Effect of Control in Oxalate and Citrate Intake on Gut Microbiota Composition in Patients With Urolithiasis: Double-blind Randomized Clinical Study
Urolithiasis (UL) is the presence of kidney stones in different compartments such as ureters, bladder and/or urethra. Based on its incidence and prevalence it is considered a public health problem worldwide. In Mexico, especially in Yucatan state, is considered an endemic area of UL with a prevalence of 5.5%. There are several risk factors associated with the development of UL, among which are genetics, age, sex, excess weight, diet, and gut microbiota. In the diet there is promoters and inhibitors of stone formation, such as oxalates and citrates respectively. The gut microbiota is the set of microorganisms that inhabit the gastrointestinal tract, which have been related to the regulation of metabolic processes such as production of short-chain fatty acids (SCFA), vitamin K synthesis, and stimulation of the immune response. However, alterations in the composition of the microbiota have been associated with the development of various pathologies including UL. Recent studies have shown that the intestinal microbiota of people with kidney stones have a lower diversity and a different bacterial composition compared with healthy people, suggesting that interactions in the gut-renal axis could have a direct effect on the development of UL. Furthermore, these modifications could modulate oxalate and citrate transporters. Dietary modifications may decrease the risk of UL formation through increased consumption of citrate-rich foods (\>40 mEq per day) and decreased consumption of oxalate-rich foods (\< 40mg per day). It is known that dietary modifications can modulate the gut microbiota, however there is no evidence about the effect of a dietary intervention with oxalate and citrate control on the modulation of the microbiota in patients with UL. Thus, it is important to search for strategies to reduce UL, as well as the complications associated with them like chronic kidney disease. The main of the study is evaluate the effect of a dietary intervention with oxalate and citrate control on the composition and diversity of the intestinal microbiota of adults with UL.
• Subjects living in Merida, Yucatan
• Female or male
• Age between 18 and 60 years
• Confirmed diagnosis of UL confirmed with ultrasound (≥5mm) and/or radiographs or who had expelled a stone in a time no longer than 7 days at the time of selection
• BMI ≥ 25 and ≤ 39.9 kg/m2; no antibiotic intake (last 30 days)
• No intake of probiotics, prebiotics or synbiotics (last 15 days)
• No intake vitamin C supplements (last 15 days)
• No intake calcium supplements (last 15 days)