Stool bacterial dysbiosis, Crystalluria and Oxaluria: A SbCO Index value may define risk for recurrence of oxalate nephrolithiasis episode

Kidney stone disease, particularly those formed from calcium oxalate crystals, is a significant health challenge, especially in geographic regions with high recurrence rates, known as stone belt regions. Early and precise prediction of stone events is crucial for effective therapeutic intervention. We propose the 'Stool bacterial dysbiosis, Crystalluria, and Oxaluria (SbCO) Value Index,' a composite of three factors: the prevalence of Oxalate Metabolising Bacterial Species (OMBS) in stool, urine crystal examination, and oxalate content in urine, as a tool to quantify the risk of recurrent oxalate nephrolithiasis. Empirical data underscored a notable correlation between gut dysbiosis, crystalluria, and oxaluria. The absence of Oxalobacter formigenes was associated with an elevated recurrence risk. Known OMBS were detected in approximately 3-18% of the general population, with species such as Oxalobacter and Prevotella being identified as key contributors. A lower recurrence risk was observed in patients with high levels of O. formigenes, Lactobacillus, and Bifidobacterium. Conversely, low bacterial levels, combined with high crystalluria and oxaluria were linked to an increased recurrence risk. Our findings suggest the potential of the SbCO index for predicting recurrent kidney stones, highlighting the utility of interventional therapies, informed by targeted analyses of the gut microbiome, as well as urine crystals and metabolites, in managing oxalate nephrolithiasis. This approach could help to pave the way for personalized, microbiome-centered therapeutic strategies.