Limited experimental evidence bridges nutrition and cancer immunosurveillance. Here, the team at IGR Paris shows that ketogenic diet (KD) or its principal ketone body, 3-hydroxybutyrate (3HB), most specifically in an intermittent scheduling, induced T cell-dependent tumour growth retardation of aggressive tumour models.
In conditions in which anti-PD-1, alone or in combination with anti-CTLA-4, failed to reduce tumour growth in mice receiving a standard diet, KD or oral supplementation of 3HB reestablished therapeutic responses. Supplementation of KD with sucrose (which breaks ketogenesis, abolishing 3HB production) or with a pharmacological antagonist of the 3HB receptor GPR109A abolished the anti-tumour effects. Mechanistically, 3HB prevented the ICB-linked up-regulation of PD-L1 on myeloid cells while favouring the expansion of CXCR3+ T cells. KD induced compositional changes of the gut microbiota with distinct species such as Eisenbergiella massiliensis commonly emerging in mice and humans subjected to carbohydrate low diet interventions and highly correlating with serum concentrations of 3HB. Altogether, these results demonstrate that KD induces a 3HB-mediated antineoplastic effect that relies on T-cell mediated cancer immunosurveillance.