The bacterial flora of the stomach and small intestine.

The alimentary tract at birth is either sterile or contains only a few micro-organisms (Wilson and Miles, 1955). Within a few days of birth a profuse flora is established in the mouth and large intestine. However, the small intestine remains relatively free from micro-organisms throughout life (Cregan and Hayward, 1953; Anderson and Langford, 1958a). Thus in health it seems that some antibacterial mechanism is present which prevents a resident flora from becoming established in the small intestine. The nature of this antibacterial mechanism is obscure. Cregan, Dunlop and Hayward (1953) have shown it to be independent of the gastric germicidal barrier. Anderson and Langford (1958a) have previously suggested that maintenance of normal intestinal motility is important. Evidence for this suggestion has been sought in the present study, which is an investigation of the flora of the small intestine in conditions where intestinal motility is affected by obstruction to the onward passage of intestinal contents. The patients examined included newborn and older children with obstructive lesions of differing aetiology and duration at differing sites along the small intestine. A search of the literature did not reveal any previous investigation in newborn or older children or even any thorough investigation of the intestinal flora in adults with intestinal obstruction. Therefore this paper will also describe the extent and nature of the flora of the small intestine in children with intestinal obstruction. The results of a similar study in adults are reported elsewhere (Bishop and Allcock, 1960).