This presentation will introduce passive immunotherapy for modulation of microbiome structure and dynamics, using avian immunoglobulins (IgY) as effector molecules. After a brief description of IgY as a technology, we discuss how it can be used to intervene in the myriad signaling pathways and event cascades that promote dysbiosis-induced pathology, giving as an example a pathway leading to colorectal cancer. Finally, we present two case studies on drug candidates developed by Scaled Microbiomics to prevent Travelers' Diarrhea and COVID-19, as illustrations of the speed with which the company's drug discovery platform can work