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Abstract:
Fecal bile acid and neutral sterol patterns were studied in eight healthy adult volunteers who were challenged with Vibrio cholerae classical Ogawa 395 strain in the course of vaccine development studies. Bacterial 7 alpha-dehydroxylation of cholic and chenodeoxycholic acids was not altered during experimentally induced cholera diarrhea, despite the fact that fecal weight in g/day (wet wt) was increased greatly during diarrhea (1913 +/- 390 vs 161 +/- 11 in controls, p less than 0.005). Consistent with the findings on bile acids, no significant changes in the production of coprostanol, epicoprostanol, or coprostanone were observed although the percentage of unmodified cholesterol was increased during the diarrheal episode (20.7 +/- 3.3% vs 11.9 +/- 2.3, p less than 0.02). Total concentrations of both bile acids and cholesterol in mg/g of feces (wet wt) were decreased considerably as a result of diarrhea). However, total bile acid and neutral steroid excretions in mg/kg/day in subjects with and without diarrhea do not appear to be different. Intestinal transit times, measured in eight subjects by the use of carmine red dye, were found to be shortened in diarrhea (5.8 +/- 1.1 hr vs 23.4 +/- 4.1 hr in controls, p less than 0.001). The results from this study are similar to those observed in experimentally induced travellers' diarrhea associated with toxigenic Escherichia coli, but they are in striking contrast to the changes in gastrointestinal steroid metabolism observed in acute shigellosis, an invasive intestinal infection.