RT Journal Article SR Electronic T1 In situ reprogramming of gut bacteria by oral delivery JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.04.15.043232 DO 10.1101/2020.04.15.043232 A1 Hsu, Bryan B. A1 Plant, Isaac N. A1 Lyon, Lorena A1 Anastassacos, Frances M. A1 Way, Jeffrey C. A1 Silver, Pamela A. YR 2020 UL http://biorxiv.org/content/early/2020/04/16/2020.04.15.043232.abstract AB Abundant links between the gut microbiota and human health indicate that the modification of bacterial function could be a powerful therapeutic strategy. The inaccessibility of the gut and inter-connections between gut bacteria and the host make it difficult to precisely target bacterial functions without disrupting the microbiota and/or host physiology. Herein we describe a multidisciplinary approach to modulate the expression of a specific bacterial gene within the gut by oral administration. We first demonstrate that an engineered temperate phage λ expressing a programmable dCas9 represses a targeted E. coli gene in the mammalian gut. To facilitate phage administration while minimizing disruption to host processes, we develop an aqueous-based encapsulation formulation with a microbiota-based release mechanism and show that it facilitates the oral delivery of phage in vivo. Finally we combine these technologies and show that bacterial gene expression in the mammalian gut can be precisely modified in situ with a single oral dose.Competing Interest StatementThe authors have declared no competing interest.