title: β2-1 Fructan supplementation alters host immune responses in a manner consistent with increased exposure to microbial components: results from a double-blinded, randomised, cross-over study in healthy adults.
abstract: β2-1 Fructans are purported to improve health by stimulating growth of colonic bifidobacteria, increasing host resistance to pathogens and stimulating the immune system. However, in healthy adults, the benefits of supplementation remain undefined. Adults (thirteen men, seventeen women) participated in a double-blinded, placebo-controlled, randomised, cross-over study consisting of two 28-d treatments separated by a 14-d washout period. Subjects' regular diets were supplemented with β2-1 fructan or placebo (maltodextrin) at 3×5 g/d. Fasting blood and 1-d faecal collections were obtained at the beginning and at the end of each phase. Blood was analysed for clinical, biochemical and immunological variables. Determinations of well-being and general health, gastrointestinal (GI) symptoms, regularity, faecal SCFA content, residual faecal β2-1 fructans and faecal bifidobacteria content were undertaken. β2-1 Fructan supplementation had no effect on blood lipid or cholesterol concentrations or on circulating lymphocyte and macrophage numbers, but significantly increased serum lipopolysaccharide, faecal SCFA, faecal bifidobacteria and indigestion. With respect to immune function, β2-1 fructan supplementation increased serum IL-4, circulating percentages of CD282+/TLR2+ myeloid dendritic cells and ex vivo responsiveness to a toll-like receptor 2 agonist. β2-1 Fructans also decreased serum IL-10, but did not affect C-reactive protein or serum/faecal Ig concentrations. No differences in host well-being were associated with either treatment, although the self-reported incidence of GI symptoms and headaches increased during the β2-1 fructan phase. Although β2-1 fructan supplementation increased faecal bifidobacteria, this change was not directly related to any of the determined host parameters.
authors.affiliation: 1Applied Bioscience Graduate Program, Faculty of Science,University of Ontario Institute of Technology,Oshawa,ON,Canada L1H 7K4.
authors.forename: Sandra T
authors.initials: ST
authors.lastname: Clarke
authors.affiliation: 1Applied Bioscience Graduate Program, Faculty of Science,University of Ontario Institute of Technology,Oshawa,ON,Canada L1H 7K4.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Green-Johnson
authors.affiliation: 2Bureau of Nutrition Research,Health Canada,Ottawa,ON,Canada K1A 0K9.
authors.forename: Stephen P J
authors.initials: SP
authors.lastname: Brooks
authors.affiliation: 3Guelph Food Research Centre,Agriculture and Agri-Food Canada,Guelph,ON,Canada N1G 5C9.
authors.forename: D Dan
authors.initials: DD
authors.lastname: Ramdath
authors.affiliation: 4McMaster University,Hamilton,ON,Canada L8S 4L8.
authors.forename: Premysl
authors.initials: P
authors.lastname: Bercik
authors.affiliation: 4McMaster University,Hamilton,ON,Canada L8S 4L8.
authors.forename: Christian
authors.initials: C
authors.lastname: Avila
authors.affiliation: 5Lethbridge Research Centre,Agriculture and Agri-Food Canada,Lethbridge,AB,Canada T1J 4B1.
authors.forename: G Douglas
authors.initials: GD
authors.lastname: Inglis
authors.affiliation: 2Bureau of Nutrition Research,Health Canada,Ottawa,ON,Canada K1A 0K9.
authors.forename: Judy
authors.initials: J
authors.lastname: Green
authors.affiliation: 5Lethbridge Research Centre,Agriculture and Agri-Food Canada,Lethbridge,AB,Canada T1J 4B1.
authors.forename: L Jay
authors.initials: LJ
authors.lastname: Yanke
authors.affiliation: 6University of Lethbridge,Lethbridge,AB,Canada T1K 6T5.
authors.forename: L Brent
authors.initials: LB
authors.lastname: Selinger
authors.affiliation: 7Atlantic Food and Horticulture Research Centre,Agriculture and Agri-Food Canada,Kentville,NS,Canada B4N 1J5.
authors.forename: Martin
authors.initials: M
authors.lastname: Kalmokoff
mesh_terms: D000293:Adolescent; D000328:Adult; D001644:Bifidobacterium / Q000187:drug effects; D002097:C-Reactive Protein / Q000378:metabolism; D003106:Colon / Q000187:drug effects / Q000382:microbiology; D018592:Cross-Over Studies; D004032:Diet; D019587:Dietary Supplements; D004311:Double-Blind Method; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005260:Female; D005630:Fructans / Q000008:administration & dosage*; D000069196:Gastrointestinal Microbiome / Q000187:drug effects; D006801:Humans; D007107:Immune System / Q000187:drug effects* / Q000378:metabolism; D007136:Immunoglobulins / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D008070:Lipopolysaccharides / Q000097:blood; D008297:Male; D008875:Middle Aged; D051195:Toll-Like Receptor 2 / Q000097:blood; D055815:Young Adult
chemical_list: C093302:(2-1)-fructan; D005232:Fatty Acids, Volatile; D005630:Fructans; D007136:Immunoglobulins; D008070:Lipopolysaccharides; C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2; D016753:Interleukin-10; D015847:Interleukin-4; D002097:C-Reactive Protein
keywords:   β2-1 Fructan; BCFA branched-chain fatty acid; GI gastrointestinal; GSRS Gastrointestinal Symptom Rating Scale; Immunology; LPS lipopolysaccharide; P3C Pam3Cys; Prebiotics; TLR toll-like receptor; Well-being; mDC myeloid dendritic cell