Oral administration of indigenous oxalate degrading lactic acid bacteria and quercetin prevents calcium oxalate stone formation in rats fed with oxalate rich diet

Beneficial effects of lactic acid bacteria (LAB) and quercetin have been used as ingredients of functional foods to promote health and prevention of disease. Dietary oxalate and oxalate mediated oxidative stress are the major predisposing factor for calcium oxalate (CaOx) stone formation. Thus, the efficacy of indigenous oxalate degrading LAB and QE on urinary oxalate excretion, CaOx crystal deposition, antioxidant activity and histopathology were evaluated in rats fed with a potassium oxalate (KOx) diet. The results indicated that LAB and LAB + QE administered rats significantly reduced the urinary oxalate level when compared to KOx fed rats. QE, LAB and QE + LAB supplemented group rats significantly altered the increased lipid peroxidation and antioxidant depletion as compared with rats fed with KOx. Combined effect of QE + LAB supplementation decreased the CaOx aggregation in urine and kidneys than other groups. The rats fed with a combination of QE + LAB significantly altered the expression of CaOx modulator genes (Osteopontin, renin and angiotensin converting enzyme) and antioxidant genes (glutathione peroxidase and superoxide dismutase). The results suggest that the probiotic LAB and QE combination could be used as ingredients of functional food to reduce oxidative stress and prevent CaOx crystal deposition.