Effects of NUTRIOSE® dietary fiber supplementation on body weight, body composition, energy intake, and hunger in overweight men

Impact of Plant-Based Dietary Fibers on Metabolic Homeostasis in High-Fat Diet Mice via Alterations in the Gut Microbiota and Metabolites

BACKGROUND

The gut microbiota contributes to metabolic disease, and diet shapes the gut microbiota, emphasizing the need to better understand how diet impacts metabolic disease via gut microbiota alterations. Fiber intake is linked with improvements in metabolic homeostasis in rodents and humans, which is associated with changes in the gut microbiota. However, dietary fiber is extremely heterogeneous, and it is imperative to comprehensively analyze the impact of various plant-based fibers on metabolic homeostasis in an identical setting and compare the impact of alterations in the gut microbiota and bacterially derived metabolites from different fiber sources.

OBJECTIVES

The objective of this study was to analyze the impact of different plant-based fibers (pectin, β-glucan, wheat dextrin, resistant starch, and cellulose as a control) on metabolic homeostasis through alterations in the gut microbiota and its metabolites in high-fat diet (HFD)-fed mice.

METHODS

HFD-fed mice were supplemented with 5 different fiber types (pectin, β-glucan, wheat dextrin, resistant starch, or cellulose as a control) at 10% (wt/wt) for 18 wk (n = 12/group), measuring body weight, adiposity, indirect calorimetry, glucose tolerance, and the gut microbiota and metabolites.

RESULTS

Only β-glucan supplementation during HFD-feeding decreased adiposity and body weight gain and improved glucose tolerance compared with HFD-cellulose, whereas all other fibers had no effect. This was associated with increased energy expenditure and locomotor activity in mice compared with HFD-cellulose. All fibers supplemented into an HFD uniquely shifted the intestinal microbiota and cecal short-chain fatty acids; however, only β-glucan supplementation increased cecal butyrate concentrations. Lastly, all fibers altered the small-intestinal microbiota and portal bile acid composition.

CONCLUSIONS

These findings demonstrate that β-glucan consumption is a promising dietary strategy for metabolic disease, possibly via increased energy expenditure through alterations in the gut microbiota and bacterial metabolites in mice.

Characterization, health benefits, and food applications of enzymatic digestion- resistant dextrin: A review

Resistant dextrin or resistant maltodextrin (RD), a short-chain glucose polymer that is highly resistant to hydrolysis by human digestive enzymes, has shown broad developmental prospects in the food industry and has gained substantial attention owing to its lack of undesirable effects on the sensory features of food or the digestive system. However, comprehensive fundamental and application information on RD and how RD improves anti-diabetes and obesity have not yet been received. Therefore, the characterization, health benefits and application of RD in various fields are summarized and discussed in the current study. Typically, RD is prepared by the acid thermal method and possesses excellent physicochemical properties, including low viscosity, high solubility, storage stability, and low retro-gradation, which are correlated with its low molecular weight (Mw) and non-digestible glycosidic linkages. In contrast, RD prepared by the simultaneous debranching and crystallization method has low solubility and high crystallinity. The ingestion of RD can positively affect metabolic diseases (diabetes and obesity) in animals and humans by producing short-chain fatty acids (SCFAs), and facilitating the inflammatory response. Moreover, RD has been widely used in the beverage, dairy products, and dessert industries due to its nutritional value and textural properties without unacceptable quality loss. More studies are required to further explore RD application potential in the food industry and its role in the management of different chronic metabolic disorders.

Improvement of energy metabolism associated with NUTRIOSE® soluble fiber, a dietary ingredient exhibiting prebiotic properties, requires intestinal gluconeogenesis

While the prevalence of obesity progresses worldwide, the consumption of sugars and dietary fiber increases and decreases, respectively. In this context, NUTRIOSE® soluble fiber is a plant-based food ingredient with beneficial effects in Humans. Here, we studied in mice the mechanisms involved, particularly the involvement of intestinal gluconeogenesis (IGN), the essential function in the beneficial effects of dietary fibers. To determine whether NUTRIOSE® exerts its beneficial effects via the activation of IGN, we studied the effects of dietary NUTRIOSE® on the development of obesity, diabetes and non-alcoholic fatty liver disease (NAFLD), which IGN is able to prevent. To assert the role of IGN in the observed effects, we studied wild-type (WT) and IGN-deficient mice. In line with our hypothesis, NUTRIOSE® exerts metabolic benefits in WT mice, but not in IGN-deficient mice. Indeed, WT mice are protected from body weight gain and NAFLD induced by a high calorie diet. In addition, our data suggests that NUTRIOSE® may improve energy balance by activating a browning process in subcutaneous white adipose tissue. While the gut microbiota composition changes with NUTRIOSE®, this is not sufficient in itself to account for the benefits observed. On the contrary, IGN is obligatory in the NUTRIOSE® benefits, since no benefit take place in absence of IGN. In conclusion, IGN plays a crucial and essential role in the set-up of the beneficial effects of NUTRIOSE®, highlighting the interest of the supplementation of food with healthy ingredients in the context of the current obesity epidemic.

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.

Prolonged Isolated Soluble Dietary Fibre Supplementation in Overweight and Obese Patients: A Systematic Review with Meta-Analysis of Randomised Controlled Trials

The prevalence of overweight and obesity is rising rapidly, currently affecting 1.9 billion adults worldwide. Prebiotic dietary fibre supplementation is a promising approach to improve weight loss and reduce metabolic complications in overweight and obese subjects due to modifications of the microbiota composition and function. Previous systematic reviews and meta-analyses addressing similar questions revealed discordant evidence and/or are outdated. We searched MEDLINE, Embase, Google Scholar, and forward and backward citations for randomised controlled trials (RCTs) with isolated soluble dietary fibre supplementation for at least 12 weeks in overweight and obese patients measuring body weight, published through April 2022. We expressed the results as mean differences (MDs) using the random-effects model of the metafor package in R and assessed risk of bias using the Cochrane RoB2 tool. We conducted the study according to the PRISMA guidelines and registered the protocol on PROSPERO (CRD42022295246). The participants with dietary fibre supplementation showed a significantly higher reduction in body weight (MD -1.25 kg, 95% CI -2.24, -0.25; 27 RCTs; 1428 participants) accompanied by a significant decrease in BMI, waist circumference, fasting blood insulin, and HOMA-IR compared to the control group. Certainty of evidence was high, paving the way for the implementation of isolated soluble dietary fibre supplementation into clinical practice.

Diet Supplementation with NUTRIOSE, a Resistant Dextrin, Increases the Abundance of Parabacteroides distasonis in the Human Gut

SCOPE

An imbalance of the gut microbiota ("dysbiosis") is associated with numerous chronic diseases, and its modulation is a promising novel therapeutic approach. Dietary supplementation with soluble fiber is one of several proposed modulation strategies. This study aims at confirming the impact of the resistant dextrin NUTRIOSE (RD), a soluble fiber with demonstrated beneficial health effects, on the gut microbiota of healthy individuals.

METHODS AND RESULTS

Fifty healthy women are enrolled and supplemented daily with either RD (n = 24) or a control product (n = 26) during 6 weeks. Characterization of the fecal metagenome with shotgun sequencing reveals that RD intake dramatically increases the abundance of the commensal bacterium Parabacteroides distasonis. Furthermore, presence in metagenomes of accessory genes from P. distasonis, coding for susCD (a starch-binding membrane protein complex) is associated with a greater increase of the species. This suggests that response to RD might be strain-dependent.

CONCLUSION

Supplementation with RD can be used to specifically increase P. distasonis in gut microbiota of healthy women. The magnitude of the response may be associated with fiber-metabolizing capabilities of strains carried by subjects. Further research will seek to confirm that P. distasonis directly modulates the clinical effects observed in other studies.

Effect of Lactobacillus rhamnosus GG fermentation on the structural and functional properties of dietary fiber in bamboo shoot and its application in bread

The purpose of this study was to investigate the effects of Lactobacillus rhamnosus GG (LGG) fermentation on the composition, structure, and functional properties of dietary fiber (DF) in bamboo shoot. Then, we added it to bread to evaluate the texture properties, digestive properties, and functionality of bread. After LGG fermentation, the DF was decomposed into pieces, which had stronger water-swelling capacity and nitrite adsorption capacity. The ability of producing short-chain fatty acids was significantly improved and the digestive resistance was remarkable enhanced as well. Except the bread hardness was increased, there was no significant difference in other texture properties when adding 3% FTDF-LGG to bread. It had good adsorption capacity of cholesterol and more than 25% reduced the release of reducing sugar. Overall, the technic of LGG fermentation had improved functional properties of DF in bamboo shoot, which could be applied to bread production for exerting its effects in the future. PRACTICAL APPLICATIONS: Bamboo shoots are immature and tender stems of bamboo, rich in nutritional value, and rich in DF. Bamboo shoot DF has been proven to have a variety of biological activities, and is the main material for bamboo shoot to exert functional activities. In this study, bamboo shoot DF was modified by LGG fermentation, which showed stronger functional activity, and was successfully applied to bread. This study lays the foundation for the fermented modified bamboo shoot DF and its application in food.

Purified diet versus whole food diet and the inconsistent results in studies using animal models

In animal models, purified diets (PDs) and whole food diets (WFDs) are used for different purposes. In similar studies, different dietary patterns may lead to inconsistent results. The aim of this study was to evaluate and compare the effects of WFDs and PDs on changes in the metabolism of mice. We found that different dietary patterns produced different results in lipid metabolism experiments. Compared with those of the PD-fed mice, the WFD-fed mice had higher body weights and serum glucose, serum lipid, and liver lipid levels (p < 0.01), as well as low glucose tolerance (p < 0.01) and insulin sensitivity (p < 0.05). The body weight and fasting blood glucose increased by 20% in the WFD-fed mice, and the white adipose tissue weight increased by ∼50%. The WFD-fed mice also had a comparatively higher abundance of Lactobacillus, Turicibacter, Bifidobacterium, Desulfovibrio, and Candidatus saccharimonas (p < 0.01), which were positively correlated with lipid accumulation. Dietary patterns should be chosen cautiously in studies that use rodents as models. Inappropriate selection of animal dietary patterns may lead to experimental systematic errors and paradoxical results.

Tapioca Resistant Maltodextrin as a Carbohydrate Source of Oral Nutrition Supplement (ONS) on Metabolic Indicators: A Clinical Trial

Tapioca resistant maltodextrin (TRM) is a novel non-viscous soluble resistant starch that can be utilized in oral nutrition supplements (ONS). This study aims to evaluate acute and long-term metabolic responses and the safe use of ONS containing TRM. This study comprised of two phases: In Phase I, a randomized-cross over control study involving 17 healthy adults was conducted to evaluate three ONS formulations: original (tapioca maltodextrin), TRM15 (15% TRM replacement), and TRM30 (30% TRM replacement). Plasma glucose, serum insulin, and subjective appetite were evaluated postprandially over 180 min. In Phase II, 22 participants consumed one serving/day of ONS for 12 weeks. Blood glucose, insulin, lipid profile, and body composition were evaluated. Gastrointestinal tolerability was evaluated in both the acute and long-term period. During phase I, TRM30 decreased in area under the curve of serum insulin by 33.12%, compared to the original formula (2320.71 ± 570.76 uIU × min/mL vs. 3470.12 ± 531.87 uIU × min/mL, p = 0.043). In Phase II, 12-week TRM30 supplementation decreased HbA1C in participants (from 5.5 ± 0.07% to 5.2 ± 0.07%, p < 0.001), without any significant effect on fasting glucose, insulin, lipid profile, and body composition. The ONS was well-tolerated in both studies. TRM is therefore, a beneficial functional fiber for various food industries.

A Specifically Tailored Multistrain Probiotic and Micronutrient Mixture Affects Nonalcoholic Fatty Liver Disease-Related Markers in Patients with Obesity after Mini Gastric Bypass Surgery

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is frequent among patients undergoing bariatric surgery. Beyond weight reduction, dietary supplements like micronutrients or probiotics that modify insulin resistance and lipotoxicity can be used to prevent or delay the progression of liver disease.

OBJECTIVES

We evaluated the effect of a dietary approach with a specifically tailored multistrain probiotic and micronutrient mixture compared with a basic care micronutrient supplement on serum alanine aminotransferase (ALAT) in obese patients after mini gastric bypass (MGB) surgery.

METHODS

This randomized, double-blind, controlled trial included 60 obese patients (age: 40 ± 10 y; BMI: 44 ± 3 kg/m²). Patients received a combination of specifically tailored multistrain probiotic powder and a specific micronutrient mixture (Pro+SM) or a control treatment consisting of a placebo and a basic care micronutrient mixture (Con+BM), with some micronutrients in lower doses than SM, for 12 wk after hospital discharge. Primary (serum ALAT) and secondary outcomes [serum aspartate aminotransferase (ASAT), fatty liver index, NAFLD fibrosis score, glucose metabolism, blood pressure (BP), heart rate] were assessed at week 0 and week 12. Data were analyzed using unpaired Student's t-tests or Mann-Whitney U tests to compare the changes due to each treatment to one another.

RESULTS

A total of 48 patients were included in the analyses. Changes in serum ALAT concentrations did not differ between groups. Compared with Con+BM, Pro+SM improved serum ASAT (difference: -8.0 U/L, 95% CI: -17.0, -4.0; P = 0.043), NAFLD fibrosis score (difference: -0.39; 95% CI: -0.78, 0; P = 0.048), serum triglycerides (difference: -22.8 mg/dL; 95% CI: -45.6, -0.1; P = 0.049) and the visceral adiposity index (difference: -0.70; 95% CI: -1.31, -0.08; P = 0.027).

CONCLUSION

Supplementation with a specifically tailored probiotic and micronutrient mixture improved NAFLD-related markers more than a basic micronutrient mixture in obese patients following MGB surgery. The trial was registered under clinicaltrials.gov as NCT03585413.

Effect of Continuous and Discontinuous Microwave-Assisted Heating on Starch-Derived Dietary Fiber Production

Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content.

Efficacy of dietary supplements containing isolated organic compounds for weight loss: a systematic review and meta-analysis of randomised placebo-controlled trials

BACKGROUND/OBJECTIVES

A systematic review with meta-analysis was conducted to synthesise evidence on the efficacy of dietary supplements containing isolated organic compounds for weight loss.

SUBJECTS/METHODS

Four electronic databases (Medline, Embase, Web of Science, Cinahl) were searched until December 2019. Sixty-seven randomised placebo-controlled trials of dietary supplements containing isolated organic compounds for weight loss were included. Meta-analyses were conducted for chitosan, glucomannan, conjugated linoleic acid and fructans, comparing mean weight difference post-intervention between participants receiving the dietary supplement or placebo.

RESULTS

Statistically significant weight differences compared to placebo were observed for chitosan (-1.84 kg; 95% confidence interval [CI] -2.79, -0.88; p < 0.01), glucomannan (-1.27 kg; 95%CI -2.45, -0.09; p = 0.04), and conjugated linoleic acid (-1.08 kg; 95%CI -1.61, -0.55; p < 0.01). None met our threshold for clinical significance (≥2.5 kg). There was no statistically significant effect on weight for fructans compared to placebo (p = 0.24). For dietary supplements with an inadequate number of trials for meta-analysis, a statistically and borderline clinically significant weight difference compared to placebo was found for modified cellulose, manno-oligosaccharides (in males), blood orange juice extract, and three multiple-ingredient dietary supplements. These were only reported in one trial of each. Thus, more evidence is needed before recommending them for weight loss.

CONCLUSIONS

While some dietary supplements containing isolated organic compounds warrant further investigation to determine efficacy and safety, there is currently insufficient evidence to recommend any of these dietary supplements for weight loss.

Impact of dietary supplementation with resistant dextrin (NUTRIOSE®) on satiety, glycaemia, and related endpoints, in healthy adults

PURPOSE

Resistant dextrin (RD) supplementation has been shown to alter satiety, glycaemia, and body weight, in overweight Chinese men; however, there are limited data on its effects in other demographic groups. Here, we investigated the effects of RD on satiety in healthy adults living in the United Kingdom.

METHODS

20 normal weight and 16 overweight adults completed this randomised controlled cross-over study. Either RD (14 g/day NUTRIOSE^® FB06) or maltodextrin control was consumed in mid-morning and mid-afternoon preload beverages over a 28-day treatment period with crossover after a 28-day washout. During 10-h study visits (on days 1, 14, and 28 of each treatment period), satietogenic, glycaemic and anorectic hormonal responses to provided meals were assessed.

RESULTS

Chronic supplementation with RD was associated with higher fasted satiety scores at day 14 (P = 0.006) and day 28 (P = 0.040), compared to control. RD also increased satiety after the mid-morning intervention drink, but it was associated with a reduction in post-meal satiety following both the lunch and evening meals (P < 0.01). The glycaemic response to the mid-morning intervention drink (0-30 min) was attenuated following RD supplementation (P < 0.01). Whilst not a primary endpoint we also observed lower systolic blood pressure at day 14 (P = 0.035) and 28 (P = 0.030), compared to day 1, following RD supplementation in the normal weight group. Energy intake and anthropometrics were unaffected.

CONCLUSIONS

RD supplementation modified satiety and glycaemic responses in this cohort, further studies are required to determine longer-term effects on body weight control and metabolic markers. CLINICALTRIALS.

GOV REGISTRATION

NCT02041975 (22/01/2014).

Optimization of wheat dextrin yogurt formulation using response surface methodology

In the current study, response surface methodology was executed to optimize the ingredient formulation and process conditions production such as wheat dextrin, starter culture and incubation time on the responses such as pH, viscosity, syneresis, overall acceptability, L* value and hardness of the wheat dextrin yogurt. The analyses showed that the wheat dextrin yogurts have a pH from 4.09 to 4.98, viscosity from 10,649.5 to 21,410.1 cP, syneresis from 2 to 26.67%, overall acceptability from 5.3 to 7.9, L* value from 81.2 to 84.3 and hardness from 506 to 5943.3 g during the optimization process. From the variance analysis, the R2 of five response variables except hardness is more than 0.73, which indicates the model explained a high proportion of variability. To conclude, based on the response surface 3D plot of the pH, viscosity, syneresis, overall acceptability, L* value, and hardness evaluation, the optimum value for the independent variables are wheat dextrin of 15 g, a starter culture of 25 g, and an incubation time of 8 h for the wheat dextrin yogurt.

Supplemental Fiber Affects Body Temperature and Fecal Metabolites but Not Respiratory Rate or Body Composition in Mid-Distance Training Sled Dogs

Dietary fiber affects canine physiology in many ways, such as increasing colonic absorption of water and improving gut health, both of which may positively impact exercise performance. The objectives of this study were to investigate the effects of increased dietary soluble fiber and incremental training on respiratory rate (RR), internal body temperature (BT), body composition, and fecal metabolites in mid-distance training sled dogs. Fourteen dogs (12 Siberian and 2 Alaskan Huskies) were blocked by age, sex, and body weight (BW) and then randomly allocated into one of two diet groups. Seven dogs were fed a dry extruded control diet (Ctl) with an insoluble:soluble fiber ratio of 4:1 (0.74% soluble fiber on a dry-matter basis), and seven dogs were fed a dry extruded treatment diet (Trt) with an insoluble:soluble fiber ratio of 3:1 (2.12% soluble fiber on a dry-matter basis). Fecal samples were taken once a week. All dogs underwent 9 weeks of incremental exercise conditioning where the running distance was designed to increase each week. Every 3 weeks, external telemetry equipment was used to non-invasively measure and record RR and internal BT at resting, working, and post-exercise recovery states. Body composition was measured on weeks −1 and 9 using quantitative magnetic resonance. Body composition, RR, BT, and fecal metabolites were analyzed using a mixed model with dog as a random effect and week and diet group as fixed effects. Dogs on Trt had lower working and post-exercise BT than Ctl (P < 0.05). In addition, Trt dogs had lower recovery BT at weeks 2 and 5 than Ctl dogs (P < 0.05). Treatment dogs had greater fecal short-chain fatty acid concentrations than Ctl (P < 0.05). Diet had no effect on RR or body composition (P > 0.10), but exercise resulted in an overall 7% increase in lean and 3.5% decrease in fat mass (P < 0.05). These data suggest that increasing dietary soluble fiber may positively influence BT and gut health; however, it has no effect on RR or body composition. Soluble fiber did not negatively impact any measures of overall health and performance and should be considered for use in performance dogs.

Attenuation of glycaemic and insulin responses following tapioca resistant maltodextrin consumption in healthy subjects: a randomised cross-over controlled trial

Resistant maltodextrin (RMD) from various sources of starch has been extensively studied. However, studies which reported the effects of tapioca RMD (TRM) on glucose and insulin response are lacking. This study investigated the effect of TRM on postprandial plasma glucose and serum insulin in healthy subjects. Additionally, satiety and gastrointestinal tolerability were also evaluated. Sixteen healthy participants received five different treatments on five separate days. Participants received 50 g of either: glucose (GL), tapioca maltodextrin (TM), TRM, MIX15% (7⋅5 g TRM + 42⋅5 g TM) or MIX50% (25 g TRM + 25 g TM). Plasma glucose, serum insulin and subjective appetite responses were measured postprandially over 180 min. Gastrointestinal symptoms were evaluated by questionnaire before and after each test day. Results showed that at 30 min after treatment drinks, plasma glucose after TRM was significantly lowest (104⋅60 (sem 2⋅63 mg/dl) than after GL (135⋅87 (sem 4⋅88) mg/dl; P <0⋅001), TM (127⋅93 (sem 4⋅05) mg/dl; P = 0⋅001), MIX15% (124⋅67 (sem 5⋅73) mg/dl; P = 0⋅039) and MIX50% (129⋅33 (sem 5⋅23) mg/dl; P = 0⋅003) (1 mg/dl = 0⋅0555 mmol/l). In addition, TRM also significantly reduced serum insulin (13⋅01 (sem 2⋅12) μIU/ml) compared with GL (47⋅90 (sem 11⋅93) μIU/ml; P = 0⋅013), TM (52⋅96 (sem 17⋅68) μIU/ml; P = 0⋅002) and MIX50% (33⋅16 (sem 4⋅99) μIU/ml; P = 0⋅008). However, there were no significant differences in subjective appetite between treatments (P > 0⋅05). A single high dose of TRM (50 g) caused flatulence (P < 0⋅05). Tapioca resistant maltodextrin has low digestibility in the small intestine and, therefore, reduced incremental plasma glucose and serum insulin, without affecting satiety in healthy subjects over 180 min. Gastrointestinal tolerability of TRM should be considered when consumed in high doses.

Effects of resistant starch interventions on circulating inflammatory biomarkers: a systematic review and meta-analysis of randomized controlled trials

Purpose

This study aimed to summarize earlier studies on the effects of RS consumption on the serum levels of inflammatory biomarkers.

Methods

A comprehensive search was done in the electronic databases that published from 1988 up to May 2019. Two reviewers independently performed screening, data extraction, and risk-of-bias assessment. We used from the effect size, as estimated by the mean difference to perform the fixed method meta-analysis.

Results

Overall, 13 studies with 14 effect sizes met the inclusion criteria and were included in the final analysis. Sample size of these studies ranged from 15 to 75 and intervention duration ranged from 4 to 14 weeks. Meta-analysis revealed that higher consumption of resistant starch caused a significant reduction in the interleukin 6 (weighted mean difference = − 1.11 pg/mL; 95% CI: − 1.72, − 0.5 pg/mL; P = < 0.001) and tumor necrosis factor alpha (weighted mean difference = − 2.19 pg/mL; 95% CI: − 3.49, − 0.9 pg/mL; P = 0.001) levels. However, no significant changes were found in C-reactive protein concentration (weighted mean difference = − 0.21 mg/L; 95% CI: − 1.06, 0.63 mg/L; P = 0.61). Moreover, the changes in interleukin 6 concentration was dependent on study quality and intervention duration.

Conclusion

The current meta-analysis indicated that RS intake can improve some inflammatory biomarkers. More research, with a large sample sizes and accurate design is recommended.

Effect of water-soluble dietary fiber resistant dextrin on flour and bread qualities

A new water-soluble resistant dextrin (WSRD), fabricated by thermal-acid treatment following amylase hydrolysis from corn starch, was expected to strengthen the dietary fibers intake of flour products. This study was to investigate the effects of WSRD on flour processing quality, and further dissect its improvement mechanisms by farinographic and rheological analysis, SDS-PAGE, Fourier transform infrared spectroscopy, texture analyzer, etc. Results showed that WSRD greatly improved the viscoelasticity and strength of dough, which was predominantly contributed by its formation of gel-like networks. Meanwhile, the WSRD-induced increase of gluten aggregates and β-sheet conformation provided the structural basis for enhancing dough quality. Notably, WSRD greatly promoted the sensory appearance and crumb quality of baked breads. Moreover, the WSRD-treated breads resisted the hydrolysis of digestive fluid and enzymes. Therefore, WSRD can strengthen the processing qualities and nutritional values of flour products, which will broaden the application of the novel dietary fiber in flour industry.

Resistant dextrin reduces obesity and attenuates adipose tissue inflammation in high-fat diet-fed mice

Resistant dextrin (RD), a short chain glucose polymer, has been shown to improve type 2 diabetes mellitus (T2DM) in clinical studies. However, the improvement of adipose tissue inflammation and specific mechanisms of RD supplementation in obesity have not been fully investigated. Therefore, we examined whether RD attenuates obesity and adipose tissue inflammation in high-fat diet (HFD)-fed mice. Male C57BL/6 mice were fed a chow diet, a HFD or a HFD with RD supplementation for 12 weeks. Body weight (BW), fasting blood glucose (FBG), epididymal fat accumulation, serum total triglyceride (TG), free fatty acid (FFA) and inflammatory cytokine levels (TNF-α, IL-1β, IL-6, IL-10) were measured. Inflammation markers and macrophage infiltration in epididymal adipose tissue were observed. After 12 weeks of intervention, the body weight gain of mice in RD supplementation group was less than that in HFD group. FBG, epididymal fat accumulation, serum TG and FFA levels were reduced in RD supplementation group compared with HFD group. Moreover, serum and mRNA levels of IL-6 were significantly reduced in the RD supplementation group. In addition, RD supplementation reduced macrophage infiltration, regulated polarization of macrophage and inhibited NF-κB signaling in epididymal adipose tissue. In conclusion, RD reduces obesity and attenuates adipose tissue inflammation in HFD-fed mice, and the inhibition of NF-κB signaling may be a presumed mechanism for its effects.

Resistant Maltodextrin and Metabolic Syndrome: A Review

Resistant maltodextrin is a non-viscous dietary fiber that is fermentable in the colon by colonic bacteria. The objective of this review is to summarize the studies of resistant maltodextrin and its effect on metabolic profile, such as blood glucose, lipid profile, and body weight. Several studies support the idea that resistant maltodextrin may improve blood glucose, insulin sensitivity, lipid profile, and obesity. However, the use of resistant maltodextrin should be limited to minimize the adverse effect on the gastrointestinal system. This review provides information regarding the benefits of resistant maltodextrin on metabolic health as well as its proposed mechanism to enhance the knowledge of this novel fiber. Key teaching points Resistant maltodextrin is a novel non-viscous dietary fiber classified as resistant starch type V that is produced by debranching of the starch structure. Resistant maltodextrin is fermentable in the colon and thus produces short-chain fatty acid. Resistant maltodextrin helps to maintain blood and lipid profiles as well as promote satiety and reducing food intake. High intake of resistant maltodextrin may cause gastrointestinal discomfort due to the gas production and increased osmotic pressure.

Effects of isolated soluble fiber supplementation on body weight, glycemia, and insulinemia in adults with overweight and obesity: a systematic review and meta-analysis of randomized controlled trials

Background: There is strong epidemiologic evidence that dietary fiber intake is protective against overweight and obesity; however, results of intervention studies have been mixed. Soluble fiber beneficially affects metabolism, and fiber supplementation may be a feasible approach to improve body composition and glycemia in adults with overweight and obesity.Objective: We evaluated randomized controlled trials (RCTs) of isolated soluble fiber supplementation in overweight and obese adults on outcomes related to weight management [body mass index (BMI; in kg/m²), body weight, percentage of body fat, and waist circumference] and glucose and insulin metabolism (homeostasis model assessment of insulin resistance and fasting insulin) through a systematic review and meta-analysis.Design: We searched PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature and Cochrane Library databases. Eligible studies were RCTs that compared isolated soluble fiber with placebo treatments without energy-restriction protocols. Random-effects models were used to estimate pooled effect sizes and 95% CIs. Meta-regressions were performed to assess outcomes in relation to the intervention duration, fiber dose, and fiber type. Publication bias was assessed via Begg's and Egger's tests and funnel plot inspection.Results: Findings from 12 RCTs (n = 609 participants) from 2 to 17 wk of duration are summarized in this review. Soluble fiber supplementation reduced BMI by 0.84 (95% CI: -1.35, -0.32; P = 0.001), body weight by 2.52 kg (95% CI: -4.25, -0.79 kg; P = 0.004), body fat by 0.41% (95% CI: -0.58%, -0.24%; P < 0.001), fasting glucose by 0.17 mmol/L (95% CI: -0.28, -0.06 mmol/L; P = 0.002), and fasting insulin by 15.88 pmol/L (95% CI: -29.05, -2.71 pmol/L; P = 0.02) compared with the effects of placebo treatments. No publication bias was identified. Considerable between-study heterogeneity was observed for most outcomes.Conclusions: Isolated soluble fiber supplementation improves anthropometric and metabolic outcomes in overweight and obese adults, thereby indicating that supplementation may improve fiber intake and health in these individuals. However, the interpretation of these findings warrants caution because of the considerable between-study heterogeneity. This trial was registered at clinicaltrials.gov as NCT03003897.

A review of the characteristics of dietary fibers relevant to appetite and energy intake outcomes in human intervention trials

Background: Many intervention studies have tested the effect of dietary fibers (DFs) on appetite-related outcomes, with inconsistent results. However, DFs comprise a wide range of compounds with diverse properties, and the specific contribution of these to appetite control is not well characterized.Objective: The influence of specific DF characteristics [i.e., viscosity, gel-forming capacity, fermentability, or molecular weight (MW)] on appetite-related outcomes was assessed in healthy humans.Design: Controlled human intervention trials that tested the effects of well-characterized DFs on appetite ratings or energy intake were identified from a systematic search of literature. Studies were included only if they reported 1) DF name and origin and 2) data on viscosity, gelling properties, fermentability, or MW of the DF materials or DF-containing matrixes.Results: A high proportion of the potentially relevant literature was excluded because of lack of adequate DF characterization. In total, 49 articles that met these criteria were identified, which reported 90 comparisons of various DFs in foods, beverages, or supplements in acute or sustained-exposure trials. In 51 of the 90 comparisons, the DF-containing material of interest was efficacious for ≥1 appetite-related outcome. Reported differences in material viscosity, MW, or fermentability did not clearly correspond to differences in efficacy, whereas gel-forming DF sources were consistently efficacious (but with very few comparisons).Conclusions: The overall inconsistent relations of DF properties with respect to efficacy may reflect variation in measurement methodology, nature of the DF preparation and matrix, and study designs. Methods of DF characterization, incorporation, and study design are too inconsistent to allow generalized conclusions about the effects of DF properties on appetite and preclude the development of reliable, predictive, structure-function relations. Improved standards for characterization and reporting of DF sources and DF-containing materials are strongly recommended for future studies on the effects of DF on human physiology. This trial was registered at http://www.crd.york.ac.uk/PROSPERO as CRD42015015336.

A randomized controlled trial on the efficacy of resistant dextrin, as functional food, in women with type 2 diabetes: Targeting the hypothalamic-pituitary-adrenal axis and immune system

OBJECTIVE

The aim of this trial was to determine the efficacy of a resistant dextrin on immune-mediated inflammation and hypothalamic-pituitary-adrenal axis in women with type 2 diabetes mellitus (T2DM).

METHODS

Females (n = 55) with T2DM were randomly allocated into intervention group (n = 30) and control group (n = 25), in which they received 10 g/d of Nutriose^®06 (a resistant dextrin) or maltodextrin for 8 weeks, respectively. Fasting blood samples were taken to measure immune system related parameters like white blood cell count, CD4, CD8, interferon-γ (IFNγ), interleukins (IL12, IL4, IL10), cortisol, tryptophan (TRP), ACTH (Adrenocorticotropic hormone), Kynurenine (KYN) and plasma lipopolysaccharide (LPS) at the beginning and end of trial. Mental health was assessed using general health questionnaire (GHQ) and depression, anxiety and stress scale (DASS).

RESULTS

Resistant dextrin caused a significant decrease in levels of cortisol, KYN, KYN/TRP ratio, IFNγ, IL12, IFNγ/IL10 ratio, LPS, and a significant increase in the monocyte, GHQ, DASS, CD8, IL10, IL4 in the intervention group as compared with baseline. A significant decrease in the level of LPS (-6.20 EU/mL, -17.8%), IFNγ (-0.6 pg/ml, -26.8%), cortisol (-2.6 μg/dl, -20.9%), IFNγ/IL10 ratio (0.01, 10%), GHQ (-5.1, -12.5%), DASS (-10.4, -38.4%), KYN/TRP ratio (6.8, 29.1%), and a significant increase in levels of CD8 (6.4%, 6.1%) and IL10 (2.6 pg/ml, 21.6%) in the intervention group as compared with the control group (P < 0.05). No significant changes were observed in white blood cell count, CD4, CD4/CD8 ratio, ACTH, KYN, TRP, IL4 and IL12 in the intervention group as compared with the control group (P > 0.05).

CONCLUSION

Supplementation of Nutriose^®06 may have beneficial effects on mental health and the immune system response in women with T2DM.

Effects of resistant dextrin for weight loss in overweight adults: a systematic review with a meta-analysis of randomized controlled trials

BACKGROUND

Randomized controlled trials (RCTs) reported that resistant dextrin (RD) exerted pleiotropic effects on humans. However, limited information is available on the effects of RD for weight loss. We conducted a systematic review with a meta-analysis to summarize the available literature and compare the efficacy of RD for weight loss with that of a placebo in overweight adults.

METHODS

We searched the electronic databases MEDLINE, EMBASE, The Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, Web of Science, ClincalTrials.gov, and Japana Centra Revuo Medicina (Ichushi-web) for studies from their onset to November 2016, and there was no language restriction. Trials were included if they were RCTs (1) comparing the effects of RD with a placebo in adults (18 years or older), (2) reporting body mass index, and (3) including overweight/obese subjects as defined by the authors of RCTs. The weighted mean difference with a 95% confidence interval (CI) was calculated using a random-effects model.

RESULTS

Of the 484 studies retrieved, 3 RCTs involving 275 subjects were included in our review. The durations of RCTs ranged between 8 and 12 weeks. All RCTs were conducted in Asian countries. RD significantly improved body mass index [mean difference -0.39 (95% CI -0.57 to -0.21) kg/m², p < 0.01] and body weight [mean difference -0.81 (95% CI -0.93 to -0.69) kg, p < 0.01] in overweight adults.

CONCLUSION

Our review suggests that RD exerts beneficial effects for weight loss in overweight adults. More RCTs with different populations and longer follow-ups are needed in order to confirm that supplementation with RD has beneficial effects for weight loss in overweight adults. We consider this review to provide important information for the future submission of food with health claims.

Resistant dextrin, as a prebiotic, improves insulin resistance and inflammation in women with type 2 diabetes: a randomised controlled clinical trial

Improvement of insulin resistance and inflammation is a basic strategy in the management of type 2 diabetes. There is limited evidence that prebiotics improve insulin resistance and inflammation. However, the ameliorating effect of resistant dextrin, as a prebiotic, on insulin resistance and inflammation in patients with type 2 diabetes has not been investigated so far. Therefore, the present study aimed to examine the effects of resistant dextrin on insulin resistance and inflammation in type 2 diabetic patients. In a randomised controlled clinical trial, fifty-five women with type 2 diabetes were assigned to two groups: the intervention group (n 30) and the control group (n 25). The intervention group received a daily supplement of 10 g resistant dextrin and the control group received a similar amount of maltodextrin as placebo for 8 weeks. Fasting plasma glucose (FPG), HbA1c, insulin, high-sensitivity C-reactive protein (hs-CRP), IL-6, TNF-α, malondialdehyde (MDA) and serum endotoxin concentrations were measured before and after the intervention. Data were analysed using SPSS (version 13). Paired and unpaired t tests and ANCOVA were used to compare quantitative variables after the intervention. Patients supplemented with resistant dextrin exhibited a significant decrease in fasting insulin (20.1 pmol/l, 22.8%), homeostasis model assessment of insulin resistance (1.3, 24.9%), quantitative insulin sensitivity check index (0.2, 7.2%), IL-6 (1.4 pg/ml, 28.4 %), TNF-α (5.4 pg/ml, 18.8 %), MDA (1.2 nmol/ml, 25.6 %) and endotoxin (6.2 endotoxin units/ml, 17.8%) concentrations than those supplemented with maltodextrin (P< 0.05). Decreases in FPG (0.05 mmol/l, 0.6%), HbA1c (0.5%, 9.6%) and hs-CRP (2.7 ng/ml, 35.1%) concentrations in the resistant dextrin group were not significant when compared with the maltodextrin group. In conclusion, resistant dextrin supplementation can modulate inflammation and improve insulin resistance in women with type 2 diabetes.

Consumption of the Soluble Dietary Fibre Complex PolyGlycopleX(®) Reduces Glycaemia and Increases Satiety of a Standard Meal Postprandially

The effect of consumption of PolyGlycopleX^® (PGX^®) was compared to wheat dextrin (WD) in combination with a standard meal, on postprandial satiety and glycaemia in a double-blind, randomised crossover trial, of 14 healthy subjects trained as a satiety panel. At each of six two-hour satiety sessions, subjects consumed one of three different test meals on two separate occasions. The test meals were: a standard meal plus 5 g PGX; a standard meal plus 4.5 g of PGX as softgels; and a standard meal plus 5 g of WD. Subjects recorded fullness using a labelled magnitude scale at 0, 15, 30, 45, 60, 90, and 120 min and the total area under the curve (AUC), mean fullness vs. time was calculated. The meals with PGX (in granular and softgel form) gave higher satiety (AUC) (477 ± 121 and 454 ± 242 cm·min), than the meal with WD (215 ± 261 cm·min) (p < 0.001). Subjects had blood glucose levels measured after the meals with PGX (granules) and WD. Glucose response (AUC) was significantly lower (p < 0.001) after the PGX meal than for the WD meal.  The high viscosity reported for PGX is a likely mechanism behind the significant satiety and blood glucose modulating effects observed in this study.

New Horizons for the Study of Dietary Fiber and Health: A Review

Dietary fibre has been consumed for centuries with known health benefits, but defining dietary fibre is a real challenge. From a functional perspective, dietary fibre is described as supporting laxation, attenuating blood glucose responses and assisting with cholesterol lowering. The problem is different types of dietary fibre have different effects, and new effects are increasingly observed, such as the influence on gut microbiota. Thus, a single definition may need to be described in more generic terms. Rather than being bound by a few functional definitions, we may need to embrace the possibilities of new horizons, and derive a working definition of dietary fibre based on a set of conceptual principles, rather than the limited definitions we have to date. To begin this process, a review of individual fibre types and their physiological effects would be helpful. Dietary fibre is a complex group of substances, and there is a growing interest in specific effects linked to fibre type. Different fractions of dietary fibre have different physiological properties, yet there is a paucity of literature covering the effects of all fibres. This paper describes a range of individual fibre types and identifies gaps in the literature which may expose new directions for a working definition of dietary fibre.

Prebiotic Effects and Fermentation Kinetics of Wheat Dextrin and Partially Hydrolyzed Guar Gum in an In Vitro Batch Fermentation System

Scientific research demonstrates that two indigenous gut bacteria, Lactobacillus and Bifidobacterium can contribute to human health. Although these bacteria can be consumed as probiotics, they can also be produced in the gut by bacteria, and are then called prebiotics. The primary objective of this in vitro study was to quantitatively analyze at the genus level how two dietary fibers, wheat dextrin (WD) and partially hydrolyzed guar gum (PHGG) changed the levels of these two gut bacteria at 12 and 24 h, via real time qualitative polymerase chain reaction (qPCR). Secondary objectives were changes in fecal pH, short chain fatty acids (SCFAs) and total gas volume produced. At 12 h WD was more bifidogenic (9.50 CFU log₁₀/mL) than PHGG (9.30 CFU log₁₀/mL) (p = 0.052), and also at 24 h WD (9.41 CFU log₁₀/mL) compared with PHGG (9.27 CFU log₁₀/mL) (p = 0.043). WD produced less total SCFAs at both 12 and 24 h than PHGG, and produced significantly lower amounts of gas at 12 and 24 h (p < 0.001). Both PHGG and WD also promoted growth of Lactobacilli when measured at 12 and 24 h compared with the 0 h analysis, indicating that both fibers are lactogenic. These results demonstrate the prebiotic effect of WD and PHGG. Based on fermentation kinetics, PHGG is more rapidly fermented than WD, and both fibers show prebiotic effects as early as 12 h.

Potential anti-obesogenic properties of non-digestible carbohydrates: specific focus on resistant dextrin

Alterations in the composition and metabolic activity of the gut microbiota appear to contribute to the development of obesity and associated metabolic diseases. However, the extent of this relationship remains unknown. Modulating the gut microbiota with non-digestible carbohydrates (NDC) may exert anti-obesogenic effects through various metabolic pathways including changes to appetite regulation, glucose and lipid metabolism and inflammation. The NDC vary in physicochemical structure and this may govern their physical properties and fermentation by specific gut bacterial populations. Much research in this area has focused on established prebiotics, especially fructans (i.e. inulin and fructo-oligosaccharides); however, there is increasing interest in the metabolic effects of other NDC, such as resistant dextrin. Data presented in this review provide evidence from mechanistic and intervention studies that certain fermentable NDC, including resistant dextrin, are able to modulate the gut microbiota and may alter metabolic process associated with obesity, including appetite regulation, energy and lipid metabolism and inflammation. To confirm these effects and elucidate the responsible mechanisms, further well-controlled human intervention studies are required to investigate the impact of NDC on the composition and function of the gut microbiota and at the same time determine concomitant effects on host metabolism and physiology.

Health benefits of prebiotic fibers

This chapter describes the various compounds that can act as prebiotic fibers: their structure, occurrence, production, and physiological effects (health effects) will be presented. The basis for the description is the latest definitions for dietary fibers and for prebiotics. Using as much as possible data from human studies, both the fiber and the prebiotic properties will be described of a variety of compounds. Based on the presented data the latest developments in the area of prebiotics, fibers and gut and immune health will be discussed in more detail as they show best what the potential impact of prebiotics on health of the human host might be.

A prebiotic fiber increases the formation and subsequent absorption of compound K following oral administration of ginseng in rats

Background

Gut microflora play a crucial role in the biotransformation of ginsenosides to compound K (CK), which may affect the pharmacological effects of ginseng. Prebiotics, such as NUTRIOSE, could enhance the formation and consequent absorption of CK through the modulation of gut microbial metabolic activities. In this study, the effect of a prebiotic fiber (NUTRIOSE) on the pharmacokinetics of ginsenoside CK, a bioactive metabolite of ginsenosides, and its mechanism of action were investigated.

Methods

Male Sprague–Dawley rats were given control or NUTRIOSE-containing diets (control diet + NUTRIOSE) for 2 wk, and ginseng extract or vehicle was then orally administered. Blood samples were collected to investigate the pharmacokinetics of CK using liquid chromatography–tandem mass spectrometry. Fecal activities that metabolize ginsenoside Rb1 to CK were assayed with fecal specimens or bacteria cultures.

Results

When ginseng extract was orally administered to rats fed with 2.5%, 5%, or 10% NUTRIOSE containing diets, the maximum plasma concentration (C_max) and area under the plasma concentration–time curve values of CK significantly increased in a NUTRIOSE content-dependent manner. NUTRIOSE intake increased glycosidase activity and CK formation in rat intestinal contents. The CK-forming activities of intestinal microbiota cultured in vitro were significantly induced by NUTRIOSE.

Conclusion

These results show that prebiotic diets, such as NUTRIOSE, may promote the metabolic conversion of ginsenosides to CK and the subsequent absorption of CK in the gastrointestinal tract and may potentiate the pharmacological effects of ginseng.

In vitro fermentation of NUTRIOSE(®) FB06, a wheat dextrin soluble fibre, in a continuous culture human colonic model system

Wheat dextrin soluble fibre may have metabolic and health benefits, potentially acting via mechanisms governed by the selective modulation of the human gut microbiota. Our aim was to examine the impact of wheat dextrin on the composition and metabolic activity of the gut microbiota. We used a validated in vitro three-stage continuous culture human colonic model (gut model) system comprised of vessels simulating anatomical regions of the human colon. To mimic human ingestion, 7 g of wheat dextrin (NUTRIOSE^® FB06) was administered to three gut models, twice daily at 10.00 and 15.00, for a total of 18 days. Samples were collected and analysed for microbial composition and organic acid concentrations by 16S rRNA-based fluorescence in situ hybridisation and gas chromatography approaches, respectively. Wheat dextrin mediated a significant increase in total bacteria in vessels simulating the transverse and distal colon, and a significant increase in key butyrate-producing bacteria Clostridium cluster XIVa and Roseburia genus in all vessels of the gut model. The production of principal short-chain fatty acids, acetate, propionate and butyrate, which have been purported to have protective, trophic and metabolic host benefits, were increased. Specifically, wheat dextrin fermentation had a significant butyrogenic effect in all vessels of the gut model and significantly increased production of acetate (vessels 2 and 3) and propionate (vessel 3), simulating the transverse and distal regions of the human colon, respectively. In conclusion, wheat dextrin NUTRIOSE^® FB06 is selectively fermented in vitro by Clostridium cluster XIVa and Roseburia genus and beneficially alters the metabolic profile of the human gut microbiota.

Findings from an online behavioural weight management programme provided with or without a fortified diet beverage

The present multi-centre randomised weight-loss trial evaluated the efficacy of a low-intensity 12-week online behavioural modification programme, with or without a fortified diet beverage using a 2 × 2 factorial design. A total of 572 participants were randomised to: (1) an online basic lifestyle information (OBLI) intervention, consisting of one online informational class about tips for weight management; (2) an online behavioural weight management (OBWM) intervention, entailing 12 weekly online classes focused on weight-loss behaviour modification; (3) an OBLI intervention plus a fortified diet cola beverage (BEV) containing green tea extract (total catechin 167 mg), soluble fibre dextrin (10 g) and caffeine (100 mg) (OBLI+BEV); (4) OBWM+BEV. Assessments included height, weight, dual-energy X-ray absorptiometry-derived body composition, and waist circumference (WC). Attrition was 15·7 %. Intention-to-treat (ITT) models demonstrated a main effect for type of Internet programme, with those assigned to the OBWM condition losing significantly more weight (F= 7·174; P= 0·008) and fat mass (F= 4·491; P= 0·035) than those assigned to the OBLI condition. However, there was no significant main effect for the OBWM condition on body fat percentage (F= 2·906; P= 0·089) or WC (F= 3·351; P= 0·068), and no significant main effect for beverage use or significant interactions between factors in ITT models. A 12-week, low-intensity behaviourally based online programme produced a greater weight loss than a basic information website. The addition of a fortified diet beverage had no additional impact.

Fiber and prebiotics: mechanisms and health benefits

The health benefits of dietary fiber have long been appreciated. Higher intakes of dietary fiber are linked to less cardiovascular disease and fiber plays a role in gut health, with many effective laxatives actually isolated fiber sources. Higher intakes of fiber are linked to lower body weights. Only polysaccharides were included in dietary fiber originally, but more recent definitions have included oligosaccharides as dietary fiber, not based on their chemical measurement as dietary fiber by the accepted total dietary fiber (TDF) method, but on their physiological effects. Inulin, fructo-oligosaccharides, and other oligosaccharides are included as fiber in food labels in the US. Additionally, oligosaccharides are the best known "prebiotics", "a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-bring and health." To date, all known and suspected prebiotics are carbohydrate compounds, primarily oligosaccharides, known to resist digestion in the human small intestine and reach the colon where they are fermented by the gut microflora. Studies have provided evidence that inulin and oligofructose (OF), lactulose, and resistant starch (RS) meet all aspects of the definition, including the stimulation of Bifidobacterium, a beneficial bacterial genus. Other isolated carbohydrates and carbohydrate-containing foods, including galactooligosaccharides (GOS), transgalactooligosaccharides (TOS), polydextrose, wheat dextrin, acacia gum, psyllium, banana, whole grain wheat, and whole grain corn also have prebiotic effects.

Impact of a resistant dextrin on intestinal ecology: how altering the digestive ecosystem with NUTRIOSE®, a soluble fibre with prebiotic properties, may be beneficial for health

OBJECTIVES

The prebiotic potential of NUTRIOSE®--a sugar-free, digestion-resistant dextrin--was evaluated in two randomized, placebo-controlled trials that included 48 and 40 healthy volunteers, respectively.

METHODS

In study 1, the effect on colonic bacteria of NUTRIOSE® 10, 15 or 20 g/day administered for 14 days was examined; in study 2, gut microbial changes in response to NUTRIOSE® 8 g/day for 14 days were monitored using real-time polymerase chain reaction analysis.

RESULTS

NUTRIOSE® increased proliferation of Bacteroides and inhibited Clostridum perfringens in both studies, increased β-glucosidase activity (at 10 and 15 g/day) and decreased colonic pH (at 20 g/day). The increase in short-chain fatty acid production with NUTRIOSE® consumption was not statistically significant. There were no indications of gastrointestinal intolerance at any dose.

CONCLUSIONS

According to commonly accepted definitions, NUTRIOSE® is a prebiotic soluble fibre that provides a beneficial effect on colonic ecology while preserving digestive comfort.

The soluble fiber NUTRIOSE induces a dose-dependent beneficial impact on satiety over time in humans

Strong evidence supports the ability of dietary fibers to improve satiety. However, large variations in the physical and chemical characteristics of dietary fiber modulate the physiologic responses. We hypothesized that a nonviscous soluble dietary fiber may influence satiety. This randomized, double-blind, placebo-controlled clinical study in 100 overweight healthy adults in China investigated the effect of different dosages of dietary supplementation with a dextrin, NUTRIOSE (ROQUETTE frères, Lestrem, France), on short-term satiety over time. Subjects were randomized by body mass index and energy intake and then assigned to receive either placebo or 8, 14, 18, or 24 g/d of NUTRIOSE mixed with orange juice (n = 20 volunteers per group). On days -2, 0, 2, 5, 7, 14, and 21, short-term satiety was evaluated with a visual analog scale, and hunger feeling status was assessed with Likert scale. NUTRIOSE exhibits a progressive and significant impact on short-term satiety, which is time and dosage correlated. Some statistical differences appear for the group 8 g/d from day 5, and from day 0 for the groups 14, 18, and 24 g/d. The hunger feeling status decreases significantly from day 5 to the end of the evaluation for the group 24 g and from day 7 for the groups 14 and 18 g. By day 5, the group 24 g showed significantly longer time to hunger between meals compared with placebo. These results suggest that dietary supplementation with a soluble fiber can decrease hunger feeling and increase short-term satiety over time when added to a beverage from 8 to 24 g/d with time- and dose-responses relationship.