Millions of people have mailed in saliva samples to discover what their genes might reveal about their future health. These tests analyze DNA, the genetic code people are born with, which remains virtually unchanged throughout their lives.
Currently, scientists are focusing on something far more dynamic. A second biological code, made up of tiny sugar molecules coating cells, constantly shifts based on health status and could detect diseases years before symptoms appear. The findings were published in the journal Nature Chemical Biology.
A dense layer of sugar chains coats the surface of nearly every cell and protein in your body. Researchers call them glycans, and for a long time, they flew under the radar.
Wei Wang, a professor at Edith Cowan University (ECU) in Perth, Australia, has spent years extracting valuable insights from this sugary layer. He contributed to a comprehensive review of the current state of the field.
DNA barely changes over a lifetime. A cheek swab taken in kindergarten and one taken at retirement would yield nearly identical results.
Glycans behave entirely differently. Their activity shifts from month to month, mirroring your diet, stress levels, and any other challenges your body is facing.
For years, researchers viewed these sugars as mere packaging with no real impact on bodily functions. That perspective has since been overturned.
Glycans sit on the surface of antibodies—immune proteins that determine how effectively your body fights infections.
Tweak the sugar coating on one of these antibodies, and the immune cells it interacts with may either ramp up aggression or shut down entirely. The same molecule. A different mission.
“Glycans are not just sitting idle. They actively regulate how our immune system works and how diseases develop,” Professor Wang said.
He and his colleagues argue that these molecules perform a genuine function, rather than merely decorating cell surfaces. Until recently, much of this remained hidden for a simple reason.
Analyzing sugar chains is notoriously difficult, and measuring their levels in thousands of blood samples was once a slow, technically demanding, and often unreliable process. Improved lab techniques and faster software have changed the game.
Now, in a single run, the structure of sugars can be read simultaneously across massive batches of samples—an achievement highlighted in a recent paper. That is the crux of it.
With enough people tracked over enough years, weak sugar-level signals stop looking like noise and start behaving like reliable biomarkers—measurable indicators that doctors use to monitor health and disease progression.
The most obvious finding so far relates to type 2 diabetes. Long-term studies have shown that people’s glycoprotein profiles in the blood began to deteriorate years before they received a diagnosis.
In blood samples collected a decade earlier, the warning was already embedded in the sugar coating. Blood that appeared outwardly healthy carried a different telltale signature.
No one could spot this until measurements became more precise. This change does not prove that sugars cause the disease. It suggests the body signals risk well before symptoms emerge, using a language doctors are just beginning to understand.
Genetics partially explains this pattern. Hormones, age, and the wear and tear of daily life constantly rewrite the rest. For two different people, the glycome—the complete set of sugar-level changes occurring in the body at any given moment—looks nothing alike. Part of this individuality is inherited. Large-scale genetic studies have identified specific genes that determine a person’s baseline sugar levels; details come from a 2025 study involving over 10,000 participants.
Because this behavioral pattern is highly personalized, it suits medicine tailored to the individual, rather than the average. Analyzing your own blood could one day pinpoint risks specific to you, not the average risks of some group you happen to resemble.
None of this will be ready for your next checkup. Two labs processing the same blood sample could produce different results.
The field currently needs standardized measurement methods and rigorous statistical approaches capable of distinguishing genuine biological signals from random ones. Another missing piece is larger and longer studies.
Tracking the same people across multiple countries for years is the only way to learn which sugar patterns truly predict diseases and which are statistical illusions.
Here is what has actually changed. A layer of biological processes once thought inert can now be studied across entire populations, and the patterns it reveals align with real diseases, sometimes years in advance.
“Instead of waiting for people to get sick, we could detect risk early and intervene sooner,” Wang said. This opens a path that medicine previously lacked.
Your genome shows what you were born with. Your glycome shows how you are doing right now. Continuously monitoring your body’s state in the future could turn a routine blood test into an early warning system.
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