{"entity":{"id":"microbiome-tumour","kind":"pathway","name":"Microbiome-tumour interactions","aka":[],"tldr":"The bacteria in the gut, and even inside tumours, influence whether cancer starts and whether immunotherapy works. Transplanting stool from responders has made some non-responders respond.","summary":"Gut microbiota modulate systemic immunity (Bifidobacterium, Akkermansia, Faecalibacterium associated with PD-1 response; antibiotics associated with worse outcomes); faecal microbiota transplant from responders converted a fraction of refractory melanoma patients to responders (2021, and 2023-25 follow-ups). Intratumoural bacteria (Fusobacterium nucleatum in colorectal cancer, Gammaproteobacteria degrading gemcitabine in pancreatic cancer) affect chemoresistance and inflammation; colibactin-producing pks+ E. coli leaves a mutational signature in CRC. 'Polymorphic microbiomes' is a 2022 hallmark. Defined consortia (VE800, SER-155) and diet interventions are in trials; causality beyond melanoma is not settled.","asOf":"2026-09-08","wikipedia":"https://en.wikipedia.org/wiki/Microbiome","links":[{"label":"Davar et al., Fecal microbiota transplant overcomes resistance to anti-PD-1 therapy in melanoma (Science 2021)","url":"https://doi.org/10.1126/science.abf3363"},{"label":"Hanahan, Hallmarks of Cancer: New Dimensions (Cancer Discovery 2022)","url":"https://doi.org/10.1158/2159-8290.CD-21-1059"}],"tags":["mechanism"],"related":[],"cancers":["melanoma","colorectal","pancreatic"],"sections":[],"technologies":[],"targets":["pd1"],"drugs":[],"companies":[],"institutions":["md-anderson","gustave-roussy","penn-abramson","johns-hopkins"],"pathways":["pd1-checkpoint","inflammation-nfkb","tumor-microenvironment"],"terms":["polymorphic-microbiomes","mutational-signature"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":["paper-davar-science"],"journals":[],"dependsOn":[],"notes":["Leading programmes: Wargo (MD Anderson); Zitvogel (Gustave Roussy); Gajewski (Chicago); Sears (Johns Hopkins) on colibactin; Straussman (Weizmann) on intratumoural bacteria."],"analogy":"Soil bacteria decide whether a garden thrives. Some feed the plants' defenders, some produce poisons, and some even eat the pesticide before it reaches the weeds.","nodes":[{"id":"gut","label":"Gut microbiota","x":15,"y":40},{"id":"meta","label":"Metabolites (SCFA, inosine, bile acids)","x":40,"y":20},{"id":"dc","label":"Dendritic / T-cell priming","x":65,"y":20},{"id":"io","label":"Immunotherapy response","x":90,"y":40,"targetId":"pd1"},{"id":"intra","label":"Intratumoural bacteria","x":40,"y":70},{"id":"chemo","label":"Chemotherapy degradation, inflammation","x":65,"y":70},{"id":"abx","label":"Antibiotics","x":15,"y":80},{"id":"colib","label":"Colibactin → mutational signature","x":90,"y":80}],"edges":[{"from":"gut","to":"meta","type":"activates"},{"from":"meta","to":"dc","type":"activates"},{"from":"dc","to":"io","type":"activates"},{"from":"abx","to":"gut","type":"inhibits"},{"from":"intra","to":"chemo","type":"activates"},{"from":"intra","to":"colib","type":"activates"},{"from":"gut","to":"intra","type":"activates"}],"interventions":["FMT from responders with PD-1 blockade (phase 2)","Defined bacterial consortia (VE800, SER-155) and diet (fibre) trials","Antibiotic stewardship around immunotherapy","Fusobacterium-targeted strategies (research)"]},"route":"/pathways/microbiome-tumour/","neighbours":{"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"malt-lymphoma","kind":"cancer","name":"Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)","route":"/cancers/malt-lymphoma/"},{"id":"marginal-zone-lymphoma","kind":"cancer","name":"Marginal zone lymphoma","route":"/cancers/marginal-zone-lymphoma/"},{"id":"melanoma","kind":"cancer","name":"Melanoma","route":"/cancers/melanoma/"},{"id":"pancreatic","kind":"cancer","name":"Pancreatic ductal adenocarcinoma","route":"/cancers/pancreatic/"}],"target":[{"id":"bcl10","kind":"target","name":"BCL10","route":"/targets/bcl10/"},{"id":"birc3","kind":"target","name":"BIRC3","route":"/targets/birc3/"},{"id":"malt1","kind":"target","name":"MALT1","route":"/targets/malt1/"},{"id":"pd1","kind":"target","name":"PD-1","route":"/targets/pd1/"},{"id":"tnfaip3","kind":"target","name":"TNFAIP3","route":"/targets/tnfaip3/"}],"institution":[{"id":"penn-abramson","kind":"institution","name":"Abramson Cancer Center, University of Pennsylvania","route":"/institutions/penn-abramson/"},{"id":"gustave-roussy","kind":"institution","name":"Gustave Roussy","route":"/institutions/gustave-roussy/"},{"id":"johns-hopkins","kind":"institution","name":"Johns Hopkins Hospital / Sidney Kimmel Comprehensive Cancer Center","route":"/institutions/johns-hopkins/"},{"id":"md-anderson","kind":"institution","name":"MD Anderson Cancer Center","route":"/institutions/md-anderson/"}],"pathway":[{"id":"inflammation-nfkb","kind":"pathway","name":"Inflammation & NF-κB","route":"/pathways/inflammation-nfkb/"},{"id":"pd1-checkpoint","kind":"pathway","name":"PD-1 / PD-L1 immune checkpoint & T-cell activation","route":"/pathways/pd1-checkpoint/"},{"id":"tumor-microenvironment","kind":"pathway","name":"Tumour microenvironment (TME)","route":"/pathways/tumor-microenvironment/"}],"term":[{"id":"tumor-promoting-inflammation","kind":"term","name":"Enabling characteristic: tumour-promoting inflammation","route":"/terms/tumor-promoting-inflammation/"},{"id":"gut-microbiome-diversity","kind":"term","name":"Gut microbiome diversity and composition","route":"/terms/gut-microbiome-diversity/"},{"id":"polymorphic-microbiomes","kind":"term","name":"Hallmark (2022): polymorphic microbiomes","route":"/terms/polymorphic-microbiomes/"},{"id":"mutational-signature","kind":"term","name":"Mutational signature","route":"/terms/mutational-signature/"}],"paper":[{"id":"paper-davar-science","kind":"paper","name":"Fecal microbiota transplant overcomes resistance to anti-PD-1 therapy in melanoma patients","route":"/key-papers/paper-davar-science/"},{"id":"paper-diaz-gay-colibactin-geographic-age-mutational-processes-nature-2025","kind":"paper","name":"Geographic and age variations in mutational processes in colorectal cancer","route":"/key-papers/paper-diaz-gay-colibactin-geographic-age-mutational-processes-nature-2025/"},{"id":"paper-hallmarks-new-dimensions-cancer-discov-2022","kind":"paper","name":"Hallmarks of Cancer 2022: adding phenotypic plasticity, epigenetic reprogramming, microbiomes and senescent cells","route":"/key-papers/paper-hallmarks-new-dimensions-cancer-discov-2022/"}],"roadmap":[{"id":"colorectal-roadmap","kind":"roadmap","name":"Colorectal cancer roadmap: from the adenoma-carcinoma sequence and the first screening trials to total mesorectal excision, oxaliplatin, RAS testing, immunotherapy for mismatch repair-deficient disease, ctDNA-guided treatment and organ preservation","route":"/roadmaps/colorectal-roadmap/"}],"idea":[{"id":"idea-crc-early-onset-cause-hunt","kind":"idea","name":"Find out what is driving early-onset bowel cancer, starting with colibactin, before extending screening any further","route":"/ideas/idea-crc-early-onset-cause-hunt/"},{"id":"idea-microbiome-io-fmt","kind":"idea","name":"Microbiome transplant as a routine immunotherapy adjunct","route":"/ideas/idea-microbiome-io-fmt/"}],"technology":[{"id":"dietary-fibre-microbiome-io","kind":"technology","name":"Dietary fibre and the gut microbiome for immunotherapy response","route":"/technologies/dietary-fibre-microbiome-io/"},{"id":"fmt-checkpoint-nonresponders","kind":"technology","name":"Faecal microbiota transplantation for PD-1 non-responders","route":"/technologies/fmt-checkpoint-nonresponders/"},{"id":"probiotics-antibiotic-stewardship-io","kind":"technology","name":"Probiotics, antibiotics and stewardship around immunotherapy","route":"/technologies/probiotics-antibiotic-stewardship-io/"}],"trial":[{"id":"fmt-pd1-refractory-melanoma-pitt","kind":"trial","name":"FMT plus pembrolizumab in anti-PD-1-refractory melanoma (Pittsburgh)","route":"/trials/fmt-pd1-refractory-melanoma-pitt/"},{"id":"mimic-01","kind":"trial","name":"MIMic-01: healthy-donor FMT plus anti-PD-1, first-line melanoma","route":"/trials/mimic-01/"}]}}