MAILLARD REACTION-PRODUCTS IN PURIFIED DIETS INDUCE TAURINE DEPLETIONIN CATS WHICH IS REVERSED BY ANTIBIOTICS

The effects of heat processing (Maillard reaction) and addition of ant ibiotics to diets on the metabolism of taurine in adult cats were stud ied. Groups of four cats were given daily 22 g/kg body weight one of f our purified diets based on casein and starch. All diets contained the same major ingredients as the control (diet 1), except for starch sub stitutions. Diet 2 was autoclaved; in diet 3, 50 g glucose replaced 50 g starch before autoclaving; in diet 4, only the casein component was autoclaved with 50 g glucose before addition to the diet. Diets were fed for 5 wk, then a mixture of antibiotics was added to all diets and they were fed for a further 5 wk, in the first (no antibiotics) perio d, cats given the Maillard reaction products (diets 3 and 4) had a sig nificant depletion of plasma and whole blood taurine and had twice the fecal, but less than half the urinary total taurine excretion of cont rol cats. The addition of antibiotics to the diets restored plasma and whole blood concentration in cats given diets 3 and 4, reduced fecal and increased urinary taurine excretion, and decreased fecal cholyltau rine hydrolase activity. These results suggest that Maillard reaction products promote an enteric flora that favors degradation of taurine a nd decreases recycling of taurine by the enterohepatic route.