Inflamm Bowel Dis  2000 May;6(2):107-15 

Probiotics and inflammatory bowel disease: is there a scientific rationale?

Shanahan F.

Department of Medicine, University College Cork, National University of Ireland.

Most conventional forms of drug therapy suppress or modify the host

immunoinflammatory response and neglect the other contributor to disease

pathogenesis-the environmental microflora. Probiotics are live microbial food

ingredients that alter the enteric microflora and have a beneficial effect on

health. The rationale for using probiotics in IBD is mainly based on evidence

from human studies and experimental animal models implicating intestinal

bacteria in the pathogenesis of these disorders. The relationship between

bacteria and intestinal inflammation is complex and does not appear to reflect a

simple cause and effect. Similarly, the field of probiotics is complex and in

need of rigorous research. Until the indigenous flora are better characterized

and mechanisms of probiotic action defined, the promise of probiotics in IBD is

unlikely to be fulfilled. Because of strain-specific variability and clinical

and therapeutic heterogeneity within Crohn's disease and ulcerative colitis, it

cannot be assumed that a given probiotic is equally suitable for all

individuals. Although preliminary results of probiotic therapy in animal models

and humans with ulcerative colitis and pouchitis have been encouraging, their

efficacy in treatment or maintenance of remission of Crohn's disease remains to

be clarified. However, the circumstantial evidence for some form of

biotherapeutic modification of the enteric flora in Crohn's disease seems

compelling. In the future, probiotics may offer a simple adjunct to conventional

therapy with the emphasis on diet shifting from one of nutritional replenishment

alone to a more functional role.