title: A Metagenomic Investigation of the Duodenal Microbiota Reveals Links with Obesity.
abstract: BACKGROUND
  Few studies have tested the small intestine microbiota in humans, where most nutrient digestion and absorption occur. Here, our objective was to examine the duodenal microbiota between obese and normal volunteers using metagenomic techniques.
  
  
  RESULTS
  We tested duodenal samples from five obese and five normal volunteers using 16S rDNA V6 pyrosequencing and Illumina MiSeq deep sequencing. The predominant phyla of the duodenal microbiota were Firmicutes and Actinobacteria, whereas Bacteroidetes were absent. Obese individuals had a significant increase in anaerobic genera (p < 0.001) and a higher abundance of genes encoding Acyl-CoA dehydrogenase (p = 0.0018) compared to the control group. Obese individuals also had a reduced abundance of genes encoding sucrose phosphorylase (p = 0.015) and 1,4-alpha-glucan branching enzyme (p = 0.05). Normal weight people had significantly increased FabK (p = 0.027), and the glycerophospholipid metabolism pathway revealed the presence of phospholipase A1 only in the control group (p = 0.05).
  
  
  CONCLUSIONS
  The duodenal microbiota of obese individuals exhibit alterations in the fatty acid and sucrose breakdown pathways, probably induced by diet imbalance.
authors.affiliation: URMITE CNRS-IRD 198 UMR 6236, Aix Marseille Université, Faculté de Médecine, 27 Bd Jean Moulin, 13385, Marseille, France.
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Angelakis
authors.affiliation: URMITE CNRS-IRD 198 UMR 6236, Aix Marseille Université, Faculté de Médecine, 27 Bd Jean Moulin, 13385, Marseille, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Armougom
authors.affiliation: CNRS, Aix Marseille Université, UMR7282 Enzymology at Interfaces and Physiology of Lipolysis, 13009, Marseille, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Carrière
authors.affiliation: URMITE CNRS-IRD 198 UMR 6236, Aix Marseille Université, Faculté de Médecine, 27 Bd Jean Moulin, 13385, Marseille, France.
authors.forename: Dipankar
authors.initials: D
authors.lastname: Bachar
authors.affiliation: Hepato-gastroenterology Department, Hôpital de la Timone, Marseille, France.
authors.forename: René
authors.initials: R
authors.lastname: Laugier
authors.affiliation: URMITE CNRS-IRD 198 UMR 6236, Aix Marseille Université, Faculté de Médecine, 27 Bd Jean Moulin, 13385, Marseille, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Lagier
authors.affiliation: URMITE CNRS-IRD 198 UMR 6236, Aix Marseille Université, Faculté de Médecine, 27 Bd Jean Moulin, 13385, Marseille, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Robert
authors.affiliation: URMITE CNRS-IRD 198 UMR 6236, Aix Marseille Université, Faculté de Médecine, 27 Bd Jean Moulin, 13385, Marseille, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Michelle
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique, Aix-Marseille Université, 13288, Marseille, France; Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Bernard
authors.initials: B
authors.lastname: Henrissat
authors.affiliation: URMITE CNRS-IRD 198 UMR 6236, Aix Marseille Université, Faculté de Médecine, 27 Bd Jean Moulin, 13385, Marseille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000328:Adult; D044822:Biodiversity; D016000:Cluster Analysis; D058893:DNA Barcoding, Taxonomic; D004386:Duodenum / Q000382:microbiology*; D005260:Female; D000069196:Gastrointestinal Microbiome; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008297:Male; D054892:Metagenome; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S