Spectrum and antibiotic sensitivity of bacteria contaminating the upper gut in patients with malabsorption syndrome from the tropics

Background: Various causes of malabsorption syndrome (MAS) are associated with intestinal stasis that may cause small intestinal bacterial overgrowth (SIBO). Frequency, nature and antibiotic sensitivity of SIBO in patients with MAS are not well understood. Methods: Jejunal aspirates of 50 consecutive patients with MAS were cultured for bacteria and colony counts and antibiotic sensitivity were performed. Twelve patients with irritable bowel syndrome were studied as controls. Results: Culture revealed growth of bacteria in 34/50 (68%) patients with MAS and 3/12 controls (p < 0.05). Colony counts ranged from 3 x 10(2) to 10(15) (median 10(5)) in MAS and 100 to 1000 (median 700) CFU/ml in controls (p 0.003). 21/ 50 (42%) patients had counts = 10(5) CFU/ml in MAS and none of controls ( p < 0.05). Aerobes were isolated in 34/34 and anaerobe in 1/34. Commonest Gram positive and negative bacteria were Streptococcus species and Escherichia coli respectively. The isolated bacteria were more often sensitive to quinolones than to tetracycline ( ciprofloxacin: 39/47 and norfloxacin: 34/47 vs. tetracycline 19/47, < 0.01), ampicillin, erythromycin and cotrimoxazole (21/44, 14/22 and 24/47 respectively vs. tetracycline, p = ns). Conclusions: SIBO is common in patients with MAS due to various causes and quinolones may be the preferred treatment. This needs to be proved further by a randomized controlled trial.