrate quality metrics to be associated with better markers of cardiometabolic disease, including lower levels of blood triglycerides:high-density lipoprotein cholesterol ratio, homeostatic model assessment of insulin resistance, and SBP.
SUMMARY
New ratio-based carbohydrate quality metrics are built around high fiber and whole grain content, combined with a low free sugar content. Such metrics allow the identification of food products of higher overall nutritional quality, and are associated with improved diet quality and certain health outcomes.
Topics: Humans; Dietary Carbohydrates; Cross-Sectional Studies; Benchmarking; Dietary Fiber; Diet; Sugars
PubMed: 37249917
DOI: 10.1097/MCO.0000000000000933