It is hypothesized that calcium-based stone formers will have an altered fecal gut microbiota compared to non-stone former controls. This altered microbiota will have a lower abundance of bacteria that produce menaquinones (vitamin K2), thus stone formers will also have a different blood menaquinone profile compared to controls. Ultimately, the different levels of menaquinones will result in increased inactive Matrix Gla protein (dp-ucMGP), which is a key protein that sequesters free calcium. To test this hypothesis, calcium-based stone former and non-stone forming controls will be recruited to a single site, observation study to collect urine, blood, and fecal samples. These samples will be used to determine dp-ucMGP levels, menaquinone profiles, the composition of the gut microbiota, and other parameters of interest.
This is an observation, single site-study with one study visit during which all data and samples will be collected. Study participants will be asked to provide blood, urine, and fecal samples so that the investigators may study the differences in the gut microbiota, vitamin K2 levels, and other parameters between participants who form kidney stones and those who do not.