Description

Studies of probiotic activity in recent years provide evidence that probiotics counter experimental and human gastrointestinal inflammation (human inflammatory bowel disease) by their effects on epithelial cell function, including epithelial cell barrier function, epithelial cytokine secretion and their antibacterial effects relating to colonization of the epithelial layer. It reduces gastrointestinal pH through the stimulation of lactic-acid-producing bacteria; provides a direct antagonistic action on gastrointestinal pathogens. Moreover, it competes with pathogens for binding and receptor sites. In addition, there is emerging evidence that probiotics induce regulatory T cells that act as a break on the effector T cells that would otherwise cause inflammation.

Lactobacilli are effective in preventing the enteropathogen-mediated infection by competing for nutrients and binding sites, by secreting antimicrobial substances such as organic acids, bacteriocins and hydrogen peroxide, and by reducing gut pH and producing biosurfactants. Bifidobacteria work by adhesion to the gut epithelium followed by colonization, production of metabolites and lowering of pH and release of bacteriocins.