CLINICAL SIGNIFICANCE OF ANAEROBIC GRAM NEGATIVE BACTERIA IN HEPATIC ENCEPHALOPATHY AND THERAPEUTIC EFFECTS OF VANCOMYCIN HYDROCHLORIDE ON HEPATIC ENCEPHALOPATHY

Recently, it was demonstrated that a significant proportion of the non-sporing anaerobes, especially Bacteroides spp., produces urease. Since these organisms account for more than 99% of the total faecal flora, it was suggested that the gram-negative anaerobes make a major contribution to the generation of ammonia in hepatic encephalopathy in liver cirrhosis, and that minor components such as aerobic gram negative bacilli would be insignificant. To make clear of the problem, we administered a nonabsorbable antibiotics, vancomycin hydrochrolide, which is effective against anaerobic but ineffective against aerobic gram negative rods, to four patients with hepatic encephalopathy repeatedly, and studied the changes in clinical symptoms, blood ammonia, EEG and in faecal flora. With the administration of vancomycin, clinical symptoms of encephalopathy were improved, blood ammonia was decreased, and EEG was improved. These improvements were followed by a decrease in number of anaerobic gram-negative rods, especially Bacteroides. Besides, almost no change was observed in number of aerobic gram negative rods. Changes in blood ammonia level corresponded very well with changes in the number of anaerobic Bacteroides. It was concluded that the major contributor to the ammonia production in hepatic encephalopathy in cirrhotics was the Bacteroides species.