Probiotics and the Management of IBD
Several probiotic mechanisms of action, relative to inflammatory bowel disease, have been elucidated:
(1) competitive exclusion, whereby probiotics compete with microbial pathogens for a limited number of receptors present on the surface epithelium;
(2) immunomodulation and/or stimulation of an immune response of gut-associated lymphoid and epithelial cells;
(3) antimicrobial activity and suppression of pathogen growth;
(4) enhancement of barrier function; and
(5) induction of T cell apoptosis in the mucosal immune compartment.
unraveling of these mechanisms of action has led to new support for
the use of probiotics in the management of clinical inflammatory bowel
disease. Though level 1 evidence now supports the therapeutic use of
probiotics in the treatment of postoperative pouchitis, only levels 2
and 3 evidence is currently available in support of the use of
probiotics in the treatment of ulcerative colitis and Crohn's disease.
Nevertheless, one significant and consistent finding has emerged
during the course of research in the past
year: not all probiotic bacteria have similar therapeutic effects.
Rigorously designed, controlled clinical trials are vital to
investigate the unresolved issues related to efficacy, dose, duration
of use, single or multi-strain formulation, and the concomitant use of
prebiotics, synbiotics, or antibiotics.