A Randomized, Double-Blind, Crossover Study to Determine the Available Energy from Soluble Fiber.

OBJECTIVE: Determining the available energy (caloric value) of dietary non-digestible fibers that are fermented to varying degrees by intestinal microbes and metabolized to short chain fatty acids is important for provision of accurate information to food and beverage manufacturers for reformulation and labeling purposes. The objective of this human study was to determine the available energy of soluble fiber products by measuring post consumption breath hydrogen, with inulin as a control. METHODS: PROMITOR® Soluble Corn Fiber 70 (SCF70) and PROMITOR® Soluble Corn Fiber 85B (SCF85B) are Tate & Lyle dietary fiber products with 70% and 85% fiber, respectively. The fiber portion of these products is structurally representative of the fiber portion of all PROMITOR® SCF products. The study conducted was a randomized, double-blind, crossover design. Breath hydrogen was quantified following consumption of beverages consisting of 8 oz. of water and: inulin (control), SCF70, or SCF85B at 5, 10, or 15 g (total ingredient weight, "as is"). Subjects were generally healthy men and women (N = 19), age 18 to 34 years, with body mass index (BMI) 19.3 to 24.8 kg/m2. The primary outcome was incremental area under the curve over 10 h (iAUC0-10 h) for inulin, SCF70, and SCF85B at each dose. The available energy (kcal/g ingredient and kcal/g fiber) from SCF70 and SCF85B at each dose was then calculated using inulin as the reference. RESULTS: Results demonstrated that breath hydrogen production was significantly lower following consumption of SCF70 and SCF85B compared to inulin at all consumption amounts. There were no significant differences in breath hydrogen production following consumption of SCF70 compared to SCF85B. CONCLUSION: The available energy per gram of fiber was not significantly different between the SCF70 and SCF85B PROMITOR® products. The available energy of the fiber portion of PROMITOR® SCF products was determined to be 0.2 kcal/gram.

Short-term, daily intake of yogurt containing Bifidobacterium animalis ssp. lactis Bf-6 (LMG 24384) does not affect colonic transit time in women.

The present study investigated the effect of Bifidobacterium animalis ssp. lactis Bf-6 (LMG 24 384) (Bf-6)-supplemented yogurt on colonic transit time (CTT). A triple-blinded, randomised, placebo-controlled, two-period cross-over trial was conducted with sixty-eight women with a self-reported history of straining during bowel movements or hard or lumpy stools in the past 2 years. As per regulatory requirements for probiotic studies, eligible women were generally healthy and not actively constipated at the time of enrolment. Participants consumed both Bf-6 and placebo yogurts for 14 d each in a randomised order, with a 6-week washout period between the treatments. The primary outcome, CTT, was assessed via Sitz marker X-rays. The average CTT was 42·1 h for the active period and 43·3 h for the control period (mean difference 1·2 h, 95 % CI - 4·9, 7·4). Since the statistical tests for the cross-over study implied that the mean CTT for the active and control periods in period 2 were biased, the standard protocol suggests examining the results of only period 1 as a traditional randomised controlled trial. This showed that the mean CTT was 35·2 h for the active period v. 52·9 h for the control period (P= 0·015). Bootstrapping demonstrated that both the mean and median differences remained significant (P= 0·016 and P= 0·045, respectively). Few adverse events were noted, with no differences among the active and control periods. The paired analysis showed no differences between the active and control periods during the cross-over trial. Further trials should be conducted in populations with underlying problems associated with disordered transit to determine the potential value of probiotic supplementation more accurately.

Reduced viscosity Barley ß-Glucan versus placebo: a randomized controlled trial of the effects on insulin sensitivity for individuals at risk for diabetes mellitus.

BACKGROUND: Prior studies suggest soluble fibers may favorably affect glucose/insulin metabolism. METHODS: This prospective, randomized, placebo controlled, double blind, parallel group trial evaluated 50 generally healthy subjects without prior diagnosis of diabetes mellitus (44 completers), who were administered beverages containing placebo (control), lower dose (3 g/d), or higher dose (6 g/d) reduced viscosity barley ß-glucan (BBG) extract. Subjects (68% women) mean age 56 years, Body Mass Index (BMI) 32 kg/m2 and baseline fasting plasma glucose 102 mg/dl were instructed to follow a weight-maintaining Therapeutic Lifestyle Changes (TLC) diet and consumed three 11 oz study beverages daily with meals for 12 weeks. The four primary study endpoint measures were plasma glucose and insulin [each fasting and post-Oral Glucose Tolerance Testing (OGTT)]. RESULTS: Compared to placebo, administration of 3 g/d BBG over 12 weeks significantly reduced glucose incremental Area Under the Curve (iAUC) measures during OGTT and 6 g/d BBG over 12 weeks significantly reduced fasting insulin as well as the related homeostasis model assessment of insulin resistance (HOMA-IR). Beverages were generally well tolerated with no serious adverse experiences and no significant differences between groups for adverse experiences. Per protocol instruction, subjects maintained body weight. CONCLUSIONS: These findings suggest 6 g/d BBG consumed in a beverage over 12 weeks may improve insulin sensitivity among hyperglycemic individuals with no prior diagnosis of diabetes mellitus, and who experience no change in body weight. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01375803.

Gastrointestinal tolerance of chicory inulin products.

BACKGROUND: The use of inulin in foods as a fiber source has increased recently. Consumption of inulin products can cause gastrointestinal (GI) distress. Acceptable intakes of inulin need to be determined. OBJECTIVE: To determine the GI tolerance of two inulin fibers, shorter chain length oligofructose and native inulin, at 5- and 10-g doses compared to a placebo. DESIGN: A randomized, double-blind, controlled, crossover design that included a phone screening and five visits for breakfast fiber challenges consisting of a bagel, cream cheese, and orange juice. SUBJECTS/SETTING: Twenty-six healthy men and women ages 18 to 60 years participated in the study. Healthy subjects with no history of GI conditions consumed diets with typical amounts of fiber. MAIN OUTCOME MEASURES: GI tolerance was calculated as the sum of scores on seven GI tolerance domains via questionnaire administered at t=0, 2, 4, 24, and 48 hours following fiber challenge. STATISTICAL ANALYSES PERFORMED: A mixed effects linear model was used to compare the tolerance scores among the five fiber challenges. RESULTS: The two inulin fibers tended to increase GI symptoms mildly. Most frequently reported symptoms were flatulence followed by bloating. The 10-g dose of oligofructose substantially increased GI symptoms compared to control. CONCLUSIONS: Doses up to 10 g/day of native inulin and up to 5 g/day of oligofructose were well-tolerated in healthy, young adults.

The effects of concentrated barley beta-glucan on blood lipids in a population of hypercholesterolaemic men and women.

Barley, like oats, is a rich source of the soluble fibre beta-glucan, which has been shown to significantly lower LDL-cholesterol (LDL-C). However, barley foods have been less widely studied. Therefore, we evaluated the LDL-C-lowering effect of a concentrated barley beta-glucan (BBG) extract as a vehicle to deliver this potential health benefit of barley. In a 10-week blinded controlled study, subjects were randomized to one of four treatment groups or control. Treatment groups included either high molecular weight (HMW) or low molecular weight (LMW) BBG at both 3 and 5 g doses. Treatment was delivered twice per day with meals in the form of two functional food products: a ready-to-eat cereal and a reduced-calorie fruit juice beverage. Levels of total cholesterol, LDL-C, HDL-cholesterol (HDL-C), and TAG were determined at baseline and after 6 weeks of treatment. The study group comprised 155 subjects. All treatments were well tolerated and after 6 weeks of treatment the mean LDL-C levels fell by 15 % in the 5 g HMW group, 13 % in the 5 g LMW group and 9 % in both the 3 g/d groups, versus baseline. Similar results were observed for total cholesterol. HDL-C levels were unchanged by treatment. Concentrated BBG significantly improves LDL-C and total cholesterol among moderately dyslipidaemic subjects. Food products containing concentrated BBG should be considered an effective option for improving blood lipids.

Reduced and high molecular weight barley beta-glucans decrease plasma total and non-HDL-cholesterol in hypercholesterolemic Syrian golden hamsters.

Consumption of concentrated barley beta-glucan lowers plasma cholesterol because of its soluble dietary fiber nature. The role of molecular weight (MW) in lowering serum cholesterol is not well established. Prior studies showed that enzymatic degradation of beta-glucan eliminates the cholesterol-lowering activity; however, these studies did not evaluate the MW of the beta-glucan. The current study was conducted to evaluate whether barley beta-glucan concentrates, partially hydrolyzed to reduce MW, possess cholesterol-lowering and antiatherogenic activities. The reduced MW fraction was compared with a high MW beta-glucan concentrate from the same barley flour. Concentrated beta-glucan preparations were evaluated in Syrian Golden F(1)B hamsters fed a hypercholesterolemic diet (HCD) with cholesterol, hydrogenated coconut oil, and cellulose. After 2 wk, hamsters were fed HCD or diets that contained high or reduced MW beta-glucan at a concentration of 8 g/100 g at the expense of cellulose. Decreases in plasma total cholesterol (TC) and non-HDL-cholesterol (non-HDL-C) concentrations occurred in the hamsters fed reduced MW and high MW beta-glucan diets. Plasma HDL-C concentrations did not differ. HCD-fed hamsters had higher plasma triglyceride concentrations. Liver TC, free cholesterol, and cholesterol ester concentrations did not differ. Aortic cholesterol ester concentrations were lower in the reduced MW beta-glucan-fed hamsters. Consumption of either high or reduced MW beta-glucan increased concentrations of fecal total neutral sterols and coprostanol, a cholesterol derivative. Fecal excretion of cholesterol was greater than in HCD-fed hamsters only in those fed the reduced MW beta-glucan. Study results demonstrate that the cholesterol-lowering activity of barley beta-glucan may occur at both lower and higher MW.