The Microbial Metabolites Database (MiMeDB) is a freely available electronic database containing detailed information about small molecule metabolites found in the human microbiome. It is intended to be used for applications in metabolomics, clinical chemistry, biomarker discovery and general education. The database is designed to contain and link metabolite data, microbe data, host data, health and bioactivity data, and exposure data. Many data fields in the database are hyperlinked to other databases (FooDB, HMDB, KEGG, PubChem, MetaCyc, ChEBI, UniProt, and GenBank). The Microbial Metabolites Database supports extensive text, sequence, spectral, chemical structure and relational query searches.

MiMeDB (The Human Microbial Metabolome Database) is a freely available, web-enabled database containing detailed information about the small molecules produced by the human microbiome. Many microbially produced chemicals play important roles in human health and disease with some (such as butyric acid) offering protection against inflammation and cancer and others (such as indoxyl sulfate) causing damage to the kidneys, heart and brain. While all microbes synthesize primary metabolites required for their own survival, they also produce a variety of exotic compounds arising from their ability to grow on many unusual substrates or host-derived food sources. For instance, many of the metabolites produced by human microbes arise from the transformation of xenobiotics arising from human consumption such as food constituents, food additives, phytochemicals, drugs, cosmetics and other exogenous or man-made chemicals. Microbes also chemically transform many host-produced (human) metabolites as well as previously host-transformed (phase I and phase II) xenobiotics. As a result, the human microbiome is believed to produce or process >55,000 different compounds – many of which affect human health, behavior and disease.

MiMeDB not only houses metabolite data (structure, names, descriptions, chemical taxonomy, chemical ontology, physico-chemical data, spectra, etc.), it also contains detailed information about the microbes that produce these chemicals, the enzymatic reactions responsible for their production (substrates and products), the bioactivity of the chemicals and even the anatomical location of these chemicals (and microbes).

MiMeDB classifies metabolites as co-host, host or microbial metabolites. This determination is made by an analysis of the chemical reactions (including the mediating enzymes and spontaneous reactions) that lead to that chemical. A microbial-only metabolite is a metabolite that can only be produced by microbial enzymes or microbially-mediated reactions. To qualify as such there must be no evidence that the metabolite has an origin other than via a microbe. A microbial-host co-metabolite is a chemical that arises from a combination of human and microbial metabolism as determined by its reaction sequence, the enzymes involved or reaction origins. In other words, the chemical must arise from at least one microbial-specific reaction with a microbial enzyme and at least one human-specific reaction with a human enzyme. A host metabolite includes items coming from what the host consumes or absorbs (if it is a food, drug, cosmetic or other synthetic compound). A host metabolite could also include a chemical that arises from human-only enzymes or human enzyme reactions.

MiMeDB also contains the food, physiological or environmental sources of many of the identified substrate chemicals, the microbial proteins and genes that catalyze the reactions, detailed genetic maps of the responsible microbes, extensive microbial taxonomy data, as well as the health effects and human protein targets that these microbial metabolites act upon. In this regard MiMeDB is a unique, multi-omic database that brings extensive information together about the human microbiome, the metabolome (human and microbial), the proteome (human and microbial) and the genome (microbial). MiMeDB offers a variety of wide variety of browsing, searching, relational querying and viewing options as well as interactive network visualization tools that allow users to explore this complex multi-omic, multi-organism universe. MiMeDB is extensively linked to other databases including FooDB, HMDB, KEGG, PubChem, MetaCyc, ChEBI, UniProt, NCBI Taxonomy, BacMap, VMH, GenBank and ChemFOnt.