The study investigates the co-evolution of mammalian gut microbiomes and their diets, using shotgun sequencing and targeted 16S rRNA gene sequencing. The researchers analyzed microbial communities from 33 mammalian species and 18 humans with detailed diet records. They found that microbiota adaptation to diet is consistent across different mammalian lineages, and functional repertoires of microbiome genes can be predicted from bacterial species assemblages. Procrustes analysis revealed a strong correlation between the functional properties of microbiomes and their bacterial species composition. The study also showed that the gut microbiome structure and function are significantly associated with dietary intake within a single human population. These findings highlight the importance of diet in shaping the gut microbiome and suggest that similar processes drive the evolution of microbiomes across different mammalian lineages.The study investigates the co-evolution of mammalian gut microbiomes and their diets, using shotgun sequencing and targeted 16S rRNA gene sequencing. The researchers analyzed microbial communities from 33 mammalian species and 18 humans with detailed diet records. They found that microbiota adaptation to diet is consistent across different mammalian lineages, and functional repertoires of microbiome genes can be predicted from bacterial species assemblages. Procrustes analysis revealed a strong correlation between the functional properties of microbiomes and their bacterial species composition. The study also showed that the gut microbiome structure and function are significantly associated with dietary intake within a single human population. These findings highlight the importance of diet in shaping the gut microbiome and suggest that similar processes drive the evolution of microbiomes across different mammalian lineages.