fig1

Figure 1. Schematic illustration of the human gastrointestinal tract and overview of the major gut models used to study host interactions between the host, the microbiota, and probiotics. The gastrointestinal tract comprises different compartments where probiotics and gut microbiota encounter various challenges. Gut models include conventional in vitro models, organoid models, organ-on-chip models and in vivo models. The annotations provide insights into the advantages and the limitations of each model. The above figure was modified from the Servier Medical Art (https://smart.servier.com/), licensed under CC BY 4.0.