Abstract: Objective To investigate the effect of intestinal lactobacillus on the maintenance of intestinal mucosa permeability and the clearance of middle and low molecular uremic solutes in rats. Methods Forty Sprague-Dawley rats were divided into 4 groups: normal control group (10 rats), with sham operation; pathological control group, 5/6 nephrotomized rats without treatment; lactobacillus treated group, 5/6 nephrotomized rats treated with lactobacilli; bifidobacterium treated group, 5/6 nephrotomized rats treated with bifidobacteria. Animal were sacrificed and blood and stool samples were taken after feeding the bacteria for one week. Middle molecular substance (MMS), urea and creatinine (Cr) in blood and stool were determined. Plasma D-lactic acid was measured by enzyme-coupled ultraviolet spectrophoto- metry. Results MMS, urea and Cr in blood and stool and D-lactic acid in plasma were increased in pathological control group (P＜0.01). In lactobacillus and bifidobacterium treated groups, however, plasma D-lactic acid, blood urea nitrogen and serum Cr decreased remarkably (P＜0.01), and urea nitrogen and Cr in stool increased (P＜0.01). Conclusions Bifidobacteria and lactobacilli can preserve the normal permeability of intestinal mucosa, promote the clearance of MMS, urea and Cr through intestinal tract, degrade intestinal urea and Cr, and thereby reduce blood urea and Cr.

Key words: Intestinal mucosa permeability, Lactobacillus, Middle molecular substances