Although melamine was known to combine with uric acid in children's bodies to produce harmful kidney stones, details of the reaction and the role of specific gut microbes were not well understood, the journal Science Translational Medicine reports.
Researchers led by Wei Jia at the University of North Carolina studied how melamine contributes to the development of kidney stones in rats.
The formation of kidney stones occurs when melamine reacts with cyanuric acid in the kidneys to form crystals, which cannot be dissolved in the bloodstream.
The study says certain species of gut microbes are responsible for converting melamine into toxic cyanuric acid, thereby accelerating the rate at which kidney stones are formed.
According to a University of North California statement, tests on rats showed that microbes of the Klebsiella family tended to facilitate the process of melamine conversion, potentially making them key players in the formation of kidney stones.
This study suggests that toxicity in this case is linked to the make-up of gut microbes in the poisoned organism.