The eGUT is a computer simulation tool that models gut microbiota and their interactions with the host and has the potential to reduce use of mammalian models in this research area. The model was developed by Dr Jan Ulrich Kreft and his team at the University of Birmingham and funded by the NC3Rs.eGUT is an extension of the individual-based Dynamics of Microbial Communities Simulator (iDynoMiCS) that is available as open source at https://github.com/kreft/iDynoMiCS.We seek collaborations with gut researchers from industry or academia to help further develop and validate eGUT and apply this in silico modelling platform to test hypotheses on the gut microbiota and within gut microbiome research problems.