Fructo-oligosaccharide tolerance in patients with hereditary fructose intolerance. A preliminary nonrandomized open challenge short-term study

Hereditary fructose intolerance (HFI) caused by fructose aldolase B deficiency results in hepatic dysfunction unless managed with severely restricted dietary intake of fructose and sucrose. The potential of FOS to provide a fructose load in compromised individuals has not been determined. The purpose of this study was to evaluate the safety and tolerance of FOS among subjects with established diagnoses of HFI. Five subjects with HFI (ages 14-52 yrs; 4 male, 1 female) participated in a prospective, non-randomized open challenge with FOS at 6 g/m(2)/d for 2 days. A female infant (5 mos) with resolved neonatal hepatitis was also studied. Diet records were maintained for the 48-hr period and analyzed for dietary fructose. Tolerance was assessed through evaluation of serum AST, ALT, GGT, glucose, bilirubin, uric acid, phosphorus, and electrolytes, upon initiation and at 12-hr intervals during the challenge. Blood chemistry values were within normal ranges and did not change appreciably during the study period, except for two patients with slight elevations of uric acid. One subject reported gastric discomfort on day 2 of the FOS challenge. These data suggest that FOS providing approximately 4.7 mg fructose/kg bw/d for 2 days is safe and well tolerated among individuals with diagnosed HFI. (C) 2003 Elsevier Inc. All rights reserved.