title: Addition of arabinoxylan and mixed linkage glucans in porcine diets affects the large intestinal bacterial populations.
abstract: OBJECTIVE
  To investigate the effects of two cereal soluble dietary fibres (SDF), wheat arabinoxylan (AX) and oat-mixed linkage glucans (MLG), on fermentative end-products and bacterial community profiles of the porcine caecum (Cae) and distal colon (DC). We hypothesised that feeding pigs these SDF would stimulate Cae and DC carbohydrate fermentation, resulting in a modification of the resident bacterial communities.
  
  
  METHODS
  Five groups of six pigs were each fed one diet based on wheat starch (WS) only, or treatment diets in which some WS was replaced by 10 % AX, or 10 % MLG, a combination of 5 % AX:5 % MLG (AXMLG), or completely replaced with ground whole wheat. Post-euthanasia, Cae and DC digesta were collected for analysis of fermentative end-products, and bacterial community profiles were determined by 16S rRNA gene amplicon 454 pyrosequencing.
  
  
  RESULTS
  Across all the SDF-containing diets, predominantly in the proximal region of the large intestine, Prevotella, Lactobacillus, Mitsuokella and Streptococcus were most significantly influenced (P < 0.05), while notable changes were observed for the Ruminococcaceae and Lachnospiraceae families in the Cae and DC. The addition of MLG or AXMLG had the greatest effect of influencing bacterial profiles, reducing sequence proportions assigned to the genus Clostridium, considered detrimental to gut health, with associated increases in short-chain fatty acid and reduced ammonia concentrations.
  
  
  CONCLUSIONS
  This study demonstrated how the cereal SDF AX and MLG altered the large intestinal bacterial community composition, particularly proximally, further giving insights into how diets rich in specific complex carbohydrates shift the bacterial population, by increasing abundance and promoting greater diversity of those bacteria considered beneficial to gut health.
authors.affiliation: ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences (CNAFS), Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, St. Lucia, QLD, 4072, Australia.
authors.forename: John B
authors.initials: JB
authors.lastname: Gorham
authors.affiliation: Commonwealth Scientific and Industrial Research Organisation (CSIRO), Queensland Bioscience Precinct, Carmody Rd, St. Lucia, QLD, 4067, Australia.
authors.forename: Seungha
authors.initials: S
authors.lastname: Kang
authors.affiliation: ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences (CNAFS), Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, St. Lucia, QLD, 4072, Australia.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Williams
authors.affiliation: ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences (CNAFS), Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, St. Lucia, QLD, 4072, Australia.
authors.forename: Lucas J
authors.initials: LJ
authors.lastname: Grant
authors.affiliation: Commonwealth Scientific and Industrial Research Organisation (CSIRO), Queensland Bioscience Precinct, Carmody Rd, St. Lucia, QLD, 4067, Australia.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: McSweeney
authors.affiliation: ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences (CNAFS), Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, St. Lucia, QLD, 4072, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gidley
authors.affiliation: ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences (CNAFS), Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, St. Lucia, QLD, 4072, Australia. d.mikkelsen@uq.edu.au.
authors.forename: Deirdre
authors.identifier: http://orcid.org/0000-0001-7113-2578
authors.initials: D
authors.lastname: Mikkelsen
mesh_terms: D000821:Animal Feed; D000818:Animals; D002432:Cecum / Q000187:drug effects / Q000382:microbiology*; D004032:Diet / Q000662:veterinary; D004043:Dietary Fiber / Q000008:administration & dosage; D002523:Edible Grain / Q000737:chemistry; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005285:Fermentation; D000069196:Gastrointestinal Microbiome; D005936:Glucans / Q000008:administration & dosage*; D007778:Lactobacillus / Q000302:isolation & purification; D018720:Prevotella / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000302:isolation & purification; D013213:Starch / Q000737:chemistry; D013291:Streptococcus / Q000302:isolation & purification; D013552:Swine; D014908:Triticum / Q000737:chemistry; D014990:Xylans / Q000008:administration & dosage*
chemical_list: D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; D005936:Glucans; D012336:RNA, Ribosomal, 16S; D014990:Xylans; D013213:Starch; C085118:arabinoxylan
keywords: 16S rRNA gene; Arabinoxylan; Mixed linkage glucans; Pig model; Pyrosequencing; Soluble dietary fibre