title: Effect of repeated Campylobacter jejuni infection on gut flora and mucosal defense in a rat model of post infectious functional and microbial bowel changes.
abstract: BACKGROUND
  Campylobacter jejuni infection is a leading cause of gastroenteritis and post infectious irritable bowel syndrome (PI-IBS). Unanswered questions include the role of cytokines, effects on gut flora, and why IBS is not more prevalent in countries with higher gastroenteritis rates. Therefore, we determined the effects of early and repeat C. jejuni infections on post infectious phenotypes, gut flora, and cytokine levels in a rat model of functional bowel and microbial changes.
  
  
  METHODS
  Sprague-Dawley rats were gavaged with 10(8)  cfu C. jejuni as juveniles and again as adults (J+/A+), as adults only (J-/A+), or vehicle (controls). Stool consistency during acute colonization, post infectious stool wet weight, total bacteria and Methanobrevibacter smithii levels in bowel segments, and ileal cytokines were evaluated.
  
  
  RESULTS
  C. jejuni colonization was longer for first exposures as juveniles (43.4 ± 1.7 days) vs. adults (30.4 ± 3.5 days) (P < 0.01) and shortest for second exposures (10.5 ± 1.7 days, P < 0.05). Small intestinal bacterial overgrowth (SIBO) was more prevalent in J+/A+ (47%) than J-/A+ rats (26%) (P = 0.019), but J-/A+ rats had greater stool consistency alterations (P < 0.01). Ileal β-defensin 2, TLR-4, IL-8, and β-defensin 6 levels were increased in J-/A+ rats and further increased in J+/A+ rats; TNF-α was highest and IL6 lowest in J-/A+ rats. Total bacteria increased, and M. smithii decreased, with successive infections.
  
  
  CONCLUSIONS
  We conclude that C. jejuni infection results in long-term alterations in small bowel flora, including methanogens. Mucosal defense mediators appear related to the number of infections, but not to SIBO development or the development of functional bowel phenotypes.
authors.affiliation: GI Motility Program, Division of Gastroenterology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
authors.forename: J
authors.initials: J
authors.lastname: Sung
authors.forename: W
authors.initials: W
authors.lastname: Morales
authors.forename: G
authors.initials: G
authors.lastname: Kim
authors.forename: V
authors.initials: V
authors.lastname: Pokkunuri
authors.forename: S
authors.initials: S
authors.lastname: Weitsman
authors.forename: E
authors.initials: E
authors.lastname: Rooks
authors.forename: Z
authors.initials: Z
authors.lastname: Marsh
authors.forename: G M
authors.initials: GM
authors.lastname: Barlow
authors.forename: C
authors.initials: C
authors.lastname: Chang
authors.forename: M
authors.initials: M
authors.lastname: Pimentel
mesh_terms: D000818:Animals; D002169:Campylobacter Infections / Q000382:microbiology*; D016123:Campylobacter jejuni; D004195:Disease Models, Animal; D041981:Gastrointestinal Tract / Q000382:microbiology*; D043183:Irritable Bowel Syndrome / Q000382:microbiology*; D051381:Rats; D017207:Rats, Sprague-Dawley