Development and implementation of a comprehensive fecal metabolites LC-MS library for dietary intervention studies using the Thermo Scientific Stellar mass spectrometer

Significance of the Topic

The development of a comprehensive fecal metabolites LC-MS library addresses critical needs in translational metabolomics. Accurate quantitation of hundreds of small molecules from complex fecal samples enables the study of host–microbiome interactions, dietary interventions, and biomarker verification for disease research. High-throughput and reliable targeted methods support large-scale studies and accelerate the path from discovery to validation of metabolite biomarkers.

Objectives and Study Overview

In this application note, researchers aimed to:

• Demonstrate rapid, intuitive method development on the Thermo Scientific™ Stellar™ mass spectrometer.
• Evaluate analytical performance—sensitivity, accuracy, and selectivity—for over 500 fecal metabolites.
• Showcase high-throughput quantitation across three LC separation modes (reversed-phase, HILIC, mixed-mode).
• Validate detection and quantitation of challenging co-eluting isomers and dietary markers in mouse fecal samples.

Methodology and Instrumentation

Pure analytical standards (500+ compounds) from MetaSci were dissolved in methanol or methanol–water mixtures. Calibration curves spanned 0 nM to 20 μM. Fecal extracts were prepared from eight-week-old mice fed standard, SFA-rich, or MUFA-rich diets for 29 days. Metabolites were extracted with 80% methanol and injected (2 μL) on a Vanquish™ Horizon UHPLC. Three LC methods (long and short gradients) were employed:

• Reversed-phase C18 (Hypersil GOLD, 2.1 × 150 mm, 1.9 μm)
• HILIC (Accucore™ Amide, 2.1 × 150 mm, 2.6 μm)
• Mixed-mode (Acclaim™ Trinity P2, 2.1 × 100 mm, 3 μm)

Instrumentation Used

The key instruments and software comprised:

• Thermo Scientific™ Stellar™ mass spectrometer (dual-pressure linear ion trap plus triple quadrupole capability)
• Vanquish™ Horizon UHPLC system with 5 °C autosampler
• Thermo Scientific™ Compound Discoverer™ software for targeted discovery omics
• PRM Conductor for dynamic retention time alignment and method generation

Main Results and Discussion

The Stellar mass spectrometer achieved rapid full-scan MS1 (polarity switching in 5 ms), MS2 at 140 Hz, and MS3 at 40 Hz. Sensitivity improved tenfold over existing platforms, with LLOQs in the low femtomole range and linear dynamic ranges spanning five orders of magnitude. Co-eluting isomers such as glycochenodeoxycholic acid and glycodeoxycholic acid were selectively quantified using diagnostic MS2/MS3 fragment ions without ion-pairing reagents. In mouse fecal samples, SFA-rich diets elevated deoxycholic acid and β-muricholic acid levels relative to MUFA-rich and standard diets. Internal standards (isotope-labeled bile acids) confirmed method robustness, with low retention time shifts and coefficient of variation below 5%.

Benefits and Practical Applications

Key advantages of this workflow include:

• Streamlined targeted method development within a single injection.
• High selectivity for co-eluting and isobaric compounds via MSn fragmentation.
• Rapid analysis with shortened LC gradients for large-scale studies.
• Seamless transition from untargeted discovery to targeted validation using Compound Discoverer and PRM Conductor.

Future Trends and Potential Uses

Ongoing developments may extend this approach to:

• Integrated lipidomics and metabolomics panels for precision nutrition studies.
• Automated method transfer and cloud-based data alignment for multi-site trials.
• Deep profiling of gut microbiome–host co-metabolism in clinical cohorts.
• Real-time adjustment of acquisition parameters using machine-learning–driven retention time models.

Conclusion

The Thermo Scientific Stellar mass spectrometer enables unparalleled sensitivity, selectivity, and throughput for fecal metabolite quantitation. Its dual-mode MSn and triple quadrupole capabilities streamline the verification of hundreds of biomarkers, accelerating translational metabolomics workflows and supporting high-throughput dietary and microbiome studies.

Reference

Amer B., Jacob C., Remes P. M., Peterman S. M., Wijeratne N. R., Deshpande R. R., Bird S. S. Application note 003114, Thermo Fisher Scientific (2024)