Probiotic administration of Escherichia coli Nissle 1917 with FCoAT expression reduces urinary oxalate in rat model

Objective To study of using E.coli Nissle1917 which can express FCoAT (EcN-Frc) as probiotic treatment to reduce urine oxalate in a rat model. Methods Thirty male SD rats were randomly divided into 6 groups (A to F). 1% oxalate was added to the diet for rats in group B, C, D, E, F; while rats in group A received regular diet. Furthermore, 30 minutes before each feeding, each rats in group B received 1 ml suspension, while those in group C, D, E, F was given 1 ml EcN-Frc suspension (103 viable bacteria). Rats in group C, D, E, F were feeding bacteria every day, once every three days, once a week, respectively. 24-hour urine specimens were obtained on days 0, 3, 6, 9, 14 by placing the rats in metabolic cages. Results Hyperoxaluria rats due to high dietary oxalate were treated by EcN-Frc. It can effectively reduce the high urinary oxalate level in rat model since day 3 after supplementation. The effect of the decrease proved directly proportional to the dose of EcN-Frc.But, one dose of EcN-Frc (103 viable bacteria) can still effectively reduce urinary oxalate in a 2 weeks period. It showed that EcN-Frc had the ability to stay stable in rat’s intestine and grew well. In addition, during 2 weeks period, all rats kept health with no signs of toxicity. Conclusions Probiotic administration of low dose EcN-Frc can effectively reduce the high urinary oxalate in hyperoxaluria rats. EcN-Frc can stay stable in rat’s intestine and play a role in degrading oxalate. This approach appears to be safe and good tolerance. Key words: FCoAT; E.coli; Oxalate; Treatment; Rat; Random