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

J Am Coll Nutr. 2021 Jul;40(5):412-418. doi: 10.1080/07315724.2020.1790440. Epub 2020 Jul 30.

Abstract

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.

Keywords: Clinical trial; breath hydrogen; caloric determination; fiber; metabolism.