eLife Assessment
This fundamental study advances our understanding of how dietary patterns shape cancer immunity by identifying a link between a Mediterranean-mimicking diet, gut bacteria, and a metabolite that enhances anti-tumor immune responses. The evidence supporting the main conclusions is solid, based on carefully controlled diet experiments, measurements of gut-derived molecules, and functional immune analyses across multiple models, together with supportive observations in human data. The work will be of broad interest to biologists working on microbiota and cancer. However, there are several issues that the authors should address to improve the manuscript.