Metabolic fluorine labeling and hotspot imaging of dynamic gut microbiota in mice

Real-time localization and microbial activity information of indigenous gut microbiota over an extended period of time remains a challenge with existing visualizing methods. Here, we report a metabolic fluorine labeling (MEFLA)–based strategy for monitoring the dynamic gut microbiota via 19 F magnetic resonance imaging ( 19 F MRI). In situ labeling of different microbiota subgroups is achieved by using a panel of peptidoglycan-targeting MEFLA probes containing 19 F atoms of different chemical shifts, and subsequent real-time in vivo imaging is accomplished by multiplexed hotspot 19 F MRI with high sensitivity and unlimited penetration. Using this method, we realize extended visualization (>24 hours) of native gut microbes located at different intestinal sections and semiquantitative analysis of their metabolic dynamics modulated by various conditions, such as the host death and different β-lactam antibiotics. Our strategy holds great potential for noninvasive and real-time assessing of the metabolic activities and locations of the highly dynamic gut microbiota.