Prebiotics are nondigestible fermentable fibers that are reported to have health benefits for the host. Older as well as more recent studies show beneficial effects in experimental colitis and lately also in human inflammatory bowel diseases (IBD), such as Crohn's disease, ulcerative colitis, and chronic pouchitis. In this review we give an overview of the benefits of prebiotics in rodent IBD models and in IBD patients and discuss their possible protective mechanisms. Commensal intestinal bacteria induce and perpetuate chronic intestinal inflammation, whereas others are protective. However, most of the current medications are directed against the exaggerated proinflammatory immune response of the host, some of them toxic and costly. Feeding prebiotics changes the composition of the intestinal microflora toward more protective intestinal bacteria and alters systemic and mucosal immune responses of the host. Therapy for IBD targeting intestinal bacteria and their function is just emerging. Prebiotics have the promise to be relatively safe, inexpensive, and easy to administer. Unraveling their protective mechanisms will help to develop rational applications of prebiotics. However, the initial promising results with dietary prebiotics in preclinical trials as well as small studies in human IBD will need to be confirmed in large randomized controlled clinical trials. Keywords ulcerative colitis; Crohn's disease; prebiotics; bifidobacteria; lactobacilli The incidence and prevalence of chronic inflammatory bowel diseases (IBD), such as Crohn's disease (CD) and ulcerative colitis (UC), are increasing in the developed northern hemisphere. Bernstein et al 1 recently published data that showed that Canada has the highest incidence and prevalence of CD thus far reported. The incidence rate for CD ranged from 8.8-20.2 per 100,000 and the prevalence ranged from 161-319 per 100,000. The incidence and prevalence of UC was lower, ranging from 9.9-19.5 and 162-249 per 100,000, respectively. Approximately 0.5% of the Canadian population has IBD. Several studies concerning the pathogenesis of IBD indicate that a combination of factors such as genetic susceptibility, intestinal microflora, dietary factors, intestinal barrier dysfunction, and an abnormal immune response to intestinal bacteria lead to chronic intestinal inflammation.
CIHR Author Manuscript
CIHR Author Manuscript
CIHR Author Manuscript
Current IBD TherapeuticsThe current medical armamentarium to treat UC and CD consists of 5-aminosalicylic acid (ASA) compounds, corticosteroids, azathioprine/6-mercaptopurine, methotrexate, and cyclosporine. Recently several biologics have been added to this list. 5 Most patients respond well to these therapies, but for some patients it is still inadequate and/or induces intolerable and serious side effects. In addition, the current therapies are mostly directed against the overly aggressive adaptive immune response of the host, but fail to correct potential environmental triggers such as the intestinal microflora that induces a...
