Does Low-Protein Diet Influence the Uremic Toxin Serum Levels From the Gut Microbiota in Nondialysis Chronic Kidney Disease Patients?
Study Goal
The researchers aimed to evaluate the effects of a low-protein diet (LPD) on uremic toxins and gut microbiota in nondialysis chronic kidney disease (CKD) patients.
Results Summary
Adherence to LPD (0.7 ± 0.2 g/kg/day) improved renal function (nonsignificantly) and reduced cholesterol levels, while significantly lowering p-cresyl sulfate levels. The gut microbiota profile also changed, with protein intake positively correlating with the number of bacterial bands.
Population
Nondialysis CKD patients (stage 3-4)
Effective Dosage
0.6 g/kg/day (prescribed), actual intake 0.7 ± 0.2 g/kg/day
Duration
6 months
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
low-protein diet (LPD) | no change | renal function | nondialysis chronic kidney disease (CKD) patients (stage 3-4) who adhered to the diet | nonsignificant | presented an improvement | #1 |
low-protein diet (LPD) | decrease | total cholesterol | nondialysis chronic kidney disease (CKD) patients (stage 3-4) who adhered to the diet | 183.9 ± 48.5 to 155.7 ± 37.2 mg/dL | reduction in | #2 |
low-protein diet (LPD) | decrease | low-density lipoprotein cholesterol | nondialysis chronic kidney disease (CKD) patients (stage 3-4) who adhered to the diet | 99.4 ± 41.3 to 76.4 ± 33.2 mg/dL | reduction in | #3 |
low-protein diet (LPD) | decrease | p-cresyl sulfate serum levels | nondialysis chronic kidney disease (CKD) patients (stage 3-4) who adhered to the LPD | 19.3 [9.6-24.7] to 15.5 [9.8-24.1] mg/L | were reduced significantly | #4 |
low-protein diet (LPD) | increase | p-cresyl sulfate serum levels | nondialysis chronic kidney disease (CKD) patients (stage 3-4) who did not adhere | 13.9 [8.0-24.8] to 24.3 [8.1-39.2] mg/L | the levels were increased | #5 |
low-protein diet (LPD) | neutral | intestinal microbiota profile | nondialysis chronic kidney disease (CKD) patients (stage 3-4) | - | it was observed change in | #6 |
- | increase | number of bands | - | - | was positively associated with | #7 |
OBJECTIVES: To evaluate the effects of low-protein diet (LPD) on uremic toxins and the gut microbiota profile in nondialysis chronic kidney disease (CKD) patients. DESIGN AND METHODS: Longitudinal study with 30 nondialysis CKD patients (stage 3-4) undergoing LPD for 6 months. Adherence to the diet was evaluated based on the calculation of protein equivalent of nitrogen appearance from the 24-hour urine analysis. Good adherence to LPD was considered when protein intake was from 90% to 110% of the prescribed amount (0.6 g/kg/day). Food intake was analyzed by the 24-hour recall method. The anthropometric, biochemical and lipid profile parameters were measured according to standard methods. Uremic toxin serum levels (indoxyl sulfate, p-cresyl sulfate, indole-3-acetic acid) were obtained by reversed-phase high-performance liquid chromatography (RP-HPLC). Fecal samples were collected to evaluate the gut microbiota profile through polymerase chain reaction and denaturing gradient gel electrophoresis. Statistical analysis was performed by the SPSS 23.0 program software. RESULTS: Patients who adhered to the diet (n = 14) (0.7 ± 0.2 g/kg/day) presented an improvement in renal function (nonsignificant) and reduction in total and low-density lipoprotein cholesterol (183.9 ± 48.5-155.7 ± 37.2 mg/dL, P = .01; 99.4 ± 41.3-76.4 ± 33.2 mg/dL, P = .01, respectively). After 6 months of nutricional intervention, p-cresyl sulfate serum levels were reduced significantly in patients who adhered to the LPD (19.3 [9.6-24.7] to 15.5 [9.8-24.1] mg/L, P = .03), and in contrast, the levels were increased in patients who did not adhere (13.9 [8.0-24.8] to 24.3 [8.1-39.2] mg/L, P = .004). In addition, using the denaturing gradient gel electrophoresis technique, it was observed change in the intestinal microbiota profile after LPD intervention in both groups, and the number of bands was positively associated with protein intake (r = 0.44, P = .04). CONCLUSION: LPD seems be a good strategy to reduce the uremic toxins production by the gut microbiota in nondialysis CKD patients.