[Tissue binding of orally administered bismuth in the rat. Effect of the digestive microbial flora].

Strains of E. coli and Str. faecalis, which do not darken in the presence of Bismuth in vitro, and which had been previously isolated from faeces of patients having presented bismuthic myoclonic encephalopathy, were implanted in the digestive tract of axenic rats. Then these monoxenic rats were treated orally for 15 days with bismuth subnitrate (0,24 millimoles = 50 mg/animal/day) and sacrificed on day 16. At this time, levels of bismuth in blood, brain, kidney and femur from these rats did not significantly differ from those obtained from axenic rats or monoxenic rats implanted with the homologous bacterial strains which darken in the presence of bismuth. Conversely, under the same conditions, levels of bismuth in kidney, muscle and femur were significantly lower in holoxenic rats than in axenic rats. Levels of bismuth in kidney and femur were also significantly lower in holoxenic rats than in monoxenic rats implanted with one of the four bacterial strains mentioned above.