OBJECTIVE To investigate the effects of lactitol on intestinal flora and the levels of plasma endotoxin in patients with chronic viral hepatitis. METHODS Sixty patients with chronic viral hepatitis and gut-derived endotoxemia were randomly divided into two groups: lactitol group (n=30) and control group (n=30). Patients in the control group received standard medical treatment for 3 weeks, while patients in the lactitol group received lactitol orally in addition to the standard medical treatment. Fecal flora and plasma endotoxin were measured before and after the treatment. RESULTS In the lactitol group, the numbers of Bifidobacterium and Lactobacillus per gram of wet feces were significantly increased (p<0.01) and Clostridium perfringens count was decreased markedly (p<0.001). The levels of plasma endotoxin decreased after the treatment from 72.89 ng/L to 33.33 ng/L in the lactitol group and from 66.00 ng/L to 51.07 ng/L in the control group, but the plasma endotoxin levels in the lactitol group decreased far more than in the control group (p<0.01). CONCLUSIONS Lactitol can decrease the levels of plasma endotoxin more effectively than standard medical treatment in patients with chronic viral hepatitis through improving intestinal microflora.