A new rat model links two contemporary theories in irritable bowel syndrome

Dig Dis Sci. 2008 Apr;53(4):982-9. doi: 10.1007/s10620-007-9977-z. Epub 2007 Oct 13.


Rationale: Two proposed hypotheses for irritable bowel syndrome (IBS) are acute gastroenteritis and bacterial overgrowth. We studied whether acute infection with Campylobacter could precipitate bacterial overgrowth in a rat model in order to link the two hypotheses.

Methods: Sprague-Dawley outbred rats were randomly administered a vehicle or Campylobacter jejuni strain 81-176 by oral gavage. Three months after clearance of the infectious agent, rats had a stool consistency evaluation. After euthanasia, lumenal bacteria counts were measured via quantitative real-time PCR from self-contained segments of the duodenum, jejunum, ileum, cecum and left colon. Adjacent sections of bowel were fixed in formalin for evaluation of intraepithelial lymphocyte counts.

Results: Three months after clearance of Campylobacter infection, 57% of Campylobacter infected rats had some alteration in stool consistency compared to 7.4% in mock-infected controls (P < 0.001). Among the rats that received Campylobacter, 27% had evidence of bacterial overgrowth by PCR. These rats also had the highest prevalence of altered stool form and had lower body weight. Consistent with post-infectious IBS in humans, bacterial overgrowth rats demonstrated a significant increase in rectal and left colon intraepithelial lymphocytes.

Conclusions: Acute infection with C. jejuni 81-176 precipitates alterations in stool consistency, bacterial overgrowth and rectal lymphocytosis consistent with findings in IBS patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Campylobacter Infections / complications*
  • Campylobacter Infections / pathology
  • Campylobacter Infections / physiopathology
  • Campylobacter jejuni*
  • Defecation / physiology
  • Disease Models, Animal*
  • Gastroenteritis / complications*
  • Gastroenteritis / pathology
  • Gastroenteritis / physiopathology
  • Irritable Bowel Syndrome / etiology*
  • Irritable Bowel Syndrome / pathology
  • Rats
  • Rats, Sprague-Dawley