title: Relationship of Enhanced Butyrate Production by Colonic Butyrate-Producing Bacteria to Immunomodulatory Effects in Normal Mice Fed an Insoluble Fraction of Brassica rapa L.
abstract: This study was performed to determine the effects of feeding a fiber-rich fraction of Brassica vegetables on the immune response through changes in enteric bacteria and short-chain fatty acid (SCFA) production in normal mice. The boiled-water-insoluble fraction of Brassica rapa L. (nozawana), which consists mainly of dietary fiber, was chosen as a test material. A total of 31 male C57BL/6J mice were divided into two groups and housed in a specific-pathogen-free facility. The animals were fed either a control diet or the control diet plus the insoluble B. rapa L. fraction for 2 weeks and sacrificed to determine microbiological and SCFA profiles in lower-gut samples and immunological molecules. rRNA-based quantification indicated that the relative population of Bacteroidetes was markedly lower in the colon samples of the insoluble B. rapa L. fraction-fed group than that in the controls. Populations of the Eubacterium rectale group and Faecalibacterium prausnitzii, both of which are representative butyrate-producing bacteria, doubled after 2 weeks of fraction intake, accompanying a marginal increase in the proportion of colonic butyrate. In addition, feeding with the fraction significantly increased levels of the anti-inflammatory cytokine interleukin-10 (IL-10) and tended to increase splenic regulatory T cell numbers but significantly reduced the population of cells expressing activation markers. We demonstrated that inclusion of the boiled-water-insoluble fraction of B. rapa L. can alter the composition of the gut microbiota to decrease the numbers of Bacteroidetes and to increase the numbers of butyrate-producing bacteria, either of which may be involved in the observed shift in the production of splenic IL-10.
authors.affiliation: Academic Assembly (Institute of Agriculture), Shinshu University, Minamiminowa, Nagano, Japan.|Faculty of Agriculture, Shinshu University, Minamiminowa, Nagano, Japan.
authors.forename: Sachi
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Faculty of Agriculture, Shinshu University, Minamiminowa, Nagano, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Faculty of Agriculture, Shinshu University, Minamiminowa, Nagano, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Faculty of Agriculture, Shinshu University, Minamiminowa, Nagano, Japan.
authors.forename: Kanon
authors.initials: K
authors.lastname: Furuya
authors.affiliation: Academic Assembly (Institute of Agriculture), Shinshu University, Minamiminowa, Nagano, Japan ytkuyeno@shinshu-u.ac.jp.|Faculty of Agriculture, Shinshu University, Minamiminowa, Nagano, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Uyeno
mesh_terms: D000818:Animals; D001419:Bacteria / Q000187:drug effects / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D041963:Bacteroidetes / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D029741:Brassica rapa; D020148:Butyric Acid / Q000378:metabolism*; D003106:Colon / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology*; D004043:Dietary Fiber / Q000008:administration & dosage*; D019587:Dietary Supplements; D005051:Eubacterium / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D000070036:Faecalibacterium / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000096:biosynthesis; D005243:Feces / Q000382:microbiology; D016753:Interleukin-10 / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; C556062:IL10 protein, mouse; D020148:Butyric Acid; D016753:Interleukin-10