Effects of intestinal flora on nitrogen metabolism in patients with chronic renal failure.

Gastrointestinal bacteria have been thought to be beneficial to uremic patients since they could provide an internal source of nitrogen by degrading urea and could function as an alternative means of clearing waste products. Data are presented to indicate that the bacteria of uremic patients do not clear significantly more urea than do the intestinal flora of normal subjects. Analysis of urea metabolism before and during oral administration of aminoglycoside antibiotics demonstrated that nitrogen derived from urea is not used by uremic patients for amino acid synthesis. In addition, it was found that nitrogen balance, on the average -0.98 +/- 0.41, significantly improved to -0.18 +/- 0.29 g N per day during the antibiotic period. The possible explanation for this are discussed. It is concluded that intestinal bacteria adversely affect uremic patients by promoting catabolism and by producing toxins which accumulate in body fluids.