Untargeted Metabolomics Analysis: A quick guide

Understand the core principles of untargeted metabolomics, from high-resolution mass spectrometry to AI-driven metabolite identification.

Recent advances in untargeted metabolomics are transforming biological research and systems biology. For instance, notable study using this technique revealed novel cancer cell biomarkers, advancingbdiagnostic tools and targeted therapies. Moreover, the method enables researchers to explore unknown metabolites, discover biomarkers, and understand metabolic pathways.

The Nature of Untargeted Metabolomics

Unlike targeted metabolomics, which focuses on predefined metabolites, untargeted metabolomics takes an expansive approach by detecting and quantifying all measurable metabolites in a sample without prior identification. This distinction is crucial, as it allows researchers to uncover novel compounds and unexpected metabolic pathways, providing an unbiased view of the metabolome. A large-scale prospective cohort study analyzing colorectal cancer risk demonstrated this approach’s power by analyzing over 5,000 metabolic features in plasma samples, identifying novel biomarkers that could predict cancer risk years before
diagnosis [1]. This comprehensive approach enables researchers to identify previously unknown metabolic signatures and pathways that might be missed in targeted analyses.

The untargeted approach is particularly valuable in hypothesis-generating studies, where researchers aim to discover new biomarkers or understand complex metabolic networks. Recent research has shown that this method can reveal subtle metabolic changes that occur long before clinical symptoms appear, making it particularly valuable for early disease detection and prevention strategies.

Core Analytical Steps

  1. Sample Preparation. Success depends on effective sample preparation. Achieving epresentative metabolite profiles requires meticulous extraction protocols specific to sample types, from cells to biofluids. The choice of extraction method can significantly impact the range and quality of metabolites detected, making this step crucial for reliable results.
  2. Data Acquisition. High-resolution mass spectrometry techniques form the foundation of analysis. LC-MS excels with more polar, larger molecular mass compounds, such as those found in biofluids, while GC-MS handles smaller, less polar compounds that tend to be volatile, effectively. These methods generate complementary data reflecting sample complexity. The combination of these techniques provides comprehensive coverage of the metabolome, ensuring that both polar and non-polar metabolites are accurately detected and measured.
  3. Data Processing. The volume of generated data necessitates advanced computational tools. Automated workflows have been developed in recent years to manage processing, while ensuring data quality and reproducibility. These tools handle various aspects of data processing, from peak detection to alignment and normalization, crucial for reliable results.
  4. Metabolite Identification. This represents the most challenging step due to chemical diversity and limited reference databases. Distinguishing between isomers requires sophisticated tools and validation. In silico (computational) methods such as SIRIUS [5] assist in predicting structures of unidentified molecules. Recent advances in artificial intelligence and machine learning have improved the accuracy and speed of metabolite dentification.
  5. Statistical Analysis. Statistical methods transform raw data into biological insights. Specifically, principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA) help identify patterns and distinguish between experimental groups, crucial for biomarker discovery. These methods enable researchers to identify significant differences between groups and potential biomarkers.
  6. Pathway Analysis. The process concludes with mapping metabolites to pathways. For this purpose, tools like Mummichog [6] enable researchers to contextualize findings within metabolic networks. This final step helps researchers understand how identified metabolites interact within biological systems and their potential roles in disease processes.

Untargeted Metabolomics Applications and Recent Discoveries

The technique spans multiple fields, with particularly promising applications in disease research and diagnosis. Recent studies have revealed its potential across various areas. A gastroesophageal cancer study demonstrated remarkable accuracy in predicting cancer formation [2], while research in Alzheimer’s disease identified distinct metabolic signatures in different brain regions, providing new insights into disease progression [3]. The systematic analysis of brain tissue revealed region-specific metabolic alterations, highlighting the complexity of neurodegenerative processes [4].

Applications include:

  • Disease biomarker identification
  • Drug metabolism studies
  • Agricultural productivity enhancement
  • Environmental monitoring

Current Challenges and Future Developments

Key challenges include:

  • Data management and interpretation
  • Limited metabolite database coverage
  • Method reproducibility

Computational advances, including rapidly developing methodologies that leverage machine learning to tackle these challenges. Integration with other “omics” technologies promises deeper biological insights. Recent developments in artificial intelligence and machine learning are helping to address these challenges, particularly in metabolite identification and data interpretation.

Future Outlook

Untargeted metabolomics continues to advance our understanding of biological systems, driving innovation across disciplines. As technologies evolve and computational methods improve, the field will further illuminate complex biochemical processes, enhancing disease comprehension and treatment approaches. The integration of metabolomics with other biological data streams promises to revolutionize our understanding of health and disease, leading to more effective, personalized therapeutic strategies. Recent studies in cancer [1,2] and neurodegenerative diseases [3,4] demonstrate the growing potential of this field in revolutionizing disease diagnosis and treatment.

Untargeted Metabolomics Service

Unlock the potential of untargeted metabolomics for your research. Our service provides a seamless integration of advanced techniques, from meticulous sample preparation to high-resolution data acquisition and pathway analysis. Whether you’re exploring novel biomarkers, mapping metabolic pathways, or conducting hypothesis-generating studies, our expertise ensures reliable and insightful results.

Let us support your research with tailored solutions and cutting-edge tools for metabolite identification and statistical analysis. Contact us to learn more about how our untargeted metabolomics service can help you achieve your scientific goals.

Are you interested in applying metabolomics to your research? Book a meeting with our experts for a free consultation on how to get started.

References
  1. Vidman L, et al. (2023). Untargeted plasma metabolomics and risk of colorectal cancer—an analysis nested within a large-scale prospective cohort. Cancer & Metabolism, 11(17).
  2. Che J, et al. (2023). Untargeted serum metabolomics reveals potential biomarkers and metabolic pathways associated with the progression of gastroesophageal cancer. BMC Cancer, 23(1238).
  3. Ambeskovic M, et al. (2023). Metabolomic Signatures of Alzheimer's Disease Indicate Brain Region-Specific Neurodegenerative Progression. Int. J. Mol. Sci., 24(19), 14769.
  4. Wilkins JM & Trushina E. (2023). Application of Metabolomics in Alzheimer's Disease. Mayo Clinic.
  5. Dührkop, K., Fleischauer, M., Ludwig, M. et al. SIRIUS 4: a rapid tool for turning tandem mass spectra into metabolite structure information. Nat Methods 16, 299–302 (2019).
  6. Karnovsky, A., Li, S. (2020). Pathway Analysis for Targeted and Untargeted Metabolomics. In: Li, S. (eds) Computational Methods and Data Analysis for Metabolomics. Methods in Molecular Biology, vol 2104. Humana, New York, NY.
Alexander Aksenov, Arome Science CSO

Alexander Aksenov

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