Small intestinal bacterial overgrowth in inactive Crohn's disease: influence of thiopurine and biological treatment

World J Gastroenterol. 2014 Oct 14;20(38):13999-4003. doi: 10.3748/wjg.v20.i38.13999.


Aim: To investigate the influence of thiopurines and biological drugs on the presence of small intestinal bacterial overgrowth (SIBO) in patients with inactive Crohn's disease (CD).

Methods: This was a prospective study in patients with CD in remission and without corticosteroid treatment, included consecutively from 2004 to 2010. SIBO was investigated using the hydrogen glucose breath test.

Results: One hundred and seven patients with CD in remission were included. Almost 58% of patients used maintenance immunosuppressant therapy and 19.6% used biological therapy. The prevalence of SIBO was 16.8%. No association was observed between SIBO and the use of thiopurine Immunosuppressant (12/62 patients), administration of biological drugs (2/21 patients), or with double treatment with an anti-tumor necrosis factor drugs plus thiopurine (1/13 patients). Half of the patients had symptoms that were suggestive of SIBO, though meteorism was the only symptom that was significantly associated with the presence of SIBO on univariate analysis (P < 0.05). Multivariate analysis revealed that the presence of meteorism and a fistulizing pattern were associated with the presence of SIBO (P < 0.05).

Conclusion: Immunosuppressants and/or biological drugs do not induce SIBO in inactive CD. Fistulizing disease pattern and meteorism are associated with SIBO.

Keywords: Bacterial overgrowth; Biologics; Crohn’s disease; Inflammatory bowel disease; Thiopurines.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Anti-Inflammatory Agents / adverse effects
  • Anti-Inflammatory Agents / therapeutic use*
  • Bacteria / drug effects*
  • Bacteria / growth & development
  • Biological Products / adverse effects
  • Biological Products / therapeutic use*
  • Breath Tests
  • Crohn Disease / diagnosis
  • Crohn Disease / drug therapy*
  • Crohn Disease / epidemiology
  • Crohn Disease / immunology
  • Crohn Disease / microbiology
  • Drug Therapy, Combination
  • Female
  • Gastrointestinal Agents / adverse effects
  • Gastrointestinal Agents / therapeutic use*
  • Humans
  • Immunosuppressive Agents / adverse effects
  • Immunosuppressive Agents / therapeutic use*
  • Intestine, Small / drug effects*
  • Intestine, Small / immunology
  • Intestine, Small / microbiology
  • Male
  • Middle Aged
  • Prevalence
  • Prospective Studies
  • Purines / adverse effects
  • Purines / therapeutic use*
  • Remission Induction
  • Risk Factors
  • Spain / epidemiology
  • Treatment Outcome
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors


  • Anti-Inflammatory Agents
  • Biological Products
  • Gastrointestinal Agents
  • Immunosuppressive Agents
  • Purines
  • Tumor Necrosis Factor-alpha