title: Molecular characterization of stool microbiota in HIV-infected subjects by panbacterial and order-level 16S ribosomal DNA (rDNA) quantification and correlations with immune activation.
abstract: BACKGROUND
  The relationship between gut microbial community composition at the higher-taxonomic order level and local and systemic immunologic abnormalities in HIV disease may provide insight into how bacterial translocation impacts HIV disease.
  
  
  METHODS
  Antiretroviral-naive patients with HIV underwent upper endoscopy before and 9 months after starting antiretroviral treatment. Duodenal tissue was paraffin-embedded for immunohistochemical analysis and digested for fluorescence activated cell sorting for T-cell subsets and immune activation (CD38+/HLA-DR+) enumeration. Stool samples were provided from patients and control subjects for comparison. Metagenomic microbial DNA was extracted from feces for optimized 16S ribosomal RNA gene (rDNA) real-time quantitative polymerase chain reaction assays designed to quantify panbacterial loads and the relative abundances of proinflammatory Enterobacteriales order and the dominant Bacteroidales and Clostridiales orders.
  
  
  RESULTS
  Samples from 10 HIV subjects before initiating and from six subjects receiving antiretroviral treatment were available for analysis. There was a trend for a greater proportion of Enterobacteriales in HIV-positive subjects compared with control subjects (P = 0.099). There were significant negative correlations between total bacterial load and duodenal CD4 and CD8 T-cell activation levels (r = -0.74, P = 0.004 and r = -0.67, P = 0.013, respectively). The proportions of Enterobacteriales and Bacteroidales were significantly correlated with duodenal CD4 T-cell depletion and peripheral CD8 T-cell activation, respectively.
  
  
  CONCLUSIONS
  These data represent the first report of quantitative molecular and cellular correlations between total/universal and order-level gut bacterial populations and gastrointestinal-associated lymphoid tissue levels of immune activation in HIV-infected subjects. The correlations between lower overall 16S rDNA levels and tissue immune activation suggest that the gut microbiome may contribute to immune activation and influence HIV progression.
authors: University of California Davis Medical Center, Internal Medicine, Sacramento, CA 95817, USA.
authors: Collin L
authors: CL
authors: Ellis
authors: Zhong-Min
authors: ZM
authors: Ma
authors: Surinder K
authors: SK
authors: Mann
authors: Chin-Shang
authors: CS
authors: Li
authors: Jian
authors: J
authors: Wu
authors: Thomas H
authors: TH
authors: Knight
authors: Tammy
authors: T
authors: Yotter
authors: Timothy L
authors: TL
authors: Hayes
authors: Archana H
authors: AH
authors: Maniar
authors: Paolo V
authors: PV
authors: Troia-Cancio
authors: Heather A
authors: HA
authors: Overman
authors: Natalie J
authors: NJ
authors: Torok
authors: Anthony
authors: A
authors: Albanese
authors: John C
authors: JC
authors: Rutledge
authors: Christopher J
authors: CJ
authors: Miller
authors: Richard B
authors: RB
authors: Pollard
authors: David M
authors: DM
authors: Asmuth
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004275:DNA, Ribosomal / Q000032:analysis*; D004386:Duodenum / Q000276:immunology; D005243:Feces / Q000382:microbiology*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology / Q000382:microbiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012336:RNA, Ribosomal, 16S / Q000235:genetics*
chemical_list: D019380:Anti-HIV Agents; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S