“…The most commonly used models are the physiologically-based pharmacokinetics (Leahy, 2003), the systems biology-based drug metabolism simulation (Bugrim et al, 2004), the quantitative structure-activity relationship modelling (Chang & Swaan, 2006), and the computational oral absorption simulation (Sugano, 2009). More specific information on the topic has been recently reviewed by Bertau et al (2008) and Pieper & Bertau (2010). A common trait of all these models is the fact they mainly focus on (hepatic) host metabolism, thereby omitting the role of the gut microbiota due to its extreme complexity and the lack of knowledge related to several metabolic processes occurring in the GIT.…”