[A 90-day subchronic oral toxicity study of Bacillus subtilis gum in F344 rats].

A 90-day subchronic toxicity study of Bacillus subtilis gum was performed in both sexes of F344 rats by feeding of CRF-1 pellet diet containing 0%, 0.18%, 0.55%, 1.66% and 5%. Rats were randomly allocated to 5 groups, each consisting of 10 males and females. No animals died during the administration period and no differences in body weights and food intakes were found among groups of either sex. Kidney weight was significantly increased in both sexes in the groups given concentrations of 1.66% or more. However, the increases of kidney weight were slight in themselves and other data on serum biochemistry and histopathology did not show any apparent toxicological signs including renal toxicity. These findings indicate that the treatment of Bacillus subtilis gum in the diet for 90 days does not exert serious toxicity in rats even at the highest dose.