Reply

Abstract

We thank Drs Ringel-Kulka and Ringel for their insightful comments on our study (Am J Gastroenterol 2006;101:1581–1590). They raise several issues that deserve further comment.1. Although we agree that the magnitude of the symptom response in the primary variable was modest, we would suggest that these individuals had mild symptoms, thus a significant challenge to demonstrate any change from baseline. Furthermore, we draw the attention of the readers to the far more impressive magnitude of the global response; a parameter that, perhaps, better reflects the totality of symptoms in such a heterogeneous disorder.2. The reviewers have astutely drawn attention to the differences in time to onset of effect between that achieved in this study and in our prior study, which used the same organism (Gastroenterology 2005;128:541–551). It is noteworthy that the latter used a milk-based delivery system whereas the current study delivered the probiotic in an encapsulated formulation. We speculate that the differences in time to onset may reflect differences in bioavailability related to the specific formulation used. Longer term prospective studies comparing these formulations are needed to address this issue.3. We echo, in the strongest terms possible, the points made by the reviewers with regard to differences between various probiotic bacteria and the importance of quality control. Recommending “any probiotic” is akin to suggesting that a patient take “any tablet” for hypertension! With regard to quality control, this field will only advance when the patient, and their physician, can be assured that the organism(s) that he, or she, is about to ingest is thoroughly characterized, well studied, and present in the concentration and form claimed to be effective by the manufacturers.4. Naturally, we are more positive regarding the impact of these 2 studies and counter by suggesting that the data presented are well within the range of that obtained in pharmaceutical products that have gained regulatory approval in IBS. We thank Drs Ringel-Kulka and Ringel for their insightful comments on our study (Am J Gastroenterol 2006;101:1581–1590). They raise several issues that deserve further comment. 1. Although we agree that the magnitude of the symptom response in the primary variable was modest, we would suggest that these individuals had mild symptoms, thus a significant challenge to demonstrate any change from baseline. Furthermore, we draw the attention of the readers to the far more impressive magnitude of the global response; a parameter that, perhaps, better reflects the totality of symptoms in such a heterogeneous disorder. 2. The reviewers have astutely drawn attention to the differences in time to onset of effect between that achieved in this study and in our prior study, which used the same organism (Gastroenterology 2005;128:541–551). It is noteworthy that the latter used a milk-based delivery system whereas the current study delivered the probiotic in an encapsulated formulation. We speculate that the differences in time to onset may reflect differences in bioavailability related to the specific formulation used. Longer term prospective studies comparing these formulations are needed to address this issue. 3. We echo, in the strongest terms possible, the points made by the reviewers with regard to differences between various probiotic bacteria and the importance of quality control. Recommending “any probiotic” is akin to suggesting that a patient take “any tablet” for hypertension! With regard to quality control, this field will only advance when the patient, and their physician, can be assured that the organism(s) that he, or she, is about to ingest is thoroughly characterized, well studied, and present in the concentration and form claimed to be effective by the manufacturers. 4. Naturally, we are more positive regarding the impact of these 2 studies and counter by suggesting that the data presented are well within the range of that obtained in pharmaceutical products that have gained regulatory approval in IBS. Probiotics in irritable bowel syndrome: Has the time arrived?GastroenterologyVol. 132Issue 2PreviewWhorwell PJ, Altringer L, Morel J, Bond Y, Charbonneau D, O’Mahony L, Kiely B, Shanahan F, Quigley EMM (Department of Medicine, University of Manchester, Manchester, UK). Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome. Am J Gastroenterol 2006;101:1581–1590. Full-Text PDF