Guide to designing, conducting, publishing and communicating results of clinical studies involving probiotic applications in human participants

The heterogeneity of human clinical trials to assess the efectiveness of probiotics presents challenges regarding interpretation and comparison. Evidence obtained from clinical trials among a population with a disease or specific risk factors may not be generalizable to healthy individuals. The evaluation of interventions in healthy persons requires careful selection of outcomes due to the absence of health indicators and the low incidence of preventable conditions. Given the tremendous resources invested in such trials, development of consistent approaches to assessing the efectiveness of probiotics would be benefcial. Furthermore, the reporting, presentation and communication of results may also afect the validity of the scientifc evidence obtained from a trial. This review outlines the challenges associated with the design, implementation, data analysis and interpretation of clinical trials in humans involving probiotics. Best practices related to their design are ofered along with recommendations for enhanced collaboration to advance research in this emerging feld.