Intestinal urea metabolism: could the bacteria involved in nitrogen cycle lead to reutilization of intestinal urea nitrogen in uremic rabbits?

We aimed to evaluate the effect of bacteria involved in the nitrogen cycle on the reutilization of intestinal urea nitrogen in uremic rabbits. New Zealand white rabbits were made uremic via bilateral nephrectomy. Study and control rabbits were given live and heat-inactivated bacteria through their jejunostomies. After they were injected with 99mTc biurea intravenously, serial serum and stool levels of labeled nitrogen were assessed by instant thin-layer chromatography, and the change in the labeled-nitrogen level was determined. The serum labeled-nitrogen level increased significantly in the study group (r=0.990); however, this level decreased in the control group (r=0.662). Furthermore, the labeled-nitrogen level in the stool samples increased throughout the study in the control rabbits, but it decreased after the 6th hour in the study group. In conclusion, the results of this study suggest that when the bacterial flora of the intestinal system is changed to include bacteria involved in the nitrogen cycle in uremic rabbits, the intraintestinal and systemic nitrogen metabolisms could both be altered in favor of positive nitrogen balance.