Background: Intestinal microflora is deranged in hemodialysis (HD) patients as increased aerobacteria such as Escherichia coli, and decreased anaerobacteria such as bifidobacteria. Indole, a precursor of indoxyl sulfate, is produced by E coli but not by bifidobacteria. The serum levels of indoxyl sulfate are increased markedly in HD patients and cannot be reduced efficiently by HD because of its albumin binding.
Methods: To compare the effect of oral administration of Bifidobacterium longum in gastro-resistant seamless capsule (Bifina) on indoxyl sulfate levels with that of Bifidobacteria in powder formulation (Lac B), Bifina was administered to 11 HD patients for 5 weeks, and Lac B to another group of 11 HD patients for 5 weeks. The authors measured the serum level of indoxyl sulfate by using high-performance liquid chromatography.
Results: The pre-HD serum levels of indoxyl sulfate significantly decreased in Bifina-treated patients (before, 4.9 +/- 1.7 mg/dL, 4.5 mg/dL, mean +/- SD, median, after 5 weeks, 3.5 +/- 1.3 mg/dL, 3.8 mg/dL; P < 0.005). However, they did not decrease in the Lac B-treated patients (before, 4.8 +/- 1.4 mg/dL, 4.5 mg/dL, after 5 weeks, 5.2 +/- 2.0 mg/dL, 5.1 mg/dL).
Conclusion: Oral administration of Bifina to HD patients is effective in reducing the serum levels of indoxyl sulfate by correcting the intestinal microflora. Gastro-resistant seamless capsule prevents bifidobacteria from its inactivation in acidic gastric juice, and allows it to be actived in the intestine.