abstract depiction of metabolites ready for metabolomics analysis in a tissue
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Metabolomics
4 min 08.25.2025

"Metabolites are not Genes" - Insights from Metabolomics Analysis

Metabolomics holds immense promise for understanding health and disease, but the field faces a reproducibility challenge, with many proposed biomarkers turning out to be statistical noise. A key reason is that most studies are too small to find a true biological signal. Discover how modern laboratory automation is tackling this issue head-on, enabling the high-throughput, high-quality sample preparation required for larger, more powerful studies and the next wave of reliable discoveries.

Gegner Hagen
Hagen Gegner

Scientific Communications Specialist

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The Promise and Challenge of Metabolomics Analysis

Metabolomics is the study of the small molecules, or metabolites, that drive life's processes. It provides a powerful way to understand the complex link between a living system's chemistry and its observable traits. One of the great promises of this field is the discovery of biomarkers, molecules that can signal health, disease, or response to treatment, offering incredible value for scientific discovery [3].

However, the journey from a biological sample to a clear insight faces a significant hurdle. A recent and sobering meta-analysis of 244 clinical studies concluded that a staggering 85% of proposed biomarkers are simply statistical noise [1]. This finding points to a reproducibility crisis, suggesting that while we are getting better at measuring metabolites, the field of metabolomics analysis needs to improve how we find the signals that truly matter.

 

The Search for a True Signal: Why Are Studies Struggling?

If so many findings are statistical noise, what is the underlying cause?

A recent study gives us a huge clue. Bifarin et al. (2025) mapped the entire metabolomics research landscape from the past two decades, analyzing over 80,000 publications. Their work revealed a critical fact: the vast majority of studies are too small to find a real signal. Based on the 2,613 studies that mentioned sample size in their abstract, a massive 70.8% used fewer than 50 samples [2].

This presents a fundamental challenge. Small studies often lack the necessary statistical power to distinguish a true biological signal from random variation. As highlighted by Xu & Goodacre (2025), this type of "short fat data", where the number of measured metabolites far exceeds the number of samples, is highly susceptible to statistical caveats. Without rigorous validation, powerful statistical models can easily find patterns in random noise, leading to over-optimistic and irreproducible results [11].

This creates a major bottleneck for the entire field, but it also highlights a clear path forward.

a, When a pathway is upregulated, all the genes involved in that pathway produce more copies. However, in linear biosynthetic pathways, metabolite levels show lower coherence during regulation. Upregulation may increase end-product abundance, while intermediate levels remain unchanged with only their turnover rate increasing (shown by the thicker arrow).

From a True Signal to a True Insight

Finding a statistically sound signal is only the first step.

The next challenge is interpreting its biological meaning, which is also filled with potential pitfalls. As Lee, Su & Huan (2025) caution, we must remember that "metabolites are not genes" [12]. Analytical tools like pathway analysis, which were originally designed for genomics, are often misapplied in metabolomics because they overlook the unique biology of metabolites.

Unlike genes, which can be switched on in parallel, metabolites in a pathway are often produced sequentially, one after another. An increase in pathway activity might only be visible in the final product, not the intermediates. Furthermore, metabolites are transported between organs and tissues. An amino acid found in a blood sample, for example, might come from diet or protein breakdown, not necessarily from active synthesis in the blood itself. A single metabolite can also be a part of many different pathways, making it difficult to pinpoint which process is truly affected.

These biological complexities mean that the interpretation of metabolomics data is incredibly sensitive to the quality of the initial measurement. Misleading or nonsensical conclusions can arise if the input data is not robust. This underscores a critical point: the entire analytical chain, from the initial automated sample preparation to the final biological interpretation, depends on the quality and integrity of the data. To get meaningful insights out, we must put high-quality data in.

Schematic representation of the automated liquid-liquid extraction platform and sample preparation workflow for the determination of urinary phthalate metabolites by UHPLC-MS/MS analysis

Automated Liquid-Liquid Extractions

The scientific community is actively rising to this challenge, with a clear consensus that quality and reproducibility are the cornerstones of trustworthy research [8]. A recent review of over 100 metabolomics studies found that while many labs use quality control samples, the information from these checks is not always used to its full potential to improve data quality [9]. This highlights a tremendous opportunity for growth, and a new wave of research shows how automation is providing the solution.

By standardizing complex and repetitive tasks, robotic platforms directly address the sources of variability. This need for consistency is especially true in large studies with hundreds or thousands of participants. Luo et al. (2025) met this challenge by developing a fully automated liquid liquid extraction platform using a PAL system. Their platform combines all the necessary steps, from temperature control and solvent addition to mixing and centrifugation, into one smooth workflow. In a study of 232 people, the automated platform proved to be highly efficient and reliable, showing its immense value for large population studies where consistency is everything [6].

Pushing the boundaries of what's possible, some researchers are developing entirely new automated methods. A remarkable example comes from He et al. (2025), who created a fully automated, high-throughput electro-extraction (EE) platform. Using an advanced dual-headed PAL RTC/RSI system, they developed a workflow that can process 120 samples per day for less than 0.1 Euro per sample. This innovative technique achieves incredible enrichment of target molecules from tiny samples, like 20 microliters of plasma or small mouse muscle tissues, with extraction recoveries up to 99%. This work represents a significant stride towards the future of bioanalysis, showing how novel automation can handle precious, mass-limited samples with exceptional efficiency and precision [7].

 

Automated Blood Analysis via GC/MS

As Dr. Gernot Poschet, Executive Managing Director of the Metabolomics Core Technology Platform at Heidelberg University, notes, automation is a "clear game-changer" for the field. In a recent interview, he emphasized that "automation of as many steps as possible can highly improve final results" by reducing human error and ensuring data consistency, which is essential for large-scale clinical studies.

This principle is powerfully demonstrated by the work of research consortia. A prime example comes from RECETOX, which developed a fully automated workflow for the metabolomic profiling of blood samples, including the increasingly popular Dried Blood Spots (DBS). Their method, using a robotic platform for direct, in-vial derivatization, achieves excellent reproducibility (CV < 30%) and a high throughput of approximately 40 samples per day. By making these robust, automated methods shareable, consortia like EIRENE benefit from standardized procedures across the field, a critical step towards solving the reproducibility crisis [13]. 

Read more about their work and open-access methods approach.

This collaborative spirit is shared by leading core facilities like the Metabolomics Core Technology Platform (MCTP) at Heidelberg University, which also relies on automated platforms like the PAL System to support a wide range of research, from basic science to large clinical consortia. By providing access to standardized, high-quality workflows, these facilities are building the foundation for more reliable and impactful science.

Building Robust and Flexible Workflows

These studies point to an exciting and optimistic trend: automation is about more than just speed. It is about fundamentally improving the quality, reliability, and consistency of metabolomic data. By letting robots handle repetitive tasks, we reduce the human introduced variability that can mask true biological discoveries.

This is where the flexible, modular design of modern robotic platforms offers a path forward. Systems like the PAL RTC and PAL RSI are designed as a "Tool Box" for the laboratory [10]. A lab can begin its automation journey with simple liquid injections and, over time, expand its capabilities by adding new modules for more advanced tasks. This modularity empowers laboratories to build custom automated systems that perfectly match their research goals.

The possibilities are vast. A single platform can be configured for headspace analysis of volatile organic compounds (VOCs), or employ dynamic headspace for greater sensitivity. It can perform solid phase microextraction (SPME) with advanced tools like the SPME Arrow, or conduct miniaturized cleanups with Micro SPE cartridges. This flexibility extends across numerous fields, enabling everything from proteomics analysis and automated sample preparation for FAME to critical environmental testing, such as PAH analysis in food or the increasingly important PFAS analysis in drinking water. By solving the challenges of variability and throughput, automation is laying the groundwork for a brighter, more reproducible, and more insightful future in metabolomics and beyond.

 

 

 

 

References

[1] Cochran, D., Noureldein, M., Bezdeková, D., Schram, A., Howard, R., & Powers, R. (2024). A reproducibility crisis for clinical metabolomics studies. TrAC Trends in Analytical Chemistry, 180, 117918.

[2] Bifarin, O. O., Yelluru, V. S., Simhadri, A., & Fernández, F. M. (2025). A Large Language Model-Powered Map of Metabolomics Research. Analytical Chemistry, 97, 14088-14096.

[3] Siuzdak, G., Activity Metabolomics and Mass Spectrometry; MCC Press: San Diego, USA, 2025. [4] CTC Analytics AG, Pitch Deck PAL System Theme 2025-02. [5] PAL System, Automated, Green, and Efficient: A Compendium on Micromethods in Analytical Sample Preparation, 2025.

[6] Luo, Y.; et al. An automated liquid-liquid extraction platform for high-throughput sample preparation of urinary phthalate metabolites in human biomonitoring. Talanta 2025, 288, 127740.

[7] He, Y.; et al. A fully automated, high-throughput electro-extraction and analysis workflow for acylcarnitines in human plasma and mouse muscle tissues. Analytica Chimica Acta 2025, 1364, 344224.

[8] Mosley, J. D.; et al. Establishing a framework for best practices for quality assurance and quality control in untargeted metabolomics. Metabolomics 2024, 20, 20.

[9] Broeckling, C. D.; et al. Current Practices in LC-MS Untargeted Metabolomics: A Scoping Review on the Use of Pooled Quality Control Samples. Anal. Chem. 2023, 95, 18645–18654.

[10] PAL System, PAL RSI and PAL RTC Sample Prep and Injection Brochure.

[11] Xu, Y., & Goodacre, R. (2025). Mind your Ps and Qs - Caveats in metabolomics data analysis. Trends in Analytical Chemistry, 183, 118064.

[12] Lee, K. S., Su, X., & Huan, T. (2025). Metabolites are not genes - avoiding the misuse of pathway analysis in metabolomics. Nature Metabolism.

[13] Jbebli, A.; et al. Automated Direct Derivatization and GC/MS Analysis: A Robust Method for Comprehensive Metabolomic Profiling of Dried Blood Spots, Serum, and Plasma. PAL System GC/MS Application Note, Feb 2025.

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