title: Functional analysis of the relationship between intestinal microbiota and the expression of hepatic genes and pathways during the course of liver regeneration.
abstract: OBJECTIVE
  The pathways regulating liver regeneration have been extensively studied within the liver. However, the signaling contribution derived from the gut microbiota to liver regeneration is poorly understood.
  
  
  METHODS
  Microbiota and expression of hepatic genes in regenerating livers obtained from mice at 0h to 9days post 2/3 partial hepatectomy were temporally profiled to establish their interactive relationships.
  
  
  RESULTS
  Partial hepatectomy led to rapid changes in gut microbiota that was reflected in an increased abundance of Bacteroidetes S24-7 and Rikenellaceae and decreased abundance of Firmicutes Clostridiales, Lachnospiraceae, and Ruminococcaceae. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to infer biological functional changes of the shifted microbiota. RNA-sequencing data revealed 6125 genes with more than a 2-fold difference in their expression levels during regeneration. By analyzing their expression pattern, six uniquely expressed patterns were observed. In addition, there were significant correlations between hepatic gene expression profiles and shifted bacterial populations during regeneration. Moreover, hepatic metabolism and immune function were closely associated with the abundance of Ruminococcacea, Lachnospiraceae, and S24-7. Bile acid profile was analyzed because bacterial enzymes produce bile acids that significantly impact hepatocyte proliferation. The data revealed that specific bacteria were closely associated with the concentration of certain bile acids and expression of hepatic genes.
  
  
  CONCLUSIONS
  The presented data established, for the first time, an intimate relationship between intestinal microbiota and the expression of hepatic genes in regenerating livers.
authors.affiliation: Department of Medical Pathology and Laboratory Medicine, University of California, Davis, Sacramento, CA, USA.
authors.forename: Hui-Xin
authors.initials: HX
authors.lastname: Liu
authors.affiliation: Department of Medical Microbiology and Immunology, University of California, Davis, Davis, CA, USA.
authors.forename: Clarissa Santos
authors.initials: CS
authors.lastname: Rocha
authors.affiliation: Department of Medical Microbiology and Immunology, University of California, Davis, Davis, CA, USA.
authors.forename: Satya
authors.initials: S
authors.lastname: Dandekar
authors.affiliation: Department of Medical Pathology and Laboratory Medicine, University of California, Davis, Sacramento, CA, USA. Electronic address: yjywan@ucdavis.edu.
authors.forename: Yu-Jui Yvonne
authors.initials: YJ
authors.lastname: Wan
mesh_terms: D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism; D000069196:Gastrointestinal Microbiome; D008099:Liver / Q000378:metabolism*; D008115:Liver Regeneration; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D059467:Transcriptome
chemical_list: D001647:Bile Acids and Salts
keywords: Bile acid; Gut-liver axis; Immune response; Metabolism; Partial hepatectomy