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Updated: Apr 21, 2026
Visualization of Gut Microbiota-host Interactions via Fluorescence In Situ Hybridization, Lectin Staining, and Imaging
Published on: July 9, 2021
The utilization of a magneto-fluorescence sequential labeling strategy for the visualization and tracking of
Meiling Jing1,2, Xiuli Wang3, Yaoxia Li3
1Department of Endodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China.
Abstract:
The microbiota of the oral-gut axis influences systemic physical health, but the exact mechanisms remain unknown. In this study, magnetic supraparticles modified with polyacrylic acid and 3-azido-D-alanine hydrochloride (MSP@PAA-ADA) were constructed, and a magneto-fluorescence sequential labeling strategy was established for microbiota viability labeling in combination with a cyanine 5-labeled D-amino acid (Cy5ADA) fluorescent probe. MSP@PAA-ADA, with a particle size of approximately 160 nm, exhibited good hydrophilicity, high magnetic responsiveness, and low bacterial toxicity. MSP@PAA-ADA achieved efficient labeling of oral bacteria through interaction with peptidoglycan in bacterial cell walls. The experimental results indicated that MSP@PAA-ADA can be able to widely bind salivary microbiota, and the labeled salivary bacteria translocated along the oral-gut axis. A small amount of fluorescent signal could still be detected in the mice 36 h after gavage. MSP@PAA-ADA was employed as a magnetic probe for the in vitro labeling of oral bacteria, and sequential labeling was conducted using the fluorescent metabolic probe Cy5ADA. The oral bacteria labeled with MSP@PAA-ADA can be effectively magnetically separated after intestinal translocation through the gastrointestinal tract. The magnetically responsive and fluorescently imaged oral bacteria demonstrate their activity after intestinal translocation. The magneto-fluorescence sequential labeling strategy that enables controllable spatiotemporal tracing and simultaneous viability assessment of intestinal oral bacteria in the gut, providing a new technical approach for dissecting biological mechanisms along the oral-gut microbiota axis.
Insights
Researchers developed a novel magneto-fluorescence labeling method to track oral bacteria. This technique visualizes oral-gut axis microbiota translocation and viability, offering new insights into systemic health mechanisms.
Area of Science:
- Microbiology
- Biotechnology
- Medical Imaging
Background:
- The oral-gut axis microbiota significantly impacts systemic health, but its mechanisms are poorly understood.
- Accurate methods are needed to trace oral bacteria and assess their viability within the gut.
- Current techniques lack the spatiotemporal control and simultaneous viability assessment required for detailed mechanistic studies.
Purpose of the Study:
- To develop a novel magneto-fluorescence sequential labeling strategy for tracing oral bacteria along the oral-gut axis.
- To assess the viability and translocation of labeled oral bacteria within the gastrointestinal tract.
- To provide a new technical approach for dissecting biological mechanisms influenced by the oral-gut microbiota axis.
Main Methods:
- Construction of magnetic supraparticles modified with polyacrylic acid and 3-azido-D-alanine hydrochloride (MSP@PAA-ADA).
- Establishment of a magneto-fluorescence sequential labeling strategy using MSP@PAA-ADA and a cyanine 5-labeled D-amino acid (Cy5ADA) fluorescent probe.
- In vitro labeling of oral bacteria, magnetic separation, and fluorescence imaging in mice models.
Main Results:
- MSP@PAA-ADA (approx. 160 nm) showed good hydrophilicity, magnetic responsiveness, and low bacterial toxicity.
- Efficient labeling of oral bacteria via peptidoglycan interaction was achieved.
- Labeled salivary bacteria translocated along the oral-gut axis, with detectable signals up to 36 hours post-gavage.
- Magnetically separated oral bacteria retained fluorescence, confirming their activity after intestinal translocation.
Conclusions:
- The magneto-fluorescence sequential labeling strategy enables controllable spatiotemporal tracing of oral bacteria in the gut.
- Simultaneous viability assessment of translocated oral bacteria is achievable.
- This approach offers a new technical avenue for investigating the biological mechanisms of the oral-gut microbiota axis.
