When microbial biofilms build kidney stones.

Qi et al.1 identify Corynebacterium glucuronolyticum-like bacteria as urinary pathobionts that promote calcium oxalate crystallization through two complementary mechanisms: degradation of the crystallization inhibitor hippuric acid and biofilm-mediated crystal aggregation. The work reframes microbiome contributions to stones as discrete, targetable microbial functions rather than generalized dysbiosis.