Metagenomics of fecal samples from ant-eating mammal species

Myrmecophagous mammals specialize in eating ants and/or termites. They do not share a direct common ancestor and have evolved convergently in five distinct placental orders. This raises questions about the underlying adaptive mechanisms and the relative contributions of natural selection and phylogenetic constraints. This can be answered by understanding how these species digest their prey. In particular, the role of their gut microbial symbionts in digesting the chitinous exoskeleton of insects has not been investigated across myrmecophagous orders. We generated 29 new gut metagenomes from nine myrmecophagous species to reconstruct more than 300 bacterial genomes from which we identified chitin-degrading enzymes. Analysis of the distribution of these chitinolytic bacteria among hosts revealed common and specific bacteria between species. Overall, our results highlight the potential role of gut symbionts in the convergent dietary adaptation of myrmecophagous mammals and the evolutionary mechanisms shaping their gut microbiota.