Screening of oxalate-degrading probiotics and preventive effect of AR1089 on kidney stones.

Calcium oxalate stone is the main type of kidney stone, so far there is no specific drug treatment. Here, we screened for oxalate-degrading probiotics and evaluated the potential preventive effect of lactic acid bacteria in rats with hyperoxaluria-induced kidney stones. The oxalate degradation efficiencies of the probiotics were determined to be 5-20% by experiments, of which the degradation efficiencies of AR342 and AR1089 were 17.32% and 14.15%, respectively. Through animal experiments, we found that AR1089 significantly attenuated kidney injury, as demonstrated by improving renal dysfunction and renal fibrosis, lowering creatinine and urea nitrogen levels. AR1089 was also effective in decreasing the number of calcium oxalate crystals in the urine and kidneys as well as ameliorating oxidative stress as evidenced by lowering the level of MDA and decreasing the level of SOD and CAT. Moreover, supplementation of AR1089 inhibited renal crystalline deposition by down-regulating the expression of KIM-1, OPN and MCP-1, and prevented hyperoxaluria-induced kidney stones by regulating the gut microbiota. Taken together, the present study shows that oral administration of AR1089, by attenuating kidney injury and regulating gut microbiota, is a potential therapy to reduce calcium oxalate crystals and prevent the progression of kidney stones.