Every living thing depends on metabolism, a biochemical process that, among other things, converts food to energy and helps eliminate waste. The molecules that help carry out these processes are known as metabolites. The quantity and type of metabolites in an organism are known as the metabolome, which is a relatively new term that was first coined in 1998 in a scientific paper1.
Why is the Metabolome Important?
Metabolomics, or the study of the metabolome, has been used in a wide range of applications, including the screening of newborns, drug trials, toxicology, and many others. Scientists are using metabolomics to help them get a better understanding of how the body’s molecular pathways are connected.
The metabolome may ultimately help researchers understand the causes of different diseases by giving them further insight into “biomarkers,” which are indicators of a particular problem. Metabolomics provides a clearer picture of how metabolites work under certain conditions to produce biomarkers.
Metabolomics, many experts believe, can deliver clinical information sooner than genomics (the study of genes) or proteomics (the study of proteins)2. One of the main reasons is that it is far less expensive to obtain profiles of metabolites compared to genes, which can cost hundreds of thousands of dollars, and proteins are much larger and more complex to analyze than metabolites, making the process extremely time-consuming.
Another advantage of metabolomics over genomics and proteomics is the fact that metabolites can easily be gathered for analysis, and the process of doing so is non-invasive. Metabolites are found just about everywhere in the body, in saliva, blood, urine, and tissues. Analyzing different types of fluid can help identify certain types of diseases. Metabolites in urine can, for example, show there could be a problem with the kidneys, whereas metabolites in saliva could indicate some sort of issue with the lungs.
Metabolomics and Breast Cancer
One specific “real world” example that shows the promise of metabolomics occurred in 2015, when Danish researchers announced they had used metabolites to create a blood test that could tell whether or not a woman is likely to develop breast cancer3.
The researchers said that the new test could predict whether or not a woman was likely to develop the disease anywhere from two to five years in advance with an accuracy rate of 80 percent. Traditional mammograms have a 75 percent accuracy rate but are only effective once the disease has already developed.
The basis of the research was blood samples as well as other data from 400 women gathered over a 20-year period by the Danish Cancer Society. The women were cancer-free when they first enrolled in the study but were later diagnosed with the disease anywhere from 2-7 years after they provided blood samples. The researchers compared those samples with another group of 400 women who had not developed breast cancer.
The scientists analyzed several different compounds in the blood samples, examining them for changes in metabolism that typically occur before tumors form. While more trials will need to be conducted before the technique is ready, early indications are that it may not only be able to better predict the development of breast cancer, but other diseases as well.
The Future of Metabolomics
The possibilities of metabolomics are extremely encouraging.4 Doctors could potentially be able to analyze how metabolites are acting within cells to identify patterns that could help them detect tumors much faster than they can through current methods. Computer programs could be developed based on metabolomics in order to make predicting the development of diseases quicker than anyone could have imagined just a few years ago.
This is not the stuff of science fiction impossibilities. A British researcher has already created a computer model using metabolites in blood plasma. This model can determine whether or not a pregnant woman is in the process of developing preeclampsia, which is a pregnancy complication characterized by extremely high blood pressure.
A researcher at Duke University is using metabolomics to design a test for schizophrenia that could also help treat people with the condition. She has found that people with schizophrenia have a certain metabolic pattern in their blood that is not found in people without the condition. This pattern might be able to show why patients respond well to certain types of antipsychotic drugs while others experience significant side effects.
Another area where analysis of the metabolome shows promise is through helping people find the diet that is best for their needs. For example, most people assume that they need to lower their fat intake in order to lose weight. But a lot of people have issues with low-fat diets because they can increase the presence of LDL (low-density lipoprotein), or “bad” cholesterol, which can lead to a heightened risk of heart disease. Metabolomics can identify the metabolic biomarkers that would put a dieter in danger of increased LDL.
Metabolites are also being used to study why certain people are more susceptible to problems such as heart disease, obesity, high blood pressure, and more. This work could eventually disprove the link between genetics and these issues. A British researcher found that while people of Chinese and Japanese descent are similar from a genetic perspective, they suffer cardiovascular issues at substantially different rates. One reason could be that there are significant differences in the kinds of metabolites in their urine as well as their blood.
There is even a study that uses metabolomics to determine why some people like chocolate and some don’t. One interesting finding was that those who do tend to have lower amounts of a dangerous type of bacteria known as bacterium Clostridium difficile. They also, according to the study, have less LDL.
It will take time, of course, for metabolome analysis to turn into tangible tests that will help doctors pinpoint the likely development of diseases in their patients. However, the potential for this area of study is limitless.
Dr. Cary Nelson
1. Oliver, Stephen. “Systematic Functional Analysis Of The Yeast Genome”. Cell.com. N.p., 1998. Web. 24 Feb. 2017.
2.”Metabolomics: What’s Happening Downstream Of DNA”. Medscape. N.p., 2017. Web. 24 Feb. 2017.
3. Russell, Peter. “Blood Test Could Give Early Breast Cancer Warning”. WebMD Boots. N.p., 2015. Web. 24 Feb. 2017.
4. “Signs Of A Long Life”. The Economist. N.p., 2008. Web. 24 Feb. 2017.