An evolutionarily conserved laterally acquired toolkit enables microbiota targeting by Trichomonas

Trichomonasspecies are a diverse group of obligate extracellular symbionts associated with or attributed to various inflammatory diseases. They colonise mucosal surfaces across a wide range of hosts, all of which harbour a resident microbiota. Their evolutionary history likely involved multiple host transfers, including zoonotic events from columbiform birds to mammals. Using comparative transcriptomics, this study examinesTrichomonas gallinaeco-cultured withEscherichia coli, identifying a molecular toolkit thatTrichomonasspecies may use to interact with bacterial members of the microbiota. Integrating transcriptomic data with comparative genomics and phylogenetics revealed a conserved repertoire of protein-coding genes likely acquired through multiple lateral gene transfers (LGT) in a columbiform-infecting ancestor. These LGT-derived genes encode muramidases, glucosaminidases, and antimicrobial peptides-enzymes and effectors capable of targeting bacterial cell walls, potentially affecting the bacterial microbiota composition across both avian and mammalian hosts. This molecular toolkit suggests thatTrichomonasspecies can actively compete with and exploit their surrounding microbiota for nutrients, potentially contributing to the dysbiosis associated withTrichomonasinfections. Their ability to target bacterial populations at mucosal surfaces provides insight into howTrichomonasspecies may have adapted to diverse hosts and how they could influence inflammatory mucosal diseases in birds and mammals.