What is Metabolomics?
Definition of
Metabolomics: It is the large-scale scientific study of small
molecules, commonly known as metabolites produced as a result of metabolism in
a biological system
Metabolism is
the sum total of chemical reactions occurring within the cell that is essential
for survival of an organism.
How metabolomics
works? Metabolomics workflow
Step 1: Collection
of biological samples from blood, urine, tissue etc.
Step 2: Data
acquisition using Nuclear magnetic Resonance (NMR) or Mass Spectroscopy (MS)
(both GC-MS and LC-MS).
The chemicals are identified and quantified using NMR and MS
Step 3: Spectral processing
Spectral processing is a methodological approach aimed at
accurately identifying and quantifying the features in the sample spectra of a
metabolomics study. Spectral processing is also necessary to guarantee that
each final measurement will refer to the same metabolomic feature in all
samples.
Spectral processing is done to avoid any errors or to improve
signal quality
Step 4: Data analysis using biostatistics
tools
a)
For
identification of biomarkers
Biomarkers are “objective
indications of medical state observed from outside the patient – which can
be measured accurately and reproducibly”. If samples are collected from a group
of patients with a particular pathological condition, if a unique chemical is present
in all the samples; that can serve as a biomarker.
Example:
• Decreased
choline and linoleic acid in serum of lung cancer patients.
• Elevated
3-hydroxypropionic acid reduced pyruvic acid (specific) in serum of gastric
cancer patients.
b)
Metabolite
identification of spectral data using metabolite databases like METLIN and Human
Metabolome Database (HMDB)
Step 5: Biological
Interpretation
The analysis of metabolomic data can often be used to build
models that attempt to describe the observed data.
Using metabolic pathway databases like KEGG Kyoto Encyclopedia of Genes and Genomes (KEGG), small
molecule pathway database (SMPDB) etc to understand the role and impact of
these chemicals in different metabolic pathways and finally proposing a
biological model based on correlation-based network analysis.
Metabolomics researchers uses wide variety of software tools
to analyze metabolomic data at the pathway level that includes Paintomics,
and Cytoscape. Both are efficient pathway visualization tools.
Major Applications of Metabolomics:
a) Biomarker
discovery
b) Toxicity
studies: In drug safety studies and food safety studies
c) Environmental
metabolomics: To assess effect of different chemical pollutants on our
metabolic profile.
To study the changes
in metabolic profile of organisms in different environments
d) Plant
metabolomics: to
study the metabolic mechanisms underlying plant responses to adverse
environmental conditions (abiotic stress) and/or plant–attacker interactions
(biotic stress) that adversely affect plant growth and development.
-Identification and enhanced
production of useful plant metabolites
-to understand the chemical
footprints during different phases of growth and development of plants and marker-assisted
selection for high-yielding varieties or plants with more beneficial nutrients.
e) Microbial
metabolomics: functional
gene research, microbial identification, metabolic pathways, antibiotic
resistance, industrial biotechnology, synthesis biology, and enzyme discovery.
Alonso, A.,
Marsal, S., & Julià, A. (2015). Analytical methods in untargeted
metabolomics: state of the art in 2015. Frontiers in bioengineering and
biotechnology, 3, 23
Misra, B. B. (2021). New software tools, databases, and
resources in metabolomics: Updates from 2020. Metabolomics, 17(5),
1-24.
