Benef Microbes. 2022 Aug 3;13(3):195-204. doi: 10.3920/BM2021.0124.Epub 2022 Jul 18.

A M van der Geest ¹, I Schukking ¹, R J M Brummer ², H Pieterse ³, M van den Nieuwboer ⁴, L H M van de Burgwal ¹, O F A Larsen ¹

Author information

¹Vrije Universiteit Amsterdam, Athena Institute, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands.

²Nutrition-Gut-Brain Interactions Research Centre, School of Medical Sciences, Faculty of Medical and Health Sciences, Örebro University, Fakultetsgatan 1, 70182 Örebro, Sweden.

³University of Ghent, Heymans Institute of Pharmacology, C. Heymanslaan 10, 9000 Ghent, Belgium.

⁴Stichting Darmgezondheid, Oversteek 35, 6717 ZS Ede, the Netherlands.

Abstract

Randomised controlled clinical trials (RCTs) offer a unique opportunity to obtain controlled efficacy and safety data to support clinical decisions. However, most RCT reporting has a stronger focus on efficacy rather than safety. This study aimed to identify the safety profile of both probiotic and drug interventions in irritable bowel syndrome (IBS). In connection to this paper, an accompanying paper was published in which a meta-analysis was conducted to evaluate the efficacy of probiotic interventions compared to that of drug interventions in IBS. Together, these two studies provide a first assessment regarding the feasibility to determine a burden to benefit ratio for both probiotic and drug interventions in IBS. RCTs including participants (>18 years old) with IBS and comparing probiotic or drugs interventions with control groups were identified by a systematic search of MEDLINE (January 2015 - Jan 2021). Reported safety profiles in drug studies were completer and more detailed as compared with studies on probiotics. Several inconsistencies in safety reporting were identified between and within drug and probiotic studies, such as: didn't report on safety; only reported adverse reactions (ARs) or adverse events (AEs) with a certain severity; didn't report the total number of AEs; didn't split in the control- or experimental arm; didn't specify AEs; and used different thresholds for 'common' AEs. Hence, it is difficult to compare safety data from drug and probiotic RCTs across and between different studies. On the current approaches to safety reporting, we could not establish an unambiguous safety profile for neither probiotic and drug interventions in IBS. These shortcomings hamper a critical comparison of the burden to benefit ratio for IBS intervention.