Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are commonly used worldwide, both as prescription-only medicines and as “over-the-counter” preparations. However, low dose use of NSAIDS, is associated with gastrointestinal (GI) injury. Strategies to prevent GI complications associated with NSAID use included are generally associated with undesired side effects, whereas live bacteria formulated as probiotics may offer a safe alternative to prevent or at least decrease negative side effects of NSAIDS such as Aspirin. Given that deleterious compositional changes to the microbiota, in addition to direct effects on mucus and epithelial tissue, may increase the risk of NSAID-enteropathy, the sponsor of the present clinical trial hypothesised that an intervention targeting microbiome-host interactions may offer an attractive, preventative strategy. Their strain selection was based on the anti-inflammatory properties of certain bifidobacteria and experimental pre-clinical evidence for the role of bifidobacteria in NSAID-associated ulceration as well as unpublished pre-clinical screening data suggesting an efficacy potential of the specific strain belonging to this genus. In addition, another Bifidobacterium breve has been shown to express a pilus-associated protein (Tad E) in vivo, but not in vitro, which promotes colonic epithelial proliferation. It is described the development of a clinical model to assess the quantitative and time-resolved induction of small intestinal injury upon ASA administration.