Psyllium supplementation in adolescents improves fat distribution & lipid profile: a randomized, participant-blinded, placebo-controlled, crossover trial

Prebiotics, probiotics, synbiotics and postbiotics to adolescents in metabolic syndrome

The prevalence of childhood and adolescent obesity has globally reached alarming dimensions and many adolescents affected by obesity already present one or more obesity-related comorbidities. In recent years, emerging evidence supporting the role of gut microbiota in the pathophysiology of metabolic diseases has been reported and the use of prebiotics, probiotics, synbiotics and postbiotics as a strategy to manipulate gut microbiota has become popular. The aim of this review is to explore the relationship between gut microbiota and metabolic syndrome in adolescents and to discuss the potential use of prebiotics, probiotics, synbiotics and postbiotics for the prevention and treatment of this clinical picture in adolescence. According to the most recent literature, prebiotics, probiotics and synbiotics have no clear effect on MetS, but a possible modulation of anthropometric parameters has been observed after synbiotic supplementation. Only one study has examined the role of postbiotics in alleviating metabolic complications in children with obesity but not in adolescents. More extensive research is needed to support the conclusions drawn so far and to develop effective microbiome-based interventions that may help improving the quality of life of children and adolescents exposed to the increasing prevalence of MetS.

Physiologic Effects of Isolated or Synthetic Dietary Fiber in Children: A Scoping Review

Background

Fiber is an integral part of a healthy diet. Studies have shown that the fiber intake in children is below adequate amounts, leading to adverse health outcomes.

Objectives

This study aimed to perform a scoping review to assess the available evidence for the impact of isolated and synthetic dietary fiber on children's health outcomes.

Methods

A systematic literature search was conducted in Ovid Medline, Ovid Global Health, Embase, and Cochrane Library via Wiley to identify randomized controlled trials (RCTs) in healthy children aged 1-18 y at baseline who consumed added, isolated, or synthetic dietary fiber. The outcomes of interest were categorized based on the Food and Drug Administration's guidance for industry on nondigestible carbohydrates and the Vahouny Fiber Symposium criteria, which included reduced fasting blood, glucose, total and/or LDL cholesterol concentrations, attenuation of postprandial glycemia/insulinemia, increased fecal bulk/laxation, reduced transit time, weight loss/reduction in adiposity, reduced energy intake from food consumption, increased satiety, bone health/enhanced mineral absorption, and blood pressure. We also cataloged additional reported outcomes.

Results

Of 3837 randomized controlled parallel or crossover trials screened at the abstract level, 160 were eligible for full-text review, and 32 included for data extraction. This scoping review presents analysis of data from 32 RCTs in children who were healthy, overweight/obese or had mild hypercholesterolemia. Inulin-type fructans (41%) and psyllium (22%) were the most frequently administered fiber types, with weight/adiposity, markers of lipid metabolism (41%), and bone-related markers (38%) being the most frequently reported health outcomes. Only a few RCTs have investigated the effects of laxation (9%), and none specifically studied the impact of fiber on reducing postprandial glycemia/insulinemia.

Conclusions

This scoping review demonstrates sufficient evidence for conducting systematic reviews and meta-analyses for several outcomes. Evidence gaps remain on the impact of isolated fibers on outcomes such as laxation, colonic transit time, and postprandial glycemia/insulinemia in children.

Reduction of small dense LDL and Il-6 after intervention with Plantago psyllium in adolescents with obesity: a parallel, double blind, randomized clinical trial

Obesity can lead children and adolescents to an increased cardiovascular disease (CVD) risk. A diet supplemented with Plantago psyllium has been shown to be effective in reducing LDL-C and IL-6 in adolescents. However, there are no studies that have explored small-dense LDL (sdLDL) or HDL subclasses. The aim of this study was to evaluate the impact of a fiber dietary intervention on LDL and HDL subclasses in adolescents with obesity. In this parallel, double blind, randomized clinical trial, the participants were assigned to Plantago psyllium or placebo (10g/day for 7 weeks). We randomized 113 participants, and evaluated and analyzed 100 adolescents (50 in each group), 15 to 19 years with a body mass index of 29-34. We measured biochemical markers LDL and HDL subclasses using the Lipoprint system (Quantimetrix) and IL-6 by ELISA. Post-treatment there was a decrease in sdLDL between the groups 2.0 (0-5.0) vs 1 (0-3.0) mg/dl (p = 0.004), IL-6 median 3.32 (1.24-5.96) vs 1.76 (0.54-3.28) pg/ml, p <0.0001. There were no differences in HDL subclasses and no adverse effects were reported in either group.Conclusions: Small dense LDL and IL-6 reduced in adolescents with obesity when consuming Plantago psyllium. This may be an early good strategy for the reduction of cardiovascular disease risk in this vulnerable population.Trial registration: ISRCTN # 14180431. Date assigned 24/08/2020 What is Known: • Supplementing the diet with Plantago psyllium lowers LDL-C levels. What is New: • First evidence that soluble fiber supplementation like Plantago psyllium decreases small dense LDL particles in association with lowered IL-6, reducing the risk of cardiovascular disease in obese adolescents.

The Cardiovascular Health Integrated Lifestyle Diet (CHILD) Lowers LDL-Cholesterol Levels in Brazilian Dyslipidemic Pediatric Patients

OBJECTIVE

To analyze the impact of the CHILD-2 diet on the lipid profile of Brazilian children and adolescents with dyslipidemia.

METHODS

This is a quasi-experimental study, where 149 participants (5-17 years) with mild-to-moderate hypercholesterolemia were divided into two groups (GI: low or normal weight; n = 58 and GII: overweight; n = 91). Both groups underwent the CHILD-2 diet, characterized by 25-30% total fat and less than 7% of low-saturated fat (SF) for 6 months. Changes from baseline in the lipid profile, including Total cholesterol (TC), LDL-C, triacylglycerols and glucose concentrations, dietary and anthropometric data were examined at 3 and 6 months. Longitudinal analyses were performed using linear mixed-effects models in SAS.

RESULTS

Serum LDL-C concentrations reduced over time compared with baseline (Δ = -5.1 mg/dL; p < 0.01), with no difference between groups (p = 0.35). TC concentrations decreased by -2.0 mg/dL (p < 0.01); but no difference was observed between groups. We found no significant changes in body mass index/age Z scores after a dietary intervention compared with baseline in both groups (p = 0.94).

CONCLUSION

Despite the modest reduction, our findings confirm that children with dyslipidemia can benefit from the CHILD-2 diet combined with a healthy lifestyle.

Antioxidant, Nutritional, Structural, Thermal and Physico-Chemical Properties of Psyllium (Plantago Ovata) Seeds

The present investigation was carried out to characterize four different types of psyllium seeds including one landrace for their nutritional, structural, antioxidant profile and biological active compounds. DSC analysis showed the highest peak temperature (TP) of 107.57 ºC in RI-89 and end set temperature (TE) of 130.2 ºC for HI-5 cultivar. FT-IR analysis displayed strong absorption bands at frequencies 960, 1380, 1740, 2280 and 3280cm-1. SEM micrographs of each cultivar showed compact and irregular mass of fiber at various magnifications. Protein, fat, ash and total carbohydrate content of psyllium seed flour were recorded up to 13.33, 0.38, 5.0 and 77.88 %, respectively. Ethanol was found to be a suitable solvent than methanol to extract the phytonutrients from psyllium seed flour. DPPH free radical scavenging activity (FRSA) of methanolic and ethanolic extract varied between 31 to 39 % and 38.9 to 43 %, respectively. However, ABTS-FRSA varied between 31.7 to 32.9 % and 33.2 to 34.3 %, for methanolic and ethanolic extract, respectively. Total flavonoids and total phenolic content was recorded up to 2.92 mg RE/g and 4.37 mg GAE/g, in ethanolic extract. The reducing power (RP) and Metal chelating activity (MCA) also varied significantly (p≤0.05) among the cultivars. The MCA ranged from 33.20 to 34.81 % in methanolic extracts and 34.62 to 36.07 % in ethanolic extracts. The lowest absorbance for reducing power was found in methanolic extract of landrace (0.16), whereas, the highest was found in ethanolic extract of RI-89 (0.37). Physico-chemical properties including oil and water absorption capacity of both seed and flour did not vary significantly among the cultivars, whereas significant difference was observed in seed hydration capacity among cultivars evaluated. Among the physical properties, L/W ratio ranged from 1.80 to 199, whereas porosity and angle of repose were of 59.2 to 67.7 % and 23.20 to 27.02º, respectively. Static coefficient of friction was found less using steel (0.484 to 0.667) as a test surface compared to wood (0.679 to 0.744) and plastic (0.536 to 0.560). Bulk density, true density and porosity of various psyllium seed cultivars varied between 0.57 to 0.63 g/cm3 and 1.50 to 1.77 g/cm3 and 58.2 to 67.7%, respectively. Geometric mean diameter (Dg), Arithmetic mean diameter (Da) and surface area of seeds (A) varied from 1.49 to 1.60 mm and 1.68 to 1.79 mm and 5.91 to 6.78 mm2, respectively.

Psyllium: a useful functional ingredient in food systems

Psyllium gum is a hydrocolloid found in the husk of seeds from Plantago ovata. Psyllium husk has been used in traditional medicine in areas of India and China. Its consumption has been shown to provide nutritional benefits, such as the capacity to reduce the glycaemic index, to minimize the risk of cardiovascular diseases, to decrease cholesterol and constipation problems and others. Thus, interest in the incorporation of psyllium in food products is twofold. First, it can be a natural alternative to the use of other gums and hydrocolloids considered additives. Second, it can be used to improve the nutritional properties of products in which it is incorporated. However, for this purpose, it is necessary to add great quantities of psyllium. This review analyses the potential use of psyllium in distinct food products, considering its advantages and inconveniences as well as possible solutions for undesired effects. Among the analyzed products there are bakery products and, in particular, gluten-free breads where psyllium has been used as a gluten substitute. The incorporation of psyllium into dairy products such as yogurts and those derived from fruits, among others, is also addressed.

Can dietary viscous fiber affect body weight independently of an energy-restrictive diet? A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The role of dietary fiber in obesity management remains debatable. Evidence suggests that intake of viscous fiber may have the potential to facilitate weight loss.

OBJECTIVE

We aimed to summarize and quantify the effects of viscous fiber on body weight, BMI, waist circumference, and body fat, independent of calorie restriction, through a systematic review and meta-analysis of randomized controlled trials.

METHODS

Trials ≥4 wk in duration that assessed the effect of viscous fiber supplemented to an ad libitum diet along with comparator diets were included. MEDLINE, EMBASE, and the Cochrane library were searched through 24 July, 2019. Two independent reviewers extracted relevant data. Data were pooled using the generic inverse variance method and random-effects models and expressed as mean differences with 95% CIs. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). The overall certainty of evidence was explored using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Findings from 62 trials (n = 3877) showed that viscous fiber reduced mean body weight (-0.33 kg; 95% CI: -0.51, -0.14 kg; P = 0.004), BMI (in kg/m2) (-0.28; 95% CI: -0.42, -0.14; P = 0.0001), and waist circumference (-0.63 cm; 95% CI: -1.11, -0.16 cm; P = 0.008), with no change in body fat (-0.78%; 95% CI: -1.56%, 0.00%; P = 0.05) when consumed with an ad libitum diet. Greater reductions in body weight were observed in overweight individuals and those with diabetes and metabolic syndrome. The certainty of evidence was graded moderate for body weight, high for waist circumference and body fat, and low for BMI.

CONCLUSIONS

Dietary viscous fiber modestly yet significantly improved body weight and other parameters of adiposity independently of calorie restriction. Future trials are warranted to address the inconsistency and imprecision identified through GRADE and to determine long-term weight-loss sustainability.This systematic review and meta-analysis was registered at clinicaltrials.gov as NCT03257449.

Natural Products from Mediterranean Diet: From Anti-hyperlipidemic Agents to Dietary Epigenetic Modulators

Background:

Cardiovascular Diseases (CVD) are, currently, the major contributor to global mortality and will continue to dominate mortality rates in the future. Hyperlipidemia refers to the elevated levels of lipids and cholesterol in the blood, and is also identified as dyslipidemia, manifesting in the form of different disorders of lipoprotein metabolism. These abnormalities may lead to the development of atherosclerosis, which can lead to coronary artery disease and stroke. In recent years, there is a growing interest in the quest for alternative therapeutic treatments based on natural products, offering better recovery and the avoidance of side effects. Recent technological advances have further improved our understanding of the role of epigenetic mechanisms in hyperlipidemic disorders and dietary prevention strategies.

Objective:

This is a comprehensive overview of the anti-hyperlipidemic effects of plant extracts, vegetables, fruits and isolated compounds thereof, with a focus on natural products from the Mediterranean region as well as the possible epigenetic changes in gene expression or cardiometabolic signaling pathways.

Methods:

For the purpose of this study, we searched the PubMed, Scopus and Google Scholar databases for eligible articles and publications over the last five years. The keywords included: “hyperlipidemia”, “plant extract”, “herbs”, “natural products”, “vegetables”, “cholesterol” and others. We initially included all relevant articles referring to in vitro studies, animal studies, Randomized Controlled Trials (RCTs) and previous reviews.

Conclusion:

Many natural products found in the Mediterranean diet have been studied for the treatment of hyperlipidemia. The antihyperlipidemic effect seems to be dose and/or consumption frequency related, which highlights the fact that a healthy diet can only be effective in reversing disease markers if it is consistent and within the framework of a healthy lifestyle. Finally, epigenetic biomarkers are increasingly recognized as new lifestyle management tools to monitor a healthy dietary lifestyle for the prevention of hyperlipidaemic disorders and comorbidities to promote a healthy life.

Meta-Analysis of Usefulness of Psyllium Fiber as Adjuvant Antilipid Therapy to Enhance Cholesterol Lowering Efficacy of Statins

Statins are usually well-tolerated drugs with a clear dose-dependent efficacy. However, manifestation of statin's side effects also bears a direct relation to higher doses necessary to achieve high impact cholesterol-lowering effects. Nevertheless, the reliance on statin efficacy alone has often left dietary intervention underutilized even though studies have shown a reduction in serum cholesterol levels when dietary fiber intake is increased. In this meta-analysis, we investigated whether the concomitant use of psyllium, a gel-forming viscous soluble fiber, would cause further overall cholesterol lowering in subjects already receiving statins. A systematic review of the medical literature was performed and identified three randomized, controlled clinical studies that evaluated the cholesterol lowering efficacy of statins when given concomitantly with psyllium as a fiber supplement. The duration of the studies ranged from 4 weeks to 12 weeks. The objective of the meta-analysis was to estimate the overall effect of psyllium plus statin versus statin alone. The results of the meta-analysis showed a clinically and statistically significant (p = 0.001) cholesterol lowering advantage for psyllium plus statin combination treatment over a statin alone. Adding psyllium fiber resulted in reductions in low-density lipoprotein-cholesterol equivalent to doubling the statin dose. In conclusion, the data support that psyllium fiber takenbefore meals adds to the efficacy of statins, providing an easy to implement dietary intervention for those who cannot tolerate side effects associated with higher-dose statins.

Lipid Lowering with Soluble Dietary Fiber

Consumption of dietary soluble fibers has been associated with health benefits such as reduced lipid levels, lower blood pressure, improved blood glucose control, weight loss, improved immune function, and reduced inflammation. Many of these health benefits relate to a reduced risk of developing cardiovascular disease. In this paper, we have reviewed recent studies on the hypocholesterolemic effects of dietary soluble fibers as well as fiber-rich foods. Findings include the following: (a) consumption of water-soluble, viscous-forming fibers can reduce total and low-density lipoprotein cholesterol levels by about 5-10 %; (b) minimal changes of high-density lipoprotein cholesterol or triglyceride levels were observed; (c) cholesterol-lowering properties of soluble fibers depend on their physical and chemical properties; and (d) medium to high molecular weight fibers are more effective in reducing lipid levels. Hypocholesterolemic benefits were also observed with some fiber-rich foods, such as whole oats, whole barley, legumes, peas, beans, flax seeds, apples, and citrus foods.

Fiber supplements and clinically proven health benefits: How to recognize and recommend an effective fiber therapy

BACKGROUND

Only 5% of adults consume the recommended level of dietary fiber. Fiber supplements appear to be a convenient and concentrated source of fiber, but most do not provide the health benefits associated with dietary fiber.

PURPOSE

This review will summarize the physical effects of isolated fibers in small and large intestines, which drive clinically meaningful health benefits.

DATA SOURCES

A comprehensive literature review was conducted (Scopus and PubMed) without limits to year of publication (latest date included: October 31, 2016).

CONCLUSIONS

The physical effects of fiber in the small intestine drive metabolic health effects (e.g., cholesterol lowering, improved glycemic control), and efficacy is a function of the viscosity of gel-forming fibers (e.g., psyllium, β-glucan). In the large intestine, fiber can provide a laxative effect if (a) it resists fermentation to remain intact throughout the large intestine, and (b) it increases percentage of water content to soften/bulk stool (e.g., wheat bran and psyllium).

IMPLICATIONS FOR PRACTICE

It is important for nurse practitioners to understand the underlying mechanisms that drive specific fiber-related health benefits, and which fiber supplements have rigorous clinical data to support a recommendation.

CLINICAL PEARL

For most fiber-related beneficial effects, "Fiber needs to gel to keep your patients well."

Drug interventions for the treatment of obesity in children and adolescents

BACKGROUND

Child and adolescent obesity has increased globally, and can be associated with significant short- and long-term health consequences.

OBJECTIVES

To assess the efficacy of drug interventions for the treatment of obesity in children and adolescents.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PubMed (subsets not available on Ovid), LILACS as well as the trial registers ICTRP (WHO) and ClinicalTrials.gov. Searches were undertaken from inception to March 2016. We checked references and applied no language restrictions.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) of pharmacological interventions for treating obesity (licensed and unlicensed for this indication) in children and adolescents (mean age under 18 years) with or without support of family members, with a minimum of three months' pharmacological intervention and six months' follow-up from baseline. We excluded interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or included participants with a secondary or syndromic cause of obesity. In addition, we excluded trials which included growth hormone therapies and pregnant participants.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data following standard Cochrane methodology. Where necessary we contacted authors for additional information.

MAIN RESULTS

We included 21 trials and identified eight ongoing trials. The included trials evaluated metformin (11 trials), sibutramine (six trials), orlistat (four trials), and one trial arm investigated the combination of metformin and fluoxetine. The ongoing trials evaluated metformin (four trials), topiramate (two trials) and exenatide (two trials). A total of 2484 people participated in the included trials, 1478 participants were randomised to drug intervention and 904 to comparator groups (91 participants took part in two cross-over trials; 11 participants not specified). Eighteen trials used a placebo in the comparator group. Two trials had a cross-over design while the remaining 19 trials were parallel RCTs. The length of the intervention period ranged from 12 weeks to 48 weeks, and the length of follow-up from baseline ranged from six months to 100 weeks.Trials generally had a low risk of bias for random sequence generation, allocation concealment and blinding (participants, personnel and assessors) for subjective and objective outcomes. We judged approximately half of the trials as having a high risk of bias in one or more domain such as selective reporting.The primary outcomes of this review were change in body mass index (BMI), change in weight and adverse events. All 21 trials measured these outcomes. The secondary outcomes were health-related quality of life (only one trial reported results showing no marked differences; very low certainty evidence), body fat distribution (measured in 18 trials), behaviour change (measured in six trials), participants' views of the intervention (not reported), morbidity associated with the intervention (measured in one orlistat trial only reporting more new gallstones following the intervention; very low certainty evidence), all-cause mortality (one suicide in the orlistat intervention group; low certainty evidence) and socioeconomic effects (not reported).Intervention versus comparator for mean difference (MD) in BMI change was -1.3 kg/m² (95% confidence interval (CI) -1.9 to -0.8; P < 0.00001; 16 trials; 1884 participants; low certainty evidence). When split by drug type, sibutramine, metformin and orlistat all showed reductions in BMI in favour of the intervention.Intervention versus comparator for change in weight showed a MD of -3.9 kg (95% CI -5.9 to -1.9; P < 0.00001; 11 trials; 1180 participants; low certainty evidence). As with BMI, when the trials were split by drug type, sibutramine, metformin and orlistat all showed reductions in weight in favour of the intervention.Five trials reported serious adverse events: 24/878 (2.7%) participants in the intervention groups versus 8/469 (1.7%) participants in the comparator groups (risk ratio (RR) 1.43, 95% CI 0.63 to 3.25; 1347 participants; low certainty evidence). A total 52/1043 (5.0%) participants in the intervention groups versus 17/621 (2.7%) in the comparator groups discontinued the trial because of adverse events (RR 1.45, 95% CI 0.83 to 2.52; 10 trials; 1664 participants; low certainty evidence). The most common adverse events in orlistat and metformin trials were gastrointestinal (such as diarrhoea, mild abdominal pain or discomfort, fatty stools). The most frequent adverse events in sibutramine trials included tachycardia, constipation and hypertension. The single fluoxetine trial reported dry mouth and loose stools. No trial investigated drug treatment for overweight children.

AUTHORS' CONCLUSIONS

This systematic review is part of a series of associated Cochrane reviews on interventions for obese children and adolescents and has shown that pharmacological interventions (metformin, sibutramine, orlistat and fluoxetine) may have small effects in reduction in BMI and bodyweight in obese children and adolescents. However, many of these drugs are not licensed for the treatment of obesity in children and adolescents, or have been withdrawn. Trials were generally of low quality with many having a short or no post-intervention follow-up period and high dropout rates (overall dropout of 25%). Future research should focus on conducting trials with sufficient power and long-term follow-up, to ensure the long-term effects of any pharmacological intervention are comprehensively assessed. Adverse events should be reported in a more standardised manner specifying amongst other things the number of participants experiencing at least one adverse event. The requirement of regulatory authorities (US Food and Drug Administration and European Medicines Agency) for trials of all new medications to be used in children and adolescents should drive an increase in the number of high quality trials.

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.

Understanding the Physics of Functional Fibers in the Gastrointestinal Tract: An Evidence-Based Approach to Resolving Enduring Misconceptions about Insoluble and Soluble Fiber

Enduring misconceptions about the physical effects of fiber in the gut have led to misunderstandings about the health benefits attributable to insoluble and soluble fiber. This review will focus on isolated functional fibers (eg, fiber supplements) whose effects on clinical outcomes have been readily assessed in well-controlled clinical studies. This review will also focus on three health benefits (cholesterol lowering, improved glycemic control, and normalizing stool form [constipation and diarrhea]) for which reproducible evidence of clinical efficacy has been published. In the small bowel, clinically meaningful health benefits (eg, cholesterol lowering and improved glycemic control) are highly correlated with the viscosity of soluble fibers: high viscosity fibers (eg, gel-forming fibers such as b-glucan, psyllium, and raw guar gum) exhibit a significant effect on cholesterol lowering and improved glycemic control, whereas nonviscous soluble fibers (eg, inulin, fructooligosaccharides, and wheat dextrin) and insoluble fibers (eg, wheat bran) do not provide these viscosity-dependent health benefits. In the large bowel, there are only two mechanisms that drive a laxative effect: large/coarse insoluble fiber particles (eg, wheat bran) mechanically irritate the gut mucosa stimulating water and mucous secretion, and the high water-holding capacity of gel-forming soluble fiber (eg, psyllium) resists dehydration. Both mechanisms require that the fiber resist fermentation and remain relatively intact throughout the large bowel (ie, the fiber must be present in stool), and both mechanisms lead to increased stool water content, resulting in bulky/soft/easy-to-pass stools. Soluble fermentable fibers (eg, inulin, fructooligosaccharide, and wheat dextrin) do not provide a laxative effect, and some fibers can be constipating (eg, wheat dextrin and fine/smooth insoluble wheat bran particles). When making recommendations for a fiber supplement, it is essential to recognize which fibers possess the physical characteristics required to provide a beneficial health effect, and which fiber supplements are supported by reproducible, rigorous evidence of one or more clinically meaningful health benefits.

Effects of dietary fibre type on blood pressure: a systematic review and meta-analysis of randomized controlled trials of healthy individuals

OBJECTIVE

To determine the effect of different types of dietary fibre on SBP and DBP.

METHODS

A systematic review of the literature and a meta-analysis of randomized controlled trials using random-effects models. Eligibility criteria for studies included randomized controlled trials of at least 6 weeks duration, testing a fibre isolate or fibre-rich diet against a control or placebo published between 1 January 1990 and 1 December 2013.

RESULTS

Twenty-eight trials met the inclusion criteria and reported fibre intake and SBP and/or DBP. Eighteen trials were included in a meta-analysis. Studies were categorized into 1 of 12 fibre-type categories. The pooled estimates for all fibre types were -0.9 mmHg [95% confidence interval (CI) -2.5 to 0.6 mmHg] and -0.7 mmHg (95% CI -1.9 to 0.5 mmHg) for SBP and DBP, respectively. The median difference in total fibre was 6 g. Analyses of specific fibre types concluded that diets rich in beta-glucans reduce SBP by 2.9 mmHg (95% CI 0.9 to 4.9 mmHg) and DBP by 1.5 mmHg (95% CI 0.2 to 2.7 mmHg) for a median difference in beta-glucans of 4 g. Heterogeneity for individual fibre types was generally low.

CONCLUSIONS

Higher consumption of beta-glucan fibre is associated with lower SBP and DBP. The results of this review are consistent with recommendations to increase consumption of foods rich in dietary fibre, but some additional emphasis on sources of beta-glucans, such as oats and barley, may be warranted.

Dietary fiber and blood pressure control

In the past few years, new strategies as dietary fiber to control blood pressure levels are emerging by developing new bioactive components of foods. The implicated mechanisms are under research.

Psyllium fiber improves glycemic control proportional to loss of glycemic control: a meta-analysis of data in euglycemic subjects, patients at risk of type 2 diabetes mellitus, and patients being treated for type 2 diabetes mellitus

BACKGROUND

A number of health benefits are associated with intake of soluble, viscous, gel-forming fibers, including reduced serum cholesterol and the attenuation of postprandial glucose excursions.

OBJECTIVE

We assess the effects of psyllium, which is a soluble, gel-forming, nonfermented fiber supplement, on glycemic control in patients who were being treated for type 2 diabetes mellitus (T2DM) and in patients who were at risk of developing T2DM.

DESIGN

A comprehensive search was performed of available published literature (Scopus scientific database) and clinical records stored by Procter & Gamble with the use of key search terms to identify clinical studies that assessed the glycemic effects of psyllium in nondiabetic, pre-T2DM, and T2DM patients.

RESULTS

We identified 35 randomized, controlled, clinical studies that spanned 3 decades and 3 continents. These data were assessed in 8 meta-analyses. In patients with T2DM, multiweek studies (psyllium dosed before meals) showed significant improvement in both the fasting blood glucose (FBG) concentration (-37.0 mg/dL; P < 0.001) and glycated hemoglobin (HbA1c) [-0.97% (-10.6 mmol/mol); P = 0.048]. Glycemic effects were proportional to baseline FBG; no significant glucose lowering was observed in euglycemic subjects, a modest improvement was observed in subjects with pre-T2DM, and the greatest improvement was observed in subjects who were being treated for T2DM.

CONCLUSIONS

These data indicate that psyllium would be an effective addition to a lifestyle-intervention program. The degree of psyllium's glycemic benefit was commensurate with the loss of glycemic control. Because the greatest effect was seen in patients who were being treated for T2DM, additional studies are needed to determine how best to incorporate psyllium into existing prevention and treatment algorithms with concomitant hypoglycemic medications.

Herbs with anti-lipid effects and their interactions with statins as a chemical anti- hyperlipidemia group drugs: A systematic review

BACKGROUND

The present systematic review aimed to express the clinical anti-lipid effects of different types of herbs, as well as described studied interactions between herbal remedies and prescribed drugs for hyperlipidemic patients which were based on in vitro experiments, animal studies, and empirical clinical experiences.

METHODS

For this systematic review, we explored 2183 published papers about herbal drugs interactions from November 1967 to August 2014, fulfilling eligibility criteria by searching in some databases such as Web of Science, Medline, Scopus, Embase, Cinahl, and the Cochrane database. The main keywords used for searching included: herbal medicine, herbs, statin, lipid, and herb-drug interaction.

RESULTS

Among published articles about herb-drug interactions, 185 papers met the initial search criteria and among them, 92 papers were potentially retrievable including a description of 17 herbs and medicinal plants. In first step and by reviewing all published manuscripts on beneficial effects of herbs on serum lipids level, 17 herbs were described to be effective on lipid profile as lowering serum triglyceride, total cholesterol, low-density lipoprotein cholesterol as well as increasing serum high-density lipoprotein level. Some herbs such as celery could even affect the hepatic triglyceride concentrations. The herbal reaction toward different types of statins is varied so that grapefruit or pomegranate was interacted with only some types of statins, but not with all statin types. In this context, administration of herbal materials can lead to decreased absorption of statins or decreased the plasma concentration of these drugs.

CONCLUSION

Various types of herbs can potentially reduce serum lipid profile with the different pathways; however, the herb-drug interactions may decrease pharmacological therapeutic effects of anti-hyperlipidemic drugs that should be considered when approved herbs are prescribed.

Effects of psyllium on LDL-cholesterol concentrations in Brazilian children and adolescents: a randomised, placebo-controlled, parallel clinical trial

The present study investigated the LDL-cholesterol (LDL-C)-lowering effects of psyllium in Brazilian dyslipidaemic children and adolescents. A total of fifty-one individuals (6–19 years) with mild-to-moderate hypercholesterolaemia were evaluated by conducting a randomised, double-blind, placebo-controlled, parallel clinical trial. Over an 8-week trial period, the participants were randomly allocated to one of two groups (control:n25 and psyllium:n26) using a computer-generated random number sequence. Fasting blood samples, dietary records and anthropometric data were collected. Both groups were treated with the National Cholesterol Education Program Step 2 diet for 6 weeks before randomisation. After this run-in period, a daily supplement of 7·0 g psyllium was given to the intervention group, while an equivalent amount of cellulose was given to the control group. Statistically significant changes between the control and intervention groups over time were observed for total cholesterol (7·7 %; − 0·39 mmol/l;P= 0·003) and LDL-C (10·7 %; − 0·36 mmol/l;P= 0·01). None of the participants reported any aversion to the smell, taste, appearance or texture of psyllium. No serious adverse effects were reported during the study. In addition to causing a significant reduction in LDL-C concentrations, psyllium therapy was found to be both safe and acceptable for the treatment of hypercholesterolaemic children and adolescents.

Fiber and functional gastrointestinal disorders

Despite years of advising patients to alter their dietary and supplementary fiber intake, the evidence surrounding the use of fiber for functional bowel disease is limited. This paper outlines the organization of fiber types and highlights the importance of assessing the fermentation characteristics of each fiber type when choosing a suitable strategy for patients. Fiber undergoes partial or total fermentation in the distal small bowel and colon leading to the production of short-chain fatty acids and gas, thereby affecting gastrointestinal function and sensation. When fiber is recommended for functional bowel disease, use of a soluble supplement such as ispaghula/psyllium is best supported by the available evidence. Even when used judiciously, fiber can exacerbate abdominal distension, flatulence, constipation, and diarrhea.