Suppression of Intestinal Putrefactive Fermentation by Bifidobacterium breve

The suppressive effects of feeding Bifidobacterium breve Yakult strain (BBY) on the intestinal putrefactive fermentation were examined in rats with human fecal flora (HF rats) prepared by administering human fecal suspension to Fischer 344/Yit germfree rats. The feeding of BBY (108-1010/rat/day) with or without simultaneous feeding of transgalactosyl oligosaccharide (TOS) significantly suppressed the amount of urinary indican (detoxicant of indole), indole-3-acetate, cadaverine, piperidine and p-cresol. Tryptophanase, lysine decarboxylase activities, cadaverine and indole concentrations in intestinal contents also significantly decreased in the rats fed BBY with TOS. The minimum effective dose of BBY was estimated as 109/day. Such suppression was effectively detected by oral or cecal loading of amino acids, which resulted in a significant amplifying of the levels of urinary putrefactive substances and intestinal bacterial enzyme activities in the control rats and in a slight amplifying of them in the feeding rats. The levels of bacterial counts, enzyme activities and putrefactive substances in feces, cecal contents or urine of HF rats used in this study were closely similar to those of donor human feces or conventional rats.