The Nutrition of the Mouse

Abstract
A study was undertaken to determine the ability of 107 cultures, isolated from high dilutions of intestinal contents of mice fed 7 different diets, to synthesize and liberate from their cells 5 vitamins — riboflavin, niacin, biotin, folic acid and pantothenic acid, and to determine whether the synthetic products of the flora were influenced by diet. A partial description was given of 7 different types of bacteria found in the top dilutions of intestinal contents of mice, with a notation as to their distribution on the various diets. Differences were observed in the ability of these cultures to grow in synthetic broths, both complete and deficient in 1 of the 5 vitamins. In some instances these differences were correlated with diet, as in the case of 2 cocci. The coccus characteristic of the flora found in mice fed dextrin-containing diets, grew well in the synthetic broth lacking folic acid, in contrast to the coccus found in animals fed a diet containing dextrose, where little or no growth was observed in the folic acid-deficient broth. These 2 cocci also exhibited differences in the extent of folic acid liberation; the coccus which grew well on the broth lacking folic acid liberated large amounts of this vitamin into the environment, while the coccus which grew poorly, or not at all, in the folic acid-deficient broth, liberated little if any of this vitamin.