Sarah Frech and colleagues have found that a skin patch containing a heat-labile enterotoxin (LT) derived from the pathogenic bacteria, enterogenic Echerichia coli, can reduce the incidence of traveller's diarrhoea. They looked at 111 healthy adults who were travelling to Mexico and Guatemala. Only 24 of the study participants had diarrhoea, and, of these, only 11 suffered diarrhoea caused by E. coli.
The patch works because the heat of the person's skin releases the enterotoxin, which acts as an antigen to E. coli and was taken up by immune cells in the skin.
