Multispecies probiotics promote perceived human health and wellbeing: insights into the value of retrospective studies on user experiences

Abstract
When taking a broader perspective on the societal impact of probiotics, engagement of end-users is important to discover unmet needs, define relevant health benefits and identify key considerations for successful implementation in daily practice. This study therefore takes a retrospective approach and analyses a database of user experiences to review the effects of four multispecies probiotic formulations. The user experiences were analysed in a dependent sample manner (without control group) and complement previous randomised controlled trials that have been performed with the formulations. The database consisted of 584 evaluable user experiences regarding the impact of probiotic supplementation on perceived quality of life (QoL), gastrointestinal (GIT) symptoms and reported stool consistency after two weeks of consumption. Two different scales were used (n=344 in a 5-point scale; n=240 in a 10-point scale), which are presented as separate analyses. In the combined population of the 5-point-scale questionnaire, a significant increase in perceived QoL and a significant reduction in perceived GIT symptoms was observed. Descriptive summaries also indicate that diarrhoea- and constipation-like stool patterns are reduced following supplementation. Moreover, half of participants indicated that probiotic supplementation had a positive effect on their unmet medical need, and 64% of users were likely to continue using the product. Similar results were observed in the 10-point scale questionnaire. Considering the clinical relevance of probiotic supplementation in specific target groups, subgroup analyses were performed on participants who consumed the products for diarrhoea, constipation, Inflammatory Bowel Disease, Irritable Bowel Syndrome, and antibiotic usage. Overall, findings support the potential of probiotics to advance perceived human health and support the daily wellbeing of users. This systematic analysis of user experiences thereby contributes to the external validity of studies evaluating clinical effects of probiotics and increases knowledge on their societal impact.