Comparison of probiotics and lactulose in the treatment of minimal hepatic encephalopathy in rats

AIM: To compare the efficacy of probiotic preparation Golden Bifid and lactulose on rat experimental model of minimal hepatic encephalopathy (MHE) induced by thioactamide (TAA). METHODS: MHE was induced by intraperitoneal injection of TAA (200 mg/kg) every 24 h for two consecutive days. Thirty-six male MHE models were then randomly divided into 3 groups: TAA group (n = 12) received tap water ad libitum only; lactulose group (n = 12) and probiotics group (n = 12) were gavaged, respectively with 8 mL/kg of lactulose and 1.5 g/kg of probiotic preparation Golden Bifid (highly concentrated combination of probiotic) dissolved in 2 mL of normal saline, once a day for 8 d (from the 5(th) d before the experiment to the 3(rd) d of the experiment). The latency of brainstem auditory evoked potentials (BAEP) I was used as an objective index of MHE. The incidence of MHE, the level of serum endotoxin, ammonia, liver function and histological grade of hepatic injury of rats were examined individually. RESULTS: There were no overt HE and rat deaths in 3 groups. The incidence of MHE, the levels of blood ammonia and endotoxin in TAA group, which were 83.3% (10/12), 168.33 +/- 15.44 mg/dL and 0.36 +/- 0.04 EU/mL, respectively, were significantly higher than those in lactulose group, which were 33.3% (4/12), 110.25 +/- 7.39 mg/dL and 0.19 +/- 0.02 EU/mL, and probiotics group, which were 33.3% (4/12), 108.58 +/- 10.24 mg/dL and 0.13 +/- 0.03 EU/mL respectively (P <0.001). It showed that either probiotics or lactulose could significantly lower the level of hyperammonemia and hyper-endotoxemia, lighten centrolobular necrotic areas as well as inflammatory reaction in the liver of rats, normalize the latency of BAEP, and decrease the incidence of MHE. However, no significant differences were observed between these two groups (P>0.05). CONCLUSION: Probiotic compound Golden Bifid is at least as useful as lactulose for the prevention and treatment of MHE. Probiotic therapy may be a safe, natural, well-tolerated therapy appropriate for the long-term treatment of MHE. (C) 2005 The WJG Press and Elsevier Inc. All rights reserved.