In addition, treatment with the dltD mutant Ku-0059436 clinical trial correlated with a significant down-regulation of Toll-like receptor-2 expression and of downstream proinflammatory cytokine expression in the colitic mice. These results show that molecular cell
surface characteristics of probiotics are crucial when probiotics are considered for use as supporting therapy in IBD. Inflammatory bowel diseases (IBD), such as Crohn’s disease (CD) and ulcerative colitis (UC), are chronic illnesses that involve inflammation of the intestinal tract . An increased prevalence of these diseases has been documented in developed countries. It is estimated that more than 3 million people are affected in North America and Europe [2,3]. The pathogenesis of these diseases is not fully understood, but besides genetic, environmental and immunoregulatory factors, the enteric microbiota seem to play an important role. It is thought that the inflammation results from an aberrant mucosal immune response against the indigenous microbiota in genetically susceptible hosts . Additionally, it has been found that IBD is linked to an altered microbiota composition (dysbiosis) . Among the mechanisms by which
bacteria may promote inflammatory signalling, recent evidence suggests that microbe-associated molecular patterns (MAMPs) derived from intestinal bacteria may modulate IBD via stimulation of their respective innate immune receptors, including Toll-like receptors (TLRs) . This is reflected, for example, by the dysregulation of several TLRs and susceptibility genes, such as nucleotide-binding oligomerization
domain-containing 2 Navitoclax chemical structure (NOD2), in colitis . Some probiotics, which are defined as ‘live micro-organisms that when administered in adequate amounts can confer a health benefit on the host’, have been suggested to help in restoring the imbalances associated with IBD [9,10]. Therefore, probiotics might be useful as supporting therapeutic agents, although the results of clinical trials were not always unambiguous [10–12]. A crucial factor might be the choice of the probiotic strain. One of the best-documented and model probiotic strains is Lactobacillus rhamnosus GG (LGG) . Well-substantiated health effects include prevention of acute diarrhoea Alectinib in children , prevention of antibiotic-associated diarrhoea [15–17], prevention of atopic disease  and treatment of recurrent Clostridium difficile-associated colitis . In IBD patients, most promising clinical effects with LGG are in prevention of pouchitis  and maintenance of remission in UC , while clinical studies with LGG in patients with CD did not result in positive outcomes [22–24]. Some molecules of LGG have been suggested to be important for the probiotic effects based on in vitro studies. For example, two secreted proteins of LGG were demonstrated to prevent cytokine-induced apoptosis in intestinal epithelial cells .