The Influence of Chronic Vitamin-A Deficiency on the Bacterial Flora of Rats *

Previous reports, reviewed in a recent symposium,2 suggest that infection of the mucous membranes in vitamin-A-deficient animals is secondary to the well-known epithelial changes such animals display and that early in the course of this avitaminosis resistance to infection is reduced. A study" 7 designed primarily to follow pathologic changes associated with a prolonged, mild, chronic vitamin-A deficiency in rats afforded an opportunity to obtain further information on this question, as well as to determine the bacteriological changes which occur during the development and course of such a deficiency. A detailed bacteriological examination of the mucosal surfaces and of the viscera of these rats was undertaken with the idea of ascertaining the value of this vitamin in infection. Furthermore, the prolongation of a mild vitamin-A deficiency would tend to establish a more chronic type of infection in the tissue and thereby give some additional information as to the nature of the immunological response elicited.