Opening the Random Forest Black Box of the Metabolome by the Application of Surrogate Minimal Depth

Soeren Wenck, Marina Creydt, Jule Hansen, Florian Gärber, Markus Fischer, Stephan Seifert

Metabolites, volume 12, number 1, pages 5, Dezember 2021, doi: 10.3390/metabo12010005

Abstract

For the untargeted analysis of the metabolome of biological samples with liquid chromatography–mass spectrometry (LC-MS), high-dimensional data sets containing many different metabolites are obtained. Since the utilization of these complex data is challenging, different machine learning approaches have been developed. Those methods are usually applied as black box classification tools, and detailed information about class differences that result from the complex interplay of the metabolites are not obtained. Here, we demonstrate that this information is accessible by the application of random forest (RF) approaches and especially by surrogate minimal depth (SMD) that is applied to metabolomics data for the first time. We show this by the selection of important features and the evaluation of their mutual impact on the multi-level classification of white asparagus regarding provenance and biological identity. SMD enables the identification of multiple features from the same metabolites and reveals meaningful biological relations, proving its high potential for the comprehensive utilization of high-dimensional metabolomics data.

Bibtex

@article{wenck2021m,
  title = {Opening the {{Random Forest Black Box}} of the {{Metabolome}} by the {{Application}} of {{Surrogate Minimal Depth}}},
  author = {Wenck, Soeren and Creydt, Marina and Hansen, Jule and G{\"a}rber, Florian and Fischer, Markus and Seifert, Stephan},
  year = {2021},
  month = dec,
  journal = {Metabolites},
  volume = {12},
  number = {1},
  pages = {5},
  issn = {2218-1989},
  doi = {10.3390/metabo12010005},
}