The intestinal flora and infant botulism.

The intestinal flora of experimental animals interferes with infection by species of Salmonella and Shigella. Protection against infection with these organisms appears to be related to high concentrations of volatile acids, low pH, and low oxidation-reduction potential of the intestinal contents of animals with an intact flora. There are no data to show that the flora influences colonization of the intestine with clostridial species, but indirect evidence suggests that the intestinal flora may be involved in this process. The impact of the intestinal flora on the ecology of the large intestine may be the most important determinant of resistance to infant botulism.