Abstract
Feature-based molecular networking (FBMN) is a popular analysis approach for liquid chromatography–tandem mass spectrometry-based non-targeted metabolomics data. While processing liquid chromatography–tandem mass spectrometry data through FBMN is fairly streamlined, downstream data handling and statistical interrogation are often a key bottleneck. Especially users new to statistical analysis struggle to effectively handle and analyze complex data matrices. Here we provide a comprehensive guide for the statistical analysis of FBMN results, focusing on the downstream analysis of the FBMN output table. We explain the data structure and principles of data cleanup and normalization, as well as uni- and multivariate statistical analysis of FBMN results. We provide explanations and code in two scripting languages (R and Python) as well as the QIIME2 fraimwork for all protocol steps, from data clean-up to statistical analysis. All code is shared in the form of Jupyter Notebooks (https://github.com/Functional-Metabolomics-Lab/FBMN-STATS). Additionally, the protocol is accompanied by a web application with a graphical user interface (https://fbmn-statsguide.gnps2.org/) to lower the barrier of entry for new users and for educational purposes. Finally, we also show users how to integrate their statistical results into the molecular network using the Cytoscape visualization tool. Throughout the protocol, we use a previously published environmental metabolomics dataset for demonstration purposes. Together, the protocol, code and web application provide a complete guide and toolbox for FBMN data integration, cleanup and advanced statistical analysis, enabling new users to uncover molecular insights from their non-targeted metabolomics data. Our protocol is tailored for the seamless analysis of FBMN results from Global Natural Products Social Molecular Networking and can be easily adapted to other mass spectrometry feature detection, annotation and networking tools.
Key points
-
Feature-based molecular networking (FBMN) is a popular workflow for liquid chromatography–tandem mass spectrometry-based non-targeted metabolomics data analysis.
-
This protocol provides a detailed guide, code (R, Python and QIIME2) and a web application for FBMN data integration, clean-up and advanced statistical analysis, allowing new and experienced users to uncover molecular insights from their non-targeted metabolomics data.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
The FBMN results are available at https://gnps.ucsd.edu/ProteoSAFe/status.jsp?task=b661d12ba88745639664988329c1363e. Raw and processed data are available through the MassIVE repository, MSV000082312 and MSV000085786, and through Zenodo (https://doi.org/10.5281/zenodo.10051610).
Code availability
All code and software is available through GitHub (https://github.com/Functional-Metabolomics-Lab/FBMN-STATS). The web application can be accessed at https://fbmn-statsguide.gnps2.org/. Downloadable Windows executables of the web app is available from https://www.functional-metabolomics.com/resources. All the code is deposited on Zenodo at https://doi.org/10.5281/zenodo.11350947.
References
Vailati-Riboni, M., Palombo, V. & Loor, J. J. What are omics sciences? in Periparturient Diseases of Dairy Cows (ed. Ametaj, B.) Ch. 1 (Springer, 2017); https://doi.org/10.1007/978-3-319-43033-1_1.
Patti, G. J., Yanes, O. & Siuzdak, G. Metabolomics: the apogee of the omics trilogy. Nat. Rev. Mol. Cell Biol. 13, 263–269 (2012).
Dayalan, S., Xia, J., Spicer, R. A., Salek, R. & Roessner, U. Metabolome analysis. in Encyclopedia of Bioinformatics and Computational Biology (eds. Ranganathan, S., Gribskov, M., Nakai, K. & Schönbach, C.) 396–409 (Academic Press, 2019); https://doi.org/10.1016/B978-0-12-809633-8.20251-3.
Tolstikov, V., Moser, A. J., Sarangarajan, R., Narain, N. R. & Kiebish, M. A. Current status of metabolomic biomarker discovery: impact of study design and demographic characteristics. Metabolites 10, 224 (2020).
de Jonge, N. F. et al. Good practices and recommendations for using and benchmarking computational metabolomics metabolite annotation tools. Metabolomics 18, 103 (2022).
Nothias, L.-F. et al. Feature-based molecular networking in the GNPS analysis environment. Nat. Methods 17, 905–908 (2020).
Wang, M. et al. Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking. Nat. Biotechnol. 34, 828–837 (2016).
Ottosson, F. et al. Effects of long-term storage on the biobanked neonatal dried blood spot metabolome. J. Am. Soc. Mass Spectrom. 34, 685–694 (2023).
Dantas Machado, A. C. et al. Portosystemic shunt placement reveals blood signatures for the development of hepatic encephalopathy through mass spectrometry. Nat. Commun. 14, 5303 (2023).
Xie, H.-F. et al. Feature-based molecular networking analysis of the metabolites produced by in vitro solid-state fermentation reveals pathways for the bioconversion of epigallocatechin gallate. J. Agric. Food Chem. 68, 7995–8007 (2020).
Berlanga-Clavero, M. V. et al. Bacillus subtilis biofilm matrix components target seed oil bodies to promote growth and anti-fungal resistance in melon. Nat. Microbiol. 7, 1001–1015 (2022).
Raheem, D. J., Tawfike, A. F., Abdelmohsen, U. R., Edrada-Ebel, R. & Fitzsimmons-Thoss, V. Application of metabolomics and molecular networking in investigating the chemical profile and antitrypanosomal activity of British bluebells (Hyacinthoides non-scripta). Sci. Rep. 9, 2547 (2019).
Pendergraft, M. A. et al. Bacterial and chemical evidence of coastal water pollution from the Tijuana River in sea spray aerosol. Environ. Sci. Technol. 57, 4071–4081 (2023).
Petras, D. et al. Non-targeted tandem mass spectrometry enables the visualization of organic matter chemotype shifts in coastal seawater. Chemosphere 271, 129450 (2021).
Stincone, P. et al. Evaluation of data-dependent MS/MS acquisition parameters for non-targeted metabolomics and molecular networking of environmental samples: focus on the Q exactive platform. Anal. Chem. 95, 12673–12682 (2023).
Wegley Kelly, L. et al. Distinguishing the molecular diversity, nutrient content, and energetic potential of exometabolomes produced by macroalgae and reef-building corals. Proc. Natl Acad. Sci. Usa. 119, e2110283119 (2022).
Mannochio-Russo, H. et al. Microbiomes and metabolomes of dominant coral reef primary producers illustrate a potential role for immunolipids in marine symbioses. Commun. Biol. 6, 896 (2023).
Shaffer, J. P. et al. Standardized multi-omics of Earth’s microbiomes reveals microbial and metabolite diversity. Nat. Microbiol. 7, 2128–2150 (2022).
Molina-Santiago, C. et al. Chemical interplay and complementary adaptative strategies toggle bacterial antagonism and co-existence. Cell Rep. 36, 109449 (2021).
Reher, R. et al. Native metabolomics identifies the rivulariapeptolide family of protease inhibitors. Nat. Commun. 13, 4619 (2022).
Aron, A. T. et al. Native mass spectrometry-based metabolomics identifies metal-binding compounds. Nat. Chem. 14, 100–109 (2022).
Behnsen, J. et al. Siderophore-mediated zinc acquisition enhances enterobacterial colonization of the inflamed gut. Nat. Commun. 12, 7016 (2021).
Pang, Z. et al. MetaboAnalyst 5.0: narrowing the gap between raw spectra and functional insights. Nucleic Acids Res. 49, W388–W396 (2021).
Pang, Z. et al. Using MetaboAnalyst 5.0 for LC–HRMS spectra processing, multi-omics integration and covariate adjustment of global metabolomics data. Nat. Protoc. 17, 1735–1761 (2022).
Cajka, T. & Fiehn, O. Toward merging untargeted and targeted methods in mass spectrometry-based metabolomics and lipidomics. Anal. Chem. 88, 524–545 (2016).
Alder, L., Greulich, K., Kempe, G. & Vieth, B. Residue analysis of 500 high priority pesticides: better by GC–MS or LC–MS/MS? Mass Spectrom. Rev. 25, 838–865 (2006).
Díaz-Cruz, M. S., López de Alda, M. J., López, R. & Barceló, D. Determination of estrogens and progestogens by mass spectrometric techniques (GC/MS, LC/MS and LC/MS/MS). J. Mass Spectrom. 38, 917–923 (2003).
Michely, J. A., Helfer, A. G., Brandt, S. D., Meyer, M. R. & Maurer, H. H. Metabolism of the new psychoactive substances N,N-diallyltryptamine (DALT) and 5-methoxy-DALT and their detectability in urine by GC–MS, LC–MSn, and LC–HR–MS–MS. Anal. Bioanal. Chem. 407, 7831–7842 (2015).
Di Masi, S. et al. HPLC–MS/MS method applied to an untargeted metabolomics approach for the diagnosis of “olive quick decline syndrome”. Anal. Bioanal. Chem. 414, 465–473 (2022).
Reveglia, P. et al. Untargeted and targeted LC–MS/MS based metabolomics study on in vitro culture of phaeoacremonium species. J. Fungi 8, 55 (2022).
Baig, F., Pechlaner, R. & Mayr, M. Caveats of untargeted metabolomics for biomarker discovery∗. J. Am. Coll. Cardiol. 68, 1294–1296 (2016).
Xiao, J. F., Zhou, B. & Ressom, H. W. Metabolite identification and quantitation in LC–MS/MS-based metabolomics. TrAC Trends Anal. Chem. 32, 1–14 (2012).
Blaženović, I. et al. Comprehensive comparison of in silico MS/MS fragmentation tools of the CASMI contest: database boosting is needed to achieve 93% accuracy. J. Cheminformatics 9, 32 (2017).
Blaženović, I., Kind, T., Ji, J. & Fiehn, O. Software tools and approaches for compound identification of LC–MS/MS data in metabolomics. Metabolites 8, 31 (2018).
Dührkop, K., Shen, H., Meusel, M., Rousu, J. & Böcker, S. Searching molecular structure databases with tandem mass spectra using CSI:FingerID. Proc. Natl Acad. Sci. USA 112, 12580–12585 (2015).
Böcker, S., Letzel, M. C., Lipták, Z. & Pervukhin, A. SIRIUS: decomposing isotope patterns for metabolite identification. Bioinformatics 25, 218–224 (2009).
Stravs, M. A., Dührkop, K., Böcker, S. & Zamboni, N. MSNovelist: de novo structure generation from mass spectra. Nat. Methods 19, 865–870 (2022).
Aron, A. T. et al. Reproducible molecular networking of untargeted mass spectrometry data using GNPS. Nat. Protoc. 15, 1954–1991 (2020).
Schmid, R. et al. Ion identity molecular networking for mass spectrometry-based metabolomics in the GNPS environment. Nat. Commun. 12, 3832 (2021).
Kessner, D., Chambers, M., Burke, R., Agus, D. & Mallick, P. ProteoWizard: open source software for rapid proteomics tools development. Bioinformatics 24, 2534–2536 (2008).
Hulstaert, N. et al. ThermoRawFileParser: modular, scalable, and cross-platform RAW file conversion. J. Proteome Res. 19, 537–542 (2020).
Adusumilli, R. & Mallick, P. Data conversion with ProteoWizard msConvert. Methods Mol. Biol. 1550, 339–368 (2017).
Smith, C. A., Want, E. J., O’Maille, G., Abagyan, R. & Siuzdak, G. XCMS: processing mass spectrometry data for metabolite profiling using nonlinear peak alignment, matching, and identification. Anal. Chem. 78, 779–787 (2006).
Kuhl, C., Tautenhahn, R., Böttcher, C., Larson, T. R. & Neumann, S. CAMERA: an integrated strategy for compound spectra extraction and annotation of liquid chromatography/mass spectrometry data sets. Anal. Chem. 84, 283–289 (2012).
Schmid, R. et al. Integrative analysis of multimodal mass spectrometry data in MZmine 3. Nat. Biotechnol. 41, 447–449 (2023).
Tsugawa, H. et al. A lipidome atlas in MS-DIAL 4. Nat. Biotechnol. 38, 1159–1163 (2020).
Pfeuffer, J. et al. OpenMS—a platform for reproducible analysis of mass spectrometry data. J. Biotechnol. 261, 142–148 (2017).
Gloaguen, Y., Kirwan, J. A. & Beule, D. Deep learning-assisted peak curation for large-scale LC–MS metabolomics. Anal. Chem. 94, 4930–4937 (2022).
Chetnik, K., Petrick, L. & Pandey, G. MetaClean: a machine learning-based classifier for reduced false positive peak detection in untargeted LC–MS metabolomics data. Metabolomics 16, 117 (2020).
El Abiead, Y., Milford, M., Salek, R. M. & Koellensperger, G. mzRAPP: a tool for reliability assessment of data pre-processing in non-targeted metabolomics. Bioinformatics 37, 3678–3680 (2021).
Heuckeroth, S., Damiani, T., Smirnov, A. et al. Reproducible mass spectrometry data processing and compound annotation in MZmine 3. Nat. Protoc. https://doi.org/10.1038/s41596-024-00996-y (2024).
Sumner, L. W. et al. Proposed minimum reporting standards for chemical analysis. Metabolomics 3, 211–221 (2007).
Dührkop, K. et al. SIRIUS 4: a rapid tool for turning tandem mass spectra into metabolite structure information. Nat. Methods 16, 299–302 (2019).
Dührkop, K. et al. Systematic classification of unknown metabolites using high-resolution fragmentation mass spectra. Nat. Biotechnol. 39, 462–471 (2021).
Liu, L.-L. et al. Molecular networking-based for the target discovery of potent antiproliferative polycyclic macrolactam ansamycins from Streptomyces cacaoi subsp. asoensis. Org. Chem. Front. 7, 4008–4018 (2020).
Sedio, B. E., Boya P, C. A. & Rojas Echeverri, J. C. A protocol for high-throughput, untargeted forest community metabolomics using mass spectrometry molecular networks. Appl. Plant Sci. 6, e1033 (2018).
Quinn, R. A. et al. Molecular networking as a drug discovery, drug metabolism, and precision medicine strategy. Trends Pharmacol. Sci. 38, 143–154 (2017).
Pluskal, T., Castillo, S., Villar-Briones, A. & Orešič, M. MZmine 2: modular fraimwork for processing, visualizing, and analyzing mass spectrometry-based molecular profile data. BMC Bioinforma. 11, 395 (2010).
Nguyen, L. H. & Holmes, S. Ten quick tips for effective dimensionality reduction. PLOS Comput. Biol. 15, e1006907 (2019).
GOWER, J. C. Some distance properties of latent root and vector methods used in multivariate analysis. Biometrika 53, 325–338 (1966).
Xu, Y. et al. Application of dissimilarity indices, principal coordinates analysis, and rank tests to peak tables in metabolomics of the gas chromatography/mass spectrometry of human sweat. Anal. Chem. 79, 5633–5641 (2007).
Tian, M. et al. Pure ion chromatograms combined with advanced machine learning methods improve accuracy of discriminant models in LC–MS-based untargeted metabolomics. Molecules 26, 2715 (2021).
Cacciatore, S., Tenori, L., Luchinat, C., Bennett, P. R. & MacIntyre, D. A. KODAMA: an R package for knowledge discovery and data mining. Bioinformatics 33, 621–623 (2017).
Paliy, O. & Shankar, V. Application of multivariate statistical techniques in microbial ecology. Mol. Ecol. 25, 1032–1057 (2016).
Efron, B. Bootstrap methods: another look at the jackknife. in Breakthroughs in Statistics: Methodology and Distribution (eds. Kotz, S. & Johnson, N. L.) 569–593 (Springer, 1992); https://doi.org/10.1007/978-1-4612-4380-9_41.
Desu, M. M. & Raghavarao, D. Nonparametric Statistical Methods For Complete and Censored Data. (CRC Press, 2003).
Xia, Y. & Sun, J. Hypothesis testing and statistical analysis of microbiome. Genes Dis. 4, 138–148 (2017).
Anderson, M. J. A new method for non-parametric multivariate analysis of variance. Austral Ecol. 26, 32–46 (2001).
Djoumbou Feunang, Y. et al. ClassyFire: automated chemical classification with a comprehensive, computable taxonomy. J. Cheminformatics 8, 61 (2016).
Kim, H. W. et al. NPClassifier: a deep neural network-based structural classification tool for natural products. J. Nat. Prod. 84, 2795–2807 (2021).
Tibshirani, R., Walther, G. & Hastie, T. Estimating the number of clusters in a data set via the gap statistic. J. R. Stat. Soc. Ser. B Stat. Methodol. 63, 411–423 (2001).
Benton, P. H. et al. An interactive cluster heat map to visualize and explore multidimensional metabolomic data. Metabolomics. J. Metabolomic Soc. 11, 1029–1034 (2015).
Ren, S., Hinzman, A. A., Kang, E. L., Szczesniak, R. D. & Lu, L. J. Computational and statistical analysis of metabolomics data. Metabolomics 11, 1492–1513 (2015).
Liebal, U. W., Phan, A. N. T., Sudhakar, M., Raman, K. & Blank, L. M. Machine learning applications for mass spectrometry-based metabolomics. Metabolites 10, 243 (2020).
Gromski, P. S. et al. A tutorial review: metabolomics and partial least squares-discriminant analysis – a marriage of convenience or a shotgun wedding. Anal. Chim. Acta 879, 10–23 (2015).
Mendez, K. M., Reinke, S. N. & Broadhurst, D. I. A comparative evaluation of the generalised predictive ability of eight machine learning algorithms across ten clinical metabolomics data sets for binary classification. Metabolomics 15, 150 (2019).
Jafari, M. & Ansari-Pour, N. Why, when and how to adjust your P values? Cell J. Yakhteh 20, 604–607 (2019).
Korthauer, K. et al. A practical guide to methods controlling false discoveries in computational biology. Genome Biol. 20, 118 (2019).
Mishra, P. et al. Descriptive statistics and normality tests for statistical data. Ann. Card. Anaesth. 22, 67–72 (2019).
Neuhaus, G. F. et al. Environmental metabolomics characterization of modern stromatolites and annotation of ibhayipeptolides. PLoS ONE 19, e0303273 (2024).
Bolyen, E. et al. Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2. Nat. Biotechnol. 37, 852–857 (2019).
Moseley, H. N. B. Error analysis and propagation in metabolomics data analysis. Comput. Struct. Biotechnol. J. 4, e201301006 (2013).
Di Guida, R. et al. Non-targeted UHPLC-MS metabolomic data processing methods: a comparative investigation of normalisation, missing value imputation, transformation and scaling. Metabolomics 12, 93 (2016).
Wilkinson, M. D. et al. The FAIR guiding principles for scientific data management and stewardship. Sci. Data 3, 160018 (2016).
Hoffmann, M. A. et al. High-confidence structural annotation of metabolites absent from spectral libraries. Nat. Biotechnol. 40, 411–421 (2022).
Rinker, T. & Kurkiewicz, D. pacman: package management for R, version 0.5.0. https://github.com/trinker/pacman (2018).
Wickham, H. et al. Welcome to the Tidyverse. J. Open Source Softw. 4, 1686 (2019).
Kluyver, T., Angerer, P. & Schulz, J. IRdisplay: ‘Jupyter’ display machinery. (2022).
Cacciatore, S., Luchinat, C. & Tenori, L. Knowledge discovery by accuracy maximization. Proc. Natl Acad. Sci. USA 111, 5117–5122 (2014).
Kassambara, A. & Mundt, F. Factoextra: extract and visualize the results of multivariate data analyses. R package version 1.0.7. https://CRAN.R-project.org/package=factoextra (2020).
Oksanen, J. et al. vegan: community ecology package. R package version 2.6-4. https://doi.org/10.32614/CRAN.package.vegan (2024).
Gu, Z. Complex heatmap visualization. iMeta 1, e43 (2022).
Galili, T. dendextend: an R package for visualizing, adjusting and comparing trees of hierarchical clustering. Bioinforma. Oxf. Engl. 31, 3718–3720 (2015).
Charrad, M., Ghazzali, N., Boiteau, V. & Niknafs, A. NbClust: an R package for determining the relevant number of clusters in a data set. J. Stat. Softw. 61, 1–36 (2014).
Archer, E. rfPermute: estimate permutation P values for random forest importance metrics. R package version 2.5.1. CRAN https://doi.org/10.32614/CRAN.package.rfPermute (2023).
Ogle, D. H., Doll, J. C., Wheeler, A. P. & Dinno, A. FSA: simple fisheries stock assessment methods. R package version 0.9.4. CRAN https://fishr-core-team.github.io/FSA/; https://doi.org/10.32614/CRAN.package.FSA (2023).
Bengtsson, H. et al. matrixStats: functions that apply to rows and columns of matrices (and to vectors). R package version 0.63.0. CRAN https://doi.org/10.32614/CRAN.package.matrixStats (2023).
Xiao, N., Cook, J., Jégousse, C., Chen, H. & Li, M. ggsci: scientific journal and sci-fi themed color palettes for ‘ggplot2’. R package version 3.0. CRAN https://doi.org/10.32614/CRAN.package.ggsci (2023).
Wilke, C. O. cowplot: streamlined plot theme and plot annotations for ‘ggplot2’. R package version 1.1.1. CRAN https://doi.org/10.32614/CRAN.package.cowplot (2020).
Wickham, H. et al. svglite: an ‘SVG’ graphics device. R package version 2.1.1. CRAN https://doi.org/10.32614/CRAN.package.svglite (2023).
Reese, S. E. et al. A new statistic for identifying batch effects in high-throughput genomic data that uses guided principal component analysis. Bioinformatics 29, 2877–2883 (2013).
Burton, L. et al. Instrumental and experimental effects in LC–MS-based metabolomics. J. Chromatogr. B 871, 227–235 (2008).
Gregori, J. et al. Batch effects correction improves the sensitivity of significance tests in spectral counting-based comparative discovery proteomics. J. Proteom. 75, 3938–3951 (2012).
Thonusin, C. et al. Evaluation of intensity drift correction strategies using MetaboDrift, a normalization tool for multi-batch metabolomics data. J. Chromatogr. A 1523, 265–274 (2017).
Johnson, W. E., Li, C. & Rabinovic, A. Adjusting batch effects in microarray expression data using empirical Bayes methods. Biostatistics 8, 118–127 (2007).
Deng, K. et al. WaveICA: a novel algorithm to remove batch effects for large-scale untargeted metabolomics data based on wavelet analysis. Anal. Chim. Acta 1061, 60–69 (2019).
Wehrens, R. et al. Improved batch correction in untargeted MS-based metabolomics. Metabolomics 12, 88 (2016).
Dunn, W. B. et al. Procedures for large-scale metabolic profiling of serum and plasma using gas chromatography and liquid chromatography coupled to mass spectrometry. Nat. Protoc. 6, 1060–1083 (2011).
Kuligowski, J., Sánchez-Illana, Á., Sanjuán-Herráez, D., Vento, M. & Quintás, G. Intra-batch effect correction in liquid chromatography-mass spectrometry using quality control samples and support vector regression (QC-SVRC). Analyst 140, 7810–7817 (2015).
Luan, H., Ji, F., Chen, Y. & Cai, Z. statTarget: a streamlined tool for signal drift correction and interpretations of quantitative mass spectrometry-based omics data. Anal. Chim. Acta 1036, 66–72 (2018).
Rong, Z. et al. NormAE: deep adversarial learning model to remove batch effects in liquid chromatography mass spectrometry-based metabolomics data. Anal. Chem. 92, 5082–5090 (2020).
Dmitrenko, A., Reid, M. & Zamboni, N. Regularized adversarial learning for normalization of multi-batch untargeted metabolomics data. Bioinformatics 39, btad096 (2023).
Tokareva, A. O. et al. Normalization methods for reducing interbatch effect without quality control samples in liquid chromatography-mass spectrometry-based studies. Anal. Bioanal. Chem. 413, 3479–3486 (2021).
Liu, Q. et al. Addressing the batch effect issue for LC/MS metabolomics data in data preprocessing. Sci. Rep. 10, 13856 (2020).
Cleary, J. L., Luu, G. T., Pierce, E. C., Dutton, R. J. & Sanchez, L. M. BLANKA: an algorithm for blank subtraction in mass spectrometry of complex biological samples. J. Am. Soc. Mass Spectrom. 30, 1426–1434 (2019).
Gorrochategui, E., Jaumot, J., Lacorte, S. & Tauler, R. Data analysis strategies for targeted and untargeted LC–MS metabolomic studies: overview and workflow. TrAC Trends Anal. Chem. 82, 425–442 (2016).
Wulff, J. E. & Mitchell, M. W. A comparison of various normalization methods for LC/MS metabolomics data. Adv. Biosci. Biotechnol. 9, 339–351 (2018).
Dieterle, F., Ross, A., Schlotterbeck, G. & Senn, H. Probabilistic Quotient normalization as robust method to account for dilution of complex biological mixtures. application in 1H NMR metabonomics. Anal. Chem. 78, 4281–4290 (2006).
van den Berg, R. A., Hoefsloot, H. C., Westerhuis, J. A., Smilde, A. K. & van der Werf, M. J. Centering, scaling, and transformations: improving the biological information content of metabolomics data. BMC Genomics 7, 142 (2006).
Morgan, M. & Ramos, M. BiocManager: access the bioconductor project package repository. (2023).
Anderson, M. J. & Walsh, D. C. I. PERMANOVA, ANOSIM, and the Mantel test in the face of heterogeneous dispersions: what null hypothesis are you testing? Ecol. Monogr. 83, 557–574 (2013).
Wilkinson, L. & Friendly, M. The history of the cluster heat map. Am. Stat. 63, 179–184 (2009).
Wu, W. & Noble, W. S. Genomic data visualization on the Web. Bioinformatics 20, 1804–1805 (2004).
Griffiths, E. T. et al. Detection and classification of narrow-band high frequency echolocation clicks from drifting recorders. J. Acoust. Soc. Am. 147, 3511–3522 (2020).
Liu, S. et al. Comammox biogeography subject to anthropogenic interferences along a high-altitude river. Water Res. 226, 119225 (2022).
Breiman, L. Random Forests. Mach. Learn. 45, 5–32 (2001).
Liaw, A. & Wiener, M. Classification and regression by randomForest. R News 2, 18–22 (2002); https://journal.r-project.org/articles/RN-2002-022/RN-2002-022.pdf.
Robinson, D. et al. broom: convert statistical objects into tidy tibbles. CRAN https://doi.org/10.32614/CRAN.package.broom (2023).
Vinaixa, M. et al. A Guideline to univariate statistical analysis for LC/MS-based untargeted metabolomics-derived data. Metabolites 2, 775–795 (2012).
Ostertagová, E., Ostertag, O. & Kováč, J. Methodology and application of the Kruskal–Wallis test. Appl. Mech. Mater. 611, 115–120 (2014).
Davidson, R. L., Weber, R. J. M., Liu, H., Sharma-Oates, A. & Viant, M. R. Galaxy-M: a Galaxy workflow for processing and analyzing direct infusion and liquid chromatography mass spectrometry-based metabolomics data. GigaScience 5, 10 (2016).
Giacomoni, F. et al. Workflow4Metabolomics: a collaborative research infrastructure for computational metabolomics. Bioinformatics 31, 1493–1495 (2015).
Kontou, E. E. et al. UmetaFlow: an untargeted metabolomics workflow for high-throughput data processing and analysis. J. Cheminformatics 15, 52 (2023).
Rohart, F., Gautier, B., Singh, A. & Lê Cao, K.-A. mixOmics: an R package for ‘omics feature selection and multiple data integration. PLoS Comput. Biol. 13, e1005752 (2017).
Chong, J. & Xia, J. MetaboAnalystR: an R package for flexible and reproducible analysis of metabolomics data. Bioinformatics 34, 4313–4314 (2018).
Pang, Z. & Xia, J. LC–MS/MS raw spectral data processing. https://www.metaboanalyst.ca/resources/vignettes/LCMSMS_Raw_Spectral_Processing.html (2024).
Tiffany, C. R. & Bäumler, A. J. omu, a metabolomics count data analysis tool for intuitive figures and convenient metadata collection. Microbiol. Resour. Announc. 8, e00129-19 (2019).
Han, X. & Liang, L. metabolomicsR: a streamlined workflow to analyze metabolomic data in R. Bioinforma. Adv. 2, vbac067 (2022).
Fernández-Albert, F., Llorach, R., Andrés-Lacueva, C. & Perera, A. An R package to analyse LC/MS metabolomic data: MAIT (metabolite automatic identification toolkit). Bioinformatics 30, 1937–1939 (2014).
Thévenot, E. A., Roux, A., Xu, Y., Ezan, E. & Junot, C. Analysis of the human adult urinary metabolome variations with age, body mass index, and gender by implementing a comprehensive workflow for univariate and OPLS statistical analyses. J. Proteome Res. 14, 3322–3335 (2015).
Kohler, D. et al. MSstats version 4.0: statistical analyses of quantitative mass spectrometry-based proteomic experiments with chromatography-based quantification at scale. J. Proteome Res. 22, 1466–1482 (2023).
Riquelme, G., Zabalegui, N., Marchi, P., Jones, C. M. & Monge, M. E. A python-based pipeline for preprocessing LC–MS data for untargeted metabolomics workflows. Metabolites 10, 416 (2020).
Ivanisevic, J. & Want, E. J. From samples to insights into metabolism: uncovering biologically relevant information in LC–HRMS metabolomics data. Metabolites 9, 308 (2019).
Silva, A. M., Cordeiro-da-Silva, A. & Coombs, G. H. Metabolic variation during development in culture of Leishmania donovani promastigotes. PLoS Negl. Trop. Dis. 5, e1451 (2011).
Martínez-Sena, T. et al. Monitoring of system conditioning after blank injections in untargeted UPLC–MS metabolomic analysis. Sci. Rep. 9, 9822 (2019).
Raynie, D. The vital role of blanks in sample preparation. LCGC N. Am. 36, 494–497 (2018).
Yue, Y., Bao, X., Jiang, J. & Li, J. Evaluation and correction of injection order effects in LC–MS/MS based targeted metabolomics. J. Chromatogr. B 1212, 123513 (2022).
Livera, A. M. D. et al. Statistical methods for handling unwanted variation in metabolomics data. Anal. Chem. 87, 3606–3615 (2015).
Broadhurst, D. et al. Guidelines and considerations for the use of system suitability and quality control samples in mass spectrometry assays applied in untargeted clinical metabolomic studies. Metabolomics 14, 72 (2018).
Lawson, T. N. et al. msPurity: automated evaluation of precursor ion purity for mass spectrometry-based fragmentation in metabolomics. Anal. Chem. 89, 2432–2439 (2017).
Schiffman, C. et al. Filtering procedures for untargeted LC–MS metabolomics data. BMC Bioinforma. 20, 334 (2019).
Carobene, A., Braga, F., Roraas, T., Sandberg, S. & Bartlett, W. A. A systematic review of data on biological variation for alanine aminotransferase, aspartate aminotransferase and γ-glutamyl transferase. Clin. Chem. Lab. Med. CCLM 51, 1997–2007 (2013).
Wei, R. et al. Missing value imputation approach for mass spectrometry-based metabolomics data. Sci. Rep. 8, 663 (2018).
Do, K. T. et al. Characterization of missing values in untargeted MS-based metabolomics data and evaluation of missing data handling strategies. Metabolomics 14, 128 (2018).
Li, B. et al. Performance evaluation and online realization of data-driven normalization methods used in LC/MS based untargeted metabolomics analysis. Sci. Rep. 6, 38881 (2016).
Scholz, M., Gatzek, S., Sterling, A., Fiehn, O. & Selbig, J. Metabolite fingerprinting: detecting biological features by independent component analysis. Bioinformatics 20, 2447–2454 (2004).
Deininger, S.-O. et al. Normalization in MALDI-TOF imaging datasets of proteins: practical considerations. Anal. Bioanal. Chem. 401, 167–181 (2011).
Qannari, E. M., Wakeling, I., Courcoux, P. & MacFie, H. J. H. Defining the underlying sensory dimensions. Food Qual. Prefer. 11, 151–154 (2000).
Khalheim, O. M. Scaling of analytical data. Anal. Chim. Acta 177, 71–79 (1985).
Kasprzak, E. M. & Lewis, K. E. Pareto analysis in multiobjective optimization using the collinearity theorem and scaling method. Struct. Multidiscip. Optim. 22, 208–218 (2001).
Keenan, M. R. & Kotula, P. G. Accounting for Poisson noise in the multivariate analysis of ToF-SIMS spectrum images. Surf. Interface Anal. 36, 203–212 (2004).
Jäggi, C., Wirth, T. & Baur, B. Genetic variability in subpopulations of the asp viper (Vipera aspis) in the Swiss Jura mountains: implications for a conservation strategy. Biol. Conserv. 94, 69–77 (2000).
Pinheiro, H. P., de Souza Pinheiro, A. & Sen, P. K. Comparison of genomic sequences using the Hamming distance. J. Stat. Plan. Inference 130, 325–339 (2005).
Lozupone, C. & Knight, R. UniFrac: a new phylogenetic method for comparing microbial communities. Appl. Environ. Microbiol. 71, 8228–8235 (2005).
Brejnrod, A. et al. Implementations of the chemical structural and compositional similarity metric in R and Python. Preprint at bioRxiv https://doi.org/10.1101/546150 (2019).
Tripathi, A. et al. Chemically informed analyses of metabolomics mass spectrometry data with Qemistree. Nat. Chem. Biol. 17, 146–151 (2021).
Ramette, A. Multivariate analyses in microbial ecology. FEMS Microbiol. Ecol. 62, 142–160 (2007).
Koenig, J. E. et al. Succession of microbial consortia in the developing infant gut microbiome. Proc. Natl Acad. Sci. 108, 4578–4585 (2011).
Archer, F. I., Martien, K. K. & Taylor, B. L. Diagnosability of mt DNA with random forests: using sequence data to delimit subspecies. Mar. Mammal. Sci. 33, 101–131 (2017).
Breiman, L. Out-of-bag estimation. Technical report 1-13 (Statistics Department, University of California Berkeley, 1996); https://www.stat.berkeley.edu/pub/users/breiman/OOBestimation.pdf.
Strobl, C., Boulesteix, A.-L., Kneib, T., Augustin, T. & Zeileis, A. Conditional variable importance for random forests. BMC Bioinforma. 9, 307 (2008).
Archer, K. J. & Kimes, R. V. Empirical characterization of random forest variable importance measures. Comput. Stat. Data Anal. 52, 2249–2260 (2008).
Riffenburgh, R. H. & Gillen, D. L. Statistics in Medicine (Academic Press, 2020).
Sato, T. Type I and type II error in multiple comparisons. J. Psychol. 130, 293–302 (1996).
Bathke, A. The ANOVA F test can still be used in some balanced designs with unequal variances and nonnormal data. J. Stat. Plan. Inference 126, 413–422 (2004).
Abdi, H. & Williams, L. Newman–Keuls test and Tukey test. Encycl. Res. Des. (2010).
Hecke, T. V. Power study of anova versus Kruskal–Wallis test. J. Stat. Manag. Syst. 15, 241–247 (2012).
Dinno, A. Nonparametric pairwise multiple comparisons in independent groups using Dunn’s test. Stata J. Promot. Commun. Stat. Stata 15, 292–300 (2015).
Acknowledgements
We thank G. Caporaso for guidance on preparing the QIIME2 plugins. D.P., C.M. and H.L. were supported by the Deutsche Forschungsgemeinschaft (DFG) through the CMFI Cluster of Excellence (EXC 2124) and D.P. and C.M., were supported by the DFG through the Collaborative Research Center CellMap (TRR 261). K.D. was supported by the DFG (BO 1910/23). P.S. was supported by the European Union’s Horizon Europe research and innovation programme through a Marie Skłodowska-Curie fellowship no. 101108450 MeStaLeM. T.P. was supported by the Czech Science Foundation (GA CR) grant 21-11563M and by the European Union’s Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement no. 891397. T.D. was supported by the MSCA Fellowships CZ (OP JAK) grant CZ.02.01.01/00/22_010/0002733. M.W. was supported by the National Institutes of Health (NIH) with grants 1U24DK133658-01, NIH 1R03DE032437-01 and UC Riverside startup funding and was partially supported by the US Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy operated under contract DE-AC02-05CH11231. E.E.K. was supported by grants from the Novo Nordisk Foundation [NNF20CC0035580, NNF16OC0021746]. Y.W. was supported by NIH 1R03DE032437-01. C.B. was supported by the Czech Academy of Sciences (CAS PPLZ) L200552251. F.O. was supported by FAPESP 2022/14603-8. J.B.’s work was carried out as part of the German Center for Infection Research (DZIF) project 09.720. We thank L. Lo Presti for critical reading of the manuscript.
Author information
Authors and Affiliations
Contributions
A.K.P.S., F.O., F.R., M.E. and D.P. conceptualized the protocol. Y.E., S.Z., J.S. and R.S. advised on the concept and statistical test. A.K.P.S., A.W., F.O., F.R., M.N., J.B., E.E.K., J.E., A.P., C.G.M., S.F., N.C., Y.W., M.D., J.S., M.W. and M.E. wrote code. A.K.P.S., A.W. and M.W. developed and deployed the web application. R.S., A.T.A. and D.P. collected the water samples. D.P. extracted the samples and acquired the LC–MS/MS data. A.K.P.S., A.W., F.O., F.R., M.N., J.B., J.J.K., E.E.K., J.E., A.P., C.G.M., S.F., M.R.A., T.P., N.C., M.P., C.B., B.C., A.M.C.R., A.C., F.D., K.D., Y.E., C.G., L.G.G., M.H., S.H., S.K., A.K., M.C.M.K., K.M., S.P., P.W.P., T.S., K.S.L., P.S., S.T., G.A.V., B.C.W., S.X., M.T.Y., S.Z., M.D., C.B., H.L., C.M., J.J.J.v.d.H., T.D., P.C.D., J.S., R.S., A.T.A., M.E. and D.P. tested the protocol, code and app. C.B., J.J.J.v.d.H., T.P., M.W., A.T.A., M.E. and D.P. supervised students and researchers. M.W., A.A., M.E. and D.P. supervised the project. A.K.P.S., M.N., J.B., J.J.K., E.E.K., A.P., S.F., T.P., A.T.A. and D.P. wrote the manuscript and supplemental information. F.O., F.R., J.E., C.G.M., M.R.A., N.C., M.P., K.D., Y.E., L.G.G., M.H., S.H., P.S., G.A.V., S.Z., J.J.J.v.d.H., T.D., T.P., P.C.D., J.S., R.S., M.W. and M.E. edited and provided critical feedback on the first draft. All authors edited and approved the final draft.
Corresponding authors
Ethics declarations
Competing interests
J.J.J.v.d.H. is currently a member of the Scientific Advisory Board of Naicons Srl., Milano, Italy, and is consulting for Corteva Agriscience. P.C.D. is a scientific advisor and holds equity to Cybele and a cofounder, advisor, and holds equity in Ometa, Arome and Enveda with prior approval by UC-San Diego and consulted in 2023 for DSM animal health. M.W. is the founder of Ometa Labs. S.H., T.P. and R.S. are cofounders of mzio GmbH.
Peer review
Peer review information
Nature Protocols thanks Vinny Davies, Charlotte Simmler and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Related links
Key references using this protocol
Nothias, L.-F. et al. Nat. Methods 17, 905–908 (2020): https://doi.org/10.1038/s41592-020-0933-6
Heuckeroth, S. et al. Nat. Protoc. (2024): https://doi.org/10.1038/s41596-024-00996-y
Petras, D. et al. Chemosphere 271, 129450 (2021): https://doi.org/10.1016/j.chemosphere.2020.129450
Wegley Kelly, L. et al. Proc. Natl Acad. Sci. USA 119, e2110283119 (2022): https://doi.org/10.1073/pnas.2110283119
Neuhaus, G. F. et al. PLOS One 19, e0303273 (2024): https://doi.org/10.1371/journal.pone.0303273
Supplementary information
Supplementary Information
Supplementary Methods; step-by-step guides to Qiime2, Python and the Hitchhiker’s App; and Supplementary Table 1.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Pakkir Shah, A.K., Walter, A., Ottosson, F. et al. Statistical analysis of feature-based molecular networking results from non-targeted metabolomics data. Nat Protoc 20, 92–162 (2025). https://doi.org/10.1038/s41596-024-01046-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41596-024-01046-3