Measurement of Metabolites in Feces of Japanese Rock Ptarmigans by LC-MS/MS

Importance of the Topic

This research addresses the urgent need for effective conservation monitoring of an endangered species by leveraging metabolomic analysis to reveal gut microbiota metabolites critical for health assessment.

Objectives and Study Overview

This study applied LC-MS/MS metabolomics to fecal samples of Japanese rock ptarmigans from in situ (Mt. Kitadake) and ex situ (artificial raising) contexts. The aim was to detect and compare metabolites reflecting environmental and dietary influences.

Methodology and Sample Preparation

Researchers collected cecal feces from adult and chick birds under both conditions. Samples were suspended in phosphate-buffered saline, vortexed, cooled, centrifuged, and filtered. Filtrates were diluted tenfold before LC-MS/MS analysis.

Instrumentation

• UHPLC: Nexera X2 system with Discovery HS F5 column (150 mm × 2.1 mm, 3 μm)
• Mobile phases: 0.1% formate in water (A) and acetonitrile (B); flow rate 0.25 mL/min; column temperature 40 °C
• Mass spectrometer: Shimadzu LCMS-8050 with ESI in positive/negative MRM mode
• Software: Traverse MSTM for principal component analysis

Key Results and Discussion

The analysis detected 60 metabolites in raised birds and 56 in wild birds, covering amino acids, nucleotides, nucleosides, and organic acids. Repeatability was high, with RSD < 20% for 54 compounds. Comparative profiles revealed significantly elevated nucleosides (adenine, adenosine, allantoin, cytidine, uridine) in wild birds (p < 0.01), while amino acids (alanine, arginine, histidine, leucine, methionine, tryptophan) were higher in artificially raised birds (p < 0.01). PCA clearly separated the two groups based on metabolite signatures.

Benefits and Practical Applications

This noninvasive fecal metabolomics approach provides biomarkers for monitoring health, diet adaptation, and microbiome activity in endangered avian species, supporting conservation and captive‐breeding programs.

Future Trends and Potential Applications

Future directions include integration with microbiome sequencing for comprehensive gut ecology, development of portable MS platforms for field studies, high‐throughput screening across populations, and targeted biomarker panels for real‐time health assessment.

Conclusion

LC-MS/MS fecal metabolomics effectively discriminated wild and captive Japanese rock ptarmigans, uncovering distinct metabolic patterns. This method offers a powerful tool for ongoing conservation monitoring and welfare evaluation.