PERTURBATION OF INTESTINAL MICROFLORA

This paper discusses the effects of antibiotics on the intestinal micr oflora, focusing on the microbial constituents, their antibiotic sensi tivities, and their metabolic activities. Many of these effects relate to therapeutic doses of antibiotics, not to the very small concentrat ions found as residues in food. The alterations associated with lower levels of antibiotics are generally unknown because they have not been studied. In the 18th century, Augustus Flemming said: ''And it is tru ly wonderful that a substance, the very aspect and odor of which are s ufficient to induce an inevitable nausea, should be regarded not merel y as a matter of curiosity and study, but held in the highest repute a s a unique and most precious treasure for the preservation of health.' ' Such is the philosophy of the many investigators of the intestinal m icroflora on whose work this article is based.