title: Responders and non-responders to probiotic interventions: how can we improve the odds?
abstract: As with many clinical studies, trials using probiotics have shown clearly that some patients benefit from the treatment while others do not. For example if treatment with probiotics leads to 36% cure rate of diarrhea, why did the other 64% not have the same result? The issue is important for human and indeed experimental animal studies for two main reasons: (i) Would changing the design of the study result in more subjects responding to treatment? (ii) If a subject does not respond what are the mechanistic reasons? In order to tackle the issue of responders and non-responders to therapy, a workshop was held by the International Scientific Association for Probiotics and Prebiotics (ISAPP). The outcome was four recommendations. 1. Clearly define the end goal: this could be supporting a health claim or having the highest clinical effect and impact. 2. Design the study to maximize the chance of a positive response by identifying precise parameters and defining the level of response that will be tested. 3. Base the selection of the intervention on scientific investigations: which strain(s) and/or product formulation should be used and why. 4. Carefully select the study cohort: use biological or genetic markers when available to stratify the patient population before enrollment and decide at what point intervention will provide the best outcome (for example, in acute phase of disease, or during remission, with or without use of pharmaceutical agents). By following these recommendations and selecting an appropriate primary outcome, it is hoped that clinical data will emerge in the future that expands our knowledge of which probiotics benefits which subjects and by what mechanism.
authors.affiliation: Lawson Health Research Institute Probiotics, London, Ontario, Canada. gregor@uwo.ca
authors.forename: Gregor
authors.initials: G
authors.lastname: Reid
authors.forename: Estelle
authors.initials: E
authors.lastname: Gaudier
authors.forename: Francisco
authors.initials: F
authors.lastname: Guarner
authors.forename: Gary B
authors.initials: GB
authors.lastname: Huffnagle
authors.forename: Jean M
authors.initials: JM
authors.lastname: Macklaim
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Munoz
authors.forename: Margaret
authors.initials: M
authors.lastname: Martini
authors.forename: Tamar
authors.initials: T
authors.lastname: Ringel-Kulka
authors.forename: Balfour
authors.initials: B
authors.lastname: Sartor
authors.forename: Robert
authors.initials: R
authors.lastname: Unal
authors.forename: Kristin
authors.initials: K
authors.lastname: Verbeke
authors.forename: Jens
authors.initials: J
authors.lastname: Walter
mesh_terms: D000818:Animals; D002986:Clinical Trials as Topic; D003967:Diarrhea / Q000188:drug therapy*; D006801:Humans; D019936:Probiotics / Q000627:therapeutic use*; D016896:Treatment Outcome