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Session: Formulating for the Future: Food Science Approaches to Improving Human Nutrition (Oral 16)

(OR16-05-23) Role of Fiber Physicochemical Properties in Fiber Intolerance

Monday, July 24, 2023
8:48 AM – 9:00 AM ET
Location:  Back Bay A

    Presenting Author(s)

  • LR

    Lavanya Reddivari, PhD

    Associate Professor
    Purdue University
    West Lafayette, Indiana, United States

    Disclosure(s): No relevant financial relationship(s) with ineligible companies to disclose.

    • Co-Author(s)

  • Edward Moncada

    PhD Student
    Purdue University
    West Lafayette, Indiana, United States

  • SL

    Shiyu Li, Post doc

    Post doc
    Purdue University
    West Lafayette, Indiana, United States

Disclosure(s):
Lavanya Reddivari, PhD: No relevant financial relationship(s) with ineligible companies to disclose.
Edward Moncada, M.S.: No relevant financial relationship(s) with ineligible companies to disclose.
Objectives: Short-chain fatty acids (SCFAs), products of fiber fermentation, are known to improve gut barrier function and gut health. However, how fiber physicochemical properties influence the health benefits given bacterial dysbiosis in a fiber-intolerant (FI) individual is not known. This study evaluated the effects of fiber solubility, fermentation rate and structural complexity on fiber tolerance, gut barrier function, and bacterial modulation in vivo using gnotobiotic IL-10 KO mice.

Methods: Resistant maltodextrins (RMD), High methoxyl Pectin (HMP), Inulin (ChIn), and Wheat bran (WB) were selected based on their physicochemical properties. Five-week-old germ-free (GF) mice were randomly assigned either to a purified diet or to a 15% fiber-supplemented diet for eight weeks. Mice were colonized with microbiota from a FI donor. Intestinal permeability was measured using FITC. SCFAs were measured by GC. RT-PCR was used to analyze the relative gene expression of cytokines. Colonic mucus thickness was assessed using Alcian-blue staining. Bacterial sequencing was done using 16S rRNA sequencing.

Results: Fecal SCFAs were higher in mice consuming fiber-supplemented diets compared to a control diet. Mice on ChIn and RMD showed intolerance-associated symptoms such as diarrhea and weight loss. ChIn consuming mice had lower relative gene expression levels of Claudin-1 and Muc-2, and reduced mucus thickness. RMD supplementation resulted in higher colon, cecum, and spleen weights along with a higher relative gene expression of IL-6 indicating inflammation. WB did not show any intolerance-associated symptoms or inflammation. HMP supplementation resulted in increased SCFAs without any intolerance symptoms, except for increased gut permeability. Overall, structural complexity appears to be the most influential property in fiber tolerance.

Conclusions: Fiber tolerance was dependent on physicochemical properties. Highly complex fibers (WB and HMP) seemed to be well tolerated compared to less-complex fibers, despite higher SCFA levels. HMP can be a promising fiber for FI individuals.

Funding Sources: Whistler Center for Carbohydrate Research, Ralph W. and Grace M. Showalter Research Trust Award, and USDA-NIFA Foundation Award 2019