Réévaluation of Nitrate and Nitrite Levels in the Human Intestine1
نویسندگان
چکیده
Analyses of human fecal and ileostomy samples by a method that is sensitive and free from interferences indicate that nitrate and nitrite levels in the intestine are lower than reported pre viously. Fecal nitrate and nitrite concentrations ranged from 0 to 14 fimol/kg (0 to 0.9 ppm) and 5 to 19 /¿mol/kg (0.3 to 0.9 ppm), respectively. Ileostomy samples contained from 0 to 7 jumol/kg (0 to 0.4 ppm) and 0 to 15 j^mol/kg (0 to 0.7 ppm) for nitrate and nitrite, respectively. We also showed that, when deliberately added to feces samples, nitrate and nitrite were destroyed during a two-hr incubation period in a reaction that depended on the presence of microorganisms. The results suggest that conditions in the lower gastrointestinal tract favor denitrification, not nitrification as had been proposed previ ously.
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