EFFECTS OF NEOMYCIN ON INTESTINAL DIGESTI ON, ABSORPTION AND FERMENTATION OF CARBOHYDRATES IN PATIENTS WITH LIVER-CIRRHOSIS - EVIDENCE OF AN ALTERNATIVE MECHANISM IN HEPATIC-ENCEPHALOPATHY

Background. Despite non absorbable antibiotics and neomycin may have a ntagonistic effects on intestinal bacterial environment, both have syn ergistic effects in the treatment of hepatic encephalopathy. This coul d be due to their action on different enteric flora or a neomicyn indu ced carbohydrate malabsorption. Aim. To investigate the effects of neo mycin on intestinal digestion, absorption and fermentation of carbohyd rates in patients with liver cirrhosis. Patients and methods. Thirty e ight Child B or C cirrhotic patients separated in three groups; subjec ts within each group were randomized to receive neomycin (2/g/day for 10 days, n=8) or placebo (n=4). Absortion of lactose and d-xylose and fermentation of d-xylose lactose and lactulose (measured using hydroge n breath tests) were studied before and after the treatment period. Re sults. Neomycin did not change lactose fermentation but reduced plasma glucose rise after lactose ingestion (38,8 +/- mg/dl to 22 +/- 6 mg/d l p < 0, 05). Plasma d-xylose levels at 30 min and its 5 h urinary exc retion were reduced by neomycin from 19 +/- 3 to 9 +/- 2 mg/dl and fro m 4.9 +/- 0,8 to 2.6 +/- 0.3 g/5h respectively (p < 0. 05). Fermentati on of d-xylose, lactose and lactulose was not reduced by neomycin. No significant changes were observed after placebo treatment Conclusions. Neomycin therapy is associated with a reduction of intestinal digesti on and absorption of carbohydrates, preserving bacterial fermentation capacity, probably increasing the non absorbable carbohydrate load rea ching the colon.