Just like a human being, a house or office has its own microbiome, with good and bad microorganisms. One researcher has a targeted idea: to customize our spaces with the right microbes.

This week’s haul of great comments includes thoughts on Jamila Lyiscott’s spoken word essay, the happy memory of an excellent teacher, and a shared photo of a cockroach carcass, inspired by Ed Yong’s tales of dastardly parasites.