title: Agave Inulin Supplementation Affects the Fecal Microbiota of Healthy Adults Participating in a Randomized, Double-Blind, Placebo-Controlled, Crossover Trial.
abstract: BACKGROUND
  Prebiotics resist digestion, providing fermentable substrates for select gastrointestinal bacteria associated with health and well-being. Agave inulin differs from other inulin type fibers in chemical structure and botanical origin. Preclinical animal research suggests these differences affect bacterial utilization and physiologic outcomes. Thus, research is needed to determine whether these effects translate to healthy adults.
  
  
  OBJECTIVE
  We evaluated agave inulin utilization by the gastrointestinal microbiota by measuring fecal fermentative end products and bacterial taxa.
  
  
  METHODS
  A randomized, double-blind, placebo-controlled, 3-period, crossover trial was undertaken in healthy adults (n = 29). Participants consumed 0, 5.0, or 7.5 g agave inulin/d for 21 d with 7-d washouts between periods. Participants recorded daily dietary intake; fecal samples were collected during days 16-20 of each period and were subjected to fermentative end product analysis and 16S Illumina sequencing.
  
  
  RESULTS
  Fecal Actinobacteria and Bifidobacterium were enriched (P < 0.001) 3- and 4-fold after 5.0 and 7.5 g agave inulin/d, respectively, compared with control. Desulfovibrio were depleted 40% with agave inulin compared with control. Agave inulin tended (P < 0.07) to reduce fecal 4-methyphenol and pH. Bivariate correlations revealed a positive association between intakes of agave inulin (g/kcal) and Bifidobacterium (r = 0.41, P < 0.001). Total dietary fiber intake (total fiber plus 0, 5.0, or 7.5 g agave inulin/d) per kilocalorie was positively associated with fecal butyrate (r = 0.30, P = 0.005), tended to be positively associated with Bifidobacterium (r = 0.19, P = 0.08), and was negatively correlated with Desulfovibrio abundance (r = -0.31, P = 0.004).
  
  
  CONCLUSIONS
  Agave inulin supplementation shifted the gastrointestinal microbiota composition and activity in healthy adults. Further investigation is warranted to determine whether the observed changes translate into health benefits in human populations. This trial was registered at clinicaltrials.gov as NCT01925560.
authors.affiliation: Departments of Food Science and Human Nutrition and.
authors.forename: Hannah D
authors.initials: HD
authors.lastname: Holscher
authors.affiliation: Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL; and.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Bauer
authors.affiliation: Ingredion Incorporated, Bridgewater, NJ.
authors.forename: Vishnupriya
authors.initials: V
authors.lastname: Gourineni
authors.affiliation: Ingredion Incorporated, Bridgewater, NJ.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Pelkman
authors.affiliation: Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL; and.
authors.forename: George C
authors.initials: GC
authors.lastname: Fahey
authors.affiliation: Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL; and ksswanso@illinois.edu.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Swanson
mesh_terms: D039903:Actinobacteria / Q000187:drug effects; D000328:Adult; D027882:Agave; D001644:Bifidobacterium / Q000187:drug effects; D018592:Cross-Over Studies; D004269:DNA, Bacterial / Q000235:genetics; D004043:Dietary Fiber / Q000008:administration & dosage; D019587:Dietary Supplements; D004311:Double-Blind Method; D005243:Feces / Q000382:microbiology*; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology; D006801:Humans; D007444:Inulin / Q000008:administration & dosage*; D008297:Male; D064307:Microbiota; D056692:Prebiotics; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial; D004043:Dietary Fiber; D056692:Prebiotics; D007444:Inulin
keywords: agave inulin; bifidobacteria; butyrate; fiber; microbiota; prebiotics