The flora of the human alimentary tract

Abstract

The flora of the human alimentary tract has been the subject of numerous investigations, but such studies during life have, of necessity, been confined to the floras of the stomach and duodenum and of the feces, except when operations or post-operative fistulæ have permitted approach to other portions of the tract. Obviously, many levels of the alimentary tract have thus been left unexplored.

To obtain a complete picture of the flora of the human alimentary tract in the living subject, and of the changes which the flora undergoes as the intestinal contents travels downward, the method pursued must permit the extraction at will of specimens from any level of the intestine. The introduction of the Einhorn intestinal tube makes it possible to fulfill these conditions. (It may be stated parenthetically that we do not yet know the extreme depth from which intestinal contents may be extracted. We have been able to obtain material from a distance of 135 inches from the lips and hope to make extractions from as far as the ileo-colic valve).

Our studies were begun in the fall of 1920. So far, we have confined our attention to the floras of the stomach, duodenum and jejunum. Certain technical difficulties which we encountered may be referred to:

Coiling of the tube in the stomach or below has occurred so often we have concluded that the true position of the tube can be ascertained only through roentgenograhpic examination. In all of our subjects, such examinations have been made after each extraction from below the stomach.

Unless the distal end of the intestinal tube is kept closed until the moment of extraction, it is impossible to tell when, or at what level, intestinal contents first enters the tube.