Alginate oligosaccharide assimilation by gut microorganisms and the potential role in gut inflammation alleviation.

Dietary fiber metabolism by gut microorganisms plays important roles in host physiology and health. Alginate, the major dietary fiber of daily diet seaweeds, is drawing more attention because of multiple biological activities. To advance the understanding of alginate assimilation mechanism in the gut, we show the presence of unsaturated alginate oligosaccharides (uAOS)-specific alginate utilization loci (AUL) in human gut microbiome. As a representative example, a working model of the AUL from the gut microorganism Bacteroides clarus was reconstructed from biochemistry and transcriptome data. The fermentation of resulting monosaccharides through Entner-Doudoroff pathway tunes the metabolism of short-chain fatty acids and amino acids. Furthermore, we show that uAOS feeding protects the mice against dextran sulfate sodium-induced acute colitis probably by remodeling gut microbiota and metabolome. IMPORTANCE: Alginate has been included in traditional Chinese medicine and daily diet for centuries. Recently discovered biological activities suggested that alginate-derived alginate oligosaccharides (AOS) might be an active ingredient in traditional Chinese medicine, but how these AOS are metabolized in the gut and how it affects health need more information. The study on the working mechanism of alginate utilization loci (AUL) by the gut microorganism uncovers the role of unsaturated alginate oligosaccharides (uAOS) assimilation in tuning short-chain fatty acids and amino acids metabolism and demonstrates that uAOS metabolism by gut microorganisms results in a variation of cell metabolites, which potentially contributes to the physiology and health of gut.

Cereals and cereal products - a scoping review for Nordic Nutrition Recommendations 2023.

Cereals and cereal products have traditionally been staple foods in many countries including in the Nordics and Baltics. Cereals can be consumed with their entire grain kernel and are then referred to as whole grains or can be consumed after removal of the bran or germ and are then referred to as refined grains. The terms cereals and grains are often used interchangeably. In this scoping review, we examine the associations between intake of cereals and cereal products and major health outcomes to contribute to up-to-date food-based dietary guidelines for the Nordic and Baltic countries in the Nordic Nutrition Recommendations 2023 project. Five qualified systematic reviews that covered non-communicable diseases, mortality, and risk factors were identified, and a supplementary literature search was performed in the MEDLINE and Cochrane databases for more recent studies and other endpoints. Compared to other high-income countries, the Nordic populations have a high consumption of whole grain foods. In some of the countries, rye constitutes a substantial fraction of the cereal consumption. However, few studies are available for specific cereals, and most of the research has been performed in predominantly wheat-consuming populations. The evidence suggests clear dose-response associations between a high intake of whole grains and lower risks of cardiovascular disease, colorectal cancer, type 2 diabetes, and premature mortality. The lowest risks of morbidity and mortality were observed for 3-7 servings of whole grains per day, equivalent of 90-210 g/day (fresh weight or ready-to-eat whole grain products, such as oatmeal or whole grain rye bread). Evidence from randomized trials indicates that a high intake of whole grains is beneficial for reducing weight gain. There is less evidence for refined grains, but the available evidence does not seem to indicate similar beneficial associations as for whole grains. It is suggested that replacing refined grains with whole grains would improve several important health outcomes. Cereals are plant foods that can be grown in most of the Nordic and Baltic regions.

Protective effect of soluble dietary fiber from Rosa roxburghii Tratt residue on dextran sulfate sodium-induced ulcerative colitis by regulating serum metabolism and NF-κB pathway in mice.

BACKGROUND: Ulcerative colitis (UC) refers to an idiopathic chronic inflammatory bowel disease that start with inflammation of the intestinal mucosa. Dietary fiber plays a crucial role in maintaining the normal architecture of the intestinal mucosa. In this study, the protective effect and potential mechanism of soluble dietary fiber from Rosa roxburghii Tratt residue (SDFR) on dextran sulfate sodium (DSS)-induced UC mice were explored. RESULTS: The results revealed that SDFR could ameliorate the body weight loss and pathological injury, improve the structure and crypt destruction in colon in DSS-induced mice. Moreover, the levels of NO, IL-1ß, TNF-α, MPO, and protein expression of iNOS and COX-2 were decreased after administration of SDFR. Notably, nontargeted metabolomics analysis indicated that there were significant differences in 51 potential metabolites in serum between the DSS and control groups. SDFR intervention could regulate aberrant alterations of these metabolites and mitigate UC via regulating metabolic pathway, including arachidonic acid and glycerophospholipid metabolism. CONCLUSION: This study provides novel evidence that SDFR could be used as a potential modulator to relieve the UC, and also the results provide theoretical basis for the utilization of by-products in Rosa roxburghii Tratt fruit processing. This article is protected by copyright. All rights reserved.

Exploring the effects of the dietary fiber compound mediated by a longevity dietary pattern on antioxidation, characteristic bacterial genera, and metabolites based on fecal metabolomics.

BACKGROUND: Age-related dysbiosis of the microbiota has been linked to various negative health outcomes. This study aims to investigate the effects of a newly discovered dietary fiber compound (DFC) on aging, intestinal microbiota, and related metabolic processes. The DFC was identified through in vitro fermentation screening experiments, and its dosage and composition were determined based on a longevity dietary pattern. METHODS: Aged SPF C57BL/6 J mice (65 weeks old) and young mice (8 weeks old) were divided into three groups: a subgroup without dietary fiber (NDF), a low DFC dose subgroup (LDF, 10% DFC), and a high DFC dose subgroup (HDF, 20% DFC). The total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD) activity, malondialdehyde (MDA) content, and glutathione peroxidase (GSH-Px) activity in liver and serum samples of the mice were measured according to the manufacturer's protocol. The expression levels of characteristic bacterial genera and fecal metabolite concentrations in mice were determined using quantitative real-time PCR (qPCR) and nuclear magnetic resonance hydrogen spectroscopy (1H NMR). Metabolomics analysis was further conducted to identify biological functions and potential pathways related to aging. RESULTS: After an 8-weeks dietary intervention, DFC supplementation significantly attenuated age-related weight loss, organ degeneration, and oxidative stress. And promoted the growth of Lactobacillus and Bifidobacterium and inhibited the growth of Escherichia coli (E. coli) and Bacteroides (p < 0.05) in the intestinal tracts of aged mice. Metabolomic analysis identified glycolipid and amino acid metabolic pathway biomarkers associated with aging that were differentially regulated by DFC consumption. Correlation analysis between the identified microbial flora and the biomarkers revealed potential mechanistic links between altered microbial composition and metabolic activity with aging markers. CONCLUSIONS: In conclusion, this study revealed an important mechanism by which DFC consumption impacts healthspan and longevity, shedding light on optimizing dietary fiber or developing fiber-based interventions to improve human health.

Characterization of the Structure and Physicochemical Properties of Soluble Dietary Fiber from Peanut Shells Prepared by Pulsed Electric Fields with Three-Phase Partitioning.

This study evaluated the impact of pulsed electric fields (PEFs) combined with three-phase partitioning (TPP) extraction methods on the physicochemical properties, functional properties, and structural characterization of the soluble dietary fiber (SDF) derived from peanut shells (PS). The findings of this study indicated that the application of a PEF-TPP treatment leads to a notable improvement in both the extraction yield and purity of SDF. Consequently, the PEF-TPP treatment resulted in the formation of more intricate and permeable structures, a decrease in molecular weight, and an increase in thermal stability compared to SDFs without TPP treatment. An analysis revealed that the PEF-TPP method resulted in an increase in the levels of arabinose and galacturonic acid, leading to enhanced antioxidant capacities. Specifically, the IC50 values were lower in SDFs which underwent PEF-TPP (4.42 for DPPH and 5.07 mg/mL for ABTS) compared to those precipitated with 40% alcohol (5.54 mg/mL for DPPH, 5.56 mg/mL for ABTS) and PEF75 (6.60 mg/mL for DPPH, 7.61 mg/mL for ABTS), respectively. Notably, the SDFs which underwent PEF-TPP demonstrated the highest water- and oil-holding capacity, swelling capacity, emulsifying activity, emulsion stability, glucose adsorption, pancreatic lipase inhibition, cholesterol adsorption, nitric ion adsorption capacity, and the least gelation concentration. Based on the synthesis scores obtained through PCA (0.536 > -0.030 > -0.33), which indicated that SDFs which underwent PEF-TPP exhibited the highest level of quality, the findings indicate that PEF-TPP exhibits potential and promise as a method for preparing SDFs.

Composition of Whole Grain Dietary Fiber and Phenolics and Their Impact on Markers of Inflammation.

Inflammation is an important biological response to any tissue injury. The immune system responds to any stimulus, such as irritation, damage, or infection, by releasing pro-inflammatory cytokines. The overproduction of pro-inflammatory cytokines can lead to several diseases, e.g., cardiovascular diseases, joint disorders, cancer, and allergies. Emerging science suggests that whole grains may lower the markers of inflammation. Whole grains are a significant source of dietary fiber and phenolic acids, which have an inverse association with the risk of inflammation. Both cereals and pseudo-cereals are rich in dietary fiber, e.g., arabinoxylan and ß-glucan, and phenolic acids, e.g., hydroxycinnamic acids and hydroxybenzoic acids, which are predominantly present in the bran layer. However, the biological mechanisms underlying the widely reported association between whole grain consumption and a lower risk of disease are not fully understood. The modulatory effects of whole grains on inflammation are likely to be influenced by several mechanisms including the effect of dietary fiber and phenolic acids. While some of these effects are direct, others involve the gut microbiota, which transforms important bioactive substances into more beneficial metabolites that modulate the inflammatory signaling pathways. Therefore, the purpose of this review is twofold: first, it discusses whole grain dietary fiber and phenolic acids and highlights their potential; second, it examines the health benefits of these components and their impacts on subclinical inflammation markers, including the role of the gut microbiota. Overall, while there is promising evidence for the anti-inflammatory properties of whole grains, further research is needed to understand their effects fully.

Modulating flavanone compound for reducing the bitterness and improving dietary fiber, physicochemical properties, and anti-adipogenesis of green yuzu powder by enzymatic hydrolysis.

Yuzu (Citrus junos Sieb.) is a peel-edible fruit with a pleasant aroma, but its bitter taste can impact consumer appeal. In this study, an efficient enzymatic method reduced bitterness in green yuzu powder (GYP). Cellulase KN and naringinase from Aspergillus oryzae NYO-2 significantly decreased naringin and neohesperidin content by over 87 %, while increasing total dietary fiber and soluble dietary fiber by up to 10 % and 51 %, respectively. Insoluble dietary fiber decreased by up to 22 %. Cellulose, hemicellulose, lignin, and pectin contents in enzyme-treated YP decreased by 1.15-2.00-fold, respectively. Enzyme-treated GYP exhibited improved physicochemical properties, including enhanced solubility, oil-holding capacity, and water swelling capacities. 3T3-L1 cells treated with cellulase-treated GYP and naringinase-treated GYP showed lower lipid accumulation and higher lipolysis capability than GYP, along with decreased fatty acid synthase contents. These findings suggest that enzyme-treated GYP holds potential as a functional ingredient in the food industry.

Dietary Fiber Intake and Risk of Advanced and Aggressive Forms of Prostate Cancer: A Pooled Analysis of 15 Prospective Cohort Studies.

BACKGROUND: Evidence of an association between dietary fiber intake and risk of advanced and aggressive forms of prostate cancer (PC) and PC mortality is limited. OBJECTIVE: To examine associations between intakes of dietary fiber overall and by food source and risk of advanced and aggressive forms of PC. DESIGN: Pooled analysis of the primary data in 15 cohorts in three continents. Baseline dietary fiber intake was assessed using a validated food frequency questionnaire or diet history in each study. PARTICIPANTS/SETTING: 842,149 men were followed for up to 9-22 years between 1985-2009 across studies. MAIN OUTCOME MEASURES: The primary outcome measures were advanced (stage T4, N1, or M1 or PC mortality), advanced restricted (excluded men with missing stage and those with localized PC who died of PC), high grade (Gleason score ≥8 or poorly differentiated/undifferentiated) PC, and PC mortality. STATISTICAL ANALYSIS: Study-specific multivariable hazard ratios (MVHR) were calculated using Cox proportional hazards regression and pooled using random effects models. RESULTS: Intake of dietary fiber overall, from fruits, and from vegetables was not associated with risk of advanced (n=4,863), advanced restricted (n=2,978), or high-grade PC (n=9,673) or PC mortality (n=3,097). Dietary fiber intake from grains was inversely associated with advanced PC (MVHR comparing the highest vs. lowest quintile=0.84, 95% confidence interval [CI] 0.76-0.93), advanced restricted PC (MVHR=0.85, 95%CI 0.74-0.97), and PC mortality (MVHR=0.78, 95%CI 0.68-0.89); statistically significant trends were noted for each of these associations (p≤0.03), while a null association was observed for high grade PC for the same comparison (MVHR=1.00, 95%CI 0.93-1.07). The comparable results were 1.06 (95%CI 1.01-1.10, p-value, test for trend=0.002) for localized (n=35,199) and 1.05 (95%CI 0.99-1.11, , p-value, test for trend=0.04) for low/intermediate grade (n=34,366) PC. CONCLUSIONS: Weak nonsignificant associations were observed between total dietary fiber intake and risk of advanced forms of PC, high grade PC, and PC mortality. High dietary fiber intake from grains was associated with a modestly lower risk of advanced forms of PC and PC mortality.

Sex difference in the association of dietary fiber intake with visceral fat volume in Japanese adults.

PURPOSE: Dietary fiber is a possible nutritional component which aids in the prevention of visceral fat accumulation. We examined the association between dietary fiber intake and visceral fat volume (VFV) by sex, and further analysed the association by major food sources of dietary fiber. METHODS: In this cross-sectional study, we measured VFV in 2779 Japanese (1564 men and 1215 women) aged 40-89 who underwent positron emission tomography/computed tomography for cancer screening between 2004 and 2005. Dietary fiber intake was calculated based on a validated semi-quantitative food frequency questionnaire. The association between dietary fiber intake and VFV was investigated using multivariate linear regression models after adjustment for potential confounders. RESULTS: Total, soluble, and insoluble fiber intakes were inversely associated with VFV in men (Q1: 3740 cm3, Q4: 3517 cm3, Ptrend: 0.0006 for total fiber), but not in women (Q1: 2207 cm3, Q4: 2193 cm3,Ptrend: 0.88 for total fiber). Statistically significant sex difference was observed (Pinteraction = 0.001 for total fiber). Subgroup analyses by major food sources revealed that dietary fiber intakes from beans, vegetables and fruits showed an inverse association with VFV in men, while cereal fiber intake showed a tendency toward a positive association in both sexes (Q1: 3520 cm3, Q4: 3671 cm3, Ptrend: 0.05 in men, Q1: 2147 cm3, Q4: 2227 cm3, Ptrend: 0.10 in women). CONCLUSION: We observed a sex-specific association between dietary fiber intake and VFV in Japanese adults. This study suggests that efforts against visceral fat accumulation should take account of the source of dietary fiber.

When simplicity triumphs: niche specialization of gut bacteria exists even for simple fiber structures.

Structurally complex corn bran arabinoxylan (CAX) was used as a model glycan to investigate gut bacteria growth and competition on different AX-based fine structures. Nine hydrolyzate segments of the CAX polymer varying in chemical structure (sugars and linkages), CAX, five less complex non-corn arabinoxylans, and xylose and glucose were ranked from structurally complex to simple. The substrate panel promoted different overall growth and rates of growth of eight Bacteroides xylan-degrading strains. For example, Bacteroides cellulosilyticus DSM 14838 (Bacteroides cellulosilyticus) grew well on an array of complex and simple structures, while Bacteroides ovatus 3-1-23 grew well only on the simple structures. In a competition experiment, B. cellulosilyticus growth was favored over B. ovatus on the complex AX-based structure. On the other hand, on the simple structure, B. ovatus strongly outcompeted B. cellulosilyticus, which was eliminated from the competitive environment by Day 11. This adaptation to fine structure and resulting competition dynamics indicate that dietary fiber chemical structures, whether complex or simple, favor certain gut bacteria. Overall, this work supports a concept that fiber degraders diversify their competitive abilities to access substrates across the spectrum of heterogeneity of fine structural features of dietary fibers.

Synthesis of Pyrodextrins and Enzymatically Resistant Maltodextrins from Makal (Xanthosoma yucatenensis) Starch.

Research background: Enzymatically resistant maltodextrins (ERM) are a resistant starch type 4, synthesized from native starch. They are obtained by the sequential application of two processes: pyrodextrinization, which produces pyrodextrins, and enzymatic hydrolysis, which produces ERM. In these processes atypical bonds are formed that confer pyrodextrins and ERM similar properties to dietary fiber, such as resistance to digestion. The aim of this work is to determine and evaluate some physicochemical properties of pyrodextrins and ERM obtained from native starch isolated from makal (Xanthosoma yucatanense) tubers. Experimental approach: Pyrodextrinization and complementary hydrolysis were conducted using factorial designs. For pyrodextrinization, factors and their levels were (m(starch):V(HCl))=80:1 and 160:1 (c(HCl)=2.2 M), temperature 90 and 110 °C and reaction time 1 and 3 h, and for CH, α-amylase per pyrodextrin volume fractions 0.5 and 1 µL/mL and reaction time 10 and 30 min. The physicochemical profile included determination of resistant starch content, estimation of color change (ΔE), microscopy and determination of dextrose equivalents (DE). Results and conclusions: According to the factorial design, the best treatment conditions for pyrodextrinization were: (m(starch):V(HCl))=160:1, 90 °C and 3 h, since they resulted in the highest resistant starch content (84.73 %) and the lowest ΔE (3.742). Due to the low DE (13.89 %), increased amount of resistant starch (90.73 %) and low ΔE (4.24) in the resulting ERM, complementary hydrolysis with α-amylase per pyrodextrin volume fraction 0.5 µL/mL and hydrolysis time 10 min was selected as the best treatment. Novelty and scientific contribution: The results show that the pyrodextrins and ERM obtained from makal can be used as ingredients for the development of functional foods, due to their high content of indigestible material and low degree of browning.

A mathematical model of competition between fiber and mucin degraders in the gut provides a possible explanation for mucus thinning.

The human gut microbiota relies on complex carbohydrates (glycans) for energy and growth, primarily dietary fiber and host-derived mucins. We introduce a mathematical model of a glycan generalist and a mucin specialist in a two-compartment chemostat model of the human colon. Our objective is to characterize the influence of dietary fiber and mucin supply on the abundance of mucin-degrading species within the gut ecosystem. Current mathematical gut reactor models that include the enzymatic degradation of glycans do not differentiate between glycan types and their degraders. The model we present distinguishes between a generalist that can degrade both dietary fiber and mucin, and a specialist species that can only degrade mucin. The integrity of the colonic mucus barrier is essential for overall human health and well-being, with the mucin specialist Akkermanisa muciniphila being associated with a healthy mucus layer. Competition, particularly between the specialist and generalists like Bacteroides thetaiotaomicron, may lead to mucus layer erosion, especially during periods of dietary fiber deprivation. Our model treats the colon as a gut reactor system, dividing it into two compartments that represent the lumen and the mucus of the gut, resulting in a complex system of ordinary differential equations with a large and uncertain parameter space. To understand the influence of model parameters on long-term behavior, we employ a random forest classifier, a supervised machine learning method. Additionally, a variance-based sensitivity analysis is utilized to determine the sensitivity of steady-state values to changes in model parameter inputs. By constructing this model, we can investigate the underlying mechanisms that control gut microbiota composition and function, free from confounding factors.

Role of dietary fiber and lifestyle modification in gut health and sleep quality.

Dietary fiber has an immense role in the gut microbiome by modulating juvenile growth, immune system maturation, glucose, and lipid metabolism. Lifestyle changes might disrupt gut microbiota symbiosis, leading to various chronic diseases with underlying inflammatory conditions, obesity, and its associated pathologies. An interventional study of 16 weeks examined the impact of psyllium husk fiber with and without lifestyle modification on gut health and sleep quality in people with central obesity (men = 60 and women = 60), those aged from 40 to 60 years, those having WC ≥ 90 cm (men) and WC ≥ 80 cm (women), and no history of any chronic disease or regular medication. The participants were subgrouped into three intervention groups, namely, the psyllium husk fiber (PSH) group, the lifestyle modification (LSM) group, and the LSM&PSH group and control group with equal gender bifurcation (men = 15 and women = 15). A 24-h dietary recall, gastrointestinal tract (GIT) symptoms, and sleep quality analysis data were collected on validated questionnaires. The analyses of variance and covariance were used for baseline and post-intervention, respectively. Student's t-test was applied for pre- and post-intervention changes on the variable of interest. The intervention effect on GIT health was highly significant (P < 0.001). The mean GIT scores of the LSM, PSH, and LSM&PSH groups were 2.99 ± 0.14, 2.49 ± 0.14, and 2.71 ± 0.14, respectively, compared to the mean GIT scores of the control group. No significant (P = 0.205) effect of either intervention was observed on sleep quality. The study concluded that psyllium husk fiber significantly improved the GIT symptoms, while no significant effect of the intervention was observed on sleep quality analysis.

Caffeic acid combined with arabinoxylan or ß-glucan attenuates diet-induced obesity in mice via modulation of gut microbiota and metabolites.

Polyphenols and dietary fibers in whole grains are important bioactive compounds to reduce risks for obesity. However, whether the combination of the two components exhibits a stronger anti-obesity effect remains unclear. Caffeic acid is a major phenolic acid in cereals, and arabinoxylan and ß-glucan are biological macromolecules with numerous health benefits. Here, we investigated the effect of caffeic acid combined with arabinoxylan or ß-glucan on glucose and lipid metabolism, gut microbiota, and metabolites in mice fed a high-fat diet (HFD). Caffeic acid combined with arabinoxylan or ß-glucan significantly reduced the body weight, blood glucose, and serum free fatty acid concentrations. Caffeic acid combined with ß-glucan effectively decreased serum total cholesterol levels and hepatic lipid accumulation, modulated oxidative and inflammatory stress, and improved gut barrier function. Compared with arabinoxylan, ß-glucan, and caffeic acid alone, caffeic acid combined with arabinoxylan or ß-glucan exhibited a better capacity to modulate gut microbiota, including increased microbial diversity, reduced Firmicutes/Bacteroidetes ratio, and increased abundance of beneficial bacteria such as Bifidobacterium. Furthermore, caffeic acid combined with ß-glucan reversed HFD-induced changes in microbiota-derived metabolites involving tryptophan, purine, and bile acid metabolism. Thus, caffeic acid and ß-glucan had a synergistic anti-obesity effect by regulating specific gut microbiota and metabolites.

Dietary fiber intake and its association with diabetic kidney disease in American adults with diabetes: A cross-sectional study.

BACKGROUND: Dietary fiber (DF) intake may have a protective effect against type 2 diabetes (T2D); however, its relationship with diabetic kidney disease (DKD) remains unclear. AIM: To investigate the potential association between DF intake and the prevalence of DKD in individuals diagnosed with T2D. METHODS: This cross-sectional study used data from the National Health and Nutrition Examination Survey collected between 2005 and 2018. DF intake was assessed through 24-h dietary recall interviews, and DKD diagnosis in individuals with T2D was based on predefined criteria, including albuminuria, impaired glomerular filtration rate, or a combination of both. Logistic regression analysis was used to assess the association between DF intake and DKD, and comprehensive subgroup and sensitivity analyses were performed. RESULTS: Among the 6032 participants, 38.4% had DKD. With lower DF intake-T1 (≤ 6.4 g/1000 kcal/day)-as a reference, the adjusted odds ratio for DF and DKD for levels T2 (6.5-10.0 g/1000 kcal/day) and T3 (≥ 10.1 g/1000 kcal/day) were 0.97 (95%CI: 0.84-1.12, P = 0.674) and 0.79 (95%CI: 0.68-0.92, P = 0.002), respectively. The subgroup analysis yielded consistent results across various demographic and health-related subgroups, with no statistically significant interactions (all P > 0.05). CONCLUSION: In United States adults with T2D, increased DF intake may be related to reduced DKD incidence. Further research is required to confirm these findings.

Recommendations for the Use of Dietary Fiber to Improve Blood Pressure Control.

According to several international, regional, and national guidelines on hypertension, lifestyle interventions are the first-line treatment to lower blood pressure (BP). Although diet is one of the major lifestyle modifications described in hypertension guidelines, dietary fiber is not specified. Suboptimal intake of foods high in fiber, such as in Westernized diets, is a major contributing factor to mortality and morbidity of noncommunicable diseases due to higher BP and cardiovascular disease. In this review, we address this deficiency by examining and advocating for the incorporation of dietary fiber as a key lifestyle modification to manage elevated BP. We explain what dietary fiber is, review the existing literature that supports its use to lower BP and prevent cardiovascular disease, describe the mechanisms involved, propose evidence-based target levels of fiber intake, provide examples of how patients can achieve the recommended targets, and discuss outstanding questions in the field. According to the evidence reviewed here, the minimum daily dietary fiber for adults with hypertension should be >28 g/day for women and >38 g/day for men, with each extra 5 g/day estimated to reduce systolic BP by 2.8 mm Hg and diastolic BP by 2.1 mm Hg. This would support a healthy gut microbiota and the production of gut microbiota-derived metabolites called short-chain fatty acids that lower BP. Awareness about dietary fiber targets and how to achieve them will guide medical teams on better educating patients and empowering them to increase their fiber intake and, as a result, lower their BP and cardiovascular disease risk.

Total dietary fiber intake is inversely associated with metabolically unhealthy status in adolescents with excess weight.

Little is known about the relationship between dietary fiber and metabolic health status in adolescents. This study was performed to investigate total dietary fiber intake and metabolic health status in a sample of Iranian adolescents with overweight/obesity. We hypothesized that higher total dietary fiber intake would reduce odds of metabolically unhealthy status. In this cross-sectional study, 203 adolescents (aged 12-18 years) with overweight/obesity were randomly recruited from several educational areas with different socioeconomic statuses using a multistage cluster sampling approach. Dietary intakes were evaluated by a validated food frequency questionnaire. Demographic, anthropometric, and cardiometabolic data were gathered through standard methods. Adolescents were categorized as having either metabolically healthy overweight/obesity or metabolically unhealthy overweight/obesity (MUO) phenotypes according to the International Diabetes Federation (IDF) and IDF/Homeostasis Model Assessment Insulin Resistance (HOMA-IR) criteria. Subjects had mean age of 13.97 (years) and mean fiber intake of 19.5 (g/d). After considering potential confounders, adolescents with the highest fiber intake, compared with the lowest intake, had decreased odds of MUO based on IDF (odds ratio [OR] = 0.14; 95% confidence interval [CI], 0.04-0.46) and IDF/HOMA-IR (OR = 0.16; 95% CI, 0.04-0.56) definitions. Also, each additional unit of total dietary fiber intake (1 g/d) was associated with lower chance of MUO phenotype considering IDF and IDF/HOMA-IR criteria. Individuals with higher intakes of dietary fiber were also less likely to have hyperglycemia (in fully adjusted model: OR = 0.17; 95% CI, 0.06-0.52). We found that consumption of total dietary fiber was inversely associated with odds of MUO among Iranian adolescents. Further prospective studies are required for confirming our results.

Physicochemical and functional properties of carboxymethylated insoluble dietary fiber of Lycium barbarum seed dreg.

Lycium barbarum seed dregs (LBSDs) were used for carboxymethyl modification, resulting in three degree of substitution samples (DS). Based on the substitution degree, samples were designated as low degree of substitution insoluble dietary fiber (L-IDF), medium degree of substitution insoluble dietary fiber (M-IDF) and high degree of substitution insoluble dietary fiber (H-IDF). Physicochemical and functional properties of IDFs were examined in relation to carboxymethylation degree. Infrared Fourier transform spectroscopy (FT-IR) confirmed the carboxymethyl group. According to the results, IDF, L-IDF, M-IDF, and H-IDF acquired higher enthalpy changes, and their thermal stability improved significantly. A higher DS resulted in an increase in hydration properties such as water retention capacity and water swelling capacity, as well as functional properties such as glucose adsorption capacity, nitrite ion adsorption capacity, and cholesterol adsorption capacity. As a result, carboxymethylation could effectively enhance the biological properties of L. barbarum seed dreg insoluble dietary fiber (LBSDIDF).

Eggs and a Fiber-Rich Diet Are Beneficially Associated with Lipid Levels in Framingham Offspring Study Adults.

Background: For many years, United States' dietary policy recommended limiting egg intake to no more than 3/wk in the belief that restricting dietary cholesterol would lower plasma cholesterol levels and thereby reduce the risk of cardiovascular disease. The evidence supporting these recommendations is controversial. Objectives: To examine the impact of eggs, a major contributor to dietary cholesterol intake, on lipid levels and to determine whether these egg effects are modified by other healthy dietary factors in adults. Methods: Males and females aged 30-64 y with available 3-d diet record data, without cardiovascular disease and not taking lipid- or glucose-lowering medications in the prospective Framingham Offspring cohort were included (n = 1852). Analysis of covariance models were used to compare mean follow-up lipid levels adjusting for age, sex, BMI, and dietary factors. Cox proportional hazard's models were used to estimate risk for elevated lipid levels. Results: Consuming ≥5 eggs/wk was not adversely associated with lipid outcomes. Among men, consuming ≥5 (compared with <0.5) eggs/wk was associated with an 8.6 mg/dL lower total cholesterol level and a 5.9 mg/dL lower LDL cholesterol level, as well as lower triglycerides. Overall, higher egg intake combined with higher dietary fiber (compared with lower intakes of both) was associated with the lowest total cholesterol, LDL cholesterol, and LDL cholesterol-to-HDL cholesterol ratio. Finally, diets with higher (compared with lower) egg intakes in combination with higher total fish or fiber intakes, respectively, were associated with lower risks of developing elevated (>160 mg/dL) LDL cholesterol levels (hazard ratio: 0.61; 95% confidence interval: 0.44, 0.84; and HR: 0.70; 95% confidence interval: 0.49, 0.98, respectively). Conclusions: Higher egg intakes were beneficially associated with serum lipids among healthy adults, particularly those who consumed more fish and dietary fiber.