title: Microbiome composition by pyrosequencing in mesenteric lymph nodes of rats with CCl4-induced cirrhosis.
abstract: BACKGROUND
  The cross talk between the gut microbiota and the immune system, which is essential to maintain homeostasis, takes place at the intestinal lymphoid tissue such as the mesenteric lymph nodes (MLNs). Here, we investigated the presence of bacterial DNA in MLNs of control and cirrhotic rats and its relationship with inflammatory responses.
  
  
  METHODS
  The MLN microbiome of cirrhotic rats with ascites, which was induced by carbon tetrachloride (CCl4), was compared to that of control rats using quantitative real-time PCR and pyrosequencing of the 16S rRNA gene. Cytokines in blood samples were assessed by ELISA.
  
  
  RESULTS
  Unexpectedly, sequence analysis revealed a high microbial diversity in the MLNs of both control and cirrhotic rats with Proteobacteria as one of the most dominant phylum. CCl4-induced liver injury was not associated with a change in bacterial load, but it was linked to a decrease in microbial diversity (p < 0.05) and alterations in the microbial community in MLNs. A high proportion of Bifidobacterium animalis was also positively correlated with elevated interleukin-10 expression (p = 0.002, false discovery rate = 0.03, r = 0.94).
  
  
  CONCLUSIONS
  For the first time, the high microbial diversity observed in MLNs of both controls and CCl4-induced cirrhotic rats provides evidence that bacterial translocation is more than a mere dichotomic phenomenon.
authors.affiliation: Centro de Investigación Biomédica en Red en el Área temática de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Cuenca
authors.forename: Elisabet
authors.initials: E
authors.lastname: Sanchez
authors.forename: Alba
authors.initials: A
authors.lastname: Santiago
authors.forename: Ismail
authors.initials: I
authors.lastname: El Khader
authors.forename: Suchita
authors.initials: S
authors.lastname: Panda
authors.forename: Silvia
authors.initials: S
authors.lastname: Vidal
authors.forename: Juan
authors.initials: J
authors.lastname: Camilo Nieto
authors.forename: Cándido
authors.initials: C
authors.lastname: Juárez
authors.forename: Francesc
authors.initials: F
authors.lastname: Sancho
authors.forename: Francisco
authors.initials: F
authors.lastname: Guarner
authors.forename: German
authors.initials: G
authors.lastname: Soriano
authors.forename: Carlos
authors.initials: C
authors.lastname: Guarner
authors.forename: Chaysavanh
authors.initials: C
authors.lastname: Manichanh
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000235:genetics / Q000276:immunology*; D044822:Biodiversity; D002251:Carbon Tetrachloride / Q000008:administration & dosage; D002478:Cells, Cultured; D004269:DNA, Bacterial / Q000032:analysis; D004195:Disease Models, Animal; D064806:Dysbiosis / Q000139:chemically induced / Q000276:immunology* / Q000382:microbiology*; D005355:Fibrosis / Q000139:chemically induced / Q000276:immunology* / Q000382:microbiology*; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D016753:Interleukin-10 / Q000235:genetics / Q000378:metabolism*; D008198:Lymph Nodes / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D008297:Male; D008643:Mesentery / Q000473:pathology*; D064307:Microbiota / Q000235:genetics; D020560:Proteobacteria / Q000235:genetics / Q000276:immunology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D016753:Interleukin-10; D002251:Carbon Tetrachloride