The role of IgA in the prevention of bacterial colonization of the jejunum in the vagotomized subject.

The efficacy of three mechanisms of defence against jejunal bacterial colonization (i.e. gastric acid, vagal and pyloric integrity and intestinal IgA) has been investigated. Only in subjects with disturbance of all three mechanisms did significant jejunal colonization occur, and this was invariably associated with severe diarrhoea. Clearly normal intestinal IgA is of critical importance in the prevention of jejunal bacterial colonization in the vagotomized subject.