摘要：Samples of the mucosal surface of the caecum and sigmoid colon were obtained from 33 colonoscopy subjects for microbiol studies using a microbiology brush system. Faecal samples and caecal lumen aspirates were also obtained. Estimated numbers of digoxin-reducing, oxalate-degrading and total anaerobic bacteria from the caecal brush samples correlated significantly with the respective concentrations of these organisms from the sigmoid area. The concentrations of oxalate-degrading bacteria and total anaerobes, but not those of digoxin-reducing organisms, were greater in the caecum than in the sigmoid colon. Eight of 23 subjects given an oral dose of digoxin excreted reduced metabolites of digoxin in the urine; high concentrations of digoxin-reducing bacteria were found in caecal and sigmoid samples from each of them. Equally high concentrations or such bacteria were found in caecal and sigmoid specimens from six subjects who did not metabolize digoxin in vivo. Caccal brush concentrations of digoxin-reducing and oxalate-degrading organisms correlated significantly with the concentrations of these bacteria in faeces. The predominant genera of bacteria cultured from caecal and sigmoid brush specimens appeared to be similar. Mean molar percentage distributions of short-chain fatty acids were similar in the caecal aspirates and stool samples.Keywords: Digoxin-reducing bacteria; Oxalate-degrading bacteria; Anaerobic bacteria; Colon; Short-chain fatty acids.
