The role of intestinal microbiota in the development of urolithiasis in patients with an irritable bowel syndrome

Abstract

Objective — to study changes in the intestinal microbiota in patients with a combination of urolithiasis and irritable bowel syndrome (IBS), as well as the effect of rifaximin courses on the recurrence rate of oxalate urolithiasis in these patients.Materials and methods. The study involved 320 patients with unilateral single oxalate stones, with concomitant IBS, who were treated in years 2015 — 2017. Among them were 131 men and 189 women, the average age was 47.4 ± 2.1 years. According to the chemical composition, the stones were distributed as follows: oxalate stones in 158 patients, and mixed oxalate-phosphate stones (more than 50 % oxalate) in 162 patients. Initially (before discharge from the urological hospital), all patients were evaluated for excess bacterial overgrowth syndrome (SIBO) and feces were taken for the subsequent polymerase chain reaction (PCR). A breath test for SIBO was performed every 6 months. After 3 years, all patients underwent an obligatory sonographic examination to detect recurrence of stones and a hydrogen respiratory test for SIBR. By random sampling, patients with urolithiasis and IBS were divided into 2 groups. The first group included 120 patients who were administered rifaximin. A second course of rifaximin was prescribed after 6 months, and while maintaining SIBO and/ or symptoms of IBS, once every 6 months. The dose of rifaximin was 1200 mg per day for 14 days. The second comparison group consisted of 200 patients.Results. In total, 309 patients completed investigation, 4 patients dropped out from the first group, and 7 subjects form the second group. IBS symptoms were reveled in 19.5 % of patients with urolithiasis. The SIBO incidence in patients with the combination of urolithiasis and IBS was in 5.2 times higher than in healthy subjects. The fecal microbiota of these patients demonstrated significantly higher number of Actinobacteria and lower Firmicutes, Faecalibacterium prausnitzii, Akkermansia muciniphila and the ratio of Firmicutes/ Bacteroidetes, which can reduce the destruction of oxalates and the increase risk of urolithiasis. Conclusioins. The use of rifaximin at 1200 mg/ day for 14 days resulted in the significant decrease in SIBO. Repeated courses of rifaximin, every 6 months, in patients with SIBO and persistent symptoms of IBS (an average of 1.07 per year) were accompanied by a significant decrease in relapses of the urolithiasis. Relative risk = 0.608; p = 0.033; NNT = 9.466.