Xanthan gum: Safety evaluation by two-year feeding studies in rats and dogs and a three-generation reproduction study in rats

Abstract

Weanling albino rats (30 males and 30 females/group) were fed xanthan gum, a hydrophilic colloid, in the diet for 2 years at dosage levels of 0, 0.25, 0.50 and 1.0 g/kg/day. No significant effect on growth rate, survival, hematologic values, organ weights or tumor incidence occurred. Soft stools were noted more frequently for the high- and middle-level males, but the differences from the control group barely reached the level of statistical significance. Groups of 4 male and 4 female beagle dogs each were fed 0, 0.25, 0.37 and 1.0 g/kg/day of xanthan gum in the diet for 2 years starting at 4–8 months of age. No differences from control dogs were seen in the treated dogs with respect to survival, food intake, body weight gain, electrocardiograms, blood pressures, hemograms, gross necropsy observations, organ weights or histopathologic observations. Blood urea nitrogen was elevated at several test intervals for one high-level male. A dose-related increase in fecal weight, an increase in the specific gravity of the urine and a more frequent presence of urinary albumin for dogs in the 1.0-g/kg/day group was seen. In a 3-generation, 6-litter rat reproduction study, treated parent rats were comparable to control parents in survival and reproductive performance. Body weights of treated parents were slightly less than those of control parents during each generation. Test and control litters were comparable in all criteria studied.