Mark Martin returns to TWiM to join the discussion of how to design a complex gut microbiome, and protection of protists from virus infection by intracellular bacterial symbionts. Hosts: Vincent Racaniello, Michael Schmidt, Michele Swanson, and Petra Levin Become a patron of TWiM. Links for this episode Design of a complex gut microbiome (Cell) Defensive symbiosis against giant viruses (PNAS) Take the TWiM Listener survey! Send your microbiology questions and comments (email or recorded audio) to twim@microbe.tv