Editor,—In their “therapy updates”, Professor Shanahan ((2001) Gut 48:609–609; OpenUrlCrossRefPubMedWeb of Science) and Professor Colombelet al ((2001) Gut 48:647–647; OpenUrlCrossRefPubMedWeb of Science), respectively, addressed the issues of “probiotics in IBD” and of “antibiotics in Crohn's disease”. I would like, shuffling the titles of their articles, to add a few comments on “probiotics in Crohn's disease”. Colombelet al pointed out the importance of intestinal flora in the pathogenesis of Crohn's disease and the therapeutic role that antibiotics can play in this disorder.

An alternative approach to the problem would be to alter the enteric microflora by employing probiotics, in the attempt to achieve therapeutic benefits without the side effects of antibiotics. Oddly enough, neither Colombel et al nor Shanahan mentioned this possibility, the latter limiting his bibliographic references to studies carried out in ulcerative colitis and pouchitis.

As both authors omitted to mention it, I feel obliged to quote our own study with Saccharomyces boulardii, carried out in patients with Crohn's disease.1 In a randomised trial, 32 patients with Crohn's disease in remission were allocated to maintenance treatment with either mesalazine 3 g daily or mesalazine 2 g daily plus a preparation of Saccharomyces boulardii, two 500 mg capsules in the morning. Clinical relapses at six months were found significantly less frequently in the group who, in addition to standard mesalazine maintenance, had been taking the probiotic agent.

Further to that study, as the product is rather expensive and is not reimbursed by our National Health Service, we tried to decrease the cost of such a therapy by reducing either the frequency of the product intake (only the first two weeks of each month) or the daily dose of the probiotic (one 500 mg capsule in the morning instead of two). Our preliminary unpublished observations seem to suggest that a lower dose may be equally effective, provided thatSaccharomyces boulardii is taken every day. Clearly, additional studies are needed before advising the use ofSaccharomyces boulardii or other probiotics in the long term management of Crohn's disease. As Colombelet al reminded us, patients should be stratified according to pathological type,2 the therapeutic effect of probiotics being probably more pronounced when the inflammatory features prevail over the fibrotic process. On the other hand, Shanahan rightly observes that it is unlikely that a single probiotic is suitable for all patients.Saccharomyces boulardii is a promising agent in the maintenance treatment of Crohn's disease but its effects in ulcerative colitis remain unknown, being currently under investigation. Probiotic cocktails may well be the right solution, but the products successfully employed in pilot studies3—excluding Crohn's disease, so far—are not commercially available and we have no idea of their price until they are launched in the market.