[Effects of fiber administration in the prevention of gallstones in obese patients on a reducing diet. A clinical trial]. / Efecto de la administración de fibra en la prevención de litiasis vesicular en obesos sometidos a dieta de reducción. Ensayo.

Nearly 30% of the obese patients treated with hypoenergetic diets for weight reduction develop gallstone disease (GD). Until the present time, the use of ursodeoxycholic acid (UDA) is the only available therapeutic measure to avoid the development of GD. Dietary fiber induce a bile acid synthesis. A double-blind clinical trial was conducted to compare the effect of rational diet plus UDA vs a rational diet supplemented with Psyllium plantago (Pp) for the prevention of GD in obese subjects undergoing a weight-reduction diet. Patients with a body mass index (BMI = weight in Kg/square height in m) of 30 Kg/m2 or more and with normal gallbladder and biliary tree ultrasound (GBUS) were included. Weight-reduction diets were individually calculated for each patient according to their energy expenditure (EE). Patients were randomly and blindly assigned either to group I (diet + 750 mg UDA + fiber placebo) or group II (diet + 15 g Pp+ UDA placebo). An anthropometric evaluation was performed to each patient before and after the two-month treatment, as well as resting EE by indirect calorimetry, GBUS and endoscopy for the determination of cholesterol crystals in duodenal bile. Weight reduction was similar in both groups (group I = 6 +/- 2 Kg vs group II = 6 +/- 3 Kg). GD development was observed in one patient of group I (5.5%) and two patients of group II (p > 0.05). All patients with GD lost a minimum of 4 Kg during the study period. GD development did not correlate with the presence of crystals in the duodenal bile at the beginning of the study. Our results suggest a beneficial effect of a rational diet with fiber supplementation to prevent GD development in obese patients included in a weight reduction program.