Imperial College London


Faculty of MedicineDepartment of Metabolism, Digestion and Reproduction

Honorary Senior Lecturer







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





James Alexander is a Clinical Lecturer in the Department of Metabolism, Digestion and Reproduction at Imperial College London and an Honorary Specialty Registrar in Gastroenterology at St Mary's Hospital, Imperial College Healthcare NHS Trust and the Royal Marsden Hospital.  He completed his PhD at Imperial College London.

Selected Publications

Journal Articles

Alexander JL, Mullish BH, Danckert NP, et al., 2023, The gut microbiota and metabolome are associated with diminished COVID-19 vaccine-induced antibody responses in immunosuppressed inflammatory bowel disease patients, Ebiomedicine, Vol:88, ISSN:2352-3964

Liu Z, Alexander J, LIN K, et al., 2023, Infliximab and tofacitinib attenuate neutralizing antibody responses against SARS-CoV-2 ancestral and Omicron variants in IBD patients following 3 doses of COVID-19 vaccine, Gastroenterology, Vol:164, ISSN:0016-5085, Pages:300-303.e3

Alexander J, Liu Z, Munoz Sandoval D, et al., 2022, COVID-19 vaccine-induced antibody and T cell responses in immunosuppressed patients with inflammatory bowel disease after the third vaccine dose: a multicentre, prospective, case-control study, The Lancet Gastroenterology & Hepatology, Vol:7, ISSN:2468-1253, Pages:1005-1015

Alexander J, Ibraheim H, Sheth B, et al., 2021, Clinical outcomes of patients with corticosteroid refractory immune checkpoint inhibitor induced enterocolitis treated with infliximab, Journal for Immunotherapy of Cancer, Vol:9, ISSN:2051-1426, Pages:1-9

Alexander J, Hart A, Segal JP, et al., 2021, SARS-CoV-2 vaccination for patients with inflammatory bowel disease: a British Society of Gastroenterology Inflammatory Bowel Disease section and IBD Clinical Research Group position statement, The Lancet Gastroenterology and Hepatology, Vol:6, ISSN:2468-1253, Pages:218-224

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, Vol:68, ISSN:0017-5749, Pages:1624-1632

Alexander JL, Wilson ID, Teare J, et al., 2017, Gut microbiota modulation of chemotherapy efficacy and toxicity., Nature Reviews Gastroenterology & Hepatology, Vol:14, ISSN:1759-5045, Pages:356-365

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