Insight Into Host-Microbe Interactions Using Microbial Flow Cytometry Coupled to Next-Generation Sequencing

Antibody-based assays have been a cornerstone of infectious disease diagnostics for over 100 years [1]. These assays rely on the exquisite sensitivity and specificity of humoral response to almost all infections. While next-generation sequencing (NGS) has tremendous potential to improve diagnostics and uncover host-microbial relationships by directly identifying nucleic acids from infectious microbes, challenges and opportunities for new approaches remain. Here, we review a group of cutting-edge techniques that couple antibody responses with flow cytometry of antibody tagged microbes and NGS. These studies are bringing into focus the dynamic relationship between our immune systems and endogenous microbial communities, which are an important source of pathogens. For simplicity, we use the umbrella term mFLOW-Seq (microbial flow cytometry coupled to NGS) to describe these approaches.