The influence of oxalate decarboxylase on the urinary oxalate excretion in swine model of nephrocalcinosis induced by hydroxyproline

Introduction. Kidney stone formation may be a result of increased urinary oxalate supersaturation. Material and Methods. Eighteen pigs were randomly divided into: Control group, where standard cereal-based feed was supplemented with 4% HP only, Prevention group, where treatment with OxDc slurry started at the end of the adaptation period when pigs were switched to 4% HP diet, Reduction group, where the treatment with OxDc lyo powder started after pigs were already on a 4% HP diet for 6 days. Results. OxDc slurry prevented oxalate excretion in urine. The reduction effect of OxDc lyo feed addition was generally visible during the first two days of the therapy (p<0.05). Both dietary intake of 4% HP and OxDc preparations did not influence weight gain, water or feed intake, urine excretion and creatinine clearance. Conclusions. The capacity of OxDc in preventing induced hyperoxaluria was moderate. Most probably, this is due to the incoherent response of animals to the HP enriched diet dependent on their gut pH, since optimum pH for OxDc is around 5-6. A higher pH essentially reduces the activity of OxDc. The capacity of OxDc in reversing the hyperoxaluria induced by a HP enriched diet was significant during the first 2 days after introducing OxDc to the diet.