Individual differences in gut microbiota composition highlight the need for methods capable of selectively enriching host-associated bacteria from complex microbial communities. Conventional cultivation approaches lack the precision required for targeted enrichment, limiting progress in personalized microbiome research. Here, we established a proof-of-concept monoclonal antibody-based strategy for the selective enrichment of a target gut bacterium. We generated a monoclonal antibody (8H2) exhibiting preferential reactivity toward the human-derived Bifidobacterium longum Jih1 and demonstrated that it selectively enriched viable Jih1 cells from a defined bacterial consortium and a human fecal sample. Proteomic and genetic analyses suggested that 8H2 recognizes glutamine synthetase (GS), an enzyme typically localized intracellularly, but detected on the surface of Jih1 cells. This surface association enables antibody binding and facilitates selective enrichment within complex microbial communities. These data support the feasibility of antibody-based, selective enrichment of viable bacteria and suggest potential applications for monitoring individual-associated bacteria in personalized nutrition and microbiome-based interventions.
Nakato et al. (Tue,) studied this question.