Printed in U.S.A. Associations of Indigenous Microorganisms with Gastrointestinal Mucosal

photomicrograph of a frozen section stained by the Weigert-Gram technique of the stomach of a normal mouse. The photomicrograph showed numerous rod-and coccus-shaped bacteria in close associa-tion with the gastric mucosa. Microorga-nisms are now known to associate with the mucosal epithelia in various areas of the alimentary tracts in several animal species (2-4), including man (5). In this report, I will present some aspects of the development and stability of microbe-epithelium interactions in the stomachs and guts of mice and rats, review some recent findings on such associations in man, and discuss some possible mechanisms underlying these associations