Rachel Armstrong, Kenneth N Timmis
Microbiome of the Built Environment research exhibits a marked 'hard-surface bias', overlooking the dynamic soft materials that dominate human-microbial exchange. We propose a theoretical reorientation: the home as a textile web of dynamic, porous microbial reactors. Grounded in immunology's Danger Theory and the principle of 'tissue-based class control', these soft interfaces function as an external tissue analog. By treating textiles as designable interfaces (ranging from airway exchange nodes to laundry bioreactors), architecture becomes a site for proactive probiotic rituals. This framework leverages competitive exclusion to support externalized mucosal 'guard duty', transitioning from prophylactic sterility to a choreography of domestic care. Notably, this reframing recognizes that hygiene encompasses more than infection prevention: domestic cleaning rituals also shape the microbial ecology that educates the immune system. Ultimately, we frame the living home as a tolerogenic exoskeleton, biologically calibrated to protect and prime the human holobiont.