The Impact of Low‐Viscosity Soluble Dietary Fibers on Intestinal Microenvironment and Experimental Colitis: A Possible Preventive Application of Alpha‐Cyclodextrin in Intestinal Inflammation

• Published in: Molecular nutrition & food research Vol. 66; no. 22; pp. e2200063 - n/a
• Main Authors: Yamanouchi, Yuka, Chudan, Seita, Ishibashi, Riko, Ohue‐Kitano, Ryuji, Nishikawa, Miyu, Tabuchi, Yoshiaki, Kimura, Ikuo, Nagai, Yoshinori, Ikushiro, Shinichi, Furusawa, Yukihiro
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.11.2022
• Subjects: Abundance; Acidification; alpha-Cyclodextrins; Animals; Bacteria; Colitis; Colitis - microbiology; Composition; Cyclodextrin; Cyclodextrins; Dietary fiber; Dietary Fiber - pharmacology; Digestive system; Drinking water; Fatty acids; Fatty Acids, Volatile - analysis; Fibers; Flow cytometry; Gas chromatography; Gastrointestinal tract; gut microbiota; Immunoregulation; Inflammation; Inflammation - prevention & control; Inflammatory bowel disease; Intestinal microflora; Intestine; Lymphocytes; Lymphocytes T; Mice; Mice, Inbred C57BL; Microbiota; Microenvironments; Probiotics; Propionic acid; regulatory T cells; RNA, Ribosomal, 16S - genetics; rRNA 16S; short‐chain fatty acids; Verrucomicrobia; Viscosity; regulatory T cells; dietary fiber; short-chain fatty acids; gut microbiota; inflammatory bowel disease
• ISSN: 1613-4125; 1613-4133
• DOI: 10.1002/mnfr.202200063

Scope The purpose of this study is to compare the impact of four low‐viscosity soluble dietary fibers (DFs) on the intestinal microenvironment, in terms of microbiota composition, short‐chain fatty acid (SCFA) production, proportion of colonic peripherally induced regulatory T cells (pTregs), and experimental colitis in mice. Methods and results Mice are administered 5% w/v low‐viscosity soluble DFs in drinking water for 2 weeks. The gut microbiota composition is determined using 16S rRNA sequencing. Luminal SCFAs are quantified by gas chromatography, and colonic pTregs are analyzed using flow cytometry. All low‐viscosity soluble DFs promote the growth of beneficial bacteria such as Akkermansia muciniphila and Bacteroides acidifaciens, while eliminating pathogenic bacteria such as Clostridium perfringens. Moreover, two low‐viscosity soluble DFs significantly increase the abundance of commensal bacteria and promote the accumulation of propionate and butyrate, leading to marked induction of colonic pTregs. Consistently, these two fibers, in particular α‐cyclodextrin, show remarkable anti‐inflammatory properties in a colitis mouse model. Conclusion Mice administered any low‐viscosity soluble DF show comparable gut microbiota compositions, but differ in terms of bacterial abundance, SCFA concentration, pTreg population, and colitis development. This exploratory study suggests that administration of α‐cyclodextrin may be a possible strategy for the prevention of colitis. Low‐viscosity soluble dietary fibers affect the composition and/or abundance of gut microbiota. This comparative study reveals that inulin and especially alpha‐cyclodextrin markedly elevate bacterial abundance and luminal short‐chain fatty acid (SCFA) levels, leading to the induction of peripherally induced regulatory T cells (Tregs) that suppress unfavorable immune responses to gut microbiota caused by 2,4,6‐trinitrobenzenesulfonic acid (TNBS).