title: Gut microbial diversity is reduced by the probiotic VSL#3 and correlates with decreased TNBS-induced colitis.
abstract: BACKGROUND
  Compositional changes within the normal intestinal microbiota have been associated with the development of various intestinal inflammatory disorders such as pouchitis and inflammatory bowel diseases (IBD). Therefore, it has been speculated that manipulation of a dysbiotic intestinal microbiota has the potential to restore microbial homeostasis and attenuate inflammation.
  
  
  METHODS
  We performed community composition analyses by terminal restriction fragment length polymorphism (T-RFLP) of the bacterial 16S ribosomal RNA gene to investigate the impact of the probiotic VSL#3 on colonic microbial community composition and development of trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats.
  
  
  RESULTS
  TNBS-induced chronic colitis was significantly reduced in VSL#3-fed rats compared to controls (P < 0.05). T-RFLP analysis revealed distinct microbial communities at luminal versus mucosal sites. Within the luminal microbiota, chronic colitis was associated with an overall decrease in bacterial richness and diversity (Margalef's richness, P < 0.01; Shannon diversity, P < 0.01). This decrease in luminal microbial diversity was enhanced in TNBS-treated rats fed VSL#3 (Margalef's richness, P < 0.001; Shannon diversity, P < 0.001) and significantly correlated with reduced clinical colitis scores (Pearson correlation P < 0.05).
  
  
  CONCLUSIONS
  Our data demonstrate that the probiotic VSL#3 alters the composition of the intestinal microbiota and these changes correlate with VSL#3-induced disease protection.
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hepatology and Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, North Carolina, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Uronis
authors.forename: Janelle C
authors.initials: JC
authors.lastname: Arthur
authors.forename: Temitope
authors.initials: T
authors.lastname: Keku
authors.forename: Anthony
authors.initials: A
authors.lastname: Fodor
authors.forename: Ian M
authors.initials: IM
authors.lastname: Carroll
authors.forename: Myrella L
authors.initials: ML
authors.lastname: Cruz
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Appleyard
authors.forename: Christian
authors.initials: C
authors.lastname: Jobin
mesh_terms: D000818:Animals; D003092:Colitis / Q000139:chemically induced / Q000382:microbiology* / Q000628:therapy*; D008297:Male; D054892:Metagenome; D019936:Probiotics / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014302:Trinitrobenzenesulfonic Acid / Q000633:toxicity*
chemical_list: D014302:Trinitrobenzenesulfonic Acid