New Study Reveals Bacteria Play Key Role in Formation of Common Kidney Stones
For centuries, kidney stones have been a painful affliction for humans, but a recent study has uncovered a crucial detail about the most prevalent type of kidney stone that has long been overlooked.
Researchers in the US have discovered live bacteria and biofilms inside calcium oxalate kidney stones, which account for nearly 80 percent of all cases. Previously, these stones were believed to be solely comprised of minerals crystallized from salts in urine.
According to the study, bacteria were not only found within these kidney stones but may also contribute to their formation. This challenges the traditional assumption that these stones develop only through chemical and physical processes.
Urologist Kymora Scotland from the University of California Los Angeles (UCLA) states, “By uncovering this novel mechanism, the study opens the door to new therapeutic strategies that target the microbial environment of kidney stones.”
Kidney stones can cause intense pain and, if left untreated, may lead to serious complications. While bacteria are known to play a role in the formation of struvite kidney stones, which are rare, the presence of bacteria in calcium stones, which affect the majority of patients, was previously unknown.

The study utilized electron and fluorescence microscopy to detect live bacteria and biofilms embedded within the crystals of calcium kidney stones, showcasing a new mechanism of stone formation that sheds light on why these stones are so prevalent.
The researchers propose that kidney stones should be viewed as an “organic–inorganic biocomposite”, highlighting the significant role of bacterial biofilms in the structure of the stones, even when traditional tests show no bacterial presence.
While the focus was on calcium kidney stones in this study, the role of bacteria in other types of kidney stones remains poorly understood and warrants further investigation.
Scotland emphasizes the importance of ongoing research to elucidate how bacteria and calcium-based kidney stones interact and why certain individuals are more prone to recurrent stone formation.
The findings of this study, published in PNAS, provide valuable insights into a common health issue affecting millions worldwide and offer potential avenues for future treatment strategies.

