Metabolic syndrome and the urinary microbiome of patients undergoing percutaneous nephrolithotomy

Objective:To identify possible stone-promoting microbes,we compared the profiles of microbes grown from stones of patients with and without metabolic syndrome(MetS).The association between MetS and urinary stone disease is well established,but the exact pathophysiologic relationship remains unknown.Recent evidence suggests urinary tract dysbiosis may lead to increased nephrolithiasis risk.Methods:At the time of percutaneous nephrolithotomy,bladder urine and stone fragments were collected from patients with and without MetS.Both sample types were subjected to expanded quantitative urine culture(EQUC)and 16 S ribosomal RNA gene sequencing.Results:Fifty-seven patients included 12 controls(21.1%)and 45 MetS patients(78.9%).Both cohorts were similar with respect to demographics and non-MetS comorbidities.No controls had uric acid stone composition.By EQUC,bacteria were detected more frequently in MetS stones(42.2%)compared to controls(8.3%)(p=0.041).Bacteria also were more abundant in stones of MetS patients compared to controls.To validate our EQUC results,we performed 16 S ribosomal RNA gene sequencing.In 12/16(75.0%)sequence-positive stones,EQUC reliably isolated at least one species of the sequenced genera.Bacteria were detected in both“infectious”and“non-infectious”stone compositions.Conclusion:Bacteria are more common and more abundant in MetS stones than control stones.Our findings support a role for bacteria in urinary stone disease for patients with MetS regardless of stone composition.

The inflammatory microenvironment and the urinary microbiome in the initiation and progression of bladder cancer

Accumulating evidence suggests that chronic inflammation may play a critical role in various malignancies,including bladder cancer.This hypothesis stems in part from inflammatory cells observed in the urethral microenvironment.Chronic inflammation may drive neoplastic transformation and the progression of bladder cancer by activating a series of in-flammatory molecules and signals.Recently,it has been shown that the microbiome also plays an important role in the development and progression of bladder cancer,which can be mediated through the stimulation of chronic inflammation.In effect,the urinary microbiome can play a role in establishing the inflammatory urethral microenvironment that may facilitate the development and progression of bladder cancer.In other words,chronic inflammation caused by the urinary microbiome may promote the initiation and progression of bladder cancer.Here,we provide a detailed and comprehensive account of the link between chronic inflammation,the microbiome and bladder cancer.Finally,we highlight that targeting the urinary microbiome might enable the development of strategies for bladder cancer prevention and personalized treatment.