[Effects of neomycin on intestinal digestion, absorption and fermentation of carbohydrates in patients with liver cirrhosis: evidence for an alternative therapeutic mechanism in hepatic encephalopathy].

BACKGROUND

Despite non absorbable antibiotics and neomycin may have antagonistic effects on intestinal bacterial environment, both have synergistic effects in the treatment of hepatic encephalopathy. This could be due to their action on different enteric flora or a neomycin induced carbohydrate malabsorption.

AIM

To investigate the effects of neomycin on intestinal digestion, absorption and fermentation of carbohydrates in patients with liver cirrhosis.

PATIENTS AND METHODS

Thirty eight Child B or C cirrhotic patients separated in three groups; subjects within each group were randomized to receive neomycin (2/g/day for 10 days, n = 8) or placebo (n = 4). Absorption of lactose and d-xylose and fermentation of d-xylose, lactose and lactulose (measured using hydrogen breath tests) were studied before and after the treatment period.

RESULTS

Neomycin did not change lactose fermentation but reduced plasma glucose rise after lactose ingestion (38.8 +/- mg/dl to 22 +/- 6 mg/dl p < 0.05). Plasma d-xylose levels at 30 min and its 5 h urinary excretion were reduced by neomycin from 19 +/- 3 to 9 +/- 2 mg/dl and from 4.9 +/- 0, 8 to 2.6 +/- 0.3 g/5h respectively (p < 0.05). Fermentation 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 digestion and absorption of carbohydrates, preserving bacterial fermentation capacity, probably increasing the non absorbable carbohydrate load reaching the colon.