biostudies-literatureUnknown119(17)Trevelline BKDiet selection is a fundamental aspect of animal behavior with numerous ecological and evolutionary implications. While the underlying mechanisms are complex, the availability of essential dietary nutrients can strongly influence diet selection behavior. The gut microbiome has been shown to metabolize many of these same nutrients, leading to the untested hypothesis that intestinal microbiota may influence diet selection. Here, we show that germ-free mice colonized by gut microbiota from three rodent species with distinct foraging strategies differentially selected diets that varied in macronutrient composition. Specifically, we found that herbivore-conventionalized mice voluntarily selected a higher protein:carbohydrate (P:C) ratio diet, while omnivore- and carnivore-conventionalized mice Proceedings of the National Academy of Sciences of the United States of Americae2117537119https://www.ebi.ac.uk/biostudies/studies/S-EPMC9169907biostudies-literatureThe gut microbiome influences host diet selection behavior.PMC9169907Trevelline BKKohl KDfalseThe gut microbiome influences host diet selection behavior.Diet selection is a fundamental aspect of animal behavior with numerous ecological and evolutionary implications. While the underlying mechanisms are complex, the availability of essential dietary nutrients can strongly influence diet selection behavior. The gut microbiome has been shown to metabolize many of these same nutrients, leading to the untested hypothesis that intestinal microbiota may influence diet selection. Here, we show that germ-free mice colonized by gut microbiota from three rodent species with distinct foraging strategies differentially selected diets that varied in macronutrient composition. Specifically, we found that herbivore-conventionalized mice voluntarily selected a higher protein:carbohydrate (P:C) ratio diet, while omnivore- and carnivore-conventionalized mice 2022-01-01T00:00:00Z2022 Apr2026-03-31T11:51:28.283Z2025-04-04T22:44:50.815ZS-EPMC91699073543906410.1073/pnas.2117537119