Filling America's fiber intake gap: summary of a roundtable to probe realistic solutions with a focus on grain-based foods

Fibre & fermented foods: differential effects on the microbiota-gut-brain axis

The ability to manipulate brain function through the communication between the microorganisms in the gastrointestinal tract and the brain along the gut-brain axis has emerged as a potential option to improve cognitive and emotional health. Dietary composition and patterns have demonstrated a robust capacity to modulate the microbiota-gut-brain axis. With their potential to possess pre-, pro-, post-, and synbiotic properties, dietary fibre and fermented foods stand out as potent shapers of the gut microbiota and subsequent signalling to the brain. Despite this potential, few studies have directly examined the mechanisms that might explain the beneficial action of dietary fibre and fermented foods on the microbiota-gut-brain axis, thus limiting insight and treatments for brain dysfunction. Herein, we evaluate the differential effects of dietary fibre and fermented foods from whole food sources on cognitive and emotional functioning. Potential mediating effects of dietary fibre and fermented foods on brain health via the microbiota-gut-brain axis are described. Although more multimodal research that combines psychological assessments and biological sampling to compare each food type is needed, the evidence accumulated to date suggests that dietary fibre, fermented foods, and/or their combination within a psychobiotic diet can be a cost-effective and convenient approach to improve cognitive and emotional functioning across the lifespan.

In Vitro Fermentation of Animal and Plant Protein Isolates by the Human Gut Microbiota Under High and Low Carbohydrate Conditions

SCOPE

There is a lack of research comparing how different protein isolates influence the microbiome, especially when carbohydrate (CHO) availability is varied. The objective is to determine changes in gut microbiota composition and function during fermentation of digested protein isolates under high and low CHO conditions.

METHODS AND RESULTS

Protein isolates from beef, egg white, milk, pea, and soy are subjected to in vitro digestion and fermentation with human fecal microbiota. Under low CHO conditions, the microbiota is primarily proteolytic with decreased concentrations of peptides and increased variance among microbial taxa and production of ammonia and branched chain fatty acids by the microbiota. Milk protein not only results in the highest production of butyrate and p-hydroxyphenylacetate but also has high concentrations of deleterious fermentation metabolites. Amino acid composition of the protein isolates is significantly correlated with abundances of many microbial taxa and metabolites, but the correlations are stronger in the low CHO medium.

CONCLUSION

This study shows that low CHO conditions increase proteolytic fermentation and result in increased differences in microbiota response to protein isolates. It also showed that amino acid composition is highly associated with microbiota composition and function especially under low CHO conditions.

Pilot Study of Heat-Stabilized Rice Bran Acceptability in Households of Rural Southwest Guatemala and Estimates of Fiber, Protein, and Micro-Nutrient Intakes among Mothers and Children

Nutrient-dense, acceptable foods are needed in low-resource settings. Rice bran, a global staple byproduct of white rice processing, is rich in amino acids, fibers, and vitamins, when compared to other cereal brans. This pilot study examines the nutritional contribution of rice bran to the daily diets of mother-child pairs in rural southwest Guatemala. Thirty households were screened. Mothers (≥18 years) and children (6 to 24 months) completed 24 h dietary recalls at baseline and after 12 weeks (endline) for diet intake and diversity analyses. During biweekly visits for 12 weeks, households with <5 members received 14 packets containing 60 g of heat-stabilized rice bran, and those with ≥5 members received 28 packets. The macro- and micro-nutrient contributions of rice bran and whole, cooked black beans were included in dietary simulation models with average intakes established between the recalls and for comparison with dietary reference intakes (DRIs). A baseline child food frequency questionnaire was administered. The 27 mothers and 23 children with complete recalls were included in analyses. Daily maternal consumption of 10 g/d of rice bran plus 100 g/d of black beans resulted in all achieving at least 50% of the fiber, protein, magnesium, niacin, potassium, and thiamin DRIs. Daily child consumption of 3 g/d of rice bran plus 10 g/d of black beans resulted in all achieving at least 50% of the magnesium, niacin, phosphorous, and thiamine DRIs. For 15/17 food categories, male children had a higher intake frequency, notably for animal-source foods and coffee. Dietary rice bran coupled with black beans could improve nutritional adequacy, especially for fiber and key micro-nutrients, with broader implications for addressing maternal and child malnutrition in low-resource settings.

Food sources of fiber and micronutrients of concern among infants and young children in Lebanon: a national cross-sectional study

BACKGROUND

Intakes of fiber, iron, zinc, calcium, vitamin D, vitamin A, and folate were shown to be low in a substantial proportion of infants and children in Lebanon. The study aims to identify the top food sources of fiber, iron, zinc, calcium, vitamin D, vitamin A, and folate amongst infants and young children in Lebanon and to evaluate the evolution of food sources of these nutrients from the beginning of the complementary feeding journey up until the age of 47.9 months.

METHODS

A national cross-sectional survey was conducted in 2012 as part of the "Early Life Nutrition and Health in Lebanon" project using stratified cluster sampling. Dietary intakes for infants and young children aged 6-47.9 months (n = 763) were assessed using 24- Hour Dietary Recall. Food items were categorized into food groups and the percent contribution of each food group to nutrient intakes was determined to identify the top food sources of fiber and selected micronutrients for three age groups: 6-11.9 m (infants), 12-23.9 m (toddlers), and 24-47.9 m (preschoolers).

RESULTS

The top food source of fiber was vegetables among children aged 6-47.9 months. Among infants and toddlers, infant/young child formula was the main contributor to iron, zinc, calcium, vitamin D, vitamin A, and folate intakes. Baby cereals also contributed to around 14% of iron intakes among infants. Among preschoolers, meat and fish contributed to 13% of iron intakes and 29% of zinc intakes, while cow's milk was the major contributor of calcium (41%), vitamin D (81%) and vitamin A (25%) intakes. Sweetened beverages and sweet bakery were also ranked among the major food sources contributing to substantial intakes of key nutrients, including fiber, iron, zinc, calcium, vitamin A, and folate among infants, toddlers, and preschoolers.

CONCLUSIONS

In addition to milk sources, vegetables, beans and legumes, breads, meats, and rice and pasta, sweet bakery and sweetened beverages have contributed to intakes of key nutrients from early ages. This calls for implementing initiatives and designing approaches to support nutrition education and improve nutrient intakes in infancy and early childhood.

Adaptation to tolerate high doses of arabinoxylan is associated with fecal levels of Bifidobacterium longum

Dietary fiber supplements are a strategy to close the 'fiber gap' and induce targeted modulations of the gut microbiota. However, higher doses of fiber supplements cause gastrointestinal (GI) symptoms that differ among individuals. What determines these inter-individual differences is insufficiently understood. Here we analyzed findings from a six-week randomized controlled trial that evaluated GI symptoms to corn bran arabinoxylan (AX; n = 15) relative to non-fermentable microcrystalline cellulose (MCC; n = 16) at efficacious supplement doses of 25 g/day (females) or 35 g/day (males) in adults with excess weight. Self-reported flatulence, bloating, and stomach aches were evaluated weekly. Bacterial taxa involved in AX fermentation were identified by bioorthogonal non-canonical amino acid tagging. Associations between GI symptoms, fecal microbiota features, and diet history were systematically investigated. AX supplementation increased symptoms during the first three weeks relative to MCC (p < 0.05, Mann-Whitney tests), but subjects 'adapted' with symptoms reverting to baseline levels toward the end of treatment. Symptom adaptations were individualized and correlated with the relative abundance of Bifidobacterium longum at baseline (rs = 0.74, p = 0.002), within the bacterial community that utilized AX (rs = 0.69, p = 0.006), and AX-induced shifts in acetate (rs = 0.54, p = 0.039). Lower baseline consumption of animal-based foods and higher whole grains associated with less severity and better adaptation. These findings suggest that humans do 'adapt' to tolerate efficacious fiber doses, and this process is linked to their microbiome and dietary factors known to interact with gut microbes, providing a basis for the development of strategies for improved tolerance of dietary fibers.

Dietary Zn deficiency, the current situation and potential solutions

Zinc (Zn) deficiency is a worldwide problem, and this review presents an overview of the magnitude of Zn deficiency with a particular emphasis on present global challenges, current recommendations for Zn intake, and factors that affect dietary requirements. The challenges of monitoring Zn status are clarified together with the discussion of relevant Zn bioaccessibility and bioavailability issues. Modern lifestyle factors that may exacerbate Zn deficiency and new strategies of reducing its effects are presented. Biofortification, as a potentially useful strategy for improving Zn status in sensitive populations, is discussed. The review proposes potential actions that could deliver promising results both in terms of monitoring dietary and physiological Zn status as well as in alleviating dietary Zn deficiency in affected populations.

Nutrition facts labels: who is actually reading them and does it help in meeting intake recommendations for nutrients of public health concern?

BACKGROUND

Fiber, potassium and calcium are nutrients of public health concern and their intakes in the United States are alarmingly low. The usage of nutrition facts labels has been reported to increase the odds for dietary reference intake of fiber in some studies. The overall evidence, however, is mixed, as some studies suggested that nutrition facts panels have little to no effect on average measures of diet quality. Here, we investigated whether the usage of nutrition facts labels was associated with meeting U.S. intake recommendations for three nutrients of public health concern: fiber, potassium and calcium.

METHODS

We used cross-sectional multistage, stratified, clustered and probability sampling design data from the U.S. National Health and Nutrition Examination Surveys 2017-2020 cycle. The sample included 5,416 individuals aged 20 years or older, which may be extrapolated to represent 146,841,866 US Americans. Nutrient intakes were compared among individuals reading nutrition facts panels "frequently", "sometimes" or "rarely" using applied survey data analyses techniques (including multivariate logistic regression and marginsplots).

RESULTS

We observed substantial sociodemographic differences between the three groups. Frequent readers were significantly more likely to be female and had higher educational levels. On average, they were also significantly older as compared to rare readers. Fiber intake in g/d was highest in frequent readers (17.09) and lowest in rare readers (14.64). The proportion of participants that met dietary fiber intake recommendations was almost four times higher in the frequent readers group (12.69%) as compared to the rare readers group (3.69%). In a bivariate logistic regression model, frequent label reading significantly increased the odds for meeting the fiber recommendations in Dietary Guidelines for Americans (OR: 2.15, p < 0.001). Rarely reading labels decreased the odds (OR: 0.57, p = 0.003). These odds remained essentially unchanged after adjusting for sociodemographic covariates, diabetes status and body mass index (OR: 1.84, p = 0.004; and OR: 0.62, p = 0.022).

CONCLUSIONS

Nutrition facts panel reading associates with fiber intake. Our findings have potential implications for public health nutrition strategies that may center around educational work.

Assessing Gastrointestinal Tolerance in Healthy Adults: Reliability and Validity of a Weekly Questionnaire

When examining gastrointestinal tolerance to nondigestible carbohydrates, a weekly vs. daily symptoms questionnaire may lessen participant burden. This secondary analysis examined the reliability and validity of the Gastrointestinal Symptom Rating Scale (GSRS) in healthy adults. The internal consistency reliability of the GSRS syndromes and a daily questionnaire (DQ) comparator were determined. The GSRS syndromes prediction of slow transit stool form was assessed by ROC analysis. The DQ (α = 0.76) and GSRS syndromes of constipation (α = 0.73; ω = 0.74), and diarrhea (α = 0.76; ω = 0.77) exhibited acceptable reliability, as did the GSRS overall (α = 0.76; ω = 0.87) but not the syndromes of abdominal pain (α = 0.54; ω = 0.54), reflux (α = 0.69; ω = 0.67), or indigestion (α = 0.64; ω = 0.67). The GSRS syndromes predicted slow transit stools (AUC = 0.855), and the GSRS items of stomach pain, nausea, flatus, constipation, and diarrhea were moderately correlated (ρ = 0.55-0.64; P < 0.001) with the corresponding DQ items. The GSRS may be useful to assess gastrointestinal tolerance and efficacy of nondigestible carbohydrates given its performance at predicting slow transit stools, suggestive of constipation.

Partially hydrolyzed guar gum is associated with improvement in gut health, sleep, and motivation among healthy subjects

Partially hydrolyzed guar gum dietary fiber is well recognized for a number of health benefits. In the present study, we aim to investigate the effects of partially hydrolyzed guar gum on constipation, intestinal microbiota as well as mental health in healthy subjects. In the randomized, parallel, double-blind, and placebo-controlled study the enrolled healthy men and women volunteers took either 3 g/day (T3) or 5 g/day (T5) of dietary fiber intakes for eight consecutive weeks compared to placebo (T0). The fecal characteristics, fecal microbiota, defecation characteristics, and quality of life (QOL) questionnaire were investigated. The results revealed a significant suppression in fecal potent harmful mucolytic bacteria in the T3 and T5 groups compared to the T0 group. The defecation frequency, excretory feeling, and scores of sleep and motivation questionnaire were also improved in the dietary fiber intake groups, showing a significant difference in the T5 group compared to the T0 group. In summary, the consumption of partially hydrolyzed guar gum dietary fiber is found effective in suppressing the potent harmful mucolytic bacteria that could be associated with the improvement of constipation-related symptoms including mental health in terms of sleep and motivation among the healthy subjects.

Perspective: Assessing Tolerance to Nondigestible Carbohydrate Consumption

Human intestinal enzymes do not hydrolyze nondigestible carbohydrates (NDCs), and thus, they are not digested and absorbed in the small intestine. Instead, NDCs are partially to completely fermented by the intestinal microbiota. Select NDCs are associated with health benefits such as laxation and lowering of blood cholesterol and glucose. NDCs provide functional attributes to processed foods, including sugar or fat replacers, thickening agents, and bulking agents. Additionally, NDCs are incorporated into processed foods to increase their fiber content. Although consumption of NDCs can benefit health and contribute functional characteristics to foods, they can cause gastrointestinal symptoms, such as flatulence and bloating. As gastrointestinal symptoms negatively affect consumer well-being and their acceptance of foods containing NDC ingredients, it is crucial to consider tolerance when designing food products and testing their physiological health benefits in clinical trials. This perspective provides recommendations for the approach to assess gastrointestinal tolerance to NDCs, with a focus on study design, population criteria, intervention, comparator, and outcome. Special issues related to studies in children and implications for stakeholders are also discussed. It is recommended that the evaluation of gastrointestinal tolerance to NDCs be conducted in randomized, blinded, controlled crossover studies using standard gastrointestinal questionnaires, with attention to study participant background diets, health status, lifestyle, and medications.

Non-starch polysaccharides in beer and brewing: A review of their occurrence and significance

It has become apparent that beer (both alcoholic and nonalcoholic) contains appreciable amounts of non-starch polysaccharides, a broad subgroup of dietary fiber. It is worth noting that the occurrence of non-starch polysaccharides in alcoholic beer does not imply this should be consumed as a source of nutrition. But the popularity of nonalcoholic beer is growing, and the lessons learnt from non-starch polysaccharides in brewing can be largely translated to nonalcoholic beer. For context, we briefly review the origins of dietary fiber, its importance within the human diet and the significance of water-soluble dietary fiber in beverages. We review the relationship between non-starch polysaccharides and brewing, giving focus to the techniques used to quantify non-starch polysaccharides in beer, how they affect the physicochemical properties of beer and their influence on the brewing process. The content of non-starch polysaccharides in both regular and low/nonalcoholic beer ranges between 0.5 - 4.0 g/L and are predominantly composed of arabinoxylans and β-glucans. The process of malting, wort production and filtration significantly affect the soluble non-starch polysaccharide content in the final beer. Beer viscosity and turbidity are strongly associated with the content of non-starch polysaccharides.

Plant-Based and Ketogenic Diets As Diverging Paths to Address Cancer: A Review

Importance

As the incidence of cancer and metabolic disorders, such as obesity, concurrently rise, there has been increasing awareness of the pervasive effect of nutrition. The whole foods plant-based diet (WFPBD) and ketogenic diet (KD) have gained popularity in oncology, and this topic is increasingly permeating clinical dialogue.

Observations

Dietary intake is associated with multiple pathways involved in carcinogenesis and tumor progression. Consumption of a plant-enriched diet is associated with reduced cancer incidence and is recommended by dietary guidelines for cancer prevention. Despite a starkly different nutrient composition, a WFPBD and KD can be associated with weight loss, decreased inflammation, and decreased insulin levels. In addition, a WFPBD is associated with increased fiber, phytochemicals, and butyrate levels and decreased insulin-like growth factor 1 levels, whereas a KD exerts potential anticancer effects by increasing β hydroxybutyrate levels. A KD may be of interest in select, less common settings, such as tumors treated with phosphatidylinositol 3-kinase inhibitors, which induce hyperinsulinemia and hyperglycemia. Completed interventional trials have focused on increasing fruit and vegetable intake or reducing fat intake but have not specifically tested WFPBD or KD for cancer prevention or treatment. Currently available data support plant-based diets as opposed to KD as part of a lifestyle associated with reduced cancer risk. In the postdiagnosis setting, there are currently no rigorously tested approaches that support the recommendation of any diet to treat cancer.

Conclusions and Relevance

The results of this review suggest that the collective evidence supports plant-enriched diets vs KD for the reduction of cancer risk and the improvement of metabolic disorders in survivors. Additional prospective randomized clinical trials are needed to encourage use of dietary modification across the cancer continuum. Rigorous trial designs that adapt classical oncologic end points may identify populations that are likely to benefit from starkly contrasting diets. Current data support prioritization of plant-based diets, and future data could further personalize dietary recommendations in cancer populations.

Multi-Omic Analyses Reveal Bifidogenic Effect and Metabolomic Shifts in Healthy Human Cohort Supplemented With a Prebiotic Dietary Fiber Blend

Dietary fiber, a nutrient derived mainly from whole grains, vegetables, fruits, and legumes, is known to confer a number of health benefits, yet most Americans consume less than half of the daily recommended amount. Convenience and affordability are key factors determining the ability of individuals to incorporate fiber-rich foods into their diet, and many Americans struggle to access, afford, and prepare foods rich in fiber. The objective of this clinical study was to test the changes in microbial community composition, human metabolomics, and general health markers of a convenient, easy to use prebiotic supplement in generally healthy young participants consuming a diet low in fiber. Twenty healthy adults participated in this randomized, placebo-controlled, double-blind, crossover study which was registered at clinicaltrials.gov as NCT03785860. During the study participants consumed 12 g of a prebiotic fiber supplement and 12 g of placebo daily as a powder mixed with water as part of their habitual diet in randomized order for 4 weeks, with a 4-week washout between treatment arms. Fecal microbial DNA was extracted and sequenced by shallow shotgun sequencing on an Illumina NovaSeq. Plasma metabolites were detected using liquid chromatography–mass spectrometry with untargeted analysis. The phylum Actinobacteria, genus Bifidobacterium, and several Bifidobacterium species (B. bifidum, B. adolescentis, B. breve, B. catenulatum, and B. longum) significantly increased after prebiotic supplementation when compared to the placebo. The abundance of genes associated with the utilization of the prebiotic fiber ingredients (sacA, xfp, xpk) and the production of acetate (poxB, ackA) significantly changed with prebiotic supplementation. Additionally, the abundance of genes associated with the prebiotic utilization (xfp, xpk), acetate production (ackA), and choline to betaine oxidation (gbsB) were significantly correlated with changes in the abundance of the genus Bifidobacterium in the prebiotic group. Plasma concentrations of the bacterially produced metabolite indolepropionate significantly increased. The results of this study demonstrate that an easy to consume, low dose (12 g) of a prebiotic powder taken daily increases the abundance of beneficial bifidobacteria and the production of health-promoting bacteria-derived metabolites in healthy individuals with a habitual low-fiber diet.

Pediatric Aspects of Nutrition Interventions for Disorders of Gut-Brain Interaction

Dietary factors may play an important role in the generation of symptoms in children with disorders of gut-brain interaction (DGBIs). Although dietary modification may provide successful treatment, there is a relative paucity of controlled trials that have shown the effectiveness of dietary interventions. This study is a narrative review that explores the existing literature on food and pediatric DGBIs. The following have been shown to be beneficial: (i) in infants with colic, removing cow's milk from the infant's diet or from the maternal diet in those who are breastfed; (ii) in infants with regurgitation, adding thickeners to the formula or removing cow's milk protein from the infant's diet or the maternal diet in those who are breastfed; and (iii) in children with pain-predominant DGBIs, using soluble fiber supplementation or a low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet. In children with functional constipation, there is no evidence that adding fiber is beneficial. Given that most dietary interventions include restriction of different foods in children, a thoughtful approach and close follow-up are needed.

Real-World Treatment Strategies to Improve Outcomes in Patients With Chronic Idiopathic Constipation and Irritable Bowel Syndrome With Constipation

Chronic idiopathic constipation and irritable bowel syndrome with constipation are complex, overlapping conditions. Although multiple guidelines have informed healthcare providers on appropriate treatment options for patients with chronic idiopathic constipation and irritable bowel syndrome with constipation, little direction is offered on treatment selection. First-line treatment options usually include fiber and over-the-counter osmotic laxatives; however, these are insufficient for many individuals. When these options fail, prescription secretagogues (plecanatide, linaclotide, lubiprostone, and tenapanor [pending commercial availability]), or serotonergic agents (prucalopride and tegaserod) are generally preferred. Individuals experiencing concurrent abdominal pain and/or bloating may experience greater overall improvements from prescription therapies because these agents have been proven to reduce concurrent abdominal and bowel symptoms. Should initial prescription treatments fail, retrying past treatment options (if not adequately trialed initially), combining agents from alternative classes, or use of adjunctive therapies may be considered. Given the broad spectrum of available agents, therapy should be tailored by mutual decision-making between the patient and practitioner. Overall, patients need to be actively monitored and managed to maximize clinical outcomes.

Perspective: Utilizing High Amylose Wheat Flour to Increase Dietary Fiber Intake of Children and Adolescents: A Health by Stealth Approach

Children and adolescents have consistently failed to meet recommended levels of dietary fiber consumption, thus making fiber a nutrient of concern. The importance of adequate dietary fiber intake to attain a healthy diet necessitates the identification of fiber-rich and readily consumed food sources by youth. Grain-based foods derived from whole grains represent a strategic initiative to increase dietary fiber consumption and is consistent with the American diet pattern. Increased intake of foods made from whole grains have been positively associated with improved health outcomes but are also less preferred among youth compared to refined grain products, which make up the majority of their carbohydrate intake. Advances in the commercialization and availability of high amylose wheat flour, a source of resistant starch fiber, provides an opportunity to remedy the suggested acceptability issues of whole grain products indicative of sensory factors, without compromising the amount of fiber ingested. Resistant starch fiber consumption has been associated with health benefits including improved blood sugar management, improved markers of digestive and gut health, increased satiety, and a reduced inflammatory response among adults. The limited studies that indicate fiber's direct benefit among youth are largely observational, thereby necessitating the need for more controlled trials for these age groups. Replacing traditional refined wheat flour with refined high amylose wheat flour has the unique ability to increase dietary fiber consumption without compromising desired sensory and finished product characteristics and thus can help increase dietary fiber consumption in children and adolescents who struggle to meet adequate intakes of fiber.

Gains and Losses of Agricultural Food Production: Implications for the Twenty-First Century

The world food supply depends on a diminishing list of plant crops and animal livestock to not only feed the ever-growing human population but also improve its nutritional state and lower the disease burden. Over the past century or so, technological advances in agricultural and food processing have helped reduce hunger and poverty but have not adequately addressed sustainability targets. This has led to an erosion of agricultural biodiversity and balanced diets and contributed to climate change and rising rates of chronic metabolic diseases. Modern food supply chains have progressively lost dietary fiber, complex carbohydrates, micronutrients, and several classes of phytochemicals with high bioactivity and nutritional relevance. This review introduces the concept of agricultural food systems losses and focuses on improved sources of agricultural diversity, proteins with enhanced resilience, and novel monitoring, processing, and distribution technologies that are poised to improve food security, reduce food loss and waste, and improve health profiles in the near future. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Feasibility of Beans/Bran Enriching Nutritional Eating For Intestinal Health & Cancer Including Activity for Longevity: A Pilot Trial to Improve Healthy Lifestyles among Individuals at High Risk for Colorectal Cancer

Purpose:

Examine the feasibility and preliminary effects of a lifestyle intervention of rice bran plus navy bean supplementation, and physical activity (PA) education on intake of fiber and whole grains, and PA levels.

Design:

Randomized-controlled, single-blinded.

Setting:

Academic institution and free-living.

Subjects:

Adults >18 years, with ≥1 adenomatous polyp removed within 3 years.

Intervention:

Participants received powder and pre-prepared meals and snacks that contained either rice bran (30 g/day) plus navy bean (30 g/day), or Fibersol-2^® (10 g/day), for 12-weeks. All participants received a 1-hour (PA) education session.

Measures:

Feasibility was assessed by recruitment and retention rates, and compliance to the study foods and procedures. Three-day food logs were analyzed using Nutritionist Pro™ to estimate fiber intake, and the Automated Self-Administered 24-hour (ASA24^®) Dietary Assessment Tool calculated Healthy Eating Index (HEI) whole grain and total scores. PA was measured using an ActivPAL™ accelerometer.

Analysis:

Continuous data were summarized as median, range, and percent change from baseline to post-intervention.

Results:

N = 20 (86.9%) completed the intervention. Compliance was 92% in the rice bran plus navy bean versus 89% in Fibersol-2^®. Navy bean consumption increased from 2 g/day to 30 g/day, and rice bran from 0 g/day to 30 g/day. Fiber intake (g/day) increased by 73% versus 82%, HEI whole grain improved by 270% versus 37%, and HEI total improved by 10% versus 9.1% in rice bran plus navy bean and Fibersol-2^®, respectively. Total PA (MET-hours/day) showed minimal change for intervention (+0.04%) and control (+4%).

Conclusion:

Findings merit a larger trial of rice bran plus navy bean and PA to evaluate efficacy for dietary and cancer prevention-related outcomes.

Nutritional, Cardiovascular Health and Lifestyle Status of 'Health Conscious' Adult Vegans and Non-Vegans from Slovenia: A Cross-Sectional Self-Reported Survey

The study aim was to investigate differences in nutritional, cardiovascular and lifestyle status of ‘health conscious’ subjects. In a partial ‘lock-down’ during the COVID-19 pandemic period, we performed a web-based, cross-sectional study. We compared 80 self-selected subjects (51 vegans, 67% females, and 29 non-vegans, 55% females, p = 0.344). Nutritional status was assessed by bio-electrical impedance and standardized food frequency questionnaires (i.e., contribution of nutrients from foods and supplementation, combined and separate). Serum lipid concentrations and blood pressure (BP) were assessed from annual or initial examination reports, while sociodemographic, economic, and lifestyle statuses were obtained by standardized questionnaires. Finally, a multivariate linear regression model was used to estimate the relationship between total fiber and saturated fatty acid (SFA) intake and low-density lipoprotein cholesterol (LDL cholesterol) values. The vegans had a significantly lower body mass index (22.8 ± 2.4 vs. 26.6 ± 3.6 kg/m², p < 0.001) and body fat % (19.3 ± 7.3 vs. 25.8 ± 8.2%, p < 0.001) than the non-vegans. There were significant differences between vegans and non-vegans in energy intake, and most macronutrient (10/12) and micronutrient (15/23) intakes in units/day. Both diets were well designed, with high fiber and low SFA and free sugar intake but remained insufficient in n-3 long chain polyunsaturated fatty acids (for vegans), vitamin D, calcium, sodium (for vegans) and iodine. Vegans also had a significantly lower lipid profile and BP than non-vegans, except for high-density lipoprotein cholesterol. However, both groups met targeted recommendations. Furthermore, fiber and SFA intake and age explained 47% of the variance in LDL cholesterol. In conclusion, ‘health conscious’ vegans and non-vegans with comparable lifestyle statuses had significant differences in dietary intake, body composition and cardiovascular health status.

β-glucan attenuates cognitive impairment via the gut-brain axis in diet-induced obese mice

BACKGROUND

"Western" style dietary patterns are characterized by a high proportion of highly processed foods rich in fat and low in fiber. This diet pattern is associated with a myriad of metabolic dysfunctions, including neuroinflammation and cognitive impairment. β-glucan, the major soluble fiber in oat and barley grains, is fermented in the lower gastrointestinal tract, potentially impacting the microbial ecosystem and thus may improve elements of cognition and brain function via the gut-brain axis. The present study aimed to evaluate the effect of β-glucan on the microbiota gut-brain axis and cognitive function in an obese mouse model induced by a high-fat and fiber-deficient diet (HFFD).

RESULTS

After long-term supplementation for 15 weeks, β-glucan prevented HFFD-induced cognitive impairment assessed behaviorally by object location, novel object recognition, and nesting building tests. In the hippocampus, β-glucan countered the HFFD-induced microglia activation and its engulfment of synaptic puncta, and upregulation of proinflammatory cytokine (TNF-α, IL-1β, and IL-6) mRNA expression. Also, in the hippocampus, β-glucan significantly promoted PTP1B-IRS-pAKT-pGSK3β-pTau signaling for synaptogenesis, improved the synaptic ultrastructure examined by transmission electron microscopy, and increased both pre- and postsynaptic protein levels compared to the HFFD-treated group. In the colon, β-glucan reversed HFFD-induced gut barrier dysfunction increased the thickness of colonic mucus (Alcian blue and mucin-2 glycoprotein immunofluorescence staining), increased the levels of tight junction proteins occludin and zonula occludens-1, and attenuated bacterial endotoxin translocation. The HFFD resulted in microbiota alteration, effects abrogated by long-term β-glucan supplementation, with the β-glucan effects on Bacteroidetes and its lower taxa particularly striking. Importantly, the study of short-term β-glucan supplementation for 7 days demonstrated pronounced, rapid differentiating microbiota changes before the cognitive improvement, suggesting the possible causality of gut microbiota profile on cognition. In support, broad-spectrum antibiotic intervention abrogated β-glucan's effects on improving cognition, highlighting the role of gut microbiota to mediate cognitive behavior.

CONCLUSION

This study provides the first evidence that β-glucan improves indices of cognition and brain function with major beneficial effects all along the gut microbiota-brain axis. Our data suggest that elevating consumption of β-glucan-rich foods is an easily implementable nutritional strategy to alleviate detrimental features of gut-brain dysregulation and prevent neurodegenerative diseases associated with Westernized dietary patterns. Video Abstract.

A Whole Food Plant-Based Diet Is Effective for Weight Loss: The Evidence

What does the best available balance of scientific evidence show is the optimum way to lose weight? Calorie density, water content, protein source, and other components significantly influence the effectiveness of different dietary regimes for weight loss. By "walling off your calories," preferentially deriving your macronutrients from structurally intact plant foods, some calories remain trapped within indigestible cell walls, which then blunts the glycemic impact, activates the ileal brake, and delivers prebiotics to the gut microbiome. This may help explain why the current evidence indicates that a whole food, plant-based diet achieves greater weight loss compared with other dietary interventions that do not restrict calories or mandate exercise. So, the most effective diet for weight loss appears to be the only diet shown to reverse heart disease in the majority of patients. Plant-based diets have also been found to help treat, arrest, and reverse other leading chronic diseases such as type 2 diabetes and hypertension, whereas low-carbohydrate diets have been found to impair artery function and worsen heart disease, the leading killer of men and women in the United States. A diet centered on whole plant foods appears to be a safe, simple, sustainable solution to the obesity epidemic.

Nutrient and Food Intake of Participants in a Whole-Food Plant-Based Lifestyle Program

OBJECTIVE

We evaluated the nutrient adequacy of a well-planned supplemented whole-food plant-based (WFPB) diet as a component of an ongoing community lifestyle optimization program. We investigated the contributions of nutrients from foods and supplements and plant-based meal replacement (SMR) separately (foods, SMR) and combined (vs recommendations) as well as food group intake, both according to sex.

METHOD

Our cross-sectional study included 151 healthy, active participants (aged 39.6 years) who were on a Western-type diet when they voluntarily joined our WFPB lifestyle program (0.5-10 years ago). We assessed diet using 3-day weighed dietary records (foods, S, and MR). After we standardized nutrient intake to 2000 kcal/d, we calculated the contribution of macro- and micronutrients from foods and SMR separately and combined (foods + SMR) (vs central European Recommendations), as well as food group intake, both according to sex.

RESULTS

All macro- and micronutrient intake (total: from foods plus SMR) exceeded the reference values, except for calcium (95% and 82% in females and males) and vitamin D (both sexes, in summertime). Compared with male participants, female participants consumed (i.e., from foods and SMR together) significantly larger amounts of 23 (/25) micronutrients (8 [/25] from foods and 22 [/25] from SMR). The diet was primarily composed of the following (by mass in descending order): unprocessed vegetables/fruits, whole grains, legumes, potatoes, nuts/seeds, MR, and spices/herbs.

CONCLUSIONS

Participants in our WFPB lifestyle program ingested a nutrient-rich WFPB diet and targeted supplementation. The presented ongoing community WFPB lifestyle program ensures a healthy, balanced, and environment-friendly dietary pattern for participants who are compliant.

Prebiotic inulin consumption reduces dioxin-like PCB 126-mediated hepatotoxicity and gut dysbiosis in hyperlipidemic Ldlr deficient mice

Exposure to some environmental pollutants increases the risk of developing inflammatory disorders such as steatosis and cardiometabolic diseases. Diets high in fermentable fibers such as inulin can modulate the gut microbiota and lessen the severity of pro-inflammatory diseases, especially in individuals with elevated circulating cholesterol. Thus, we aimed to test the hypothesis that hyperlipidemic mice fed a diet enriched with 8% inulin would be protected from the pro-inflammatory toxic effects of PCB 126. Four groups of male Ldlr^-/- mice were fed a high cholesterol diet containing 8% inulin or 8% cellulose (control) for 12 weeks. At weeks 2 and 4, mice were exposed to PCB 126 or vehicle (control). PCB 126 exposure induced wasting and impaired glucose tolerance, which were attenuated by inulin consumption. PCB 126 exposure induced hepatic lipid accumulation and increased inflammatory gene expression, which were both decreased by inulin consumption. In addition, inulin feeding decreased atherosclerotic lesion development in the aortic root and modulated the expression of enzymes related to glycolysis. Finally, 16S rRNA sequencing of gut microbial populations showed that PCB 126 modulated multiple microbiota genera (e.g., 3-fold decrease in Allobaculum and 3-fold increase in Coprococcus) which were normalized in inulin fed mice. Overall our data support the hypothesis that a dietary intervention that targets the gut microbiota may be an effective means of attenuating dioxin-like pollutant-mediated diseases.

Curdlan Prevents the Cognitive Deficits Induced by a High-Fat Diet in Mice via the Gut-Brain Axis

A high-fat (HF) diet is a major predisposing factor of neuroinflammation and cognitive deficits. Recently, changes in the gut microbiota have been associated with neuroinflammation and cognitive impairment, through the gut-brain axis. Curdlan, a bacterial polysaccharide widely used as food additive, has the potential to alter the composition of the microbiota and improve the gut-brain axis. However, the effects of curdlan against HF diet-induced neuroinflammation and cognitive decline have not been investigated. We aimed to evaluate the neuroprotective effect and mechanism of dietary curdlan supplementation against the obesity-associated cognitive decline observed in mice fed a HF diet. C57Bl/6J male mice were fed with either a control, HF, or HF with curdlan supplementation diets for 7 days (acute) or 15 weeks (chronic). We found that acute curdlan supplementation prevented the gut microbial composition shift induced by HF diet. Chronic curdlan supplementation prevented cognitive declines induced by HF diet. In addition, curdlan protected against the HF diet-induced abnormities in colonic permeability, hyperendotoxemia, and colonic inflammation. Furthermore, in the prefrontal cortex (PFC) and hippocampus, curdlan mitigated microgliosis, neuroinflammation, and synaptic impairments induced by a HF diet. Thus, curdlan—as a food additive and prebiotic—can prevent cognitive deficits induced by HF diet via the colon-brain axis.

Dietary fiber intake and total and cause-specific mortality: the Japan Public Health Center-based prospective study

BACKGROUND

An inverse association has been shown between dietary fiber intake and several noncommunicable diseases. However, evidence of this effect remains unclear in the Asian population.

OBJECTIVE

We examined the association between dietary fiber intake and all-cause and cause-specific mortality, as well as the association between fiber intake from dietary sources and all-cause mortality.

METHODS

We conducted a large-scale population-based cohort study (Japan Public Health Center-based prospective study). A validated questionnaire with 138 food items was completed by 92,924 participants (42,754 men and 50,170 women) aged 45-74 y. Dietary fiber intake was calculated and divided into quintiles. HR and 95% CI of total and cause-specific mortality were reported.

RESULTS

During the mean follow-up of 16.8 y, 19,400 deaths were identified. In multivariable adjusted models, total, soluble, and insoluble fiber intakes were inversely associated with all-cause mortality. The HRs of total mortality in the highest quintile of total fiber intake compared with the lowest quintile were 0.77 (95% CI: 0.72, 0.82; Ptrend <0.0001) in men and 0.82 (95% CI: 0.76, 0.89; Ptrend <0.0001) in women. Increased quintiles of dietary fiber intake were significantly associated with decreased mortality due to total cardiovascular disease (CVD), respiratory disease, and injury in both men and women, whereas dietary fiber intake was inversely associated with cancer mortality in men but not women. Fiber from fruits, beans, and vegetables, but not from cereals, was inversely associated with total mortality.

CONCLUSION

In this large-scale prospective study with a long follow-up period, dietary fiber was inversely associated with all-cause mortality. Since intakes of dietary fiber, mainly from fruits, vegetables, and beans were associated with lower all-cause mortality, these food sources may be good options for people aiming to consume more fiber.

Impact of defined thermomechanical treatment on the structure and content of dietary fiber and the stability and bioaccessibility of polyphenols of chokeberry (Aronia melanocarpa) pomace

Dietary fiber is a potential replacement for other ingredients such as starch in reformulated extruded breakfast cereals. Analysis of chokeberry pomace powder revealed a total dietary fiber content of 57.8 ± 2 g/100 g with 76% being insoluble, 20% high molecular soluble and 4% low molecular soluble dietary fiber. The fiber polysaccharide composition was analyzed in detail by using a variety of analytical approaches. Extrusion-like processing conditions were studies in a Closed Cavity Rheometer enabling the application of defined thermal (temperature range 100-160 °C) and mechanical treatments (shear rates between 0.1 s^-1 and 50 s^-1) to chokeberry pomace powder. Application of temperatures up to 140 °C irrespective of the mechanical treatment does not remarkably alter dietary fiber structure or content, but reduces the initial content of total polyphenols by about 40% to a final content of 3.3 ± 0.5 g/100 g including 0.63 ± 0.1 g/100 g of anthocyanins, 0.18 ± 0.02 g/100 g of phenolic acids and 0.090 ± 0.007 g/100 g of flavonols, respectively. The retained polyphenols are fully bioaccessible after in vitro digestion, and antioxidant capacity remains unchanged as compared to the untreated pomace powder. Glucose bioaccessibility remains unaffected, whereas glucose content is reduced. It is concluded that chokeberry pomace powder is a good source of dietary fiber with the potential to partially substitute starch in extruded breakfast cereals.

Increasing the nutritional value of strawberry puree by adding xylo-oligosaccharides

The present study identified the threshold concentration of xylo-oligosaccharides (XOS) that resulted in minimal quality changes (rheology, color, water activity, pH, and total soluble solids) in strawberry puree. Optimization of XOS concentration to 5% (w/w) did not significantly alter the quality attributes of the strawberry puree. In addition, this study also monitored the rheological properties, composition (total soluble solids, total phenolic content, flavonoids, and tannin content), physicochemical attributes (color, water activity, pH) and sensorial properties of XOS-enhanced (5%, w/w) strawberry puree after thermal processing (HTST: 75 °C, 15s and UHT: 121 °C, 2s) and storage after 1, 15, and 36 days at 4 °C and 55 °C. At 5% (w/w) concentration, the addition of XOS increased consumer preference without significantly compromising quality attributes. Thermally treated strawberry puree (HTST and UHT) were less preferred by consumers than fresh puree. However, all strawberry samples incorporated with XOS (5%, w/w) received statistically higher scores than the samples without the XOS addition. Thus, the proposed supplementation of strawberry puree with XOS could be a viable solution to increase consumers' dietary fiber intake with little need for behavioral changes.

Supplement of microbiota-accessible carbohydrates prevents neuroinflammation and cognitive decline by improving the gut microbiota-brain axis in diet-induced obese mice

Background

Western pattern diets induce neuroinflammation and impair cognitive behavior in humans and animals. Neuroinflammation and cognitive impairment have been associated with microbiota dysbiosis, through the gut-brain axis. Furthermore, microbiota-accessible carbohydrates (MACs) found in dietary fiber are important in shaping the microbial ecosystem and have the potential to improve the gut-brain-axis. However, the effects of MACs on neuroinflammation and cognition in an obese condition have not yet been investigated. The present study aimed to evaluate the effect of MACs on the microbiota-gut-brain axis and cognitive function in obese mice induced by a high-fat and fiber deficient (HF-FD) diet.

Methods

C57Bl/6 J male mice were fed with either a control HF-FD or a HF-MAC diet for 15 weeks. Moreover, an additional group was fed with the HF-MAC diet in combination with an antibiotic cocktail (HF-MAC + AB). Following the 15-week treatment, cognitive behavior was investigated; blood, cecum content, colon, and brain samples were collected to determine metabolic parameters, endotoxin, gut microbiota, colon, and brain pathology.

Results

We report MACs supplementation prevented HF-FD-induced cognitive impairment in nesting building and temporal order memory tests. MACs prevented gut microbiota dysbiosis, including increasing richness, α-diversity and composition shift, especially in Bacteroidetes and its lower taxa. Furthermore, MACs increased colonic mucus thickness, tight junction protein expression, reduced endotoxemia, and decreased colonic and systemic inflammation. In the hippocampus, MACs suppressed HF-FD-induced neuroglia activation and inflammation, improved insulin IRS-pAKT-pGSK3β-pTau synapse signaling, in addition to the synaptic ultrastructure and associated proteins. Furthermore, MACs’ effects on improving colon–cognitive parameters were eliminated by wide spectrum antibiotic microbiota ablation.

Conclusions

These results suggest that MACs improve cognitive impairments via the gut microbiota-brain axis induced by the consumption of an HF-FD. Supplemental MACs to combat obesity-related gut and brain dysfunction offer a promising approach to prevent neurodegenerative diseases associated with Westernized dietary patterns and obesity.

The Effect of Isolated and Synthetic Dietary Fibers on Markers of Metabolic Diseases in Human Intervention Studies: A Systematic Review

Observational studies provide strong evidence for the health benefits of dietary fiber (DF) intake; however, human intervention studies that supplement isolated and synthetic DFs have shown inconsistent results. Therefore, we conducted a systematic review to summarize the effects of DF supplementation on immunometabolic disease markers in intervention studies in healthy adults, and considered the role of DF dose, DF physicochemical properties, intervention duration, and the placebo used. Five databases were searched for studies published from 1990 to 2018 that assessed the effect of DF on immunometabolic markers. Eligible studies were those that supplemented isolated or synthetic DFs for ≥2 wk and reported baseline data to assess the effect of the placebo. In total, 77 publications were included. DF supplementation reduced total cholesterol (TC), LDL cholesterol, HOMA-IR, and insulin AUC in 36-49% of interventions. In contrast, <20% of the interventions reduced C-reactive protein (CRP), IL-6, glucose, glucose AUC, insulin, HDL cholesterol, and triglycerides. A higher proportion of interventions showed an effect if they used higher DF doses for CRP, TC, and LDL cholesterol (40-63%), viscous and mixed plant cell wall DFs for TC and LDL cholesterol (>50%), and longer intervention durations for CRP and glucose (50%). Half of the placebo-controlled studies used digestible carbohydrates as the placebo, which confounded findings for IL-6, glucose AUC, and insulin AUC. In conclusion, interventions with isolated and synthetic DFs resulted mainly in improved cholesterol concentrations and an attenuation of insulin resistance, whereas markers of dysglycemia and inflammation were largely unaffected. Although more research is needed to make reliable recommendations, a more targeted supplementation of DF with specific physicochemical properties at higher doses and for longer durations shows promise in enhancing several of its health effects.

Gastrointestinal Tolerance and Microbiome Response to Snacks Fortified with Pea Hull Fiber: A Randomized Trial in Older Adults

BACKGROUND

Consuming foods with added fiber may help older adults achieve fiber recommendations; however, many high-fiber ingredients have little effect on laxation and may contribute to unpleasant gastrointestinal side effects.

OBJECTIVES

The aim of the study was to determine the effects of consuming snacks fortified with pea hull fiber (PHF) on stool frequency and form, gastrointestinal symptoms, and appetite in older adults. An exploratory aim was to determine if PHF altered the microbiota profile.

METHODS

A 10-wk, randomized, blinded, crossover study was carried out. Following a 2-wk baseline period, participants [aged (mean ± SD) 69.7 ± 6.5 y; n = 31; 14 men, 17 women] consumed snacks providing 10 g/d of PHF or a control, each for 2-wk periods followed by 2-wk washouts. Participants used the Bristol Stool Form Scale (BSFS) to record daily stool frequency and gastrointestinal symptoms, and completed the Gastrointestinal Symptom Rating Scale (GSRS) and Simplified Nutritional Appetite Questionnaire (SNAQ) biweekly. One stool was collected per period for 16S ribosomal RNA high-throughput amplicon sequencing of the fecal microbiota profile.

RESULTS

Participants reported 1.63 ± 0.05 stools/d and 76.6% normal transit stool form at baseline and no change with PHF. GSRS syndrome scores were similarly unchanged. Daily abdominal noises and bloating were higher for PHF versus control, and flatulence was higher for PHF versus baseline, suggesting fermentation in some individuals. There was no evidence to suggest a common PHF-induced microbiome response for the group as a whole; however, a subgroup of participants (n = 7) who responded with increased flatulence (fermenters), harbored many different taxa than nonfermenters, and demonstrated lower abundance of Clostridiales with PHF. Appetite was unchanged with PHF.

CONCLUSIONS

PHF did not modulate stool form or frequency in older adults with normal bowel habits. Because snacks fortified with PHF did not suppress appetite, PHF may be an appropriate fiber source for older adults at nutritional risk. Microbiome profile may be predictive of gastrointestinal symptom response to PHF. This trial was registered at www.clinicaltrials.gov as NCT02778230.

Nutrient intakes and sources of fiber among children with low and high dietary fiber intake: the 2016 feeding infants and toddlers study (FITS), a cross-sectional survey

BACKGROUND

Increasing dietary fiber intake in children may improve overall diet quality. The purpose of this study was to compare nutrient intakes and sources of fiber between young children with low and high fiber intakes utilizing data from the Feeding Infants and Toddlers Study (FITS) 2016.

METHODS

The FITS 2016 was a nationwide, cross sectional survey of caregivers designed to assess food and nutrient intakes, feeding behaviors, and dietary patterns among infants and young children living in the U.S. Energy adjusted macro and micronutrient intakes (nutrients/1000 kcals) of children with energy adjusted fiber intakes (g/1000 kcals) in the highest quartile were compared to those in the lowest quartile with paired t-tests. Sources of fiber for each quartile were ranked according to percent of total fiber intake.

RESULTS

Children with fiber intakes in the highest quartile had significantly lower intakes of total fat (mean difference ranged from 7.4-9.6 g, p < 0.0005) and saturated fat (mean difference ranged from 4 to 5.8 g, p < 0.0005), and significantly higher intakes of vitamin B-6 (mean difference ranged from 0.3-0.4 mg, p < 0.0005), magnesium (mean difference ranged from 57.2-61.8 mg, p < 0.0005), iron (mean difference ranged from 2.2-3.7 mg, p < 0.0005), and potassium (mean difference ranged from 318.2 mg to 446.1 mg, p < 0.0005) compared to children in the lowest quartile across all age groups. Children in the highest quartile had higher intakes of nut butters, legumes, fruits, and vegetables and consumed a greater percentage of grains as whole grains than those in the lowest quartile.

CONCLUSION

Encouraging intake of fruits, vegetables, legumes, nut butters, and at least 75% of grains as whole grains may help young children improve dietary fiber intake and overall diet quality.

Perspective: Refined Grains and Health: Genuine Risk, or Guilt by Association?

Refined grain intake is widely assumed to be associated with adverse health outcomes, including increased risk for cardiovascular disease (CVD), type 2 diabetes (T2D), and obesity. The 2015 Dietary Guidelines Advisory Committee recommended that to improve dietary quality, the US population should replace most refined grains with whole grains. This recommendation was based largely on results from studies that examined dietary patterns, not separate food groups. A Western dietary pattern typically includes red and processed meat, sugar-sweetened foods and beverages, French fries, and high-fat dairy products, as well as refined grains, and has been linked to increased risk of many chronic diseases. However, when evaluated as a distinct food category, 11 meta-analyses of prospective cohort studies, which included a total of 32 publications with data from 24 distinct cohorts, demonstrated that refined grain intake was not associated with all-cause mortality, T2D, CVD, coronary heart disease (CHD), stroke, hypertension, or cancer. By contrast, consumption of red and processed meat was consistently associated with increased risk of these same health outcomes. Refined grain consumption up to 6-7 servings/d (1 serving = 30 g) was not associated with higher risk of CHD, T2D, hypertension, or all-cause mortality. Moreover, total grain intake was not associated with risk of CVD, CHD, stroke, or cancer, but was associated with lower risk of all-cause mortality. Consequently, the recommendation to reduce refined grain intake based on results from studies linking a Western dietary pattern to numerous adverse health outcomes is contrary to a substantial body of published scientific evidence. Future research needs to better define refined grain intake to distinguish between staple grain foods and indulgent grain foods, and to better design randomized controlled trials to resolve discrepancies between results from observational studies and such trials with regard to determining the benefits of whole grains compared with refined grains.

The effects of psyllium supplementation on body weight, body mass index and waist circumference in adults: A systematic review and dose-response meta-analysis of randomized controlled trials

Background: Previous studies reported inconsistent findings regarding the effects of psyllium supplementation on obesity measures. This systematic review and meta-analysis was performed to summarize data from available randomized clinical trials (RCTs) on the effect of psyllium supplementation on body weight, body mass index (BMI), and waist circumference (WC) in adults.Methods: PubMed, SCOPUS, Cochrane Library, and Google Scholar were searched to identify relevant articles up to August 2018. The effect sizes were presented as weighted mean difference (WMD) and 95% confidence intervals (CI) by using random effects model. To detect dose-response relationships, we used fractional polynomial modeling.Results: A total of 22 RCTs were included. Meta-analysis did not find any significant effect of psyllium supplementation on body weight (MD: -0.28 kg, 95% CI: -0.78, 0.21, p = 0.268), BMI (MD: -0.19 kg/m², 95% CI: -0.55, 0.15, p = 0.27) and WC (MD: -1.2 cm, 95% CI: -2.6, 0.2, p = 0.09). Subgroup analysis showed that psyllium dosage, kind of psyllium administration, duration of trial, study design, sample size, and gender were potential sources of heterogeneity. Moreover, there was nonlinear association between duration of psyllium consumption, BMI and WC.Conclusion: Psyllium supplementation does not reduce body weight, BMI, and WC significantly.

An empirical investigation of the impact of smoking on body weight using an endogenous treatment effects model approach: the role of food consumption patterns

BACKGROUND

This study explored the influence of cigarette smoking and food consumption patterns on BMI after adjusting for various socio-demographic characteristics. Since weight-based stereotypes may have an impact on smoking behaviour and both obesity and smoking have been associated with detrimental health effects, an interdependency between them is quite possible.

METHODS

Cross-sectional data were collected via a formal standardized questionnaire administered in personal interviews and two additional self-completion questionnaires from a random sample of 3471 German adults. The empirical framework considered potential endogeneity between smoking and body weight by employing an endogenous treatment effects model with an ordered outcome. The estimations derived from the endogenous treatment effects approach were also compared to the univariate ordered probit model results.

RESULTS

Our findings showed that ignoring potential endogeneity may affect both the statistical significance of the smoking estimate and the direction of the influence of smoking on BMI. Smoking was positively associated with BMI in both male (β = 1.236, p < 0.01) and female (β = 0.634, p < 0.10) participants. Smokers presented a 23.1% higher risk of obesity and a 24.3% lower likelihood of being within a healthy weight range. Male smokers also appeared to have a considerably augmented probability of being obese compared to their female counterparts (23.6% vs 15.1%). The relationship between smoking and BMI may be attributed to dietary practices, since smoking was correlated with poor dietary habits characterized by the frequent intake of more energy-dense foods (meat products and white-toasted bread) and less frequent consumption of healthy food items, such as whole-grain bread, vegetables and fruits. Concerning the impact of eating habits on body weight, frequent consumption of meat products and confectionery was found to have a direct association with BMI in both genders. Furthermore, white-toasted bread consumption was negatively linked with body weight in males (β = - 0.337, p < 0.01).

CONCLUSIONS

Our findings raised questions about the general belief that smoking is an effective weight control tool. Health interventions should be oriented toward a simultaneous decrease in smoking and obesity, since both behaviours seem to be interdependent. Nutrition programmes should also be designed according to the characteristics of different target groups in order to promote a healthy lifestyle.

Beneficial Effect of Intestinal Fermentation of Natural Polysaccharides

With the rapid development of modern society, many chronic diseases are increasing including diabetes, obesity, cardiovascular diseases, etc., which further cause an increased death rate worldwide. A high caloric diet with reduced natural polysaccharides, typically indigestible polysaccharides, is considered a health risk factor. With solid evidence accumulating that indigestible polysaccharides can effectively prevent and/or ameliorate symptoms of many chronic diseases, we give a narrative review of many natural polysaccharides extracted from various food resources which mainly contribute their health beneficial functions via intestinal fermentation.

Replacement of glycaemic carbohydrates by inulin-type fructans from chicory (oligofructose, inulin) reduces the postprandial blood glucose and insulin response to foods: report of two double-blind, randomized, controlled trials

PURPOSE

Inulin-type fructans are recognized as prebiotic dietary fibres and classified as non-digestible carbohydrates that do not contribute to glycaemia. The aim of the present studies was to investigate the glycaemic response (GR) and insulinaemic response (IR) to foods in which sucrose was partially replaced by inulin or oligofructose from chicory.

METHODS

In a double-blind, randomized, controlled cross-over design, 40-42 healthy adults consumed a yogurt drink containing oligofructose or fruit jelly containing inulin and the respective full-sugar variants. Capillary blood glucose and insulin were measured in fasted participants and at 15, 30, 45, 60, 90, and 120 min after starting to drink/eat. For each test food, the incremental area under the curve (iAUC) for glucose and insulin was calculated and the GR and IR determined.

RESULTS

Consumption of a yogurt drink with oligofructose which was 20% reduced in sugars significantly lowered the glycaemic response compared to the full-sugar reference (iAUC120min 31.9 and 37.3 mmol/L/min, respectively; p < 0.05). A fruit jelly made with inulin and containing 30% less sugars than the full-sugar variant likewise resulted in a significantly reduced blood glucose response (iAUC120min 53.7 and 63.7 mmol/L/min, respectively; p < 0.05). In both studies, the postprandial insulin response was lowered in parallel (p < 0.05). The reduction of postprandial glycaemia was positively correlated to the proportion of sugars replaced by inulin-type fructans (p < 0.001).

CONCLUSIONS

In conclusion, the studies confirmed that substitution of glycaemic sugars by inulin or oligofructose from chicory may be an effective strategy to reduce the postprandial blood glucose response to foods.

Package Information Used by Older Adults to Identify Whole Grain Foods

A structured interview protocol was used to investigate the ability of older adults (n = 89, age ≥ 65 years) to accurately determine whether three common food items were whole grain, and to assess the package information used in their decision process. Cereal and crackers, which were both whole grain products, were correctly identified by 63% and 66% of participants, respectively. Bread (a refined product), was correctly identified by only 19% of participants, while 46% of participants misidentified the bread as being whole grain. The ingredient list was the information most frequently cited in deciding if a food was whole grain, but participants varied in their ability to accurately interpret it. Package information considered nonpertinent (e.g., the Nutrition Facts label) in identifying a whole grain product was used almost as often as the ingredient list. Older adults would benefit from whole grain education programs that focus on accurately interpreting package information.

Whole Grains Contribute Only a Small Proportion of Dietary Fiber to the U.S. Diet

Dietary fiber (DF), found in whole fruits, vegetables, and whole grains (WG), is considered a nutrient of concern in the US diet and increased consumption is recommended. The present study was designed to highlight this critical importance of the difference between WG, high-fiber WG, and sources of fiber that are not from WG. The study is based on the two-day diets reported consumed by the nationally representative sample of Americans participating in What We Eat In America, the dietary component of the National Health and Nutrition Examination Survey from 2003–2010. Foods consumed were classified into tertiles of DF and WG and the contribution of fiber by differing levels of WG content were examined. Foods containing high amounts of WG and DF only contributed about 7% of total fiber intake. Overall, grain-based foods contributed 54.5% of all DF consumed. Approximately 39% of DF came from grain foods that contained no WG, rather these foods contained refined grains, which contain only small amounts of DF but are consumed in large quantities. All WG-containing foods combined contributed a total of 15.3% of DF in the American diet. Thus, public health messaging needs to be changed to specifically encourage consumption of WG foods with high levels of DF to address both recommendations.

Effect on Insulin, Glucose and Lipids in Overweight/Obese Australian Adults of 12 Months Consumption of Two Different Fibre Supplements in a Randomised Trial

Higher fibre intakes are associated with risk reduction for chronic diseases. This study investigated the effects of supplementation with PolyGlycopleX^® (PGX), a complexed polysaccharide, on insulin, glucose and lipids in overweight and obese individuals. In this double-blind 12 months study, participants were randomised into three groups: control (rice flour); PGX or psyllium (PSY). Participants followed their usual lifestyle and diet but consumed 5 g of their supplement before meals. Insulin was significantly lower in the PGX and PSY groups compared to control at 3 and 6 months and in the PSY group compared to control at 12 months. Serum glucose was significantly lower in the PGX group at 3 months compared to control. Total cholesterol was significantly lower in the PGX and PSY groups compared to control at 3 and 6 months. High density lipoprotein (HDL) cholesterol was significantly increased in the PGX group compared to control at 12 months. low density lipoprotein (LDL) cholesterol was significantly lower in the PGX group at 3 and 6 months compared to control and in the PSY group at 3 months compared to control. A simple strategy of fibre supplementation may offer an effective solution to glucose, insulin and lipid management without the need for other nutrient modification.

Health Benefits of Fiber Fermentation

Although fiber is well recognized for its effect on laxation, increasing evidence supports the role of fiber in the prevention and treatment of chronic disease. The aim of this review is to provide an overview of the health benefits of fiber and its fermentation, and describe how the products of fermentation may influence disease risk and treatment. Higher fiber intakes are associated with decreased risk of cardiovascular disease, type 2 diabetes, and some forms of cancer. Fiber may also have a role in lowering blood pressure and in preventing obesity by limiting weight gain. Fiber is effective in managing blood glucose in type 2 diabetes, useful for weight loss, and may provide therapeutic adjunctive roles in kidney and liver disease. In addition, higher fiber diets are not contraindicated in inflammatory bowel disease or irritable bowel syndrome and may provide some benefit. Common to the associations with disease reduction is fermentation of fiber and its potential to modulate microbiota and its activities and inflammation, specifically the production of anti-inflammatory short chain fatty acids, primarily from saccharolytic fermentation, versus the deleterious products of proteolytic activity. Because fiber intake is inversely associated with all-cause mortality, mechanisms by which fiber may reduce chronic disease risk and provide therapeutic benefit to those with chronic disease need further elucidation and large, randomized controlled trials are needed to confirm causality.Teaching Points• Strong evidence supports the association between higher fiber diets and reduced risk of cardiovascular disease, type 2 diabetes, and some forms of cancer.• Higher fiber intakes are associated with lower body weight and body mass index, and some types of fiber may facilitate weight loss.• Fiber is recommended as an adjunctive medical nutritional therapy for type 2 diabetes, chronic kidney disease, and certain liver diseases.• Fermentation and the resulting shifts in microbiota composition and its activity may be a common means by which fiber impacts disease risk and management.

Banana Blossom (Musa acuminate Colla) Incorporated Experimental Diets Modulate Serum Cholesterol and Serum Glucose Level in Wistar Rats Fed with Cholesterol

Hypocholesterolaemic and hypoglycaemic effect of banana blossom were studied in high-cholesterol fed rats. Experimental groups were fed for 4 weeks, with casein as the basal diet (CN), in comparison with two diets containing 0.5% cholesterol (CD) and 0.5% cholesterol + 21% banana blossom powder (CDB). Serum total cholesterol, non-HDL-cholesterol level, and serum glucose concentrations were lower in CDB fed group compared with CD fed group. Lower serum cholesterol and glucose level (P < 0.05) in CDB fed group were followed by higher faecal weight, caecal weight, caecal Lactobacilli, and Bifidobacteria population in CDB fed group compared to CD diet fed group. Lower serum AST level in banana blossom fed rats showed the reduction in oxidative stress induced by high cholesterol diet. Based on these data, it could be speculated that banana blossom incorporated experimental diets may modulate the hypocholesterolaemic and hypoglycaemic responses in Wistar rats.

Closing America's Fiber Intake Gap: Communication Strategies From a Food and Fiber Summit

Adequate intake of dietary fiber is associated with digestive health and reduced risk for heart disease, stroke, hypertension, certain gastrointestinal disorders, obesity, type 2 diabetes, and certain cancers. According to consumer research, the public is aware of the benefits of fiber and most people believe they consume enough fiber. However, national consumption surveys indicate that only about 5% of the population meets recommendations, and inadequate intakes have been called a public health concern. To address the fiber consumption gap and formulate potential solutions, researchers, educators, and communicators convened at a Food & Fiber Summit on January 28, 2014, in Washington, DC. Panelists and attendees devised communication strategies to correct consumer misperceptions about fiber. These misperceptions include commonly held beliefs that all whole-grain foods are good sources of fiber and that foods with fiber are expensive, unpalatable, and complicated to prepare. To help close the fiber intake gap, nutrition and health educators can use communication strategies such as providing clear and concise information, recommending flavorful fiber-rich foods, and describing the benefits of adequate fiber intake. Several supporting messages were developed to effectively communicate about fiber. An example is to advise people to consistently check nutrition labels to find good sources of fiber.

Effect on body weight and composition in overweight/obese Australian adults over 12 months consumption of two different types of fibre supplementation in a randomized trial

BACKGROUND/OBJECTIVES

Higher fibre intakes are associated with risk reduction for chronic diseases. However, many people find difficulty in consuming sufficient fibre through their diet. Supplements may be an effective alternative. We aimed to investigate the effects of PolyGlycopleX® (PGX®), a proprietary polysaccharide complex and a proprietary Psyllium product (PgxSyl™) (PSY) on diet, body weight and composition in overweight and obese individuals.

SUBJECTS/METHODS

This was a double-blind 52 weeks study with 159 people randomized to 3 groups: control (rice flour); PGX (PGX) and proprietary psyllium (PSY). Participants did not change any of their usual habits or diet except they consumed 5 g of supplement taken with a total of 500 ml of water 5-10 min before meals.

RESULTS

Weight was significantly lower in the PGX group compared to control at 3 (-1.6 kg [0.57, 2.67, p = 0.003]), 6 (-2.6 kg [1.01, 4.13, p = 0.001]) and 12 months (-2.6 kg [0.59, 4.64, p = 0.012]) and in the PSY group compared to control group at 3 (-1.1 kg [0.07, 2.12, p = 0.037]) and 6 months (-2.4 kg [0.95, 3.93, p = 0.002]). This was a difference of - 2.8% for the PGX group and - 1.5% for the PSY group compared to control after 12 months supplementation. Body Fat was significantly lower in PGX compared to control at 6 (-1.8 kg [0.63, 2.95, p = 0.003]) and 12 months (-1.9 kg [0.43, 3.36, p = 0.012]) and in PSY compared to control at 6 (-1.9 kg [0.84, 3.04, p = 0.001]) and 12 months (-1.4 kg [0.08, 2.71, p = 0.038]).

CONCLUSIONS

PGX was better than PSY at maintaining dietary changes and weight loss over the 12 month intervention period, with no change to exercise. A simple strategy of PGX supplementation may offer an effective solution to long-term weight-loss and then management without the need for other nutrient modification.

TRIAL REGISTRATION

ANZCTR: ACTRN12611000415909. Registered 20 April 2011.

Resistant Starch Bagels Reduce Fasting and Postprandial Insulin in Adults at Risk of Type 2 Diabetes

BACKGROUND

Type 2 diabetes (T2D) incidence continues to rise. Although increasing dietary fiber intake is an established strategy for improved glycemic control, most adults consume insufficient amounts. Fiber-enhanced functional foods can increase fiber intake, and there is particular interest in resistant starch (RS) as a high-fiber ingredient. Studies show that high-amylose maize resistant starch, type 2 (HAM-RS2) improves acute and chronic glycemic responses, but more studies are needed in individuals at high risk of T2D with RS delivered in commonly consumed foods.

OBJECTIVE

The objective of this study was to examine the chronic effects of consuming bagels high in HAM-RS2 on fasting and postprandial glycemic markers in adults at increased risk of T2D.

METHODS

With the use of a randomized, double-blind crossover design, 24 men and women with a mean ± SE age of 55.3 ± 1.59 y and body mass index (in kg/m²) of 30.2 ± 0.57 consumed 1 bagel containing 25 g HAM-RS2/d or 1 control wheat bagel/d for 56 d each, separated by a 4-wk washout. Fasting and postprandial oral-glucose-tolerance test (OGTT) glucose and insulin were measured on study days 1 and 57 of each bagel treatment.

RESULTS

The RS bagel treatment resulted in significantly lower fasting (22.1%, P = 0.04), 2-h (23.3%, P < 0.008), and 3-h (18.9%, P = 0.05) insulin incremental areas under the curve and fasting insulin resistance (homeostasis model assessment of insulin resistance; 23.1%, P = 0.04) than did the control bagel treatment. Fasting and postprandial OGTT glucose concentrations did not differ between the RS and control bagel treatments on study days 1 or 57.

CONCLUSIONS

These data suggest that consumption of a high-HAM-RS2 bagel improves glycemic efficiency by reducing the amount of insulin required to manage postprandial glucose while improving fasting insulin sensitivity in adults at increased risk of T2D. This research provides support for a feasible dietary strategy for T2D risk reduction. This trial was registered at clinicaltrials.gov as NCT02129946.