Effects of the soluble fiber complex PolyGlycopleX® (PGX®) on glycemic control, insulin secretion, and GLP-1 levels in Zucker diabetic rats

Porang (Amorphophallus oncophyllus) Flour Macerated with Strobilanthes crispus Reduced the Blood Glucose Levels of Streptozotocin-Induced Diabetic Rats

BACKGROUND: Diabetes mellitus (DM) is a group of metabolic diseases indicated by hyperglycemia. Dietary regulation represents a viable means of controlling blood glucose levels. Porang (Amorphophallus oncophyllus) is a local tuber that has a low glycemic index due to its high glucomannan content. In combination with Strobilanthes crispus (SC), which is rich in antioxidants, porang flour could be a promising treatment approach for DM. AIM: This study aimed to determine the effect of porang flour macerated with SC on the blood glucose levels of diabetic rats. METHODS: Thirty-five Wistar (Rattus norvegicus) rats were divided into five groups on the basis of their diets: Normal/negative control (NC) group (non-diabetic, standard AIN-93 diet), positive control (PC) group (streptozotocin [STZ]-induced diabetic), glibenclamide (GB) group (STZ-induced diabetic, medicated with GB 100 mg/200 g body weight [BW]), porang (NP) group (modified AIN-93 diet, fiber substituted with 11% porang flour [equal to 1.1 g/200 g BW]), and SC-macerated porang (SP) group (modified AIN-93 diet, fiber substituted with 11% porang flour macerated with SC [equal to 1.1 g/200 g BW]). The rats’ food intakes, stools, and BWs were recorded throughout the study, while their blood glucose levels were measured before the induction of DM, 3 days after the induction of DM, and at the end of the study (14-day treatment period). The data were statistically analyzed using a one-way analysis of variance combined with Duncan’s multiple range test. RESULTS: The rats’ feed intakes during the 14-day treatment period were almost the same, which influenced their BWs. After the induction of DM, the rats’ BWs appeared to decrease, albeit not to a statistically significant extent. This weight loss may have been better controlled in the treatment groups because the glucomannan content of the porang led to an improvement in the rats’ glucose metabolism, especially in the NP and SP groups. The rats’ stools appeared normal in consistency and moisture, and it was confirmed that there were no diarrhea incidents. The glucomannan content also decreased the blood glucose levels in the NP and SP groups. The SP group showed the best results in terms of decreased glucose levels due to the addition of SC as a source of antioxidants. CONCLUSION: Porang exerted an antidiabetic effect that was comparable with the effect of GB (a commercial drug). In combination with SC, it provided a high level of antioxidants. Porang should be further studied to optimize its antidiabetic potency and potential for use as a functional food or nutraceutical.

Prebiotic and Exercise Do Not Alter Knee Osteoarthritis in a Rat Model of Established Obesity

OBJECTIVE

Metabolic disturbance is a known risk factor for cardiovascular disease and has been identified as a risk factor for the development of knee osteoarthritis. In this study, we sought to determine the effects of prebiotic fiber supplementation, aerobic exercise, and the combination of the 2 interventions, on the progression of knee osteoarthritis in a high-fat/high-sucrose diet-induced rat model of metabolic disturbance.

DESIGN

Twelve-week-old male CD-Sprague-Dawley rats were either fed a standard chow diet, or a high-fat/high-sucrose diet. After 12 weeks on diets, rats consuming the high-fat/high-sucrose diet were randomized into 4 subgroups: a sedentary, an aerobic exercise, a prebiotic fiber supplementation, and an aerobic exercise combined with prebiotic fiber supplementation group. The aerobic exercise intervention consisted of a progressive treadmill training program for 12 weeks, while the prebiotic fiber was added to the high-fat/high-sucrose diet at a dose of 10% by weight for 12 weeks. Outcome measures included knee joint damage, body mass, percent body fat, bone mineral density, insulin sensitivity, and serum lipid profile.

RESULTS

Aerobic exercise, or the combination of prebiotic fiber and aerobic exercise, improved select markers of metabolic disturbance, but not knee joint damage. However, these results need to be considered in view of the fact that the chow-fed rats had similar knee OA-like damage as the high-fat/high-sucrose-fed rats.

CONCLUSION

Exercise or prebiotics did not increase joint damage and might be good strategies for populations with metabolic knee osteoarthritis to alleviate other health-related problems, such as diabetes or cardiovascular disorders.

Bacterial Fermentation of Water-Soluble Cellulose Acetate Raises Large-Bowel Acetate and Propionate and Decreases Plasma Cholesterol Concentrations in Rats

We hypothesized that water-soluble cellulose acetate (WSCA) could be useful tool for the delivery of short-chain fatty acids to the large intestine. Rats were fed a control diet or a diet containing graded levels of WSCA for up to 21 days. Consuming WSCA dose-dependently increased large-bowel acetate and propionate concentrations through the bacterial fermentation. When WSCA was used as substrate, acetyl esterase activity in the cecal bacteria was detected solely in rats fed WSCA, in which the activity increased over time accompanied by an increased number of Bacteroides xylanisolvens. Consuming WSCA at a 4% level increased the goblet cell numbers and mucin contents in the cecum and lowered plasma cholesterol concentrations, which tended to correlate with the portal plasma concentrations of propionate. The results suggest that bacterial fermentation of WSCA is characterized by the greater production of acetate and propionate, which may contribute to the physiologic alterations.

Safety of alginate-konjac-xanthan polysaccharide complex (PGX) as a novel food pursuant to Regulation (EC) No 258/97

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on alginate-konjac-xanthan polysaccharide complex (PGX) as a novel food (NF) submitted pursuant to Regulation (EC) No 258/97. The NF is an off-white granular powder composed of three non-starch polysaccharides: konjac glucomannan, xanthan gum and sodium alginate. The information provided on the composition, the specifications, the batch-to-batch variability and the stability of the NF is sufficient and does not raise safety concerns. The production process is sufficiently described and does not raise concerns about the safety of the NF. The applicant intends to add the NF to a variety of foods as well as to market the NF in capsules. The recommended maximum daily intake of the NF from fortified foods and food supplements is 15 g. The target population proposed by the applicant is adults from 18 to 64 years of age. Considering the no observed adverse effect level of 1.8 g/kg body weight (bw) per day in a subchronic toxicity study with PGX and the highest mean and 95th percentile anticipated daily intake of NF from fortified foods, the margin of exposure (MoE) is 12 and 6, respectively, whereas the MoE for the NF from food supplements is 9. The Panel concludes that the safety of the novel food, PGX, for the intended uses and use levels as proposed by the applicant, has not been established.

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

BACKGROUND/OBJECTIVES

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

SUBJECTS/METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

ANZCTR: ACTRN12611000415909. Registered 20 April 2011.

Long-term antihypertensive effect of a soluble cocoa fiber product in spontaneously hypertensive rats

Background and Methods

This study evaluates the antihypertensive effect of long-term intake of a soluble cocoa fiber product (SCFP). Different doses of SCFP were evaluated (200, 400, and 800 mg/kg/day) and a dose of 800 mg/kg/day of beta-glucan 0.75 (BETA-G) was used as a standard fiber. Water, a neutral vehicle, was used as negative control, and 50 mg/kg/day captopril was used as positive control. Systolic blood pressure (SBP) was measured weekly by the tail cuff method. Body weight, food, and liquid intake were also registered weekly in the rats from 10 to 24 weeks of life. Glucose, total cholesterol, and triglyceride levels; redox status; and the angiotensin-converting enzyme activity were also studied in the plasma samples of these animals.

Results

Throughout the 10 weeks of treatment, captopril and SCFP (400 mg/kg/day) demonstrated blood pressure lowering effects in the spontaneously hypertensive rats (p<0.05; n=8). Paradoxically, neither the highest dose (800 mg/kg/day) of SCFP decreased SBP nor 800 mg/kg/day BETA-G (p>0.05; n=8). When the corresponding antihypertensive treatment, was disrupted the SBP values of the 400 mg/kg/day SCFP treated animals returned to control values (p>0.05; n=8). In addition, the SCFP significantly decreased (p<0.05; n=4) the glucose, cholesterol, and triglyceride levels and also the liver and plasma malondaldehyde levels. Moreover, the SCFP slightly increased the reduced glutathione levels in the liver.

Conclusion

The SCFP could be used to control the blood pressure of hypertensive subjects for a long period of time and could improve metabolic complications associated to cardiovascular diseases.

The Rationale for Continuous Glucose Monitoring-based Diabetes Treatment Decisions and Non-adjunctive Continuous Glucose Monitoring Use

Self-monitoring of blood glucose (SMBG) is now recognised as a core component of diabetes self-management. However, there are many limitations to SMBG use in individuals with diabetes who are treated with intensive insulin regimens. Many individuals do not test at the recommended frequencies. Additionally, because SMBG only provides a blood glucose reading at a single point in time, hypoglycaemia and hyperglycaemia can easily go undetected, limiting the user's ability to take corrective action. Inaccuracies due to user error, environmental factors and weaknesses in SMBG system integrity further limit the utility of SMBG. Real-time continuous glucose monitoring (CGM) displays the current glucose, direction and velocity of glucose change and provides programmable alarms. This trending information and 'around-the-clock' vigilance provides a significant safety advantage relative to SMBG. No published clinical studies have evaluated outcomes when CGM is used as a replacement for SMBG; however, recent in silico studies support this indication. This article reviews the limitations of SMBG and discusses recent evidence that supports CGM-based decisions as an effective approach to managing insulin-treated diabetes.

Cooking enhances beneficial effects of pea seed coat consumption on glucose tolerance, incretin, and pancreatic hormones in high-fat-diet-fed rats

Pulses, including dried peas, are nutrient- and fibre-rich foods that improve glucose control in diabetic subjects compared with other fibre sources. We hypothesized feeding cooked pea seed coats to insulin-resistant rats would improve glucose tolerance by modifying gut responses to glucose and reducing stress on pancreatic islets. Glucose intolerance induced in male Sprague-Dawley rats with high-fat diet (HFD; 10% cellulose as fibre) was followed by 3 weeks of HFD with fibre (10%) provided by cellulose, raw-pea seed coat (RP), or cooked-pea seed coat (CP). A fourth group consumed low-fat diet with 10% cellulose. Oral and intraperitoneal glucose tolerance tests (oGTT, ipGTT) were done. CP rats had 30% and 50% lower glucose and insulin responses in oGTT, respectively, compared with the HFD group (P < 0.05) but ipGTT was not different. Plasma islet and incretin hormone concentrations were measured. α- and β-cell areas in the pancreas and density of K- and L-cells in jejunum and ileum were quantified. Jejunal expression of hexose transporters was measured. CP feeding increased fasting glucagon-like peptide 1 and glucose-stimulated gastric inhibitory polypeptide responses (P < 0.05), but K- and L-cells densities were comparable to HFD, as was abundance of SGLT1 and GLUT2 mRNA. No significant difference in β-cell area between diet groups was observed. α-cell area was significantly smaller in CP compared with RP rats (P < 0.05). Overall, our results demonstrate that CP feeding can reverse adverse effects of HFD on glucose homeostasis and is associated with enhanced incretin secretion and reduced α-cell abundance.

Effect of the novel functional fibre, polyglycoplex (PGX), on body weight and metabolic parameters: A systematic review of randomized clinical trials

BACKGROUND & AIMS

Hundreds of dietary supplements are marketed as weight loss pills, but the evidence for effectiveness for most is unproven. The objective of this review was to critically appraise and evaluate the evidence from published randomized clinical trials (RCTs) examining the effectiveness of polyglycoplex (PGX), a novel functional fibre, on body weight and metabolic parameters.

METHODS

We conducted electronic searches in Medline, Embase, Amed, Cinahl and The Cochrane Library. Only double-blinded RCTs were considered for inclusion. The reporting quality of included studies was assessed using the Cochrane criteria. Two reviewers independently determined eligibility, assessed the quality of reporting, and extracted the data.

RESULTS

We included four RCTs with a total of 217 participants. The RCTs varied in the quality of their reporting. The evidence from the RCTs suggested that PGX has no significant effects on body weight; however, significant reductions were noted for total and LDL cholesterol. Adverse events reported included diarrhea and abdominal bloating.

CONCLUSION

The evidence from available RCTs does not indicate that PGX intake causes reductions in body weight. PGX may cause reductions in total and LDL cholesterol. Few trials examining the effects of PGX have been conducted; they are characterized by small sample sizes, deficiencies in reporting quality, and are funded by a single manufacturer. Future clinical trials evaluating its effect should be adequately powered and better reported.

High-viscosity dietary fibers reduce adiposity and decrease hepatic steatosis in rats fed a high-fat diet

Viscous dietary fiber consumption lowers the postprandial glucose curve and may decrease obesity and associated comorbidities such as insulin resistance and fatty liver. We determined the effect of 2 viscous fibers, one fermentable and one not, on the development of adiposity, fatty liver, and metabolic flexibility in a model of diet-induced obesity. Rats were fed a normal-fat (NF) diet (26% energy from fat), a high-fat diet (60% energy from fat), each containing 5% fiber as cellulose (CL; nonviscous and nonfermentable), or 5% of 1 of 2 highly viscous fibers-hydroxypropyl methylcellulose (HPMC; nonfermentable) or guar gum (GG; fermentable). After 10 wk, fat mass percentage in the NF (18.0%; P = 0.03) and GG groups (17.0%; P < 0.01) was lower than the CL group (20.7%). The epididymal fat pad weight of the NF (3.9 g; P = 0.04), HPMC (3.9 g; P = 0.03), and GG groups (3.6 g; P < 0.01) was also lower than the CL group (5.0 g). The HPMC (0.11 g/g liver) and GG (0.092 g/g liver) groups had lower liver lipid concentrations compared with the CL group (0.14 g/g liver). Fat mass percentage, epididymal fat pad weight, and liver lipid concentration were not different among the NF, HPMC, and GG groups. The respiratory quotient was higher during the transition from the diet-deprived to fed state in the GG group (P = 0.002) and tended to be higher in the HPMC group (P = 0.06) compared with the CL group, suggesting a quicker shift from fatty acid (FA) to carbohydrate oxidation. The HPMC group [15.1 nmol/(mg ⋅ h)] had higher ex vivo palmitate oxidation in muscle compared with the GG [11.7 nmol/(mg ⋅ h); P = 0.04] and CL groups [10.8 nmol/(mg ⋅ h); P < 0.01], implying a higher capacity to oxidize FAs. Viscous fibers can reduce the adiposity and hepatic steatosis that accompany a high-fat diet, and increase metabolic flexibility, regardless of fermentability.

Safety and efficacy of the nonsystemic chewable complex carbohydrate dietary supplement PAZ320 on postprandial glycemia when added to oral agents or insulin in patients with type 2 diabetes mellitus

OBJECTIVE

Our primary objective was to evaluate the effect of the dietary supplement PAZ320 on postprandial glucose excursion. PAZ320 is derived from glucomannan and acts by blocking carbohydrate hydrolyzing enzymes and by binding to ingested polysaccharides. Endpoints included area under the curve during postprandial glucose excursion (gAUC) and adverse reactions.

METHODS

In an open-label, sequential dose-escalation, prospective study, we examined the efficacy and safety of PAZ320 in 24 subjects with type 2 diabetes treated with oral agents and/or insulin. Subjects consumed 75 g jasmine rice alone or with low-dose (8 g) or high-dose (16 g) PAZ320. A real-time blinded continuous glucose monitor (CGM) was used to assess 3-hour postprandial glycemia.

RESULTS

We found that 45% of subjects responded to high-dose PAZ320 as evidenced by a decrease in gAUC of 40% compared to baseline in a dose-dependent manner. The effect of PAZ320 does not correlate with duration of diabetes and seems to work regardless of concurrent diabetes medications. The responders had higher postmeal glucose elevation at baseline, while the nonresponders showed no effect or paradoxic glucose response to PAZ320. There was no severe hypoglycemia, and the gastrointestinal side effects were mild.

CONCLUSIONS

PAZ320 may be useful as an adjunct to decrease postprandial glycemia in type 2 diabetes, although patients should verify its effect on postprandial glucose due to a possible paradoxic response. Its safety profile is reassuring. Further study is required to determine its long-term effects on glycated hemoglobin (HbA1c) and to further define which subpopulation may respond to PAZ320.

Combining sitagliptin/metformin with a functional fiber delays diabetes progression in Zucker rats

Our primary objective was to determine whether administering the viscous and fermentable polysaccharide PolyGlycopleX (PGX) with metformin (MET) or sitagliptin/metformin (S/MET) reduces hyperglycemia in Zucker diabetic fatty (ZDF) rats more so than monotherapy of each. Glucose tolerance, adiposity, satiety hormones and mechanisms related to dipeptidyl peptidase 4 activity, gut microbiota and, hepatic and pancreatic histology were examined. Male ZDF rats (9-10 weeks of age) were randomized to: i) cellulose/vehicle (control, C); ii) PGX (5% wt/wt)/vehicle (PGX); iii) cellulose/metformin (200  mg/kg) (MET); iv) cellulose/S/MET (10  mg/kg+200  mg/kg) (S/MET); v) PGX (5%)+MET (200  mg/kg) (PGX+MET); vi) cellulose/sitagliptin/MET (5%)+(10  mg/kg+200  mg/kg) (PGX+S/MET) for 6 weeks. PGX+MET and PGX+S/MET reduced glycemia compared with C and singular treatments (P=0.001). Weekly fasted and fed blood glucose levels were lower in PGX+MET and PGX+S/MET compared with all other groups at weeks 4, 5, and 6 (P=0.001). HbA1c was lower in PGX+S/MET than C, MET, S/MET, and PGX at week 6 (P=0.001). Fat mass was lower and GLP1 was higher in PGX+S/MET compared with all other groups (P=0.001). β-cell mass was highest and islet degeneration lowest in PGX+S/MET. Hepatic lipidosis was significantly lower in PGX+S/MET compared with PGX or S/MET alone. When combined with PGX, both MET and S/MET markedly reduce glycemia; however, PGX+S/MET appears advantageous over PGX+MET in terms of increased β-cell mass and reduced adiposity. Both combination treatments attenuated diabetes in the obese Zucker rat.

Meal replacements and fibre supplement as a strategy for weight loss. Proprietary PGX® meal replacement and PGX® fibre supplement in addition to a calorie-restricted diet to achieve weight loss in a clinical setting

Meal replacements and viscous soluble fibre represent safe and sustainable aids for weight loss. Our purpose was to determine if PGX® meal replacements and PGX(®) fibre complex in combination with a calorie-restricted diet would aid in weight loss in a clinical setting. Fifty-two overweight and obese participants (49 women, 3 men; average age 47.1 years) with a mean body mass index (BMI) of 33.8 ± 6.4 kg/m(2) consumed 57 g of proprietary PGX® meal replacement product at breakfast and another 57 g at lunch for 12 weeks. In addition to the meal replacements, they were also asked to consume 5 g/day of PGX® fibre in the form of granules, powder or capsules together with 250 mlwater. A registered dietician recommended low-fat, low-glycaemic-index foods for snacks and the dinner menus such that each volunteer was consuming a total of 1200 kcal/day. All participants (n = 52) lost a significant amount of weight from baseline (-4.69 ± 3.73 kg), which was further reflected in the reductions in their waist (-7.11 ± 6.35 cm) and hip circumference (-5.59 ± 3.58 cm) over the 12-week study (p < 0.0001). BMI scores (n = 51) were reduced by 1.6 ± 1.4 kg/m(2). The use of PGX® meal replacements and PGX(®) fibre along with a controlled dietary caloric intake is of benefit for short-term weight loss.

Sitagliptin reduces hyperglycemia and increases satiety hormone secretion more effectively when used with a novel polysaccharide in obese Zucker rats

The novel polysaccharide (NPS) PolyGlycopleX (PGX) has been shown to reduce glycemia. Pharmacological treatment with sitagliptin, a dipeptidyl peptidase 4 (DPP4) inhibitor, also reduces glycemia by increasing glucagon-like peptide-1 (GLP-1). Our objective was to determine if using NPS in combination with sitagliptin reduces hyperglycemia in Zucker diabetic fatty (ZDF) rats more so than either treatment alone. Male ZDF rats were randomized to: 1) cellulose/vehicle [control (C)]; 2) NPS (5% wt:wt)/vehicle (NPS); 3) cellulose/sitagliptin [10 mg/(kg · d) (S)]; or 4) NPS (5%) + S [10 mg/(kg · d) (NPS+S)]. Glucose tolerance, adiposity, satiety hormones, and mechanisms related to DPP4 activity and hepatic and pancreatic histology were examined. A clinically relevant reduction in hyperglycemia occurred in the rats treated with NPS+S (P = 0.001) compared with NPS and S alone. Blood glucose, measured weekly in fed and feed-deprived rats and during an oral glucose tolerance test, was lower in the NPS+S group compared with all other groups (all P = 0.001). At wk 6, glycated hemoglobin was lower in the NPS+S group than in the C and S (P = 0.001) and NPS (P = 0.06) groups. PGX (P = 0.001) and S (P = 0.014) contributed to increased lean mass. Active GLP-1 was increased by S (P = 0.001) and GIP was increased by NPS (P = 0.001). Plasma DPP4 activity was lower in the NPS+S and S groups than in the NPS and C groups (P = 0.007). Insulin secretion and β-cell mass was increased with NPS (P < 0.05). NPS alone reduced LDL cholesterol and hepatic steatosis (P < 0.01). Independently, NPS and S improve several metabolic outcomes in ZDF rats, but combined, their ability to markedly reduce glycemia suggests they may be a promising dietary/pharmacological co-therapy for type 2 diabetes management.

The role of nutrients in the development, progression, and treatment of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in adults and children and is currently the third most common indication for liver transplantation in North America. Its pathogenesis is thought to be secondary to multiple "hits" derived from the dietary components, adipose tissue, immune system, and intestinal microbiota. Lack of physical activity may contribute as well. Nutrients may exert their effect directly or through alteration of the intestinal microbiota. Research focusing on specific dietary components predisposing to NAFLD has shown conflicting results. Total energy intake, and macronutrients, has been linked to the development of NAFLD. Fructose not only contributes to hepatic steatosis but may trigger inflammatory signals as well. Polyunsaturated fatty acids are thought to exert anti-inflammatory effects. The role of vitamins as well as minerals in this field is actively being investigated. In this review, we discuss the evidence-linking macronutrients (such as carbohydrates and fat in general and fructose, fiber, short chain fatty acids, polyunsaturated fatty, and choline specifically) and micronutrients (such as vitamin E and C and minerals) with the development and treatment of NAFLD. We also discuss the literature on physical activity and NAFLD.

Is There a Place for Dietary Fiber Supplements in Weight Management?

Inadequate dietary fiber intake is common in modern diets, especially in children. Epidemiological and experimental evidence point to a significant association between a lack of fiber intake and ischemic heart disease, stroke atherosclerosis, type 2 diabetes, overweight and obesity, insulin resistance, hypertension, dyslipidemia, as well as gastrointestinal disorders such as diverticulosis, irritable bowel disease, colon cancer, and cholelithiasis. The physiological effects of fiber relate to the physical properties of volume, viscosity, and water-holding capacity that the fiber imparts to food leading to important influences over the energy density of food. Beyond these physical properties, fiber directly impacts a complex array of microbiological, biochemical, and neurohormonal effects directly through modification of the kinetics of digestion and through its metabolism into constituents such as short chain fatty acids, which are both energy substrates and important enteroendocrine ligands. Of particular interest to clinicians is the important role dietary fiber plays in glucoregulation, appetite, and satiety. Supplementation of the diet with highly functional fibers may prove to play an important role in long-term obesity management.

Effect of PGX, a novel functional fibre supplement, on subjective ratings of appetite in overweight and obese women consuming a 3-day structured, low-calorie diet

Introduction:

Dietary factors that help control perceived hunger might improve adherence to calorie-reduced diets.

Objectives:

The objective of the study was to investigate the effect of supplementing a three-day, low-calorie diet with PolyGlycopleX (PGX), a highly viscous fibre, on subjective ratings of appetite compared with a placebo.

Methods:

In a double-blind crossover design with a 3-week washout, 45 women (aged 38±9 years, body mass index 29.9±2.8 kg m⁻²) were randomised to consume a 1000-kcal per day diet for 3 days, supplemented with 5 g of PGX or placebo at each of breakfast, lunch and dinner. Subjective appetite was assessed using 100 mm visual analogue scales that were completed daily before, between and after consumption of meals.

Results:

Thirty-five women completed the study. Consumption of PGX compared with placebo led to significantly lower mean area under the curve for hunger on day 3 (440.4 versus 375.4; P=0.048), prospective consumption on day 3 (471.0 versus 401.8; P=0.017) and the overall 3-day average (468.6 versus 420.2; P=0.026). More specifically, on day 3 PGX significantly reduced total appetite, hunger, desire to eat and prospective consumption for 2.5 and 4.5 h after lunch and before dinner times, with hunger also being reduced 2.5 h after dinner (P<0.05).

Conclusion:

The results show that adding 5 g of PGX to meals during consumption of a low-calorie diet reduces subjective ratings of prospective consumption and increases the feelings of satiety, especially during afternoon and evening. This highly viscous polysaccharide may be a useful adjunct to weight-loss interventions involving significant caloric reductions.

Effects of added PGX®, a novel functional fibre, on the glycaemic index of starchy foods

The development of lower-glycaemic index (GI) foods requires simple, palatable and healthy strategies. The objective of the present study was to determine the most effective dose of a novel viscous fibre supplement (PGX®) to be added to starchy foods to reduce their GI. Healthy subjects (n 10) consumed glucose sugar (50 g in water × 3) and six starchy foods with a range of GI values (52–72) along with 0 (inert fibre), 2·5 or 5 g granular PGX® dissolved in 250 ml water. GI testing according to ISO Standard 26 642-2010 was used to determine the reduction in GI. PGX® significantly reduced the GI of all six foods (P < 0·001), with an average reduction of 19 % for the 2·5 g dose and 30 % for the 5 g dose, equivalent to a reducing the GI by 7 and 15 units, respectively. Consuming small quantities of the novel functional fibre PGX®, mixed with water at the start of a meal, is an effective strategy to reduce the GI of common foods.

Effects of the Soluble Fiber Complex PolyGlycopleX on Glucose Homeostasis and Body Weight in Young Zucker Diabetic Rats

Dietary fiber can reduce insulin resistance, body weight, and hyperlipidemia depending on fiber type, water solubility, and viscosity. PolyGlycopleX(®) (PGX(®)) is a natural, novel water soluble, non-starch polysaccharide complex that with water forms a highly viscous gel compared to other naturally occurring dietary fiber. We determined the effect of dietary PGX(®) vs. cellulose and inulin on the early development of insulin resistance, body weight, hyperlipidemia, and glycemia-induced tissue damage in young Zucker diabetic rats (ZDFs) in fasted and non-fasted states. ZDFs (5 weeks old) were fed a diet containing 5% (wgt/wgt) cellulose, inulin, or PGX(®) for 8 weeks. Body weight, lipids, insulin, and glucose levels were determined throughout the study and homeostasis model assessment (HOMA) was used to measure insulin sensitivity throughout the study in fasted animals. At study termination, insulin sensitivity (oral glucose tolerance test, OGTT) and kidney, liver, and pancreatic histopathology were determined. Body weight and food intake were significantly reduced by PGX(®) vs. inulin and cellulose. Serum insulin in fasted and non-fasted states was significantly reduced by PGX(®) as was non-fasted blood glucose. Insulin resistance, measured as a HOMA score, was significantly reduced by PGX(®) in weeks 5 through 8 as well as terminal OGTT scores in fed and fasted states. Serum total cholesterol was also significantly reduced by PGX(®). PGX(®) significantly reduced histological kidney and hepatic damage in addition to reduced hepatic steatosis and cholestasis. A greater mass of pancreatic β-cells was found in the PGX(®) group. PGX(®) therefore may be a useful dietary additive in the control of the development of the early development of the metabolic syndrome.