Metabolomics is the study of small molecules called metabolites in biological samples. Studying these molecules helps us understand what the body is actually able to do.

What is a metabolic pathway?

A metabolic pathway is a series of chemical reactions that perform a specific function (e.g., produce energy). A chemical reaction takes one or more molecules (reactants) and turns them into another molecule (product). The reactants and products in a metabolic pathway are called metabolites. Therefore, metabolomics is a way of measuring what chemical reactions are taking place, or how a metabolic pathway is behaving.

How is metabolomics used in ME/CFS research?

Take energy metabolism as an example of where metabolomics tells an important story in ME/CFS and related conditions. There are three major metabolic pathways that produce energy in the form of ATP: glycolysis, the TCA cycle, and OXPHOS. Glycolysis, for example, takes glucose (the reactant) and turns it into pyruvate (a product), creating ATP along the way. This metabolic pathway might not work properly in ME/CFS, though. Performing metabolomics to measure the metabolites, or the reactants and products, involved in glycolysis can tell us if the pathway is behaving abnormally.

How do you measure metabolites?

Metabolomics is typically measured through two techniques: nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). NMR spectroscopy sends radio waves into a sample and measures how the molecules in the sample interact with those waves. Different molecules interact with the waves differently, so the signal that’s produced helps identify specific molecules in that sample. In MS, the sample is modified so the molecules become positively charged. They are then moved through a device using an electric or magnetic field. The molecules will separate based on the ratio of their size to how positively charged they are, therefore helping identify which molecules are in the sample.

The OMF Melbourne ME/CFS Collaboration often focuses on metabolic studies, which typically include NMR and MS metabolomics analyses. One such study tries to understand the metabolic differences between ME/CFS and two of its common comorbidities: irritable bowel syndrome (IBS) and fibromyalgia. To read more about this study, click here.