Small intestinal bacteria overgrowth decreases small intestinal motility in the NASH rats

World J Gastroenterol. 2008 Jan 14;14(2):313-7. doi: 10.3748/wjg.14.313.


Aim: To explore the relationship between small intestinal motility and small intestinal bacteria overgrowth (SIBO) in Nonalcoholic steatohepatitis (NASH), and to investigate the effect of SIBO on the pathogenesis of NASH in rats. The effect of cidomycin in alleviating severity of NASH is also studied.

Methods: Forty eight rats were randomly divided into NASH group (n = 16), cidomycin group (n = 16) and control group (n = 16). Then each group were subdivided into small intestinal motility group (n = 8), bacteria group (n = 8) respectively. A semi-solid colored marker was used for monitoring small intestinal transit. The proximal small intestine was harvested under sterile condition and processed for quantitation for aerobes (E. coli) and anaerobes (Lactobacilli). Liver pathologic score was calculated to qualify the severity of hepatitis. Serum ALT, AST levels were detected to evaluate the severity of hepatitis.

Results: Small intestinal transit was inhibited in NASH group (P < 0.01). Rats treated with cidomycin had higher small intestine transit rate than rats in NASH group (P < 0.01). High fat diet resulted in quantitative alterations in the aerobes (E. coli) but not in the anoerobics (Lactobacill). There was an increase in the number of E. coli in the proximal small intestinal flora in NASH group than in control group (1.70 +/- 0.12 log10 (CFU/g) vs 1.28 +/- 0.07 log10 (CFU/g), P < 0.01). TNF-alpha concentration was significantly higher in NASH group than in control group (1.13 +/- 0.15 mmol/L vs 0.57 +/- 0.09 mmol/L, P < 0.01). TNF-alpha concentration was lower in cidomycin group than in NASH group (0.63 +/- 0.09 mmol/L vs 1.13 +/- 0.15 mmol/L, P < 0.01). Treatment with cidomycin showed its effect by significantly lowering serum ALT, AST and TNF-alpha levels of NASH rats.

Conclusion: SIBO may decrease small intestinal movement in NASH rats. SIBO may be an important pathogenesis of Nash. And treatment with cidomycin by mouth can alleviate the severity of NASH.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Bacteria / drug effects
  • Bacteria / growth & development
  • Fatty Liver / drug therapy
  • Fatty Liver / microbiology*
  • Gastrointestinal Motility / drug effects
  • Gastrointestinal Motility / physiology*
  • Gentamicins / pharmacology
  • Intestine, Small / microbiology*
  • Intestine, Small / physiology*
  • Male
  • Rats
  • Rats, Sprague-Dawley


  • Anti-Bacterial Agents
  • Gentamicins