Oxalate metabolism and role of oxalobacter formigenes in the development of urolitiasis

Urolithiasis is a widespread urological disease. With the implementation of the minimal invasive technologies for the stone disintegration the efficacy of the treatment was substantially improved, though, all of these methods could not be used for the treatment of urolithiasis itself and no guarantee could be given regarding the recurrence. Therefore, the questions of the recurrence prophylactics are today of the main value in the treatment of the nephrolithiasis. Among all the types of urolithiasis, Ca-oxalate type is the most frequent (75-85%). Hyperoxaluria is considered to be an important metabolic risk factor for the formation of the oxalate stones, even more important than hypercalciuria. There are 2 forms of the oxalate - exogenic (up to 30%). In the last time the results of the studies were obtained, which show that concentration of oxalic acid in the urine is influenced by the gram-negative anaerobic bacteria Oxalobacter formigenes. This bacteria lives in the gut, and the colonization could occur in the lifetime. This type of organisms work as symbiots, they can prevent the absorption of the oxalic acid in the gut, by means of which the concentration in the blood and in the urine are decreased. Preliminary results with the use of the Oxalobacter formigenes show the reduce of the hyperoxaluria, which is indeed a very important alteration during the urolithiasis.