Small intestinal bacterial overgrowth and celiac disease: A systematic review with pooled-data analysis

Neurogastroenterol Motil. 2017 Jun;29(6). doi: 10.1111/nmo.13028. Epub 2017 Feb 12.


Background: A link between small intestinal bacterial overgrowth (SIBO) and celiac disease (CD) has been hypothesized.

Methods: Literature search was performed in main medical databases. Methods of analysis/inclusion criteria were based on Preferred Reporting Items for Systematic reviews and Meta-Analyses recommendations. The end-point was to estimate, by a pooled-data analysis, SIBO prevalence in CD. Proportions/percentages and their 95% confidence intervals (CI) were calculated by inverse variance method, whereas odd ratios (OR) and their 95% CI were estimated, where available, based on the Mantel-Haenszel method. Data were entered into the RevMan 5.3 software.

Key results: Eleven articles fulfilled considered criteria. The pooled mean prevalence of SIBO in CD was 20% (95% CI of 10%-30%). In comparison to asymptomatic controls, CD was associated to higher risk of SIBO, with an OR of 10.52 (95% CI 2.69-41.21, P=.0007). Jejunal aspirate culture assessed SIBO prevalence of 11% (95% CI 3%-19%) in CD, whereas breath tests detected a higher value (23%, 95% CI 10%-37%). The pooled prevalence of SIBO in CD patients who were symptomatic despite a GFD was 28% (95% CI 10%-47%), higher than in asymptomatic celiac patients (pooled prevalence of 10%, with a 95% CI of 3%-16%), despite not statistically significant (P=.06). When GFD-unresponsive CD was defined only by clinical persistence of symptoms, the prevalence of SIBO was higher than in the case of villous atrophy association (31% vs 16% P=.33).

Conclusions: The heterogeneity of available studies may not support a relationship SIBO-CD. Nevertheless, SIBO could be more common in CD when symptoms do not improve after GFD.

Keywords: breath test; celiac disease; gluten-free diet; small intestinal bacterial overgrowth.

Publication types

  • Review
  • Systematic Review

MeSH terms

  • Bacterial Infections / complications
  • Bacterial Infections / epidemiology*
  • Celiac Disease / complications
  • Celiac Disease / epidemiology*
  • Celiac Disease / microbiology*
  • Humans
  • Intestine, Small / microbiology*