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Food Research International (Ottawa,... Nov 2023Previous studies have shown that high intake of dietary fiber (DF) and efficient levels of physical activity are beneficial for cardiometabolic health in middle-aged and... (Randomized Controlled Trial)
Randomized Controlled Trial
Previous studies have shown that high intake of dietary fiber (DF) and efficient levels of physical activity are beneficial for cardiometabolic health in middle-aged and elderly populations with cardiometabolic disease. However, evidence from young adults with low cardiometabolic risk is lacking. This study aimed to investigate the effects of various interventions including a high-fiber (HF) diet and the rope-skipping (RS) exercise on cardiometabolic risk factors (CRFs) and the composition of the gut microbiota in young adults. A 12-week parallel-designed randomized controlled trial was conducted in undergraduates (n = 96), who were randomly assigned to the HF group (≥20 g/d DF), the RS group (2000 jumps/week), and the control (CON) group. Among the 84 people who completed the trial, measurements of anthropometric characteristics, biochemical parameters, and gut microbiota were taken at the beginning and end of the intervention. After the intervention, the RS exercise led to a significant decrease in the heart rate and triglyceride levels compared to the CON group (all P < 0.05), but there was no significant difference in CRFs between the HF and CON groups. When compared to baseline, the 12-week HF diet intervention resulted in an increase in fat-free mass, and a decrease in the percentage of body fat and waist circumference (all P < 0.05). With regard to gut microbiota alterations after intervention, we found that compared with the CON group, the relative abundance of Lactobacillus decreased significantly in both the HF group and the RS group, Muribaculaceae decreased in the RS group, and Eubacterium_coprostanoligenes_group decreased in the HF group (all P < 0.05). Finally, shifts in 7 metabolic pathways were detected in the RS group using predictive functional profiling, while only one pathway was altered in the HF group (all P < 0.05). In conclusion, the RS exercise improved body composition compared to the CON group in young adults, while the HF diet just enhanced CRFs in contrast to baseline. Furthermore, both RS and HF interventions altered Lactobacillus and various other gut microbiota. The results indicated that the HF diet and RS exercise could partly benefit cardiometabolic health and modulate gut microbiota in young adults. Trial registration: ClinicalTrials.gov, NCT04834687.
Topics: Middle Aged; Aged; Humans; Young Adult; Gastrointestinal Microbiome; Dietary Fiber; Diet; Cardiovascular Diseases
PubMed: 37803759
DOI: 10.1016/j.foodres.2023.113421 -
Nutrients Sep 2023Consumption of plant foods, including whole grains, vegetables, fruits, pulses, nuts, and seeds, is linked to improved health outcomes. Dietary fiber is a nutrient in... (Review)
Review
Consumption of plant foods, including whole grains, vegetables, fruits, pulses, nuts, and seeds, is linked to improved health outcomes. Dietary fiber is a nutrient in plant foods that is associated with improved health outcomes, including a lower risk of chronic diseases such as cardiovascular disease, type 2 diabetes, and certain cancers. Different fibers deliver different health benefits based on their physiochemical properties (solubility, viscosity) and physiological effects (fermentability). Additionally, plant foods contain more than dietary fiber and are rich sources of bioactives, which also provide health benefits. The concept of the solubility of fiber was introduced in the 1970s as a method to explain physiological effects, an idea that is no longer accepted. Dividing total dietary fiber (TDF) into insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) is an analytical distinction, and recent work finds that IDF intake is linked to a wide range of health benefits beyond increased stool weight. We have focused on the IDF content of plant foods and linked the concept of IDF to the bioactives in plant foods. Ancestral humans might have consumed as much as 100 g of dietary fiber daily, which also delivered bioactives that may be more important protective compounds in disease prevention. Isolating fibers to add to human diets may be of limited usefulness unless bioactives are included in the isolated fiber supplement.
Topics: Humans; Diabetes Mellitus, Type 2; Dietary Fiber; Vegetables; Diet; Fruit
PubMed: 37836422
DOI: 10.3390/nu15194138 -
Nutrients Oct 2023Dietary fiber plays a potential role in regulating energy intake and stabilizing postprandial blood glucose levels. Soluble dietary fiber has become an important entry... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Dietary fiber plays a potential role in regulating energy intake and stabilizing postprandial blood glucose levels. Soluble dietary fiber has become an important entry point for nutritional research on the regulation of satiety.
METHODS
this was a double-blind, randomized cross-over trial enrolling 12 healthy subjects to compare the effects of RPG (R+PolyGly) dietary fiber products (bread, powder, and capsule) and pectin administered with a standard meal on satiety, blood glucose, and serum insulin level.
RESULTS
Adding 3.8% RPG dietary fiber to bread significantly increased the volume, water content, hardness, and chewiness of bread compared to 3.8% pectin bread and white bread and significantly improved the sensory quality of bread. RPG bread had better appetite suppression effects at some time points than the other two groups and the best postprandial blood glucose lowering effects among the three groups. Administration of RPG capsules containing 5.6 g of RPG dietary fiber with meals improved satiety and reduced hunger compared to 6 g of RPG powder and 6 g of pectin, which had the greatest effect on suppressing appetite and reducing prospective food consumption. The peak level of serum glucagon-like peptide-1 (GLP-1) in the RPG capsule group (578.17 ± 19.93 pg/mL) was significantly higher than that in other groups at 0 min and 30 min after eating. RPG powder had the best effect in reducing postprandial blood glucose and increasing serum insulin levels; the total area under the curve (AUC) of serum insulin with RPG powder was higher than other groups (5960 ± 252.46 μU min/mL).
CONCLUSION
RPG dietary fiber products can improve the sensory properties of food, reduce postprandial blood glucose, and enhance satiety, especially in capsule and powder forms. Further research on the physiological effects of RPG dietary fiber is required to facilitate its use as a functional ingredient in food products.
Topics: Adult; Humans; Blood Glucose; Bread; Cross-Over Studies; Dietary Fiber; Insulin; Pectins; Postprandial Period; Powders
PubMed: 37960222
DOI: 10.3390/nu15214569 -
Circulation Research Mar 2024Consistent evidence suggests diabetes-protective effects of dietary fiber intake. However, the underlying mechanisms, particularly the role of gut microbiota and host...
BACKGROUND
Consistent evidence suggests diabetes-protective effects of dietary fiber intake. However, the underlying mechanisms, particularly the role of gut microbiota and host circulating metabolites, are not fully understood. We aimed to investigate gut microbiota and circulating metabolites associated with dietary fiber intake and their relationships with type 2 diabetes (T2D).
METHODS
This study included up to 11 394 participants from the HCHS/SOL (Hispanic Community Health Study/Study of Latinos). Diet was assessed with two 24-hour dietary recalls at baseline. We examined associations of dietary fiber intake with gut microbiome measured by shotgun metagenomics (350 species/85 genera and 1958 enzymes; n=2992 at visit 2), serum metabolome measured by untargeted metabolomics (624 metabolites; n=6198 at baseline), and associations between fiber-related gut bacteria and metabolites (n=804 at visit 2). We examined prospective associations of serum microbial-associated metabolites (n=3579 at baseline) with incident T2D over 6 years.
RESULTS
We identified multiple bacterial genera, species, and related enzymes associated with fiber intake. Several bacteria (eg, , ) and enzymes involved in fiber degradation (eg, xylanase EC3.2.1.156) were positively associated with fiber intake, inversely associated with prevalent T2D, and favorably associated with T2D-related metabolic traits. We identified 159 metabolites associated with fiber intake, 47 of which were associated with incident T2D. We identified 18 of these 47 metabolites associated with the identified fiber-related bacteria, including several microbial metabolites (eg, indolepropionate and 3-phenylpropionate) inversely associated with the risk of T2D. Both and were associated with these favorable metabolites. The associations of fiber-related bacteria, especially and , with T2D were attenuated after further adjustment for these microbial metabolites.
CONCLUSIONS
Among United States Hispanics/Latinos, dietary fiber intake was associated with favorable profiles of gut microbiota and circulating metabolites for T2D. These findings advance our understanding of the role of gut microbiota and microbial metabolites in the relationship between diet and T2D.
Topics: Humans; Gastrointestinal Microbiome; Diabetes Mellitus, Type 2; Diet; Bacteria; Dietary Fiber
PubMed: 38547246
DOI: 10.1161/CIRCRESAHA.123.323634 -
Cell Host & Microbe Dec 2023Exclusive enteral nutrition, a diet lacking fiber, is used to treat pediatric Crohn's disease. In this issue of Cell Host & Microbe, Kuffa et al. find that a...
Exclusive enteral nutrition, a diet lacking fiber, is used to treat pediatric Crohn's disease. In this issue of Cell Host & Microbe, Kuffa et al. find that a fiber-deficient diet thins the mucus layer and alters microbial cross-feeding, causing pro-inflammatory Mucispirillum to move away from the epithelium, which ameliorates colitis.
Topics: Child; Humans; Crohn Disease; Enteral Nutrition; Diet; Dietary Fiber; Microbiota
PubMed: 38096786
DOI: 10.1016/j.chom.2023.11.014 -
Current Opinion in Clinical Nutrition... Nov 2023Metabolic syndrome (MetS) refers to a group of risk factors, which increase the risk of cardiovascular disease (CVD), type 2 diabetes (T2D), and other chronic diseases.... (Review)
Review
PURPOSE OF REVIEW
Metabolic syndrome (MetS) refers to a group of risk factors, which increase the risk of cardiovascular disease (CVD), type 2 diabetes (T2D), and other chronic diseases. Dietary fiber has been shown to mitigate many of the effects of various risk factors associated with MetS. Our review summarizes the recent findings on the association between dietary fiber deficiency and MetS.
RECENT FINDINGS
A number of studies have shown that dietary fiber deficiency is associated with an increased risk of MetS. The main mechanisms by which dietary fiber may reduce the risk of MetS include reduction of cholesterol levels; improvement of blood sugar control; reduction of inflammation; and promotion of weight loss.
SUMMARY
Literature suggests that a deficiency in dietary fiber consumption is a risk factor for MetS. An increase in dietary fiber intake may help to reduce the risk of developing MetS and its associated chronic diseases.
Topics: Humans; Metabolic Syndrome; Diabetes Mellitus, Type 2; Risk Factors; Dietary Fiber; Chronic Disease
PubMed: 37751374
DOI: 10.1097/MCO.0000000000000971 -
Food & Function May 2024Cereals are the main source of energy in the human diet. Compared to refined grains, whole grains retain more beneficial components, including dietary fiber,... (Review)
Review
Cereals are the main source of energy in the human diet. Compared to refined grains, whole grains retain more beneficial components, including dietary fiber, polyphenols, proteins, vitamins, and minerals. Dietary fiber and bound polyphenols (biounavailable) in cereals are important active substances that can be metabolized by the gut microorganisms and affect the intestinal environment. There is a close relationship between the gut microbiota structures and various disease phenotypes, although the consistency of this link is affected by many factors, and the specific mechanisms are still unclear. Remodeling unfavorable microbiota is widely recognized as an important way to target the gut and improve diseases. This paper mainly reviews the interaction between the gut microbiota and cereal-derived dietary fiber and polyphenols, and also summarizes the changes to the gut microbiota and possible molecular mechanisms of related glycolipid metabolism. The exploration of single active ingredients in cereals and their synergistic health mechanisms will contribute to a better understanding of the health benefits of whole grains. It will further help promote healthier whole grain foods by cultivating new varieties with more potential and optimizing processing methods.
Topics: Polyphenols; Dietary Fiber; Humans; Gastrointestinal Microbiome; Whole Grains; Animals; Edible Grain
PubMed: 38590246
DOI: 10.1039/d4fo00715h -
Nutrients Oct 2023Lead (Pb) exposure is a well-established risk factor for dyslipidemia, and people are exposed to it in multiple ways daily. Dietary fiber is presumed to improve lipid...
Adequate Intake of Dietary Fiber May Relieve the Detrimental Impact of Blood Lead on Dyslipidemia among US Adults: A Study of Data from the National Health and Nutrition Examination Survey Database.
Lead (Pb) exposure is a well-established risk factor for dyslipidemia, and people are exposed to it in multiple ways daily. Dietary fiber is presumed to improve lipid metabolism disorders, but it is still unknown whether it can relieve the detrimental impact of Pb on dyslipidemia. We used publicly accessible data from the 2011-2016 cycles of the National Health and Nutrition Examination Survey (NHANES). A total of 2128 US adults were enrolled for the subsequent analysis. Heavy metal concentrations in blood were measured using inductively coupled plasma mass spectrometry (ICP-MS). A weighted logistic regression was conducted to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The dose-response relationship between blood heavy metals and dyslipidemia was explored using a weighted restricted cubic spline (RCS) analysis. After fully adjusting for potential confounding factors (age, gender, race, education level, ratio of family income to poverty, marital status, body mass index, physical activity, waist circumference, smoke, alcohol drinking and history of metabolic syndrome, hypertension, and diabetes), a positive association between blood Pb levels and dyslipidemia risk was revealed (OR = 1.20, 95% CI: 1.03-1.40). Dietary fiber intake may significantly modify the association between blood Pb levels and dyslipidemia (-interaction = 0.049), with a stronger association (OR = 1.26, 95% CI: 1.05-1.52) being revealed in individuals with an inadequate intake of dietary fiber (<14 g/1000 kcal/day), but a null association (OR = 1.01, 95% CI: 0.72-1.42) being observed in those with an adequate intake of dietary fiber (≥14 g/1000 kcal/day). Moreover, the weighted RCS analysis showed that compared with the average blood Pb exposure level (4.24 µg/dL), a lower blood Pb exposure level (3.08 µg/dL) may contribute to the risk of dyslipidemia in the group with an inadequate dietary fiber intake. Our findings suggest that Pb exposure in blood may be a risk factor for dyslipidemia. However, an adequate dietary fiber intake may offset the risk of dyslipidemia caused by blood Pb exposure. Since avoiding Pb exposure in daily life is difficult, increasing dietary fiber intake in the future might be a promising approach to alleviate dyslipidemia caused by Pb exposure.
Topics: Humans; Adult; Nutrition Surveys; Lead; Diet; Dyslipidemias; Metals, Heavy; Dietary Fiber
PubMed: 37892509
DOI: 10.3390/nu15204434 -
Clinical Nutrition (Edinburgh, Scotland) Jan 2024Accumulating evidence supports the effects of dietary fiber on the risk of non-communicable diseases (NCDs). However, there is no updated systematic review and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Accumulating evidence supports the effects of dietary fiber on the risk of non-communicable diseases (NCDs). However, there is no updated systematic review and meta-analysis that compares and pools the effect of different types of fiber on mortality.
METHODS
In this systematic review and meta-analysis, all prospective cohort studies that evaluated the relationship between dietary fiber intake and all-cause or cause-specific mortality were included. The PubMed, SCOPUS, and Web of Science databases were searched up to October 2022. Data extraction and quality assessment were performed by two researchers independently. Heterogeneity between studies was assessed using Chi-square based test. Random/fixed effect meta-analysis was used to pool the hazard ratios (HR) or relative risks (RR) and 95 % confidence intervals (CI) for the association between different types of fiber and mortality.
RESULTS
This systematic review included 64 eligible studies, with a total sample size of 3512828 subjects, that investigated the association between dietary fiber intake and mortality from all-cause, cardiovascular disease (CVD), and cancer. Random-effect meta-analysis shows that higher consumption of total dietary fiber, significantly decreased the risk of all-cause mortality, CVD-related mortality, and cancer-related mortality by 23, 26 and 22 % (HR:0.77; 95%CI (0.73,0.82), HR:0.74; 95%CI (0.71,0.77) and HR:0.78; 95%CI (0.68,0.87)), respectively. The consumption of insoluble fiber tended to be more effective than soluble fiber intake in reducing the risk of total mortality and mortality due to CVD and cancer. Additionally, dietary fiber from whole grains, cereals, and vegetables was associated with a reduced risk of all-cause mortality, while dietary fiber from nuts and seeds reduced the risk of CVD-related death by 43 % (HR:0.57; 95 % CI (0.38,0.77)).
CONCLUSION
This comprehensive meta-analysis provides additional evidence supporting the protective association between fiber intake and all-cause and cause-specific mortality rates.
Topics: Humans; Cause of Death; Prospective Studies; Cardiovascular Diseases; Dietary Fiber; Neoplasms; Risk Factors
PubMed: 38011755
DOI: 10.1016/j.clnu.2023.11.005 -
The British Journal of Nutrition Oct 2023The current definition of dietary fibre was adopted by the Codex Alimentarius Commission in 2009, but implementation requires updating food composition databases with...
The current definition of dietary fibre was adopted by the Codex Alimentarius Commission in 2009, but implementation requires updating food composition databases with values based on appropriate analysis methods. Previous data on population intakes of dietary fibre fractions are sparse. We studied the intake and sources of total dietary fibre (TDF) and dietary fibre fractions insoluble dietary fibre (IDF), dietary fibre soluble in water but insoluble in 76 % aqueous ethanol (SDFP) and dietary fibre soluble in water and soluble in 76 % aqueous ethanol (SDFS) in Finnish children based on new CODEX-compliant values of the Finnish National Food Composition Database Fineli. Our sample included 5193 children at increased genetic risk of type 1 diabetes from the Type 1 Diabetes Prediction and Prevention birth cohort, born between 1996 and 2004. We assessed the intake and sources based on 3-day food records collected at the ages of 6 months, 1, 3 and 6 years. Both absolute and energy-adjusted intakes of TDF were associated with age, sex and breast-feeding status of the child. Children of older parents, parents with a higher level of education, non-smoking mothers and children with no older siblings had higher energy-adjusted TDF intake. IDF was the major dietary fibre fraction in non-breastfed children, followed by SDFP and SDFS. Cereal products, fruits and berries, potatoes and vegetables were major food sources of dietary fibre. Breast milk was a major source of dietary fibre in 6-month-olds due to its human milk oligosaccharide content and resulted in high SDFS intakes in breastfed children.
Topics: Female; Humans; Child; Finland; Diabetes Mellitus, Type 1; Dietary Fiber; Energy Intake; Milk, Human
PubMed: 36803617
DOI: 10.1017/S0007114523000466