Objective To explore the effects of fecal microbiota transplantation （FMT） on oxalate metabolism and renal protection in rats fed a high oxalate diet. Methods Twenty-four male SD rats were randomly divided into four groups： SC， SC + FMT， OD + PBS and OD + FMT. The SC group was set as the control group and was fed standard rat chow. The OD + PBS group and OD + FMT group were fed a diet containing 5% oxalate. Starting from day 14， the OD + PBS group， OD + FMT group and SC + FMT group received intragastric administration of PBS solution or filtered faecal microbiota solution from guinea pigs for 7 consecutive days. The 24-hour urine， feces， and venous serum of the rats were collected from the rats of all groups to determine the gut microbiota and biochemical markers. Real-time quantitative PCR and immunohistochemistry were conducted on the rat kidneys to detect the expression of renin， ACE， and OPN. Results The fecal microbiota transplantation altered the gut microbiota of rats. The gut microbiota of the SC + FMT group deviated from that of the SC group and showed increased similarity to that of the guinea pigs. Compared to the OD + PBS group， the OD + FMT group exhibited significant reductions in the urinary oxalate， urinary urea， uric acid， urinary creatinine， serum urea nitrogen/creatinine， and serum uric acid. Furthermore， after FMT treatment， the OD + FMT group exhibited reduced upregulation of renin mRNA expression and restored downregulation of OPN mRNA expression compared to the OD + PBS group； similar results were obtained from immunohistochemistry. Conclusion Fecal microbiome trans-plantation activated the microbial network in the rat gut， particularly the oxalate-degrading bacteria represented by Muribaculaceae. The kidney injury induced by high oxalate was partially restored by the microbiota network's degradation of oxalate， indicating the protective effect of fecal microbiota transplantation on the rat kidneys.