BIOINFORMATICS APPLICATIONS NOTE doi:10.1093/bioinformatics/btu019 Systems biology Advance Access publication January 17, 2014 ProbMetab: an R package for Bayesian probabilistic annotation of LC–MS-based metabolomics

Summary: We present ProbMetab, an R package that promotes sub-stantial improvement in automatic probabilistic liquid chromatog-raphy–mass spectrometry-based metabolome annotation. The inference engine core is based on a Bayesian model implemented to (i) allow diverse source of experimental data and metadata to be systematically incorporated into the model with alternative ways to calculate the likelihood function and (ii) allow sensitive selection of biologically meaningful biochemical reaction databases as Dirichlet-categorical prior distribution. Additionally, to ensure result interpret-ation by system biologists, we display the annotation in a network where observed mass peaks are connected if their candidate metab-olites are substrate/product of known biochemical reactions. This graph can be overlaid with other graph-based analysis, such as partial correlation networks, in a visualization scheme exported t