The mechanism that explains this effect is related to its high production of lactic acid in the intestinal lumen that not only inhibits the growth of salmonellae, but also stimulates the increase of the population of Lactobacillus spp, beneficial flora. Another important effect observed is Cylactin's capacity to stimulate poultry's immune system, increasing the amount of CD4 and CD8 lymphocytes T in chickens' intestinal lumen at 7 days of age, which is an important primary barrier against pathogens and can potentiate the effect of live vaccines.