Lactulose-L-rhamnose intestinal permeability test in patients with liver cirrhosis.

A lactulose-L-rhamnose intestinal permeability test was conducted on 35 patients with liver cirrhosis and six normal controls. Gas chromatography was used to measure lactulose and L-rhamnose concentrations in blood and urine specimens. The excretion of each molecule was expressed as the percentage of the orally administrated dose and the lactulose-L-rhamnose ratio as the ratio of the percentage of each probe molecule excreted. The mean 8-h lactulose excretion ratios were 0.56 and 0.16% in patients with liver cirrhosis and the control subjects, respectively (P<0.05), whereas the corresponding excretion ratios for L-rhamnose were 4.40 and 3.49%. The mean lactulose-L-rhamnose excretion ratios in patients with liver cirrhosis and the control subjects were 0.124 and 0.049, respectively (P<0.05). The lactulose-L-rhamnose excretion ratio increased in patients with liver cirrhosis complicated by large intestinal vascular ectasia of the large intestine or rectal varices, which were used as parameters for evaluating the effects of portal hypertension on the lower digestive tract. These results suggest that an increase in lactulose intestinal permeability in patients with liver cirrhosis proves the effects of portal hypertension extending to the lower digestive tract.