Effect of orally administered neomycin on uterine growth in young mice and rats

Neomycin has been widely used as a gut antibiotic in preconditioning animals for the experimental evaluation of biomaterials and biomedical devices. As a chance observation during a routine conditioning process, it was noticed that orally administered neomycin retarded uterine growth in growing mice and rats. Body weights and the weights of liver and spleen were uneffected, although there was a marginal increase in the kidneys' weight. This finding is consistent with the theory that a change induced in intestinal flora activity mediated a uterotrophic influence of dietary fiber.