Dietary fibre: a roughage guide

Diet-Induced Gut Dysbiosis and Leaky Gut Syndrome

Chronic gut inflammation promotes the development of metabolic diseases such as obesity. There is growing evidence which suggests that dysbiosis in gut microbiota and metabolites disrupt the integrity of the intestinal barrier and significantly impact the level of inflammation in various tissues, including the liver and adipose tissues. Moreover, dietary sources are connected to the development of leaky gut syndrome through their interaction with the gut microbiota. This review examines the effects of these factors on intestinal microorganisms and the communication pathways between the gut-liver and gut-brain axis. The consumption of diets rich in fats and carbohydrates has been found to weaken the adherence of tight junction proteins in the gastrointestinal tract. Consequently, this allows endotoxins, such as lipopolysaccharides produced by detrimental bacteria, to permeate through portal veins, leading to metabolic endotoxemia and alterations in the gut microbiome composition with reduced production of metabolites, such as short-chain fatty acids. However, the precise correlation between gut microbiota and alternative sweeteners remains uncertain, necessitating further investigation. This study highlights the significance of exploring the impact of diet on gut microbiota and the underlying mechanisms in the gut-liver and gut-brain axis. Nevertheless, limited research on the gut-liver axis poses challenges in comprehending the intricate connections between diet and the gut-brain axis. This underscores the need for comprehensive studies to elucidate the intricate gut-brain mechanisms underlying intestinal health and microbiota.

Microbiome and pregnancy: focus on microbial dysbiosis coupled with maternal obesity

Obesity is becoming a worldwide pandemic with over one billion people affected. Of women in the United States, who are of childbearing age, two-thirds of them are considered overweight/obese. Offspring of women with obesity have a greater likelihood of developing cardiometabolic disease later in life, therefore making obesity a transgenerational issue. Emerging topics such as maternal microbial dysbiosis with altered levels of bacterial phyla and maternal obesity programming offspring cardiometabolic disease are a novel area of research discussed in this review. In the authors' opinion, beneficial therapeutics will be developed from knowledge of bacterial-host interactions at the most specific level possible. Although there is an abundance of obesity-related microbiome research, it is not concise, readily available, nor easy to interpret at this time. This review details the current knowledge regarding the relationship between obesity and the gut microbiome, with an emphasis on maternal obesity.

Short-chain fatty acids and insulin sensitivity: a systematic review and meta-analysis

CONTEXT

There is substantial evidence that reduced short-chain fatty acids (SCFAs) in the gut are associated with obesity and type 2 diabetes, although findings from clinical interventions that can increase SCFAs are inconsistent.

OBJECTIVE

This systematic review and meta-analysis aimed to assess the effect of SCFA interventions on fasting glucose, fasting insulin, and homeostatic model assessment of insulin resistance (HOMA-IR).

DATA SOURCES

Relevant articles published up to July 28, 2022, were extracted from PubMed and Embase using the MeSH (Medical Subject Headings) terms of the defined keywords [(short-chain fatty acids) AND (obesity OR diabetes OR insulin sensitivity)] and their synonyms. Data analyses were performed independently by two researchers who used the Cochrane meta-analysis checklist and the PRISMA guidelines.

DATA EXTRACTION

Clinical studies and trials that measured SCFAs and reported glucose homeostasis parameters were included in the analysis. Standardized mean differences (SMDs) with 95%CIs were calculated using a random-effects model in the data extraction tool Review Manager version 5.4 (RevMan 5.4). The risk-of-bias assessment was performed following the Cochrane checklist for randomized and crossover studies.

DATA ANALYSIS

In total, 6040 nonduplicate studies were identified, 23 of which met the defined criteria, reported fasting insulin, fasting glucose, or HOMA-IR values, and reported change in SCFA concentrations post intervention. Meta-analyses of these studies indicated that fasting insulin concentrations were significantly reduced (overall effect: SMD = -0.15; 95%CI = -0.29 to -0.01, P = 0.04) in treatment groups, relative to placebo groups, at the end of the intervention. Studies with a confirmed increase in SCFAs at the end of intervention also had a significant effect on lowering fasting insulin (P = 0.008). Elevated levels of SCFAs, compared with baseline levels, were associated with beneficial effects on HOMA-IR (P < 0.00001). There was no significant change in fasting glucose concentrations.

CONCLUSION

Increased postintervention levels of SCFAs are associated with lower fasting insulin concentrations, offering a beneficial effect on insulin sensitivity.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42021257248.

Dietary outcomes of community-based CVD preventive interventions: a systematic review and meta-analysis

OBJECTIVE

We aimed to synthesise available evidence on the effects of community-based interventions in improving various dietary outcome measures.

DESIGN

Systematic review and meta-analysis.

SETTING

We searched databases including Medline, EMBASE, PSYCINFO, CINAHL and the Cochrane registry for studies reported between January 2000 and June 2022. The methodological quality of the included studies was evaluated using the Cochrane risk of bias tools for each study type. For some of the outcomes, we pooled the effect size using a random-effects meta-analysis.

PARTICIPANTS

A total of fifty-one studies, thirty-three randomised and eighteen non-randomised, involving 100 746 participants were included.

RESULTS

Overall, thirty-seven studies found a statistically significant difference in at least one dietary outcome measure favouring the intervention group, whereas fourteen studies found no statistically significant difference. Our meta-analyses indicated that, compared with controls, interventions were effective in decreasing daily energy intake (MJ/d) (mean difference (MD): -0·25; 95 % CI: -0·37, -0·14), fat % of energy (MD: -1·01; 95 % CI: -1·76, -0·25) and saturated fat % of energy (MD: -1·54; 95 % CI: -2·01, -1·07). Furthermore, the interventions were effective in improving fibre intake (g/d) (MD: 1·08; 95 % CI: 0·39, 1·77). Effective interventions use various strategies including tailored individual lifestyle coaching, health education, health promotion activities, community engagement activities and/or structural changes.

CONCLUSION

This review shows the potential of improving dietary patterns through community-based CVD preventive interventions. Thus, development and implementation of context-specific preventive interventions could help to minimise dietary risk factors, which in turn decrease morbidity and mortality due to CVD and other non-communicable diseases.

Associations of Dietary Intake with the Intestinal Microbiota and Short-Chain Fatty Acids Among Young Adults with Type 1 Diabetes and Overweight or Obesity

BACKGROUND

Diet, a key component of type 1 diabetes (T1D) management, modulates the intestinal microbiota and its metabolically active byproducts-including SCFA-through fermentation of dietary carbohydrates such as fiber. However, the diet-microbiome relationship remains largely unexplored in longstanding T1D.

OBJECTIVES

We evaluated whether increased carbohydrate intake, including fiber, is associated with increased SCFA-producing gut microbes, SCFA, and intestinal microbial diversity among young adults with longstanding T1D and overweight or obesity.

METHODS

Young adult men and women with T1D for ≥1 y, aged 19-30 y, and BMI of 27.0-39.9 kg/m² at baseline provided stool samples at baseline and 3, 6, and 9 mo of a randomized dietary weight loss trial. Diet was assessed by 1-2 24-h recalls. The abundance of SCFA-producing microbes was measured using 16S rRNA gene sequencing. GC-MS measured fecal SCFA (acetate, butyrate, propionate, and total) concentrations. Adjusted and Bonferroni-corrected generalized estimating equations modeled associations of dietary fiber (total, soluble, and pectins) and carbohydrate (available carbohydrate, and fructose) with microbiome-related outcomes. Primary analyses were restricted to data collected before COVID-19 interruptions.

RESULTS

Fiber (total and soluble) and carbohydrates (available and fructose) were positively associated with total SCFA and acetate concentrations (n = 40 participants, 52 visits). Each 10 g/d of total and soluble fiber intake was associated with an additional 8.8 μmol/g (95% CI: 4.5, 12.8 μmol/g; P = 0.006) and 24.0 μmol/g (95% CI: 12.9, 35.1 μmol/g; P = 0.003) of fecal acetate, respectively. Available carbohydrate intake was positively associated with SCFA producers Roseburia and Ruminococcus gnavus. All diet variables except pectin were inversely associated with normalized abundance of Bacteroides and Alistipes. Fructose was inversely associated with Akkermansia abundance.

CONCLUSIONS

In young adults with longstanding T1D, fiber and carbohydrate intake were associated positively with fecal SCFA but had variable associations with SCFA-producing gut microbes. Controlled feeding studies should determine whether gut microbes and SCFA can be directly manipulated in T1D.

The role of dietary fibers in regulating appetite, an overview of mechanisms and weight consequences

Dietary fibers prevent obesity through reduction of hunger and prolongation of satiety. A number of mechanical and endocrine signals from gastrointestinal tract are stimulated by fibers and their fermentation products, reach regions of brain involved in the regulation of appetite, and ultimately reduce food intake. Gastric distention, delayed gastric emptying, prevention of hypoglycemic, increased amounts of unabsorbed nutrients reaching to the ileum, and stimulation of enteroendocrine cells for secretion of cholecystokinin, glucagon-like peptide-1 (GLP-1), and peptide YY are among mechanisms of fibers in decreasing hunger and prolongation of satiety. Fermentation of fibers produces short-chain fatty acids that also stimulates enteroendocrine cells to secrete GLP-1 and PYY. Randomized controlled trials have shown reductions in energy intake and body weight along with increased satiation and reduced hunger following consumption of fibers. Prospective cohort studies have confirmed these results but the extent of weight loss in some studies has been small. Controversies exist between studies particularly for the effect of fibers on the gastrointestinal hormones, subsequent food intake, and the resultant weight loss. More studies are needed before a clear conclusion can be drawn especially for the effect of fibers on appetite-related hormones and weight loss.

Investigation of Content Parameters in Wet-Fractionated Fibre from Various Plants for Potential Use in Human Nutrition

Green biorefining uses fresh lignocellulosic biomass to produce green juice and pressed fibre fractions by wet fractionation. The latter is a byproduct, accounting for 25-32% of the starting material. In this study, the composition (glucan, xylan, arabinan, lignin, total phenol, flavonoid and protein) of pressed fibres obtained from four alfalfa, four soy and one broccoli varieties were determined at different harvest times. Statistical analyses were performed to determine the effects of harvest time and variety on the measured parameters. In most of the cases, there were interactions between the effects of harvest time and variety. Among alfalfa varieties, OLI1 had the highest carbohydrate (52.09 w/w%) and DIM3 had the lowest lignin (13.02 w/w%) content. In the case of soy, the ADV2 variety had the highest carbohydrate (53.47 w/w%) and PK1 had the lowest lignin (11.14 w/w%) content. Broccoli contained low amounts of carbohydrates (44.94 w/w%) and lignin (10.16 w/w%). The phenolic and flavonoid contents were similar for each species, but the protein content was the highest in alfalfa fibre. Based on these data, the most promising species, varieties and harvesting time can be selected in terms of a certain component that could be essential to produce functional foods with enhanced nutritional value.

Short-term intestinal effects of water intake in fibre supplementation in healthy, low-habitual fibre consumers: a phase 2 clinical trial

A randomised clinical trial was conducted on 20 healthy, low-habitual fibre consumers to assess the short-term effects of water intake (2 l/day) on fibre supplementation with wheat bran, pectin, and green banana flour. During the 14-days trial, fibre intake doubled in both fibre (n = 10) and fibre/water (n = 10) interventions (p < 0.001), whereas daily water intake increased from 538 to 1990 ml in the fibre/water group (p < 0.001). Weekly bowel movements increased similarly in both interventions (fibre: 6.8-8.8; fibre/water: 8.6-10; p < 0.01), while faecal weight (71-126 g; p = 0.009) increased in the fibre/water group. This group showed higher counts of faecal Bacteroides and Prevotella, Faecalibacterium prausnitzii, and Bifidobacterium, whereas both interventions decreased the count of Desulfovibrio. Transient abdominal symptoms occurred less frequently in the fibre/water than in the fibre group (3 vs. 9 participants; p = 0.020). In healthy, low-habitual fibre consumers, short-term water intake helps the intestinal adaptation to fibre supplementation.CLINICAL TRIAL REGISTRATION NUMBER: NCT02838849.

Lack of association between nuts and legumes consumption and metabolic syndrome in young Iranian nurses

BACKGROUND

Most studies have investigated the association between dietary pattern and risk of metabolic syndrome. Limited studies have examined the association between nuts and legumes as a food group and metabolic syndrome. This study explored the association between nuts and legumes and components of metabolic syndrome in Iranian nurses.

METHODS

This cross-sectional study included a representative sample of 420 female nurses of Isfahan who were randomly selected. Nuts and legumes consumption was assessed using a validated dish-based semi quantitative food frequency questionnaire (FFQ). Metabolic syndrome was defined by the National Cholesterol Education Program's Adult Treatment Panel III (ATP III). Linear and logistic regression tests were used to study the association between nuts and legumes consumption and metabolic syndrome and its components.

RESULTS

Mean age of study participants was 35 years. The prevalence of the metabolic syndrome among study participants was 3.6%. Consumption of nuts and legumes was not associated with waist circumference either before (β = -0.01, P = 0.24) or after adjusting for potential confounders (β = -0.18, P = 0.41). The same findings were also observed for diastolic blood pressure (DBP) (β = 0.001, P = 0.42), serum triglyceride (TG) (β = 0.07, P = 0.32), high-density lipoprotein cholesterol (HDL-C) (β = 0.008, P = 0.65) and fasting blood sugar (FBS) (β = -0.001, P = 0.94). We failed to find a significant association between consumption of nuts and legumes and systolic blood pressure (SBP) after adjusting for confounders (β = 0.002, P = 0.38). Individuals in the highest category of nuts and legume consumption did not had elevated odds for metabolic syndrome after adjusting for potential confounders (OR = 0.89, 95% CI = 0.08-9.80, P = 0.93).

CONCLUSIONS

Nuts and legumes consumption was not associated with metabolic syndrome or its components. Prospective studies are needed to investigate further this association.

Nutritional Considerations When Dealing with an Obese Adult Equine

Equine obesity is common, reducing quality of life and requiring dietary energy restriction. Equine obesity is identified using subjective body condition scoring. Considerations are given for life stage and health status when managing obese equines. Every effort should be made to maximize feeding duration, and minimize time spent without feed while meeting all essential nutrient requirements. Limiting total daily dry matter intake to 2% of current bodyweight per day of a low caloric, forage-based diet may result in adequate body weight loss. Weight loss and weight management plans should be monitored for success and potential gastrointestinal, metabolic, and/or behavioral complications.

Dietary Fiber Drives IL-1β-Dependent Peritonitis Induced by Bacteroides fragilis via Activation of the NLRP3 Inflammasome

Intestinal barrier is essential for dietary products and microbiota compartmentalization and therefore gut homeostasis. When this barrier is broken, cecal content overflows into the peritoneal cavity, leading to local and systemic robust inflammatory response, characterizing peritonitis and sepsis. It has been shown that IL-1β contributes with inflammatory storm during peritonitis and sepsis and its inhibition has beneficial effects to the host. Therefore, we investigated the mechanisms underlying IL-1β secretion using a widely adopted murine model of experimental peritonitis. The combined injection of sterile cecal content (SCC) and the gut commensal bacteria Bacteroides fragilis leads to IL-1β-dependent peritonitis, which was mitigated in mice deficient in NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) inflammasome components. Typically acting as a damage signal, SCC, but not B. fragilis, activates canonical pathway of NLRP3 promoting IL-1β secretion in vitro and in vivo. Strikingly, absence of fiber in the SCC drastically reduces IL-1β production, whereas high-fiber SCC conversely increases this response in an NLRP3-dependent manner. In addition, NLRP3 was also required for IL-1β production induced by purified dietary fiber in primed macrophages. Extending to the in vivo context, IL-1β-dependent peritonitis was worsened in mice injected with B. fragilis and high-fiber SCC, whereas zero-fiber SCC ameliorates the pathology. Corroborating with the proinflammatory role of dietary fiber, IL-1R-deficient mice were protected from peritonitis induced by B. fragilis and particulate bran. Overall, our study highlights a function, previously unknown, for dietary fibers in fueling peritonitis through NLRP3 activation and IL-1β secretion outside the gut.

In vitro fermentation of flaxseed polysaccharide by fecal bacteria inhibits energy intake and adipogenesis at physiological concentration

Obesity and its related metabolic disorders have been a global pandemic. Recently, we found an anti-obesity effect of flaxseed polysaccharide (FP) that could be achieved by regulating intestinal microbiota. The anti-obesity effect of FP is mainly attributed to the metabolites produced by the interaction with FP, which remains to be elucidated. In this research, the in vitro effects of metabolites of FP fermented by fecal bacteria on energy metabolism and adipogenesis were investigated. The effect of energy metabolism was analyzed by mRNA and protein expression of the intestinal glucose transporters, including sodium dependent glucose transporter (SGLT1) and glucose transporter 2 (GLUT2), and glucose uptake in intestinal Caco-2 cells. The lipogenic effect were evaluated by Oil red O staining of intracellular lipid droplets and the mRNA and protein expression of peroxisome proliferator-activated receptor (PPAR) γ, CCAAT-enhancer-binding proteins (C/EBP) α and β in 3T3-L1 cells. The results showed the metabolites significantly inhibited glucose intake through downregulating the mRNA and protein expression of GLUT2 and SGLT1 in Caco-2 cells. Besides, they also led to the decrease of lipid accumulation through downregulating the mRNA and protein expression of PPARγ, C/EBPα, and C/EBPβ in differentiating adipocytes. The inhibitory effects on energy intake and adipogenesis were concentration dependent, and metabolites at physiological concentration showed the most significant effect. Metabolites of fecal bacteria fermenting FP inhibited energy intake and adipogenesis at physiological concentration, which might be one of the weight-loss mechanisms of FP-diet.

Internalization-Dependent Free Fatty Acid Receptor 2 Signaling Is Essential for Propionate-Induced Anorectic Gut Hormone Release

The ability of propionate, a short-chain fatty acid produced from the fermentation of non-digestible carbohydrates in the colon, to stimulate the release of anorectic gut hormones, such as glucagon like peptide-1 (GLP-1), is an attractive approach to enhance appetite regulation, weight management, and glycemic control. Propionate induces GLP-1 release via its G protein-coupled receptor (GPCR), free fatty acid receptor 2 (FFA2), a GPCR that activates Gαi and Gαq/11. However, how pleiotropic GPCR signaling mechanisms in the gut regulates appetite is poorly understood. Here, we identify propionate-mediated G protein signaling is spatially directed within the cell whereby FFA2 is targeted to very early endosomes. Furthermore, propionate activates a Gαi/p38 signaling pathway, which requires receptor internalization and is essential for propionate-induced GLP-1 release in enteroendocrine cells and colonic crypts. Our study reveals that intestinal metabolites engage membrane trafficking pathways and that receptor internalization could orchestrate complex GPCR pathways within the gut.

Amorphous cellulose feed supplement alters the broiler caecal microbiome

The grains that form the basis of most commercial chicken diets are rich in cellulose, an unbranched β-1,4-linked D-glucopyranose polymer, used as a structural molecule in plants. Although it is a predominant polysaccharide in cereal hulls, it is considered an inert non-fermentable fiber. The aim of the current study was to analyze the effect of in-feed supplementation of cellulose on the gut microbiota composition of broilers. Administration of cellulose to chickens, on top of a wheat-based diet, changed the caecal microbiota composition, as determined using pyrosequencing of the 16S rRNA gene. At day 26, a significantly (P < 0.01) higher relative abundance of the Alistipes genus was observed in the caeca of broilers fed the cellulose-supplemented diet, compared to animals fed the control diet. An in vitro batch fermentation assay showed a significant (P < 0.01) growth stimulation of Alistipes finegoldii in the presence of cellulose. In conclusion, in-feed supplementation of cellulose alters the microbiota composition at the level of the phylum Bacteroidetes, specifically the Alistipes genus. This suggests that cellulose is not essentially inert but can alter the gut micro-environment.

Associations of dietary macronutrient and fibre intake with glycaemia in individuals with Type 1 diabetes

AIMS

To study the association between dietary intake and glycaemia in Type 1 diabetes.

METHODS

Data on energy and nutrient intakes, and the mean and coefficient of variation of self-monitored blood glucose measurements were obtained from records completed by 1000 adults with Type 1 diabetes. Associations between these measures of glycaemia and dietary intake were investigated using generalized linear regression, with and without macronutrient substitution.

RESULTS

In the first set of analyses, fibre intake was associated with lower mean self-monitored blood glucose values (β = -0.428, 95% CI -0.624 to -0.231; P<0.001). In these same analyses, carbohydrate (β = 0.011, 95% CI 0.002 to 0.020; P=0.014), alcohol (β = 0.013, 95% CI 0.003 to 0.023; P=0.009) and monounsaturated fatty acid intakes (β=0.012, 95% CI 0.001 to 0.023; P=0.029) were associated with higher variability in blood glucose measurements. In the macronutrient substitution analyses, substituting proteins for either carbohydrates (β = -0.026, 95% CI -0.040 to -0.013; P<0.001), fats (β = -0.018, 95% CI -0.033 to -0.004; P=0.014), or alcohol (β = -0.026, 95% CI -0.045 to -0.006; P=0.010), or fats for carbohydrates (β=-0.009, 95% CI -0.017 to -0.001; P=0.030), were all associated with lower variability in the measured blood glucose values. After adjusting for fibre intake, no significant results were observed in analyses of mean self-monitored blood glucose.

CONCLUSIONS

This observational, cross-sectional study indicates that dietary fibre is associated with lower mean blood glucose concentrations in people with Type 1 diabetes. Glycaemic excursions were reduced when protein was substituted for other macronutrients and when fat replaced carbohydrate, after adjusting for fibre intake.

Connection between gut microbiome and the development of obesity

The potential role of the gut microbiota in various human diseases has attracted considerable attention worldwide. Here, we discuss the vital role of the intestinal microbiota in the development of obesity. First, we describe how the gut microbiota promotes fat accumulation. Additionally, a high-fat diet leads to structural instability among in the gut microbiota, further leading to an increase in endotoxins, which aggravates obesity. We then discuss how gut microbiota metabolites, including short-chain fatty acids and lipopolysaccharides, affect the host. Finally, we review several strategies for regulating the intestinal flora.

Nutritional, antioxidant, glycaemic index and Antihyperglycaemic properties of improved traditional plantain-based (Musa AAB) dough meal enriched with tigernut (Cyperus esculentus) and defatted soybean (Glycine max) flour for diabetic patients

The study aimed at determining nutritional, antioxidant and blood glucose lowering potentials of improved plantain-based dough meals enriched with defatted soybean and tigernut flour. The constituted dough meals [PSB (plantain 64.46, defatted soybean 35.54%), TNS (tigernut 59.83, defatted soybean 40.17%); PTS (plantain 51.07, tigernut, 11.50, defatted soybean, 37.43%); TNT (100% tigernuts); PLT (100% plantain) and CNT (a commercial flour)] were evaluated for nutritional, antioxidant and blood glucose concentration in streptozotocin-induced diabetics rats. The improved dough meals contained appreciable amount of protein, energy value, and high in antioxidative activity than PLT. Blood glucose reducing potential of improved plantain-based dough meals (60.5-71.9%) in streptozotocin-induced diabetic rats was higher than PLT, but comparable to acarbose (anti-diabetic drug) (69%). The present study established that improved traditional plantain-based dough meals (particularly PTS) was high in essential nutrients, antioxidative activities, and blood glucose reducing potentials. Hence, the dough-meals may be suitable for diabetes management.

Relationship between carbohydrate and dietary fibre intake and the risk of cardiovascular disease mortality in Japanese: 24-year follow-up of NIPPON DATA80

BACKGROUND/OBJECTIVES

The association between carbohydrate intake and cardiovascular disease (CVD) risk has been investigated, but whether the quality of carbohydrate is more important than its amount is not known. We examined the associations between intake of dietary fibre (DF), carbohydrate, available carbohydrate, and starch with long-term CVD mortality in a Japanese population.

SUBJECTS/METHODS

We prospectively followed 8925 participants (3916 men and 5009 women) aged 30-79 years without CVD at baseline who participated in the National Nutrition Survey in Japan. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs) for CVD mortality by quartiles of exposure variables.

RESULTS

During 24 years of follow-up, 823 CVD deaths were observed. In men, the multivariable-adjusted HR for CVD mortality was lower in the highest quartile of DF intake (HR: 0.64; 95% CI: 0.47-0.87; P_trend = 0.007) compared with the lowest quartile. This association was not significant in women. Multivariable-adjusted HR for total stroke mortality was lower in the highest quartile of DF intake (HR: 0.61; 95% CI: 0.38-0.98; P_trend = 0.046) compared with the lowest quartile in women. Carbohydrate, available carbohydrate, and starch intake were not associated with CVD mortality.

CONCLUSIONS

Higher intake of DF was associated significantly with a lower risk of CVD mortality in men and lower risk of stroke mortality in women. Intake of carbohydrate, available carbohydrate, and starch were not associated with the risk of CVD mortality in men or women.

Dietary Fiber Intake, Myocardial Injury, and Major Adverse Cardiovascular Events Among End-Stage Kidney Disease Patients: A Prospective Cohort Study

Introduction

Dialysis patients are frequently advised to restrict fruit and vegetable intake due to their high potassium content. This study aimed to evaluate the association between dietary fiber intake and major adverse cardiovascular events (MACE) among dialysis patients.

Methods

A total of 219 prevalent dialysis patients were prospectively recruited from a major university teaching hospital and regional dialysis center in Hong Kong. Dietary fiber intake estimated using a 7-day locally validated food frequency questionnaire was examined in relation to a primary composite outcome of MACE over a follow-up period of 4 years.

Results

A total of 127 patients were complicated with 1 or more MACE. In the multivariable Cox regression analysis, every 1 g higher fiber intake, and every 1 g/d per 1000 kcal higher fiber intake density were associated with an 11% (95% confidence interval [CI]: 0.81-0.97) and a 13% lower risk of MACE (95% CI: 0.77-0.99), respectively, independent of clinical, demographic, biochemical, hemodynamic, adequacy parameters, dietary protein, energy intake, inflammatory, and cardiac markers. Patients in the lower tertile of fiber intake density showed an increased hazard for MACE (adjusted hazard ratio: 1.78; 95% CI: 1.13-2.80) than those in the upper tertile.

Conclusion

Higher fiber intake and higher fiber intake density may be associated with less inflammation, less myocardial hypertrophy, injury, and lower risk of MACE in dialysis patients. These data form an important basis for a randomized controlled trial to examine fiber supplementation on cardiovascular outcomes in the dialysis population.

Potential for Prebiotics as Feed Additives to Limit Foodborne Campylobacter Establishment in the Poultry Gastrointestinal Tract

Campylobacter as an inhabitant of the poultry gastrointestinal tract has proven to be difficult to reduce with most feed additives. In-feed antibiotics have been taken out of poultry diets due to the negative reactions of consumers along with concerns regarding the generation of antibiotic resistant bacteria. Consequently, interest in alternative feed supplements to antibiotics has grown. One of these alternatives, prebiotics, has been examined as a potential animal and poultry feed additive. Prebiotics are non-digestible ingredients by host enzymes that enhance growth of indigenous gastrointestinal bacteria that elicit metabolic characteristics considered beneficial to the host and depending on the type of metabolite, antagonistic to establishment of pathogens. There are several carbohydrate polymers that qualify as prebiotics and have been fed to poultry. These include mannan-oligosaccharides and fructooligosaccharides as the most common ones marketed commercially that have been used as feed supplements in poultry. More recently, several other non-digestible oligosaccharides have also been identified as possessing prebiotic properties when implemented as feed supplements. While there is evidence that prebiotics may be effective in poultry and limit establishment of foodborne pathogens such as Salmonella in the gastrointestinal tract, less is known about their impact on Campylobacter. This review will focus on the potential of prebiotics to limit establishment of Campylobacter in the poultry gastrointestinal tract and future research directions.

Healthier diet quality and dietary patterns are associated with lower risk of mobility limitation in older men

Purpose

To investigate associations between diet quality, dietary patterns and mobility limitation 15 years later in a population-based sample of older British men.

Methods

We used longitudinal data from 1234 men from the British Regional Heart Study, mean age 66 years at baseline. Mobility limitation was defined as difficulty going up- or downstairs or walking 400 yards as a result of a long-term health problem. Dietary intake was measured using a food frequency questionnaire data from which the Healthy Diet Indicator (HDI), the Elderly Dietary Index (EDI), and three a posteriori dietary patterns were derived. The a posteriori dietary patterns were identified using principal components analysis: (1) high fat/low fibre, (2) prudent and (3) high sugar.

Results

Men with greater adherence to the EDI or HDI were less likely to have mobility limitation at follow-up, top vs bottom category odds ratio for the EDI OR 0.50, 95% CI 0.34, 0.75, and for the HDI OR 0.55, 95% CI 0.35, 0.85, after adjusting for age, social class, region of residence, smoking, alcohol consumption and energy intake. Men with a higher score for the high-fat/low-fibre pattern at baseline were more likely to have mobility limitation at follow-up, top vs bottom quartile odds ratio OR 3.28 95% CI 2.05, 5.24. These associations were little changed by adjusting for BMI and physical activity.

Conclusion

Our study provides evidence that healthier eating patterns could contribute to prevention or delay of mobility limitation in older British men.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1786-y) contains supplementary material, which is available to authorized users.

Integrative Medicine for Cardiovascular Disease and Prevention

Cardiovascular disease (CVD) is traditionally treated through medications and lifestyle modifications, yet adherence to these treatments is often poor. The use of complementary therapies is increasing, and it is vital for physicians to be aware of the risks and benefits of these options. This article summarizes the current evidence base on integrative therapies for the prevention and treatment of CVD, including hypertension, hyperlipidemia, coronary artery disease, heart failure, and arrhythmias. Where applicable, recommendations are included for therapies that may be used as an adjunct to traditional medical care to improve cardiovascular health and quality of life.

Intake of dietary fibre and lifetime non-steroidal anti-inflammatory drug (NSAID) use and the incidence of colorectal polyps in a population screened for colorectal cancer

Background

There is suggestive evidence that increased intake of dietary fibre and the use of non-steroidal anti-inflammatory drugs (NSAIDs) are generally associated with decreased colorectal cancer risk. However, the effects on precursors of colorectal cancer, such as adenomatous polyps, are mixed. We present the associations between dietary fibre intake and NSAID use on the presence and type of colorectal polyps in a screening population.

Methods

A cross-sectional study of 2548 individuals undergoing colonoscopy at the Forzani & MacPhail Colon Cancer Screening Centre (Calgary, Canada) was conducted. Dietary fibre intake and NSAID use were assessed using the Diet History Questionnaire I or II and the Health and Lifestyle Questionnaire. Colorectal outcomes were documented as a polyp or high-risk adenomatous polyp (HRAP; villous histology, high-grade dysplasia, ≥10 mm or ≥3 adenomas). Crude and ORs and 95% CIs were estimated using unconditional logistic regression.

Results

There were 1450 negative colonoscopies and 1098 patients with polyps, of which 189 patients had HRAPs. Total dietary fibre intake was associated with a decreased presence of HRAPs (OR=0.50, 95% CI: 0.29 to 0.86) when comparing the highest to lowest quartiles and was observed with both soluble (OR=0.51, 95% CI: 0.30 to 0.88) and insoluble (OR=0.51, 95% CI: 0.30 to 0.86) fibres. Ever use of NSAIDs was also inversely associated with HRAPs (OR=0.65, 95% CI: 0.47 to 0.89), observed with monthly (OR=0.60, 95% CI: 0.37 to 0.95) and daily (OR=0.53, 95% CI: 0.32 to 0.86) use.

Conclusions

Dietary fibre intake and NSAID use were associated with a decreased risk of having a HRAP at screening.

The acute effects of inulin and resistant starch on postprandial serum short-chain fatty acids and second-meal glycemic response in lean and overweight humans

BACKGROUND/OBJECTIVES

Colonic fermentation of dietary fiber to short-chain fatty acids (SCFA) may protect against obesity and diabetes, but excess production of colonic SCFA has been implicated in the promotion of obesity. We aimed to compare the effects of two fermentable fibers on postprandial SCFA and second-meal glycemic response in healthy overweight or obese (OWO) vs lean (LN) participants.

SUBJECTS/METHODS

Using a randomized crossover design, 13 OWO and 12 LN overnight fasted participants were studied for 6 h on three separate days after consuming 300 ml water containing 75 g glucose (GLU) as control or with 24 g inulin (IN) or 28 g resistant starch (RS). A standard lunch was served 4 h after the test drink.

RESULTS

Within the entire group, compared with control, IN significantly increased serum SCFA (P<0.001) but had no effect on free-fatty acids (FFA) or second-meal glucose and insulin responses. In contrast, RS had no significant effect on SCFA but reduced FFA rebound (P<0.001) and second-meal glucose (P=0.002) and insulin responses (P=0.024). OWO had similar postprandial serum SCFA and glucose concentrations but significantly greater insulin and FFA than LN. However, the effects of IN and RS on SCFA, glucose, insulin and FFA responses were similar in LN and OWO.

CONCLUSIONS

RS has favorable second-meal effects, likely related to changes in FFA rather than SCFA concentrations. However, a longer study may be needed to demonstrate an effect of RS on SCFA. We found no evidence that acute increases in SCFA after IN reduce glycemic responses in humans, and we were unable to detect a significant difference in SCFA responses between OWO vs LN subjects.

Modulation of type 1 and type 2 diabetes risk by the intestinal microbiome

The prevalence of type 1 and type 2 diabetes have both risen dramatically over the last 50 years. Recent findings point towards the gut microbiota as a potential contributor to these trends. The hundred trillion bacteria residing in the mammalian gut have established a symbiotic relation with their host and influence many aspects of host metabolism, physiology, and immunity. In this review, we examine recent data linking gut microbiome composition and function to anti-pancreatic immunity, insulin-resistance, and obesity. Studies in rodents and human longitudinal studies suggest that an altered gut microbiome characterized by lower diversity and resilience is associated with type 1 and type 2 diabetes. Through its metabolites and enzymatic arsenal, the microbiota shape host metabolism, energy extracted from the diet and contribute to the normal development of the immune system and to tissue inflammation. Increasing evidence underscores the importance of the maternal microbiome, the gestational environment and the conditions of newborn delivery in establishing the gut microbiota of the offspring. Perturbations of the maternal microbiome during gestation, or that of the offspring during early infant development may promote a pro-inflammatory environment conducive to the development of autoimmunity and metabolic disturbance. Collectively the findings reviewed herein underscore the need for mechanistic investigations in rodent models and in human studies to better define the relationships between microbial and host inflammatory activity in diabetes, and to evaluate the potential of microbe-derived therapeutics in the prevention and treatment of both forms of diabetes.

Dietary fibre for the primary prevention of cardiovascular disease

BACKGROUND

The prevention of cardiovascular disease (CVD) is a key public health priority. A number of dietary factors have been associated with modifying CVD risk factors. One such factor is dietary fibre which may have a beneficial association with CVD risk factors. There is a need to review the current evidence from randomised controlled trials (RCTs) in this area.

OBJECTIVES

The primary objective of this systematic review was to determine the effectiveness of dietary fibre for the primary prevention of CVD.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, Ovid MEDLINE (1946 to January 2015), Ovid EMBASE (1947 to January 2015) and Science Citation Index Expanded (1970 to January 2015) as well as two clinical trial registers in January 2015. We also checked reference lists of relevant articles. No language restrictions were applied.

SELECTION CRITERIA

We selected RCTs that assessed the effects of dietary fibre compared with no intervention or a minimal intervention on CVD and related risk factors. Participants included adults who are at risk of CVD or those from the general population.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, extracted data and assessed risk of bias; a third author checked any differences. A different author checked analyses.

MAIN RESULTS

We included 23 RCTs (1513 participants randomised) examining the effect of dietary fibre. The risk of bias was unclear for most studies and studies had small sample sizes. Few studies had an intervention duration of longer than 12 weeks. There was a wide variety of fibre sources used, with little similarity between groups in the choice of intervention.None of the studies reported on mortality (total or cardiovascular) or cardiovascular events. Results on lipids suggest there is a significant beneficial effect of increased fibre on total cholesterol levels (17 trials (20 comparisons), 1067 participants randomised, mean difference -0.23 mmol/L, 95% CI -0.40 to -0.06), and LDL cholesterol levels (mean difference -0.14 mmol/L, 95% CI -0.22 to -0.06) but not on triglyceride levels (mean difference 0.00 mmol/L, 95% CI -0.04 to 0.05), and there was a very small but statistically significant decrease rather than increase in HDL levels with increased fibre intake (mean difference -0.03 mmol/L, 95% CI -0.06 to -0.01). Fewer studies (10 trials, 661 participants randomised) reported blood pressure outcomes where there is a significant effect of increased fibre consumption on diastolic blood pressure (mean difference -1.77 mmHg, 95% CI -2.61 to -0.92) whilst there is a reduction in systolic blood pressure with fibre but this does not reach statistical significance (mean difference -1.92 mmHg, 95% CI -4.02 to 0.19). There did not appear to be any subgroup effects by the nature of the type of intervention (fibre supplements or provision of foods/advice to increase fibre consumption) or the type of fibre (soluble/insoluble) although the number of studies contributing to each subgroup were small. All analyses need to be viewed with caution given the risks of bias observed for total cholesterol and the statistical heterogeneity observed for systolic blood pressure. Adverse events, where reported, appeared to mostly reflect mild to moderate gastrointestinal side-effects and these were generally reported more in the fibre intervention groups than the control groups.

AUTHORS' CONCLUSIONS

Studies were short term and therefore did not report on our primary outcomes, CVD clinical events. The pooled analyses for CVD risk factors suggest reductions in total cholesterol and LDL cholesterol with increased fibre intake, and reductions in diastolic blood pressure. There were no obvious effects of subgroup analyses by type of intervention or fibre type but the number of studies included in each of these analyses were small. Risk of bias was unclear in the majority of studies and high for some quality domains so results need to be interpreted cautiously. There is a need for longer term, well-conducted RCTs to determine the effects of fibre type (soluble versus insoluble) and administration (supplements versus foods) on CVD events and risk factors for the primary prevention of CVD.

Impact of Nutrition on Cerebral Circulation and Cognition in the Metabolic Syndrome

The increasing prevalence of Metabolic Syndrome (MetS), defined as the clustering of abdominal obesity, dyslipidemia, hypertension, and hyperglycemia, appears to be driving the global epidemics cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Nutrition has a major impact on MetS and plays an important role in the prevention, development, and treatment of its features. Structural and functional alterations in the vasculature, associated with MetS, might form the link between MetS and the increased risk of developing CVD and T2DM. Not only does the peripheral vasculature seem to be affected, but the syndrome has a profound impact on the cerebral circulation and thence brain structure as well. Furthermore, strong associations are shown with stroke, cognitive impairment, and dementia. In this review the impact of nutrition on the individual components of MetS, the effects of MetS on peripheral and cerebral vasculature, and its consequences for brain structure and function will be discussed.

Effects of Xylo-Oligosaccharides on Broiler Chicken Performance and Microbiota

In broiler chickens, feed additives, including prebiotics, are widely used to improve gut health and to stimulate performance. Xylo-oligosaccharides (XOS) are hydrolytic degradation products of arabinoxylans that can be fermented by the gut microbiota. In the current study, we aimed to analyze the prebiotic properties of XOS when added to the broiler diet. Administration of XOS to chickens, in addition to a wheat-rye-based diet, significantly improved the feed conversion ratio. XOS significantly increased villus length in the ileum. It also significantly increased numbers of lactobacilli in the colon and Clostridium cluster XIVa in the ceca. Moreover, the number of gene copies encoding the key bacterial enzyme for butyrate production, butyryl-coenzyme A (butyryl-CoA):acetate CoA transferase, was significantly increased in the ceca of chickens administered XOS. In this group of chickens, at the species level, Lactobacillus crispatus and Anaerostipes butyraticus were significantly increased in abundance in the colon and cecum, respectively. In vitro fermentation of XOS revealed cross-feeding between L. crispatus and A. butyraticus. Lactate, produced by L. crispatus during XOS fermentation, was utilized by the butyrate-producing Anaerostipes species. These data show the beneficial effects of XOS on broiler performance when added to the feed, which potentially can be explained by stimulation of butyrate-producing bacteria through cross-feeding of lactate and subsequent effects of butyrate on gastrointestinal function.

The role of short chain fatty acids in appetite regulation and energy homeostasis

Over the last 20 years there has been an increasing interest in the influence of the gastrointestinal tract on appetite regulation. Much of the focus has been on the neuronal and hormonal relationship between the gastrointestinal tract and the brain. There is now mounting evidence that the colonic microbiota and their metabolic activity have a significant role in energy homeostasis. The supply of substrate to the colonic microbiota has a major impact on the microbial population and the metabolites they produce, particularly short chain fatty acids (SCFAs). SCFAs are produced when non-digestible carbohydrates, namely dietary fibres and resistant starch, undergo fermentation by the colonic microbiota. Both the consumption of fermentable carbohydrates and the administration of SCFAs have been reported to result in a wide range of health benefits including improvements in body composition, glucose homeostasis, blood lipid profiles and reduced body weight and colon cancer risk. However, published studies tend to report the effects that fermentable carbohydrates and SCFAs have on specific tissues and metabolic processes, and fail to explain how these local effects translate into systemic effects and the mitigation of disease risk. Moreover, studies tend to investigate SCFAs collectively and neglect to report the effects associated with individual SCFAs. Here, we bring together the recent evidence and suggest an overarching model for the effects of SCFAs on one of their beneficial aspects: appetite regulation and energy homeostasis.

Changes in meal composition and duration affect postprandial endothelial function in healthy humans

Endothelial function, measured by flow-mediated dilatation (FMD), predicts cardiovascular events and is impaired postprandially. The objective of this study was to evaluate the effects of changes in composition or duration of ingestion of a meal, which slows gastric emptying and/or small intestinal nutrient exposure, on postprandial endothelial function. Twelve healthy subjects (6 male, 6 female; 33 ± 6 yr) were each studied on three occasions, in a randomized crossover design. After an overnight fast, subjects consumed a [(13)C]octanoic acid-labeled mashed potato meal ("meal 1"), or meal 1 mixed with 9 g guar ("meal 2") within 10 min, or meal 1 divided into 12 equal portions over 60 min ("meal 3"). Brachial artery FMD was measured every 30 min for 120 min. Blood glucose, serum insulin, and gastric emptying (breath test) were evaluated for 240 min. Data are means ± SE. Compared with meal 1, meal 2 was associated with slower gastric emptying (half-emptying time 285 ± 27 vs. 208 ± 15 min, P < 0.05), lower postprandial blood glucose and insulin (P < 0.001 for both), and a delayed, but more sustained, suppression of FMD (P < 0.001). After meal 3, both glycemic increment and reduction in FMD were less than after meal 2 (P < 0.05 for both). The decrement in FMD was directly related to the increment in blood glucose (r = 0.46, P = 0.02). We conclude that, in health, postprandial FMD is influenced by perturbation of gastric emptying and the duration of meal consumption, which also impact on glycemia.

Dietary fibre intake and risk of ischaemic and haemorrhagic stroke in the UK Women's Cohort Study

BACKGROUND

Stroke risk is modifiable through many risk factors, one being healthy dietary habits. Fibre intake was associated with a reduced stroke risk in recent meta-analyses; however, data were contributed by relatively few studies, and few examined different stroke types.

METHODS

A total of 27,373 disease-free women were followed up for 14.4 years. Diet was assessed with a 217-item food frequency questionnaire and stroke cases were identified using English Hospital Episode Statistics and mortality records. Survival analysis was applied to assess the risk of total, ischaemic or haemorrhagic stroke in relation to fibre intake.

RESULTS

A total of 135 haemorrhagic and 184 ischaemic stroke cases were identified in addition to 138 cases where the stroke type was unknown or not recorded. Greater intake of total fibre, higher fibre density and greater soluble fibre, insoluble fibre and fibre from cereals were associated with a significantly lower risk for total stroke. For total stroke, the hazard ratio per 6 g/day total fibre intake was 0.89 (95% confidence intervals: 0.81-0.99). Different findings were observed for haemorrhagic and ischaemic stroke in healthy-weight or overweight women. Total fibre, insoluble fibre and cereal fibre were inversely associated with haemorrhagic stroke risk in overweight/obese participants, and in healthy-weight women greater cereal fibre was associated with a lower ischaemic stroke risk. In non-hypertensive women, higher fibre density was associated with lower ischaemic stroke risk.

CONCLUSIONS

Greater total fibre and fibre from cereals are associated with a lower stroke risk, and associations were more consistent with ischaemic stroke. The different observations by stroke type, body mass index group or hypertensive status indicates potentially different mechanisms.

Dietary total and insoluble fiber intakes are inversely associated with prostate cancer risk

Although experimental data suggest a potentially protective involvement of dietary fiber in prostate carcinogenesis, very few prospective studies have investigated the relation between dietary fiber intake and prostate cancer risk, and those have had inconsistent results. Our objective was to study the association between dietary fiber intake (overall, insoluble, soluble, and from different sources, such as cereals, vegetables, fruits, and legumes) and prostate cancer risk. Stratifications by excess weight status, insulin-like growth factors, and amount of alcohol intake were also considered. This prospective analysis included 3313 men from the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort who completed at least 3 24-h dietary records. One hundred thirty-nine incident prostate cancers were diagnosed between 1994 and 2007 (median follow-up of 12.6 y). Associations between quartiles of energy-adjusted dietary fiber intake and prostate cancer risk were characterized by multivariate Cox proportional hazards models. Prostate cancer risk was inversely associated with total dietary fiber intake (HR of quartile 4 vs. quartile 1 = 0.47; 95% CI: 0.27, 0.81; P = 0.001), insoluble (HR = 0.46; 95% CI: 0.27, 0.78; P = 0.001), and legume (HR = 0.55; 95% CI: 0.32, 0.95; P = 0.04) fiber intakes. In contrast, we found no association between prostate cancer risk and soluble (P = 0.1), cereal (P = 0.7), vegetable (P = 0.9), and fruit (P = 0.4) fiber intakes. In conclusion, dietary fiber intake (total, insoluble, and from legumes but not soluble or from cereals, vegetables, and fruits) was inversely associated with prostate cancer risk, consistent with mechanistic data.

Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis

OBJECTIVE

To investigate dietary fibre intake and any potential dose-response association with coronary heart disease and cardiovascular disease.

DESIGN

Systematic review of available literature and dose-response meta-analysis of cohort studies using random effects models.

DATA SOURCES

The Cochrane Library, Medline, Medline in-process, Embase, CAB Abstracts, ISI Web of Science, BIOSIS, and hand searching.

ELIGIBILITY CRITERIA FOR STUDIES

Prospective studies reporting associations between fibre intake and coronary heart disease or cardiovascular disease, with a minimum follow-up of three years and published in English between 1 January 1990 and 6 August 2013.

RESULTS

22 cohort study publications met inclusion criteria and reported total dietary fibre intake, fibre subtypes, or fibre from food sources and primary events of cardiovascular disease or coronary heart disease. Total dietary fibre intake was inversely associated with risk of cardiovascular disease (risk ratio 0.91 per 7 g/day (95% confidence intervals 0.88 to 0.94)) and coronary heart disease (0.91 (0.87 to 0.94)). There was evidence of some heterogeneity between pooled studies for cardiovascular disease (I(2)=45% (0% to 74%)) and coronary heart disease (I(2)=33% (0% to 66%)). Insoluble fibre and fibre from cereal and vegetable sources were inversely associated with risk of coronary heart disease and cardiovascular disease. Fruit fibre intake was inversely associated with risk of cardiovascular disease.

CONCLUSIONS

Greater dietary fibre intake is associated with a lower risk of both cardiovascular disease and coronary heart disease. Findings are aligned with general recommendations to increase fibre intake. The differing strengths of association by fibre type or source highlight the need for a better understanding of the mode of action of fibre components.

Prospective association between dietary fiber intake and breast cancer risk

BACKGROUND

Mechanistic hypotheses suggest a potential effect of dietary fiber on breast carcinogenesis through the modulation of insulin-like growth factor bioactivity, estrogen metabolism and inflammation. An association between dietary fiber intake and breast cancer risk has been suggested in epidemiological studies but remains inconclusive. In particular, data is lacking regarding the different types of dietary fibers.

OBJECTIVE

The objective was to investigate the prospective relationship between dietary fiber intake and breast cancer risk, taking into account different types of dietary fiber (overall, insoluble, soluble and from different food sources: cereals, vegetables, fruits and legumes).

DESIGN

4684 women from the SU.VI.MAX cohort were included in this analysis as they completed at least three 24h-dietary records within the first two years of follow-up. Among them, 167 incident invasive breast cancers were diagnosed during a median follow-up of 12.6 years (between 1994 and 2007). The associations between quartiles of dietary fiber intake and breast cancer risk were characterized using multivariate Cox proportional hazards models.

RESULTS

Total fiber intake was not associated with breast cancer risk (HR(Quartile4vs.Quartile1) = 1.29 (95%CI 0.66-2.50), P-trend = 0.5), nor was fiber intake from cereals (P-trend = 0.1), fruits (P-trend = 0.9) and legumes (P-trend = 0.3). In contrast, vegetable fiber intake was related to a decreased risk of breast cancer (HR(Q4vs.Q1) = 0.50 (0.29-0.88), P-trend = 0.03). Overall vegetable intake (in g/day) was not associated with breast cancer risk (P-trend = 0.2).

CONCLUSION

This prospective study suggests that vegetable fiber intake may contribute to reduce breast cancer risk, in line with experimental mechanistic data.

Intake and serum profile of fatty acids are weakly correlated with global dietary quality in European adolescents

OBJECTIVE

The present study assessed whether compliance with the Food-Based Dietary Guidelines is related to habitual fatty acid (FA) intake and blood lipid parameters.

METHODS

Dietary information was collected by two non-consecutive 24-h recalls in 1804 European adolescents. Compliance with the Food-Based Dietary Guidelines was expressed by calculating the Diet Quality Index for Adolescents (DQI-A). Blood samples were collected in a randomly selected subset (n = 552). Relations between FA intake/serum concentrations and DQI-A were tested with multilevel regression analysis to correct for the study design (clustering within cities). Analyses were stratified for gender; age was entered as a covariate.

RESULTS

Better DQI-A scores were related to increased proportional intakes of energy from total fat, saturated FA, monounsaturated FA, and cholesterol (P < 0.001), whereas no significant association was observed with polyunsaturated FA intakes. In adolescents with higher compared with lower DQI-A scores, dairy products contributed more (21.0% versus 12.7%) and low-nutrient, energy-dense items contributed less (17.2% versus 26.3%) to the intake of total fat. A positive association was observed between the DQI-A scores and serum concentrations of eicosapentaenoic acid and docosahexaenoic acid (all P < 0.005). The latter, however, was significant only in girls. In boys, higher DQI-A scores were inversely associated with serum cholesterol concentrations (P < 0.05).

CONCLUSION

Although compliance with the Food-Based Dietary Guidelines was not always associated with a favorable FA intake pattern, a significant favorable association with some serum biomarkers was observed. This outcome underlines the importance of considering dietary habits instead of single-nutrient intakes.

Dietary fiber intake and risk of first stroke: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Fiber intake is associated with reduced stroke risk in prospective studies, but no meta-analysis has been published to date.

METHODS

Multiple electronic databases were searched for healthy participant studies reporting fiber intake and incidence of first hemorrhagic or ischemic stroke, published between January 1990 and May 2012.

RESULTS

Eight cohort studies from the United States, northern Europe, Australia, and Japan met inclusion criteria. Total dietary fiber intake was inversely associated with risk of hemorrhagic plus ischemic stroke, with some evidence of heterogeneity between studies (I(2); relative risk per 7 g/day, 0.93; 95% confidence interval, 0.88-0.98; I(2)=59%). Soluble fiber intake, per 4 g/day, was not associated with stroke risk reduction with evidence of low heterogeneity between studies, relative risk 0.94 (95% confidence interval, 0.88-1.01; I(2)=21%). There were few studies reporting stroke risk in relation to insoluble fiber or fiber from cereals, fruit, or vegetables.

CONCLUSIONS

Greater dietary fiber intake is significantly associated with lower risk of first stroke. Overall, findings support dietary recommendations to increase intake of total dietary fiber. However, a paucity of data on fiber from different foods precludes conclusions regarding the association between fiber type and stroke. There is a need for future studies to focus on fiber type and to examine risk for ischemic and hemorrhagic strokes separately.

Nutritional quality and health benefits of chickpea (Cicer arietinumL.): a review

Chickpea (Cicer arietinumL.) is an important pulse crop grown and consumed all over the world, especially in the Afro-Asian countries. It is a good source of carbohydrates and protein, and protein quality is considered to be better than other pulses. Chickpea has significant amounts of all the essential amino acids except sulphur-containing amino acids, which can be complemented by adding cereals to the daily diet. Starch is the major storage carbohydrate followed by dietary fibre, oligosaccharides and simple sugars such as glucose and sucrose. Although lipids are present in low amounts, chickpea is rich in nutritionally important unsaturated fatty acids such as linoleic and oleic acids. β-Sitosterol, campesterol and stigmasterol are important sterols present in chickpea oil. Ca, Mg, P and, especially, K are also present in chickpea seeds. Chickpea is a good source of important vitamins such as riboflavin, niacin, thiamin, folate and the vitamin A precursor β-carotene. As with other pulses, chickpea seeds also contain anti-nutritional factors which can be reduced or eliminated by different cooking techniques. Chickpea has several potential health benefits, and, in combination with other pulses and cereals, it could have beneficial effects on some of the important human diseases such as CVD, type 2 diabetes, digestive diseases and some cancers. Overall, chickpea is an important pulse crop with a diverse array of potential nutritional and health benefits.

Food choice as a key management strategy for functional gastrointestinal symptoms

Recognition of food components that induce functional gut symptoms in patient's functional bowel disorders (FBD) has been challenging. Food directly or indirectly provides considerable afferent input into the enteric nervous system. There is an altered relationship between the afferent input and perception/efferent response in FBD. Defining the nature of food-related stimuli may provide a means of minimizing such an input and gut symptoms. Using this premise, reducing the intake of FODMAPs (fermentable oligo-, di-, and mono-saccharides and polyols)--poorly absorbed short-chain carbohydrates that, by virtue of their small molecular size and rapid fermentability, will distend the intestinal lumen with liquid and gas--improves symptoms in the majority of patients. Well-developed methodologies to deliver the diet via dietician-led education are available. Another abundant source of afferent input is natural and added food chemicals (such as salicylates, amines, and glutamates). Studies are needed to assess the efficacy of the low food chemical dietary approach. A recent placebo-controlled trial of FODMAP-poor gluten provided the first valid evidence that non-celiac gluten intolerance might actually exist, but its prevalence and underlying mechanisms require elucidation. Food choice via the low FODMAP and potentially other dietary strategies is now a realistic and efficacious therapeutic approach for functional gut symptoms.

Effects of high and moderate non-structural carbohydrate hay on insulin, glucose, triglyceride, and leptin concentrations in overweight Arabian geldings

The objective of this study was to determine the effects of high and moderate non-structural carbohydrates (NSC) hay on insulin, glucose, triglyceride, and leptin concentrations in overweight Arabian geldings. Eight adult overweight (average BCS 7 [9-point scale]) Arabian geldings were fed each of two orchardgrass hays, high NSC (18% DM) and moderate NSC (12% DM), in a cross over design during two 28-day periods. Body weight and body condition score assessment along with blood sampling to measure insulin, glucose, leptin, and triglyceride concentrations were performed on days 0, 7, 14, 21 and 28 of each period. Effects of hay, period, day, and day*hay on plasma glucose and serum leptin were not detected. Serum insulin was influenced by hay (p = 0.001), day (p = 0.03), and day*hay (p = 0.04). Insulin concentrations were higher on day 7 in the high NSC group (15.6 μIU/ml) than the moderate NSC group (9.5 μIU/ml), but not by day 14 (p = 0.0007). Plasma triglyceride was influenced by period (p = 0.0003), day*period (p < 0.0001), and day*hay (p = 0.02). Hyperinsulinaemia was not observed in the overweight Arabian geldings fed either a moderate or high NSC hay.

Antiproliferative activity of melanoidins isolated from heated potato fiber (potex) in glioma cell culture model

Potex constitutes a potato fiber preparation widely used as an ingredient to meat and bakery products which thermal treatment results in creation of new compounds. Melanoidins are high molecular weight brown end products of Maillard reaction, and few data presenting tumor cell growth inhibiting activity of melanoidins have been reported. Thus, in present study we utilized water extract of Potex roasted (180 °C for 2 h), whose chemical characterization revealed the presence of melanoidin complexes. Heated Potex extract inhibited C6 glioma cell proliferation in a dose-dependent manner measured by MTT method. High molecular weight components present in initial extract were responsible for stronger antiproliferative effect compared with low molecular weight fraction. Impaired MAPK (mitogen-activated protein kinase) and Akt signaling was found in cells treated with the extract. Moreover, flow cytometry analyses revealed the extract to induce G1/S arrest in glioma cells. Simultaneously, Western blot analysis showed elevated levels of p21 protein with concomitant decrease of cyclin D1. In conclusion, observed antiproliferative activity of melanoidins present in heated Potex was linked to disregulated MAPK and Akt signaling pathways, as well as to cell cycle cessation. These results suggest potential application of Potex preparation as a functional food ingredient and chemopreventive agent.

Dietary fiber type reflects physiological functionality: comparison of grain fiber, inulin, and polydextrose

Dietary fiber is a nutritional concept based not on physiological functions but on defined chemical and physical properties. Recent definitions of dietary fiber differentiate inherent plant cell wall-associated fiber from isolated or synthetic fiber. For the latter to be defined as fiber, beneficial physiological effects should be demonstrated, such as laxative effects, fermentability, attenuation of blood cholesterol levels, or postprandial glucose response. Grain fibers are a major natural source of dietary fiber worldwide, while inulin, a soluble indigestible fructose polymer isolated from chicory, and polydextrose, a synthetic indigestible glucose polymer, have more simple structures. Inulin and polydextrose show many of the same functionalities of grain fiber in the large intestine, in that they are fermentable, bifidogenic, and laxative. The reported effects on postprandial blood glucose and fasting cholesterol levels have been modest, but grain fibers also show variable effects. New biomarkers are needed to link the physiological functions of specific fibers with long-term health benefits.

Carbohydrate-rich foods: glycaemic indices and the effect of constituent macronutrients

The glycaemic index (GI) ranks foods according to their acute glycaemic impact and is used in planning meals for patients invoking glycaemic control through diet. Kurakkan (Eleusine coracana) flour roti, rice flour roti, atta flour roti, boiled breadfruit (Artocarpus altilis/Artocarpus communis) and boiled legumes (mungbean, cowpea and chickpea) were categorized as low-GI foods (relative to white bread; Prima Crust Top), and the corresponding GI (+/- standard error of the mean) values were 70+/-8, 69+/-7, 67+/-9, 64+/-7, 57+/-6, 49+/-8 and 29+/-5, respectively. Kurakkan flour pittu and wheat flour roti were classified as medium-GI foods with GI values of 85+/-6 and 72+/-6. Hoppers, rice flour pittu, wheat flour pittu and Olu-milk rice (seeds of Nymphaea lotus) were categorized as high-GI foods, and the corresponding GI (+/- standard error of the mean) values were 120+/-8, 103+/-7, 101+/-8 and 91+/-8, respectively. The GI values significantly (P<0.01) and negatively correlated with the insoluble dietary fibre (rho = - 0.780), soluble dietary fibre (rho = - 0.712) and protein (rho = - 0.738) contents in grams per 100 g digestible starch containing foods.