The Effect of Penicillin on the Intestinal Synthesis of Thiamine in the Rat

Abstract

By the use of C¹⁴-labeled thiamine it was found that the amount of available thiamine supplied by the intestinal microflora in rats given diets either adequate or limiting in the vitamin was increased in the presence of 50 mg of penicillin per killogram of diet. The amounts of the available microbial thiamine under the different treatments were estimated. In rats which were fed a sucrose diet adequate in vitamins, no thiamine other than that supplied in the diet could be detected in the liver.