Searching for Alzheimer’s Biomarkers: David Wishart Describes Foundational Research

How do doctors measure your liver function, kidney function, cholesterol levels, and heart disease? They use biomarkers, and David Wishart helps identify biomarkers with analytical chemistry, mass spectrometry, and other bioinformatics tools. He and his colleagues look at blood or urine and other biological fluids to help in the diagnosis and characterization of human diseases. He explains

• What characterizes a useful and reliable biomarker and how low false positive rates distinguish them,
• How the receiver operating characteristic (ROC) curve works and where common tests fall in the curve,
• What’s the history of biomarker testing and how it’s been improved, and
• How he’s meeting the challenging task of identifying Alzheimer’s biomarkers in his research.

David Wishart is a professor in the Departments of Biological Sciences and Computing Science at the University of Alberta. He works with bioinformatics software, nanobiology, and machine learning in healthcare to fine tune the use of biomarkers in diagnostics. He explains that historically, most biomarkers have been proteins. But developments in identifying cancer biomarkers, for example, have focused on metabolomics. “Cancer is very much a metabolic disorder,” he explains, “and some of the very first changes that happen in cancer are fundamental changes in metabolism.” Furthermore, tests can be combined, like a “gene test with a protein test with a chemical test,” and that improves sensitivity and the chances of catching a cancer earlier.

Neurodegenerative diseases pose a particular challenge, he explains. An Alzheimer’s biomarker is hard to identify because the consequences of the disease and causes are not always clear. Researchers are even pointing to microbiome connections and brain metabolism. Therefore, it may actually be a gut microbiome test that indicates Alzheimer’s. He adds, “we're finding, for instance, bile acids in the brains of Alzheimer's patients.” He describes what other chemicals they’re finding and how this research might lead to better understandings of its pathogenesis and how earlier testing and prevention might be possible. Episode also available on Apple Podcasts: apple.co/30PvU9C