Antibiotic efficacy in small intestinal bacterial overgrowth-related chronic diarrhea: a crossover, randomized trial.
OBJECTIVE
No controlled trial has examined the clinical efficacy of antibiotics in small bowel bacterial overgrowth.


METHODS
Ten patients with bacterial overgrowth-related diarrhea underwent the following five 7-day treatment periods: untreated (control period), then placebo, and subsequently, in random order and blinded fashion, norfloxacin (800 mg/day), amoxicillin-clavulanic acid (1500 mg/day), and Saccharomyces boulardii (1500 mg/day). A hydrogen breath test was performed on the first and last day of each period.


RESULTS
Daily stool frequency was similar during the control and placebo periods (4.2 +/- 0.6 vs. 3.9 +/- 0.6 [mean +/- SEM], respectively). Norfloxacin and amoxicillin-clavulanic acid led to a significant reduction in daily stool frequency (2.3 +/- 0.4 and 3.0 +/- 0.5, respectively; P < 0.01 vs. placebo period) after 2.0 +/- 1.4 and 1.2 +/- 0.4 days, which was maintained for 6.1 +/- 3.7 and 6.0 +/- 9.6 days, respectively. Breath-expired H(2) volume decreased with norfloxacin (37 +/- 8 to 12 +/- 5 mL per 2 hours; P < 0.01) and amoxicillin-clavulanic acid (24 +/- 6 to 8 +/- 4 mL per 2 hours, respectively; P = 0.01), but H(2) breath test result was negative in only 3 and 5 patients.


CONCLUSIONS
Norfloxacin and amoxicillin-clavulanic acid are effective in the treatment of bacterial overgrowth-related diarrhea.
Attar
A
A
Département de Gastroentérologie, Hôpital Lariboisère Saint Lazare, Paris, France. alain.attar@lrb.ap-hop-paris.fr
Flourié
B
B
Rambaud
J C
JC
Franchisseur
C
C
Ruszniewski
P
P
Bouhnik
Y
Y
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000658:Amoxicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000890:Anti-Infective Agents / Q000627:therapeutic use; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development*; D001944:Breath Tests / Q000379:methods; D002908:Chronic Disease; D019818:Clavulanic Acid / Q000627:therapeutic use; D018592:Cross-Over Studies; D003967:Diarrhea / Q000188:drug therapy* / Q000382:microbiology*; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D006801:Humans; D006859:Hydrogen / Q000378:metabolism; D007421:Intestine, Small / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009643:Norfloxacin / Q000627:therapeutic use; D010406:Penicillins / Q000627:therapeutic use; D019936:Probiotics / Q000627:therapeutic use; D012119:Respiration; D012440:Saccharomyces
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D004338:Drug Combinations; D010406:Penicillins; D019818:Clavulanic Acid; D006859:Hydrogen; D000658:Amoxicillin; D009643:Norfloxacin