{"entity":{"id":"idea-nl-diet-covariates-io-trials","kind":"idea","name":"Capture diet, fibre and antibiotic exposure in every immunotherapy pivotal trial","aka":[],"tldr":"Gut bacteria appear to influence whether immunotherapy works, and diet and antibiotics shape gut bacteria. Yet almost no drug trial records what patients ate or which antibiotics they took. Recording it would cost almost nothing.","summary":"Fibre intake, probiotic use, antibiotics and proton-pump inhibitors are each associated with checkpoint-inhibitor outcomes in observational cohorts, but the data come from single centres with recall questionnaires. Pivotal trials enrol tens of thousands of patients under protocol with concomitant medication logs already captured; adding a short validated diet screener and banking a baseline stool sample would generate the largest and cleanest dataset on host factors in immunotherapy, and allow stratified or covariate-adjusted analyses that could explain part of the variability in response.","asOf":"2026-09-08","links":[{"label":"Bottleneck evidence (No one can predict who responds to immunotherapy): Haslam & Prasad (JAMA Network Open 2019)","url":"https://doi.org/10.1001/jamanetworkopen.2019.2535"}],"tags":[],"related":["idea-bio2-antibiotic-stewardship-io","idea-bio2-fibre-diet-io-trial"],"cancers":["melanoma","nsclc","rcc"],"sections":["nutrition-lifestyle","immunotherapy"],"technologies":["dietary-fibre-microbiome-io","probiotics-antibiotic-stewardship-io","checkpoint-inhibitor"],"targets":[],"drugs":["pembrolizumab","nivolumab"],"companies":[],"institutions":[],"pathways":[],"terms":["gut-microbiome-diversity","dietary-pattern-scores"],"trials":[],"people":[],"bottlenecks":["b-immunotherapy-response","b-trial-design","b-data-silos"],"keyPapers":["paper-haslam-jama-netw-open"],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"Across pooled pivotal checkpoint-inhibitor trials, baseline fibre intake and peri-treatment antibiotic exposure are independent predictors of progression-free survival with effect sizes comparable to PD-L1 expression, and adjusting for them reduces between-trial heterogeneity.","rationale":"Regulators already require concomitant medication recording; FDA and EMA have encouraged patient-reported outcome and biomarker collection. A 10-item diet screener and a stool kit add minutes and a few hundred dollars per patient against trial costs of tens of thousands.","test":"Pilot in two ongoing cooperative-group immunotherapy trials with pre-specified analysis; if predictive value is confirmed, FDA and EMA guidance recommending standardised diet and antibiotic capture in immuno-oncology trials, with pooled analysis through Project Data Sphere or similar.","maturity":"speculative","actor":"regulator","cost":"small","horizonYears":3},"route":"/ideas/idea-nl-diet-covariates-io-trials/","neighbours":{"idea":[{"id":"idea-bio2-antibiotic-stewardship-io","kind":"idea","name":"Protect the gut flora of patients about to start immunotherapy","route":"/ideas/idea-bio2-antibiotic-stewardship-io/"},{"id":"idea-bio2-fibre-diet-io-trial","kind":"idea","name":"Test a high-fibre diet as an immunotherapy adjunct","route":"/ideas/idea-bio2-fibre-diet-io-trial/"}],"cancer":[{"id":"melanoma","kind":"cancer","name":"Melanoma","route":"/cancers/melanoma/"},{"id":"nsclc","kind":"cancer","name":"Non-small-cell lung cancer","route":"/cancers/nsclc/"},{"id":"rcc","kind":"cancer","name":"Renal cell carcinoma","route":"/cancers/rcc/"}],"section":[{"id":"nutrition-lifestyle","kind":"section","name":"Diet, Exercise & Lifestyle","route":"/fronts/nutrition-lifestyle/"},{"id":"immunotherapy","kind":"section","name":"Immunotherapy","route":"/fronts/immunotherapy/"}],"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":"checkpoint-inhibitor","kind":"technology","name":"Immune checkpoint inhibitors","route":"/technologies/checkpoint-inhibitor/"},{"id":"probiotics-antibiotic-stewardship-io","kind":"technology","name":"Probiotics, antibiotics and stewardship around immunotherapy","route":"/technologies/probiotics-antibiotic-stewardship-io/"}],"drug":[{"id":"nivolumab","kind":"drug","name":"Nivolumab","route":"/drugs/nivolumab/"},{"id":"pembrolizumab","kind":"drug","name":"Pembrolizumab","route":"/drugs/pembrolizumab/"}],"term":[{"id":"dietary-pattern-scores","kind":"term","name":"Dietary pattern scores (Mediterranean, HEI, AHEI, DASH, WCRF/AICR)","route":"/terms/dietary-pattern-scores/"},{"id":"gut-microbiome-diversity","kind":"term","name":"Gut microbiome diversity and composition","route":"/terms/gut-microbiome-diversity/"}],"bottleneck":[{"id":"b-data-silos","kind":"bottleneck","name":"Data silos","route":"/bottlenecks/b-data-silos/"},{"id":"b-immunotherapy-response","kind":"bottleneck","name":"No one can predict who responds to immunotherapy","route":"/bottlenecks/b-immunotherapy-response/"},{"id":"b-trial-design","kind":"bottleneck","name":"Trial design, endpoints and cost","route":"/bottlenecks/b-trial-design/"}],"paper":[{"id":"paper-haslam-jama-netw-open","kind":"paper","name":"Estimation of the Percentage of US Patients With Cancer Who Are Eligible for and Respond to Checkpoint Inhibitor Immunotherapy Drugs","route":"/key-papers/paper-haslam-jama-netw-open/"}]}}