Lee KA, Shaw HM, Bataille V, et al. - As the health of the gut microbiome (GM) is strongly linked with therapeutic responses to immune-checkpoint inhibitors (ICIs), researchers sought to determine the implications of diet and medication on the GM for patients receiving ICI. Based on findings from short-term clinical and observational studies identified, they emphasize avoiding antibiotics before ICI initiation, and suggest providing consideration to a temporary delay of initiation of non-urgent ICI in cases having broad spectrum antibiotics within 1 month of planned treatment initiation. Discontinuation of proton pump inhibitor use is emphasized when not clearly indicated and potential switch to a histamine H2-receptor antagonist considered. Minimization of animal meat intake and maximization of plants, aiming to consume ≥ 30 plant types weekly, should be advised to patients. The chance of ICI response is reported to improve in correlation with a high fibre intake (> 30 g/day). Given the possible beneficial impact of fermented foods on the GM, their introduction is emphasized where possible. Ideally, referral of all patients to a nutritionist or dietician with knowledge of GM before commencing ICI should be done.