Effect of High Fat Diets on Intestinal Microflora and Serum Cholesterol in Rats

Abstract

Graber , C. D. (Baylor University College of Medicine, Houston, Tex.), R. M. O'Neal, and E. R. Rabin . Effect of high fat diets on intestinal microflora and serum cholesterol in rats. J. Bacteriol. 89: 47–51. 1965.—Differential bacterial counts of feces and total plasma cholesterol determinations were performed on 60 Wistar rats fed several high lipid diets for a period of approximately 6 months. Fecal flora remained relatively stable irrespective of diet, but cholesterol levels rose in animals fed butter and sodium cholate. The six most commonly cultured organisms in all diets were enterococci, Proteus , lactobacilli, Escherichia coli, Staphylococcus aureus , and other micrococci. No enteric pathogens which did not ferment lactose or fermented it slowly were grown. Fungi and yeasts were rare. Aerobes generally outnumbered anaerobes in proportions which were sometimes as high as 300:1. Clostridium perfringens isolations were consistently high in animals given the butter diets, particularly when sodium cholate was added. Evidence is reviewed which indicates that this organism may play a role in bile salt and cholesterol metabolism. This experiment would seem to demonstrate that differences in plasma-cholesterol levels among the various dietary groups of rats were the result of dietary factors rather than alteration in intestinal flora.