Colonization of the stratified squamous epithelium of the nonsecreting area of horse stomach by lactobacilli

Selective adhesion to only certain epithelia is particularly common among t he bacterial members of the indigenous microflora of mammals, We have found that the stratified squamous epithelium of the nonsecreting area of horse stomach is colonized by gram-positive rods. The microscopic features of a d ense layer of these bacteria on the epithelium were found to be similar to those reported in mice, rats, and swine. Adhering microorganisms were isola ted and identified as Lactobacillus salivarius, L. crispatus, L. reuteri, a nd L. agilis by DNA-DNA hybridization and 16S rRNA gene sequencing techniqu es. These lactobacilli associated with the horse, except for L. reuteri, we re found to adhere to horse epithelial cells in vitro but not to those of r ats. A symbiotic relationship of these lactobacilli with the horse is sugge sted.