Significance of the Intestinal Flora in Nutrition of the Guinea Pig. ∗

Abstract

Summary

An investigation was made on the cecal flora of guinea pigs receiving a purified basal diet and the basal diet supplied with gum arabic, potassium acetate and magnesium oxide. Significantly more coliform and anaerobic bacteria were found in the ceca of animals on the more complete diet. The urinary excretion of riboflavin and folic acid was also greater in this group of animals. It seems probable that the beneficial effect of gum arabic as well as that of potassium acetate and magnesium oxide on the growth rate of guinea pigs is based on the formation and maintenance of a proper intestinal flora. Evidently there is a well balanced symbiosis between the host animal and the different bacteria, and the bacterial flora has important functions in the physiology of the animal. Artificial, purified diets can easily disturb this balance and thus produce nutritional disturbances in the animal. On a basal purified diet growth is always very poor. The gum arabic induces conditions in which a proper flora can develop. For a normal flora and normal growth other supplements like potassium and magnesium salts are usually needed.