City, University of London Institutional Repository Citation: Lucas, G. ORCID: 0000-0001-5941-5233 (2018). Gut thinking: the gut microbiome and mental health beyond the head. Microbial Ecology in Health and Disease, 29(2), 1548250.. doi: 10.1080/16512235.2018.1548250 This is the published version of the paper. This version of the publication may differ from the final published version. Permanent repository link: http://openaccess.city.ac.uk/21080/ Link to published version: http://dx.doi.org/10.1080/16512235.2018.1548250 Copyright and reuse: City Research Online aims to make research outputs of City, University of London available to a wider audience. Copyright and Moral Rights remain with the author(s) and/or copyright holders. URLs from City Research Online may be freely distributed and linked to. City Research Online: http://openaccess.city.ac.uk/ publications@city.ac.uk City Research Online