Oral Microencapsulated Live Saccharomyces cerevisiae Cells for Use in Renal Failure Uremia: Preparation and In Vivo Analysis

Orally administrable alginate-poly-L-lysine-alginate (APA) microcapsules containing live yeast cells was investigated for use in renal failure. At all times, yeast cells remain inside the microcapsules, which are then excreted in the stool. During their gastrointestinal passage, small molecules, like urea, diffuse into the yeast microcapsules where they are hydrolyzed. Orally administrating these microcapsules to uremic rats was found to decrease urea concentrations from 7.29 +/- 0.89 mmol/L to 6.12 +/- 0.90 mmol/L over a treatment period of eight weeks. After stopping the treatment, the urea concentrations increased back to uremic levels of 7.64 +/- 0.77 mmol/L. The analysis of creatinine concentrations averaged 39.19 +/- 4.33 micromol/L, 50.83 +/- 5.55 micromol/L, and 50.28 +/- 7.10 micromol/L for the normal-control, uremic-control and uremic-treatment groups, respectively. While creatinine concentrations for both uremic-control and uremic-treatment groups did not differ among each other (P > .05), they were, however, significantly higher than those of the normal control group (P < .05). Uric acid concentrations averaged 80.08 +/- 26.49 micromol/L, 99.92 +/- 26.55 micromol/L, and 86.49 +/- 28.42 micromol/L for the normal-control, uremic-control and uremic-treatment groups, respectively. There were no significant differences in both calcium and phosphate concentrations among all three groups (P > .05). The microbial populations of five tested types of bacteria were not substantially altered by the presence of the yeast APA encapsulated yeast (P > .05).