HMDB

HMDB
Name	Human Metabolome Database
Type	Scientific database
Scope	Human metabolites and metabolomics
Established	2007
Curator	University of Alberta Metabolomics Centre
Access	Public

HMDB

HMDB is a curated electronic resource that catalogs thousands of small molecule metabolites found in human biofluids, tissues, cells and excreta. It supports researchers in biomedicine, pharmacology, and clinical chemistry by linking chemical structures to spectral data, biochemical pathways, and disease associations. HMDB is used alongside resources such as PubMed, UniProt, PubChem, KEGG, and ChEBI in metabolomics workflows, clinical metabolite identification, and biomarker discovery.

Overview

HMDB aggregates chemical, spectral, clinical, and biochemical information for endogenous and exogenous human metabolites and connects entries to external authorities like Human Genome Project, Protein Data Bank, Ensembl, ClinicalTrials.gov, and Gene Ontology. The resource interlinks metabolite records with pathway maps referenced by Reactome, BioCyc, MetaCyc, and integrates annotations that reference World Health Organization classification systems, disease nomenclature from ICD-10, and enzymatic information linked to IntEnz and BRENDA. HMDB entries typically include identifiers cross-referenced to databases such as CAS Registry Number and standards maintained by InChI and SMILES registries.

History and Development

HMDB originated from initiatives in systems biology and metabolomics during the early 2000s that paralleled projects like the Human Genome Project, the Human Proteome Organization, and the development of public chemical repositories including DrugBank and PubChem. Key development milestones involved collaborations among academic centres, notably the University of Alberta Metabolomics Centre, international metabolomics consortia, and funding agencies similar to CIHR and NSERC. Subsequent releases expanded content, spectral libraries, and pathway integrations in step with advances reported in conferences such as the Metabolomics Society annual meetings and publications in journals like Nature Medicine and Nucleic Acids Research.

Content and Data Types

HMDB stores diverse data types: chemical structures with stereochemistry, mass spectra (MS), nuclear magnetic resonance (NMR) spectra, concentration ranges, pathway participation, enzymatic reactions, and clinical disease links. Spectral datasets link to instruments and methods used in studies published in venues like Journal of Proteome Research and Analytical Chemistry and are annotated with metadata referencing standards from organizations such as NIH and IUPAC. Clinical annotations connect metabolites to phenotypes described in studies indexed by PubMed Central and clinical resources such as OMIM and Orphanet. Cross-references to chemical ontologies provided by ChEBI and enzyme resources like UniProt contextualize molecular function and biological role.

Database Structure and Access

HMDB’s schema organizes records by unique accession numbers, chemical identifiers, spectral entries, pathway models, and clinical notes. The database supports web-based browsing, programmatic retrieval via APIs, and bulk downloads compatible with bioinformatics tools used by groups associated with European Bioinformatics Institute, National Center for Biotechnology Information, and academic bioinformatics cores. Data export formats include structured files interoperable with XML schemas and exchange standards endorsed by consortia such as the Metabolomics Standards Initiative. Authentication and licensing follow norms similar to public repositories hosted by institutions like Stanford University and MIT open-access collections.

Applications and Use Cases

Researchers employ HMDB for metabolite identification in untargeted metabolomics studies leveraging platforms like LC–MS, GC–MS, and NMR spectroscopy; clinical laboratories use it to interpret metabolite panels related to disorders catalogued in OMIM and clinical guidelines from bodies such as American College of Medical Genetics and Genomics. Pharmaceutical scientists use HMDB alongside DrugBank and KEGG DRUG for ADME and biomarker investigations; epidemiologists integrate HMDB-derived metabolite profiles with cohorts such as Framingham Heart Study and UK Biobank for population-level metabolomics. Systems biologists incorporate HMDB annotations in network models built with tools like Cytoscape and pathway simulation platforms referenced to SBML standards.

Integration and Interoperability

HMDB achieves interoperability by mapping identifiers to external resources including PubChem, ChEBI, KEGG, UniProt, and Ensembl allowing federated queries with resources hosted at EBI and NCBI. Integration efforts align HMDB with community standards from the Metabolomics Standards Initiative and exchange formats compatible with software like MetaboAnalyst and XCMS. Harmonization with clinical terminologies such as SNOMED CT and ICD-10 enables translational applications spanning research institutions, hospital laboratories, and regulatory agencies like FDA where metabolite-disease evidence informs biomarker qualification.

Category:Biological databases