ABSTRACT
Inflammatory Bowel Disease (IBD), including Crohn’s Disease (CD) and Ulcerative Colitis (UC), are chronic relapsing disorders characterized by intestinal inflammation. Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disorder with significant negative impact on the quality of life of its patients. The pathogenesis of both diseases involves the disruption of the gut microbiota composition, function, and diversity. One of the strategies proposed to positively modulate the gut microbiota is the administration of probiotic microorganisms in food products or as supplements. Several mechanisms of action appear to be involved in probiotic based protection such as competition with pathogens for nutrients and space, promotion of epithelial barrier function and mucus secretion from intestinal goblet cells, increasing antimicrobial peptide and short chain fatty acid production, and modulation of the immune system through the expression of anti-inflammatory cytokines. Positive results in IBD and IBS patients have been reported with single or multiple probiotic strains. However, the results are highly dependent on the probiotic strain and dosage, stage of disease and baseline microbiota composition of the host. Therefore, additional studies following the strict definition of probiotics along with rigorous methodological design are necessary before probiotics can be strongly recommended to IBD and IBS patients.
