title: Gut metabolites and bacterial community networks during a pilot intervention study with flaxseeds in healthy adult men.
abstract: METHODS
  Flaxseeds contain the phytoestrogens lignans that must be activated to enterolignans by intestinal bacteria. We investigated the impact of flaxseeds on fecal bacterial communities and their associations with fecal and blood metabolites.
  
  
  RESULTS
  Nine healthy male adult subjects ingested 0.3 g/kg/day flaxseeds during 1 week. Gut bacteria as well as blood and fecal metabolites were analyzed. Ingestion of flaxseeds triggered a significant increase in the blood concentration of enterolignans, accompanied by fecal excretion of propionate and glycerol. Overall diversity and composition of dominant fecal bacteria remained individual specific throughout the study. Enterolactone production was linked to the abundance of two molecular species identified as Ruminococcus bromii and Ruminococcus lactaris. Most dominant species of the order Bacteroidales were positively associated with fecal concentrations of either acetic, isovaleric, or isobutyric acid, the latter being negatively correlated with blood levels of triglycerides. The relative sequence abundance of one Gemmiger species (Ruminococcaceae) and of Coprococcus comes (Lachnospiraceae) correlated positively with blood levels of LDL cholesterol and triglycerides, respectively.
  
  
  CONCLUSIONS
  Flaxseeds increase enterolignan production but do not markedly alter fecal metabolome and dominant bacterial communities. The data underline the possible role of members of the family Ruminococcaceae in the regulation of enterolignan production and blood lipids.
authors.affiliation: Research Group Intestinal Microbiome, ZIEL Institute for Food and Health, Technische Universität München, Freising, Germany.|Chair of Nutrition and Immunology, Technische Universität München, Freising, Germany.
authors.forename: Ilias
authors.initials: I
authors.lastname: Lagkouvardos
authors.affiliation: Research Group Intestinal Microbiome, ZIEL Institute for Food and Health, Technische Universität München, Freising, Germany.
authors.forename: Karoline
authors.initials: K
authors.lastname: Kläring
authors.affiliation: Analytical BioGeoChemistry, Helmholtz Zentrum München, Neuherberg, Freising, Germany.
authors.forename: Silke S
authors.initials: SS
authors.lastname: Heinzmann
authors.affiliation: Food Chemistry, Hamburg University, Hamburg, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Platz
authors.affiliation: General Food Technology, Technische Universität München, Freising, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Scholz
authors.affiliation: General Food Technology, Technische Universität München, Freising, Germany.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Engel
authors.affiliation: Analytical BioGeoChemistry, Helmholtz Zentrum München, Neuherberg, Freising, Germany.|Chair of Analytical Food Chemistry, Technische Universität München, Freising, Germany.
authors.forename: Philippe
authors.initials: P
authors.lastname: Schmitt-Kopplin
authors.affiliation: Chair of Nutrition and Immunology, Technische Universität München, Freising, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Haller
authors.affiliation: Food Chemistry, Hamburg University, Hamburg, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Rohn
authors.affiliation: ZIEL Human Study Unit, Technische Universität München, Freising, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Skurk
authors.affiliation: Research Group Intestinal Microbiome, ZIEL Institute for Food and Health, Technische Universität München, Freising, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Clavel
mesh_terms: D000328:Adult; D041963:Bacteroidetes / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D004032:Diet; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005285:Fermentation; D019597:Flax / Q000737:chemistry*; D000069196:Gastrointestinal Microbiome; D005990:Glycerol / Q000032:analysis / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000382:microbiology; D017705:Lignans / Q000008:administration & dosage* / Q000032:analysis / Q000097:blood / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D058889:Molecular Typing; D010865:Pilot Projects; D056692:Prebiotics; D011422:Propionates / Q000032:analysis / Q000378:metabolism; D045857:Ruminococcus / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D012639:Seeds / Q000737:chemistry*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D017705:Lignans; D008055:Lipids; D056692:Prebiotics; D011422:Propionates; D005990:Glycerol
keywords: Flaxseeds; Intestinal microbiota; Lignans; Metabolome; Ruminococcaceae