Washington: Kidney stones are very common and painful in men, and can be removed only through operation. But a new study has raised the hope for a probiotic treatment.

Researchers at the Boston University have claimed that bacteria could soon be used to effectively reduce the risk of recurrent kidney stones -- ranging in size from a grain of sand to a pearl -- in patients.

In the study, they've found that bacterium Oxalobacter formigenes is associated with almost a 70 per cent reduction in the risk of repeatedly developing painful kidney stones, the Journal of the American Society of Nephrology reported.

According to the researchers, up to 80 per cent of kidney stones are predominately composed of a compound called calcium oxalate. O. Formigenes breaks down oxalate in the intestinal tract and is present in a large proportion of the normal adult population.

The Boston team compared 247 patients with recurrent calcium oxalate kidney stones with 259 people with no history of the condition and found just 17 per cent of the kidney stones group were colonised with O. Formigenes, compared with 38 per cent of healthy group.

"We observed a strong inverse association between colonisation with O. Formigenes and recurrent CaOx kidney stones, with a 70 per cent reduction in overall risk."

"Our findings are of potential clinical importance. The possibility of using the bacterium as a probiotic is currently in the early stages of investigation," according to lead researcher Prof David Kaufman. Kidney stones are small, hard lumps formed of waste products contained in the urine.

Once a stone forms in kidney, it may travel down through the other parts of the urinary system, where they can slow the flow of urine, cause pain and infection, and even lead to kidney failure.