Imperial College London


Faculty of MedicineDepartment of Surgery & Cancer

Professor of Digestive Health



+44 (0)20 3312 6197j.marchesi




Queen Elizabeth the Queen Mother Wing (QEQM)St Mary's Campus





Julian Marchesi graduated from Cardiff University with a PhD in biochemistry (1992) and became interested in the role bacteria play in ecosystem function. During his post-doctoral years he developed an interest in the contribution of uncultured microbes to the maintenance and function of ecosystems i.e. molecular microbial ecology. He subsequently secured a Wellcome Trust Fellowship which extended his molecular microbial ecology interest and investigated, with culture independent methods, the diversity and distribution of genes involved in biodegradation of priority pollutants in pristine environments. After a short time investigating the deep biosphere he obtained a Lectureship (2001) in the Department of Microbiology, University College Cork, Ireland where he transferred these “omic” skills into the human gut and started to investigate the human gut ecosystem in health and disease. After 7 years in UCC, he moved back to Cardiff University in 2008 to a senior lectureship, where he investigates the role of the gut microbiome in maintaining host health and initiating diseases not only of the gut, but throughout the host system.  In 2015 he was promoted to Professor at Cardiff and in 2016 to Professor at Imperial College London.

His work uses a variety of “omic” approaches such as metagenomics, metatranscriptomics, metabonomics and molecular ecology.  Over his 22 year career he has authored over 75 peer-reviewed publications and is an editor/senior editor for ISME Journal, FEMS Microbiology Ecology and BMC genomics and is a current member of the editorial boards of Journal of Medical Microbiology and Microbiome and past member of the Journal Microbiology Methods, Current Issues in Molecular Biology, and Molecular Biology Today.



Scott AJ, Alexander JL, Merrifield CA, et al., 2019, International Cancer Microbiome Consortium consensus statement on the role of the human microbiome in carcinogenesis, Gut, ISSN:0017-5749

Allegretti JR, Hurtado J, Carrellas M, et al., 2019, 7 – The icon study: Inflammatory bowel disease and recurrent clostridium difficile infection: Outcomes after fecal microbiota transplantation, Gastroenterology, Vol:156, ISSN:0016-5085, Pages:S-2-S-3

McDonald JA, Perez JL, Mullish BH, et al., 2019, Mo1953 – Growth inhibition of clostridioides difficile by short and medium chain fatty acids, Gastroenterology, Vol:156, ISSN:0016-5085, Pages:S-898-S-898

Churchward MA, Michaud ER, Blanco JM, et al., 2019, Sa1924 – Effect of short chain fatty acids on gut-brain axis using a microglial cell model, Gastroenterology, Vol:156, ISSN:0016-5085, Pages:S-455-S-455

Allegretti JR, Kassam Z, Chiang AL, et al., 2019, 621 – Fecal microbiota transplantation for the treatment of obesity: A randomized, placebo-controlled pilot trial, Gastroenterology, Vol:156, ISSN:0016-5085, Pages:S-129-S-129

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