Effects of SIBO and rifaximin therapy on MHE caused by hepatic cirrhosis.

Aim: To determine the effects of small-intestinal bacterial overgrowth (SIBO) and rifaximin therapy on minimal hepatic encephalopathy (MHE) with liver cirrhosis.

Methods: A total of 60 patients with cirrhosis were included in this study. Patients were evaluated by three neuropsychometric tests including number connection-A (NCT-A), number connection-BC (NCT-BC) and digit symbol test (DST) to diagnose the MHE. Glucose breath testing was used to determine the presence of SIBO. Patients with MHE were then treated with 200 mg of rifaximin orally three times a day for a week. Glucose breath testing and psychometric tests were repeated upon 4 weeks after antibiotic completion. Blood ammonia levels were also monitored before and after rifaximin treatment.

Results: Of the 60 patients enrolled, 26 were diagnosed with MHE. The mean blood ammonium level in MHE group was 48.7 ± 8.8 μmol/L, while in non-MHE it was 34.9 ± 7.5 μmol/L, demonstrating an increase (t = 6.55, P < 0.05). One third of patients had an abnormal glucose hydrogen breath test, indicating the presence of SIBO. Abnormal breath test results were present in 3 of the 34 patients (8%) without MHE, 17 of the 26 patients (65.4%) with MHE. One week after rifaximin antibiotic therapy, the number of the MHE patients reduced from 26 to 11. Among 17 MHE patients with SIBO, 13 became SIBO negative. Blood ammonium level in MHE patients with SIBO decreased from 51.6 ± 5.4 μmol/L to 39.1 ± 7.6 μmol/L (P < 0.01), while in MHE patients without SIBO decreased from 45.3 ± 9.8 μmol/L to 36.9 ± 8.8 μmol/L (P < 0.01). Higher reduction was observed in SIBO group. All three psychometric test results showed significant (P < 0.01) improvement after rifaximin treatment.

Conclusions: SIBO is prevalent in MHE patients with liver cirrhosis, and short-term treatment with rifaximin can effectively reduce blood ammonia level and improve psychometric test.