Postprandial effects of polydextrose on satiety hormone responses and subjective feelings of appetite in obese participants

Chronic consumption of a blend of inulin and arabinoxylan reduces energy intake in an ad libitum meal but does not influence perceptions of appetite and satiety: a randomised control-controlled crossover trial

PURPOSE

Prebiotic foods can be used to increase production of short-chain fatty acids (SCFA) in the gut. Of the SCFA, propionate is credited with the strongest anorectic activity. In previous work, a 50/50 blend of inulin and arabinoxylan was produced (I + AX) that significantly increased propionate production in an in vitro gut model. This study sought to establish whether chronic consumption of a prebiotic blend of I + AX decreases appetite and energy intake and increases intestinal propionate production in human participants.

METHODS

MIXSAT (clinicaltrials.gov id: NCT02846454, August 2016) was a double-blind randomised acute-within-chronic crossover feeding trial in healthy adult men (n = 20). Treatments were 8 g per day I + AX for 21 days or weight-matched maltodextrin control. The primary outcome measure was perceived satiety and appetite during an acute study visit. Secondary outcomes were energy intake in an ad libitum meal, faecal SCFA concentration, and faecal microbiota composition.

RESULTS

Perceived satiety and appetite were not affected by the intervention. I + AX was associated with a reduction in energy intake in an ad libitum meal, increased faecal SCFA concentration, and an increase in cell counts of Bifidobacteria, Lactobacilli, and other microbial genera associated with health.

IMPLICATIONS

Chronic consumption of this blend of prebiotics decreased energy intake in a single sitting. Further studies are needed to confirm mechanism of action and to determine whether this might be useful in weight control.

Influence of the gut microbiota on satiety signaling

Recent studies show a link between the gut microbiota and the regulation of satiety and energy intake, processes that contribute to the development and pathophysiology of metabolic diseases. However, this link is predominantly established in animal and in vitro studies, whereas human intervention studies are scarce. In this review we focus on recent evidence linking satiety and the gut microbiome, with specific emphasis on gut microbial short-chain fatty acids (SCFAs). Based on a systematic search we provide an overview of human studies linking the intake of prebiotics with gut microbial alterations and satiety signaling. Our outcomes highlight the importance of in-depth examination of the gut microbiota in relation to satiety and provide insights into recent and future studies in this field.

Bioactive compounds in childhood obesity and associated metabolic complications: Current evidence, controversies and perspectives

Obesity represents the most frequent chronic disease among children worldwide, with a significant global burden on society. Metabolically unhealthy obesity (MUO) can affect children since their first years of life, and novel therapeutic strategies to tackle metabolic complications are under investigation. This review focuses on bioactive compounds and their possible beneficial effects on obesity, particularly omega-3, docosahexaenoic acid, vitamin D, biotics, polysaccharide macromolecules, polyphenols, inositols, alpha lipoic acid, and bromelaine. Our aim is to summarize current evidence about bioactive compounds in the treatment of obesity, highlighting recent findings on their use in children and adolescents. Most studied molecules are omega-3 and vitamin D, despite the heterogeneity between the studies. Moreover, given the emerging interest in the gut-brain axis in the link between metabolic health and microbiota, various studies on prebiotics, probiotics, synbiotics, postbiotics and polysaccharide macromolecules have been considered. Some preclinical studies seem to highlight a possible role of the polyphenols, even if their clinical evidence is still discussed. Lastly, we describe possible effects of inositols and alpha-lipoic acid. Despite some dietary supplements seem to be promising in overweight subjects, only in a few of them a dose/response efficacy has been found in the pediatric age. Innovative, well-designed and targeted clinical trials are then needed to prove the beneficial effects of these compounds that could support the standard behavioral therapy for obesity.

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.

Potential health benefits of lowering gas production and bifidogenic effect of the blends of polydextrose with inulin in a human gut model

Polydextrose is a nutrient supplement, which is widely applied in the food industry. The use of polydextrose in combination with prebiotics and probiotics has recently increased, whereas the fermentation properties of its blend have not yet been fully revealed. We evaluated the metabolic profile of polydextrose, inulin, and their blends by a batch in vitro fermentation of fifteen human fecal inocula. After 24 h of fermentation, polydextrose increased the production of gas, ammonia, and several short chain fatty acids, including propionate and butyrate, when compared to its blends, inulin, and fructo-oligosaccharides. Furthermore, polydextrose had the slowest degradation rate of all the carbohydrates tested, consistent with its partial fermentation in the distal colon. The 16S rRNA gene sequencing analysis of the gut microbiome exhibited significantly increased relative abundance of Clostridium_XVIII, Megamonas, Mitsuokella, and Erysipelotrichaceae_incertae_sedis in polydextrose compared to other carbohydrates. On the other hand, the blends of polydextrose and inulin (1:1 or 2:1) showed reduced gas production and similar bifidogenicity to inulin alone. The blends not only had similar alpha-diversity and PCoA to inulin but also had a similar abundance of beneficial bacteria, such as Faecalibacterium and Roseburia, suggesting potential health benefits. Also their low gas production was likely due to the abundance of Faecalibacterium and Anaerostipes, which were negatively correlated with gas production. Additionally, our in vitro fermentation model shows advantages in the large-scale assessment of fermentation performance.

Impact of TOTUM-63, a fibre and polyphenol rich plant-based composition, on gut and pancreatic hormone secretion in diet-induced obese mice

BACKGROUND AND AIMS

TOTUM-63, a fibre and polyphenol rich plant-based composition, has been demonstrated to significantly improve body weight and glucose homeostasis in animal models of obesity. Our study aimed at exploring whether the mechanisms include modulation of gut (glucose-dependent insulinotropic peptide (GIP), glucagon-like petide-1 (GLP-1), cholecystokinin (CCK), peptide YY (PYY)) and pancreatic (insulin, glucagon) hormones, all important regulators of glucose control, appetite and body weight.

METHODS AND RESULTS

Male C57BL/6JRJ mice were assigned to either standard chow (CON), high fat diet (HF, 60% energy from fat) or HF-TOTUM-63 (HF diet 60% supplemented with TOTUM-63 2.7%) for 10 weeks. In vivo glucose homeostasis (oral glucose tolerance test (OGTT), intraperitoneal pyruvate tolerance test (ipPTT)), glucose-induced portal vein hormone concentration, gut hormone gene expression and protein content as well as enteroendocrine cell contents were assessed at the end of the dietary intervention. The present study evidenced that TOTUM-63 reduced food intake, limited weight gain and improved glucose and pyruvate tolerance of HF-fed animals. This was associated with an increase in PYY content in the colon, an altered pattern of PYY secretion between fasted and glucose-stimulated states, and with a significant improvement in the portal vein concentration of GLP-1, insulin and glucagon, but not GIP and CCK, in response to glucose stimulation.

CONCLUSION

Overall, these data suggest that TOTUM-63 might have a specific impact on gut L-cells and on the expression and secretion of GLP-1 and PYY incretins, potentially contributing to the reduced food intake, body weight gain and improved glucose homeostasis.

Prebiotic potential of enzymatically prepared resistant starch in reshaping gut microbiota and their respond to body physiology

The increase in consumer demand for high-quality food products has led to growth in the use of new technologies and ingredients. Resistant starch (RS) is a recently recognised source of fibre and has received much attention for its potential health benefits and functional properties. However, knowledge about the fate of RS in modulating complex intestinal communities, the microbial members involved in its degradation, enhancement of microbial metabolites, and its functional role in body physiology is still limited. For this purpose, the current study was designed to ratify the physiological and functional health benefits of enzymatically prepared resistant starch (EM-RSIII) from maize flour. To approve the beneficial health effects as prebiotic, EM-RSIII was supplemented in rat diets. After 21 days of the experiment, EM-RSIII fed rats showed a significant reduction in body weight gain, fecal pH, glycemic response, serum lipid profile, insulin level and reshaping gut microbiota, and enhancing short-chain fatty acid compared to control. The count of butyrate-producing and starch utilizing bacteria, such as Lactobacillus, Enterococcus, and Pediococcus genus in rat’s gut, elevated after the consumption of medium and high doses of EM-RSIII, while the E. coli completely suppressed in high EM-RSIII fed rats. Short-chain fatty acids precisely increased in feces of EM-RSIII feed rats. Correlation analysis demonstrated that the effect of butyrate on functional and physiological alteration on the body had been investigated during the current study. Conclusively, the present study demonstrated the unprecedented effect of utilising EM-RSIII as a diet on body physiology and redesigning gut microorganisms.

Gut Microbiome Composition Is Predictive of Incident Type 2 Diabetes in a Population Cohort of 5,572 Finnish Adults

OBJECTIVE

To examine the previously unknown long-term association between gut microbiome composition and incident type 2 diabetes in a representative population cohort.

RESEARCH DESIGN AND METHODS

We collected fecal samples from 5,572 Finns (mean age 48.7 years; 54.1% women) in 2002 who were followed up for incident type 2 diabetes until 31 December 2017. The samples were sequenced using shotgun metagenomics. We examined associations between gut microbiome composition and incident diabetes using multivariable-adjusted Cox regression models. We first used the eastern Finland subpopulation to obtain initial findings and validated these in the western Finland subpopulation.

RESULTS

Altogether, 432 cases of incident diabetes occurred over the median follow-up of 15.8 years. We detected four species and two clusters consistently associated with incident diabetes in the validation models. These four species were Clostridium citroniae (hazard ratio [HR] 1.21; 95% CI 1.04-1.42), C. bolteae (HR 1.20; 95% CI 1.04-1.39), Tyzzerella nexilis (HR 1.17; 95% CI 1.01-1.36), and Ruminococcus gnavus (HR 1.17; 95% CI 1.01-1.36). The positively associated clusters, cluster 1 (HR 1.18; 95% CI 1.02-1.38) and cluster 5 (HR 1.18; 95% CI 1.02-1.36), mostly consisted of these same species.

CONCLUSIONS

We observed robust species-level taxonomic features predictive of incident type 2 diabetes over long-term follow-up. These findings build on and extend previous mainly cross-sectional evidence and further support links between dietary habits, metabolic diseases, and type 2 diabetes that are modulated by the gut microbiome. The gut microbiome can potentially be used to improve disease prediction and uncover novel therapeutic targets for diabetes.

Polydextrose with and without Bifidobacterium animalis ssp. lactis 420 drives the prevalence of Akkermansia and improves liver health in a multi-compartmental obesogenic mice study

The past two decades of research have raised gut microbiota composition as a contributing factor to the development of obesity, and higher abundance of certain bacterial species has been linked to the lean phenotype, such as Akkermansia muciniphila. The ability of pre- and probiotics to affect metabolic health could be via microbial community alterations and subsequently changes in metabolite profiles, modulating for example host energy balance via complex signaling pathways. The aim of this mice study was to determine how administration of a prebiotic fiber, polydextrose (PDX) and a probiotic Bifidobacterium animalis ssp. lactis 420 (B420), during high fat diet (HFD; 60 kcal% fat) affects microbiota composition in the gastrointestinal tract and adipose tissue, and metabolite levels in gut and liver. In this study C57Bl/6J mice (N = 200) were split in five treatments and daily gavaged: 1) Normal control (NC); 2) HFD; 3) HFD + PDX; 4) HFD + B420 or 5) HFD + PDX + B420 (HFD+S). At six weeks of treatment intraperitoneal glucose-tolerance test (IPGTT) was performed, and feces were collected at weeks 0, 3, 6 and 9. At end of the intervention, ileum and colon mucosa, adipose tissue and liver samples were collected. The microbiota composition in fecal, ileum, colon and adipose tissue was analyzed using 16S rDNA sequencing, fecal and liver metabolomics were performed by nuclear magnetic resonance (NMR) spectroscopy. It was found that HFD+PDX intervention reduced body weight gain and hepatic fat compared to HFD. Sequencing the mice adipose tissue (MAT) identified Akkermansia and its prevalence was increased in HFD+S group. Furthermore, by the inclusion of PDX, fecal, lleum and colon levels of Akkermansia were increased and liver health was improved as the detoxification capacity and levels of methyl-donors were increased. These new results demonstrate how PDX and B420 can affect the interactions between gut, liver and adipose tissue.

Effects of high-carbohydrate versus mixed-macronutrient meals on female soccer physiology and performance

PURPOSE

Athletes are often told to minimize intakes of fiber, fat, and protein in pre-competition meals to avoid gut distress, but this guidance is based on scant direct evidence. This study evaluated the physiological and perceptual effects of pre-competition mixed-macronutrient (MM) and high-carbohydrate (HCHO) meals in collegiate female soccer players.

METHODS

Fifteen players participated in this randomized, investigator-blinded, crossover study involving two ~ 1000-kcal meals (HCHO and MM) consumed 4 h prior to 70-min scrimmages. Assessments included global positioning system (GPS) tracking, heart rate (HR), perceived exertion (RPE), ratings of fatigue (ROF), gut symptoms, and perceptions of satiety, hunger, and fullness. Differences between conditions for HR, RPE, ROF, and gut symptoms were evaluated with Wilcoxon signed-rank tests. GPS data and hunger, satiety, and fullness scores were compared using within-subjects repeated measures ANOVAs.

RESULTS

No statistically significant differences were found between the conditions at any time point for HR, RPE, ROF, or gut symptoms. Significant time effects were found for two GPS variables (total distance covered and high-speed running), indicating that participants covered less distance during the second half of the scrimmages in comparison to the first half. However, there were no significant condition or condition × time interactions for GPS data. Finally, there were no condition or condition × time interactions for hunger, fullness, and satiety, though significant time effects were observed.

CONCLUSION

A MM meal consumed 4 h prior to 70 min of soccer competition does not increase gut symptoms and can be similarly ergogenic as a HCHO meal.

Acute postprandial effect of yacon syrup ingestion on appetite: A double blind randomized crossover clinical trial

Yacon syrup is a rich source of fructooligosaccharides (FOS); however, its diet supplementation effect on subjective sensation and appetite biomarkers in human is still unknown. This study aimed to evaluate the acute postprandial effect of yacon syrup ingestion on appetite. The double-blind crossover clinical trial was carried out with 40 adult women: 20 eutrophic and 20 obese grade I. On each day, the first blood collection was performed after a 12-h fast. Then, the volunteers ingested either intervention A (breakfast + 40 g of placebo) or intervention B (breakfast + 40 g of yacon syrup, containing 14 g of FOS). New aliquots of blood were collected at 45, 60, 90, 120, and 180 min. Appetite was assessed by estimating ghrelin and glucagon-like peptide-1 (GLP-1) levels and by assessing subjective appetite sensation. Analysis was performed using two-way ANOVA, followed by Bonferroni's multiple comparison test. No effect of yacon syrup was observed on postprandial ghrelin and GLP-1 levels at all times evaluated. Similar observations were made after stratifying the analysis by BMI (body mass index) (eutrophic and obese). The effect of yacon syrup on postprandial subjective sensations of hunger, satiety, fullness, and desire to eat was not evident in the total group of women evaluated and even after BMI stratification. We concluded that yacon syrup had no effect on postprandial ghrelin and GLP-1 levels and on the subjective appetite sensation in young adult women.

Supplementation with a prebiotic (polydextrose) in obese mouse pregnancy improves maternal glucose homeostasis and protects against offspring obesity

OBJECTIVES

We hypothesised that maternal diet-induced-obesity has adverse consequences for offspring energy expenditure and susceptibility to obesity in adulthood, and that the prebiotic polydextrose (PDX) would prevent the consequences of programming by maternal obesity.

METHODS

Female mice were fed a control (Con) or obesogenic diet (Ob) for 6 weeks prior to mating and throughout pregnancy and lactation. Half the obese dams were supplemented with 5% PDX (ObPDX) in drinking water throughout pregnancy and lactation. Offspring were weaned onto standard chow. At 3 and 6 months, offspring energy intake (EI) and energy expenditure (EE by indirect calorimetry) were measured, and a glucose-tolerance test performed. Offspring of control (OffCon), obese (OffOb) and PDX supplemented (OffObP) dams were subsequently challenged for 3 weeks with Ob, and energy balanced reassessed. Potential modifiers of offspring energy balance including gut microbiota and biomarkers of mitochondrial activity were also evaluated.

RESULTS

Six-month-old male OffOb demonstrated increased bodyweight (BW, P < 0.001) and white adipose tissue mass (P < 0.05), decreased brown adipose tissue mass (BAT, P < 0.01), lower night-time EE (P < 0.001) versus OffCon, which were prevented in OffObP. Both male and female OffOb showed abnormal glucose-tolerance test (peak [Glucose] P < 0.001; AUC, P < 0.05) which was prevented by PDX. The Ob challenge resulted in greater BW gain in both male and female OffOb versus OffCon (P < 0.05), also associated with increased EI (P < 0.05) and reduced EE in females (P < 0.01). OffObP were protected from accelerated BW gain on the OB diet compared with controls, associated with increased night-time EE in both male (P < 0.05) and female OffObP (P < 0.001). PDX also prevented an increase in skeletal muscle mtDNA copy number in OffOb versus OffCon (P < 0.01) and increased the percentage of Bacteroides cells in faecal samples from male OffObP relative to controls.

CONCLUSIONS

Maternal obesity adversely influences adult offspring energy balance and propensity for obesity, which is ameliorated by maternal PDX treatment with associated changes in gut microbiota composition and skeletal muscle mitochondrial function.

Gut microbiota-derived metabolites in obesity: a systematic review

Recent evidence suggests that gut microbiota-derived metabolites affect many biological processes of the host, including appetite control and weight management. Dysbiosis of the gut microbiome in obesity influences the metabolism and excretion of gut microbiota byproducts and consequently affects the physiology of the host. Since identification of the gut microbiota-host co-metabolites is essential for clarifying the interactions between the intestinal flora and the host, we conducted this systematic review to summarize all human studies that characterized the gut microbiota-related metabolites in overweight and obese individuals. A comprehensive search of the PubMed, Web of Science, and Scopus databases yielded 2,137 articles documented up to July 2018. After screening abstracts and full texts, 12 articles that used different biosamples and methodologies of metabolic profiling and fecal microbiota analysis were included. Amino acids and byproducts of amino acids, lipids and lipid-like metabolites, bile acids derivatives, and other metabolites derived from degradation of carnitine, choline, polyphenols, and purines are among the gut microbiota-derived metabolites which showed alterations in obesity. These metabolites play an important role in metabolic complications of obesity, including insulin resistance, hyperglycemia, and dyslipidemia. The results of this study could be useful in development of therapeutic strategies with the aim of modulating gut microbiota and consequently the metabolic profile in obesity.

Policaptil Gel Retard Intake Reduces Postprandial Triglycerides, Ghrelin and Appetite in Obese Children: A Clinical Trial

The aim of this study is to test the hypothesis that the intake of Policaptil Gel Retard^® (PGR) is able to affect appetite, metabolic and hormonal postprandial profile in obese children. 46 obese children were randomly assigned to treatment with PGR or placebo, in a double blind clinical trial. Two PGR tablets or placebo were given in fasting condition, before the ingestion of a mixed meal (15 kcal/kg lean body mass). Blood samples were taken at baseline and for 4 hours, for measuring blood lipids, glucose, insulin, ghrelin, and glucagon like peptide-1 (GLP-1). Appetite was quantified using a visual analog scale. Children assuming PGR had a significantly lower increase of postprandial triglycerides (area under the curve (AUC): 3021 (2879) vs. 5038 (3738) mg × 240 min/Dl) and appetite (-234 (274) vs. 36 (329)) than children assuming placebo. The AUC of ghrelin was significantly lower after PGR ingestion, than after placebo (-8179 (8073) vs. -2800 (7579) pg × 240 min/mL). Blood glucose, insulin, non-esterified fatty acids (NEFA) and GLP-1 profiles were not significantly different in the two groups. In conclusion, a single intake of two tablets of PGR was associated with a significant reduction of appetite, ghrelin, and triglycerides in the postprandial period in obese children. Further investigation will assess if a chronic intake of PGR may affect body weight and glucose metabolism.

Inulin fiber dose-dependently modulates energy balance, glucose tolerance, gut microbiota, hormones and diet preference in high-fat-fed male rats

Inulin, a popular prebiotic fiber, has been reported to promote satiety and fat loss; however, the dose-response effects of inulin on energy balance and diet preference, and whether the metabolic effects are independent of calorie restriction are not well characterized. Therefore, we compared the effects of diets varying in inulin concentrations on food intake, energy expenditure, body composition, gut microbiota and hormones, and assessed whether inulin-induced hypophagia was due to reduced diet preference. In experiment 1, male rats were randomized to six high-fat diet groups: control (CON, 0% inulin), 2.5% inulin (2.5IN), 10% inulin (10IN), 25% inulin (25IN), 25% cellulose (25CE) or pair-fed to 25IN (25PF) for 21 days. We demonstrate that inulin dose-dependently decreased caloric intake and respiratory quotient; improved glucose tolerance; increased the abundance of Bacteroidetes and Bifidobacterium spp.; decreased Clostridium clusters I and IV; increased butyryl-CoA:acetate CoA-transferase in cecum; upregulated peptide YY, cholecystokinin and proglucagon transcripts in the cecum and colon; and increased plasma peptide YY and glucagon-like peptide-1 concentrations. Importantly, unlike 25PF, 25IN attenuated the reduction in energy expenditure associated with calorie restriction and decreased adiposity. In experiment 2, following four training periods, diet preferences were determined. Although 10IN and 25IN decreased caloric intake, and 25CE increased caloric intake, during training, all high-fiber diets were less preferred. Taken together, this work demonstrates that inulin dose-dependently decreased caloric intake, modulated gut microbiota and upregulated satiety hormones, with metabolic effects being largely independent of caloric restriction.

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.

Polydextrose changes the gut microbiome and attenuates fasting triglyceride and cholesterol levels in Western diet fed mice

Obesity and dyslipidemia are hallmarks of metabolic and cardiovascular diseases. Polydextrose (PDX), a soluble fiber has lipid lowering effects. We hypothesize that PDX reduces triglycerides and cholesterol by influencing gut microbiota, which in turn modulate intestinal gene expression. C57BL/6 male mice were fed a Western diet (WD) ±75 mg PDX twice daily by oral gavage for 14 days. Body weight and food intake were monitored daily. Fasting plasma lipids, caecal microbiota and gene expression in intestine and liver were measured after 14 days of feeding. PDX supplementation to WD significantly reduced food intake (p < 0.001), fasting plasma triglyceride (p < 0.001) and total cholesterol (p < 0.05). Microbiome analysis revealed that the relative abundance of Allobaculum, Bifidobacterium and Coriobacteriaceae taxa associated with lean phenotype, increased in WD + PDX mice. Gene expression analysis with linear mixed-effects model showed consistent downregulation of Dgat1, Cd36, Fiaf and upregulation of Fxr in duodenum, jejunum, ileum and colon in WD + PDX mice. Spearman correlations indicated that genera enriched in WD + PDX mice inversely correlated with fasting lipids and downregulated genes Dgat1, Cd36 and Fiaf while positively with upregulated gene Fxr. These results suggest that PDX in mice fed WD promoted systemic changes via regulation of the gut microbiota and gene expression in intestinal tract.

Significance of Microbiota in Obesity and Metabolic Diseases and the Modulatory Potential by Medicinal Plant and Food Ingredients

Metabolic syndrome is a cluster of three or more metabolic disorders including insulin resistance, obesity, and hyperlipidemia. Obesity has become the epidemic of the twenty-first century with more than 1.6 billion overweight adults. Due to the strong connection between obesity and type 2 diabetes, obesity has received wide attention with subsequent coining of the term "diabesity." Recent studies have identified unique contributions of the immensely diverse gut microbiota in the pathogenesis of obesity and diabetes. Several mechanisms have been proposed including altered glucose and fatty acid metabolism, hepatic fatty acid storage, and modulation of glucagon-like peptide (GLP)-1. Importantly, the relationship between unhealthy diet and a modified gut microbiota composition observed in diabetic or obese subjects has been recognized. Similarly, the role of diet rich in polyphenols and plant polysaccharides in modulating gut bacteria and its impact on diabetes and obesity have been the subject of investigation by several research groups. Gut microbiota are also responsible for the extensive metabolism of polyphenols thus modulating their biological activities. The aim of this review is to shed light on the composition of gut microbes, their health importance and how they can contribute to diseases as well as their modulation by polyphenols and polysaccharides to control obesity and diabetes. In addition, the role of microbiota in improving the oral bioavailability of polyphenols and hence in shaping their antidiabetic and antiobesity activities will be discussed.

Hunger and satiety responses to high-fat meals after a high-polyunsaturated fat diet: A randomized trial

OBJECTIVE

Previous studies have shown that polyunsaturated fats (PUFAs) elicit a greater response in satiety after a single-meal challenge compared with other types of fats. The long-term effects of PUFAs on satiety, however, remain unknown. The aim of this study was to determine subjective and physiological hunger and satiety responses to high-fat (HF) meals before and after a 7-d PUFA-rich diet.

METHODS

Twenty-six, healthy weight (body mass index 18-24.9 kg/m²), sedentary adults were randomly assigned to either a 7-d PUFA-rich diet (n = 8 men and n = 8 women) or a 7-d control diet (n = 5 men and n = 5 women). After a 3-d lead-in diet, participants reported for the baseline visit where anthropometrics, fasting visual analog scale (VAS) measurements, and a fasting blood sample were collected. Then, two HF meals (breakfast and lunch) were consumed. Postprandial blood draws and VAS measures were collected approximately every 30 min for 4 h after each meal, for a total of 8 h.

RESULTS

From pre- to post-PUFA-rich diet, there was a decrease in fasting ghrelin (P < 0.05) and an increase in fasting peptide YY (PYY; P < 0.05); however, there were no changes in fasting insulin or leptin concentrations. The postprandial response for PYY was higher after the PUFA-rich diet visit compared to baseline (P < 0.01). However, there were no differences in the postprandial response for ghrelin, insulin, leptin, or VAS measures from pre- to post-diet in either the PUFA-rich diet or control (ns).

CONCLUSION

A PUFA-rich diet consumed for 7 d favorably altered fasting and postprandial physiological markers of hunger and satiety; yet, did not alter subjective ratings of hunger or fullness.

Effects of polydextrose with breakfast or with a midmorning preload on food intake and other appetite-related parameters in healthy normal-weight and overweight females: An acute, randomized, double-blind, placebo-controlled, and crossover study

Polydextrose (PDX) reduces subsequent energy intake (EI) when administered at midmorning in single-blind trials of primarily normal-weight men. However, it is unclear if this effect also occurs when PDX is given at breakfast time. Furthermore, for ecological validity, it is desirable to study a female population, including those at risk for obesity. We studied the effects of PDX, served as part of a breakfast or midmorning preload, on subsequent EI and other appetite-related parameters in healthy normal-weight and overweight females. Per earlier studies, the primary outcome was defined as the difference in subsequent EI when PDX was consumed at midmorning versus placebo. Thirty-two volunteers were enrolled in this acute, double-blind, placebo-controlled, randomized, and crossover trial to examine the effects of 12.5 g of PDX, administered as part of a breakfast or midmorning preload, on subsequent EI, subjective feelings of appetite, well-being, and mood. Gastric emptying rates and the blood concentrations of glucose, insulin, cholecystokinin, ghrelin, glucagon-like peptide 1 (GLP-1), and peptide tyrosine-tyrosine were measured in the group that received PDX as part of their breakfast. There were no differences in EI between volunteers who were fed PDX and placebo. PDX intake with breakfast tended to elevate blood glucose (P = 0.06) during the postabsorptive phase, significantly lowered insulin by 15.7% (P = 0.04), and increased GLP-1 by 39.9% (P = 0.02); no other effects on blood parameters or gastric emptying rates were observed. PDX intake at midmorning reduced hunger by 31.4% during the satiation period (P = 0.02); all other subjective feelings of appetite were unaffected. Volunteers had a uniform mood profile during the study. PDX was well tolerated, causing one mild adverse event throughout the trial.

Quality of meal and appetite sensation

PURPOSE OF REVIEW

The scope of this review is to summarize recent studies assessing the role of meal composition on appetite sensation.

RECENT FINDINGS

Currently, data confirm a positive effect on appetite sensations following protein-rich meals, suggesting that at least 25-30-g protein/meal provide potential improvements on appetite, but further long-term studies are required to confirm the results. A greater interest has been showed in the interaction between short-chain fatty acids produced by gut microbiota, following dietary fiber consumption, and appetite sensation, but research is ongoing. Finally, as reflected in the recent literature, new systematic reviews should be carried out to assess the effect of dietary fibers on appetite sensation.

SUMMARY

Meal composition, in terms of nutrients, widely differs in the ability to affect appetite sensation. This mostly depends on the content of protein and dietary fibers in a meal. The effect of higher protein intake on appetite sensation has been well documented with positive results, whereas dietary fibers, although the majority of evidence suggests positive results, still show inconsistent data because of various methodological approaches. Generally, more research both in the short and long term is required to investigate the underlying mechanism associated with appetite sensation.

Effect of Polydextrose on Subjective Feelings of Appetite during the Satiation and Satiety Periods: A Systematic Review and Meta-Analysis

Introduction: Subjective feelings of appetite are measured using visual analogue scales (VAS) in controlled trials. However, the methods used to analyze VAS during the Satiation (pre- to post-meal) and Satiety (post-meal to subsequent meal) periods vary broadly, making it difficult to compare results amongst independent studies testing the same product. This review proposes a methodology to analyze VAS during both the Satiation and Satiety periods, allowing us to compare results in a meta-analysis. Methods: A methodology to express VAS results as incremental areas under the curve (iAUC) for both the Satiation and Satiety periods is proposed using polydextrose as a case study. Further, a systematic review and meta-analysis on subjective feelings of appetite was conducted following the PRISMA methodology. Meta-analyses were expressed as Standardized Mean Difference (SMD). Results: Seven studies were included in the meta-analysis. There were important differences in the methods used to analyze appetite ratings amongst these studies. The separate subjective feelings of appetite reported were Hunger, Satisfaction, Fullness, Prospective Food Consumption, and the Desire to Eat. The method proposed here allowed the results of the different studies to be homogenized. The meta-analysis showed that Desire to Eat during the Satiation period favors polydextrose for the reduction of this subjective feeling of appetite (SMD = 0.24, I² < 0.01, p = 0.018); this effect was also significant in the sub-analysis by sex for the male population (SMD = 0.35, I² < 0.01, p = 0.015). There were no other significant results. Conclusion: It is possible to compare VAS results from separate studies. The assessment of iAUC for both the Satiation and Satiety periods generates results of homogeneous magnitudes. This case study demonstrates, for the first time, that polydextrose reduces the Desire to Eat during the Satiation period. This may explain, at least in part, the observed effects of polydextrose on the reduction of levels of energy intake at subsequent meals.

The role of polydextrose in body weight control and glucose regulation

PURPOSE OF REVIEW

The purpose of this review was to highlight recent research developments on effects of the dietary fibre polydextrose (PDX) on appetite, satiety and energy intake and glucose metabolism. For this purpose, clinically relevant human studies were reviewed and putative mechanisms and pathways were discussed.

RECENT FINDINGS

A number of acute human intervention studies provide strong indications for an energy and glucose metabolism-regulating role of PDX. These effects might be mediated via a reduced gastro-intestinal transit reducing glycaemia and insulinemia after PDX ingestion and the potential of PDX as soluble dietary fibre to alter the intestinal microbial composition, which might lead to changes in signalling in both peripheral and central pathways involved in energy metabolism and glucose homeostasis.

SUMMARY

In acute studies, PDX seems to have an inhibiting effect on energy intake and satiety and to reduce glycaemic and insulinemic response through effect on gastro-intestinal transit time and macronutrient absorption as well as through effects of the microbial products such as short-chain fatty acids on energy and substrate metabolism. In particular, well controlled human intervention studies are required to confirm these effects in the long term. Overall, supplement PDX to the daily diet may be a promising approach for the management and treatment of obesity and associated metabolic disorders.

Postprandial triglyceride response in normolipidemic, hyperlipidemic and obese subjects - the influence of polydextrose, a non-digestible carbohydrate

BACKGROUND

Three independent trials were conducted to evaluate postprandial triglyceride (TG) responses in subjects with different lipid metabolism. The effect of polydextrose (PDX), a soluble non-digestible carbohydrate, on postprandial response was also studied using practically relevant, high fat meal interventions.

METHODS

A total of 19 normolipidemic (average BMI 24.1 kg/m(2)), 21 overweight/hyperlipidemic (average BMI 29.6 kg/m(2)) and 18 obese/non-diabetic subjects (average BMI 33.6 kg/m(2)) were included in the study. On two separate occasions all subjects ate two high-fat meals (4293 kJ, 36% from fat), one with PDX (either 12.5 g or 15 g) and one without PDX during placebo-controlled, double-blind, crossover and randomized trials. To obtain the triglyceride measurements venous blood samples were taken before the consumption of the test meal and five times afterwards, up to 6 h post-test meal. The triglyceride responses were modeled using a mixed-effects linear model.

RESULTS

The key variables that explain the variation of the postprandial triglyceride response in the different subject groups were: baseline triglyceride concentration, time point, and PDX vs. placebo treatment (p < 0.05). The maximum postprandial TG concentration was more pronounced in hyperlipidemic group compared to normolipidemic (p < 0.001) or obese groups (p < 0.01). The modeled TG response analysis showed that irrespective of the study population PDX supplementation was one of the factors significantly reducing triglyceride response compared to the placebo treatment (p < 0.05).

CONCLUSIONS

Subjects with elevated fasting triglyceride levels display exaggerated and prolonged postprandial triglyceride responses. PDX, a soluble non-digestible carbohydrate, may offer a dietary concept for reducing the postprandial triglyceride response after the consumption of a meal containing a high concentration of fat.