People who naturally carry a probiotic bacteria called Oxalobacter formigenes are 70 percent less likely to develop kidney stones than people whose dietary tracts lack the bacteria, according to a study conducted by researchers from Boston University and published in the Journal of the American Society of Nephrology.
Researchers compared 247 people who suffered from recurring calcium oxalate kidney stones with 259 people with no history of kidney stones. They found that while 38 percent of the people in the healthy group had O. formigenes in their intestines, only 17 percent of people in the kidney stone group did.
"Our findings are of potential clinical importance," researcher David Kaufman said. "The possibility of using the bacterium as a probiotic is currently in the early stages of investigation."
Approximately 80 percent of all kidney stones are made of the compound calcium oxalate, which builds up in the kidneys in small, hard lumps. Kidney stones can also move into other parts of the urinary tract, causing intense pain, infection and even kidney failure. Kidney stones have a tendency to recur, meaning that a single person can suffer from them many times.
"For some people kidney stones can be an ongoing lifelong problem," Kaufman said. "And in some cases a stone can destroy kidney function before it is even identified."
O. formigenes is believed to prevent kidney stone formation by breaking down calcium oxalate in the intestinal tract before it can move into the kidneys.
The exact reasons for kidney stone formation are not known, but scientists believe that the problem is related to dehydration and a high rate of calcium excretion. Most patients are treated through the use of shock waves to break up the stones, a treatment that is only sometimes effective.
According to Derek Machin, clinical director of urology at University Hospital, Aintree, any more effective treatment would be a major advance.